Soft transition from Gflags and Glog to Abseil. Some CI fixes

.clang-tidy

@@ -120,7 +120,6 @@ Checks: '-*,
         readability-uppercase-literal-suffix'
 WarningsAsErrors: ''
 HeaderFilterRegex: ''
-AnalyzeTemporaryDtors: false
 FormatStyle: 'file'
 CheckOptions:
   - key:             performance-unnecessary-copy-initialization.ExcludedContainerTypes

.github/workflows/main.yml

@@ -57,8 +57,7 @@ jobs:
           rm /usr/local/bin/python3.1* || true
           export HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK=1
           brew link --overwrite python@3.12
-          brew install ninja hdf5 automake armadillo lapack libmatio \
-          gflags glog gnuradio log4cpp openssl pugixml protobuf
+          brew install ninja hdf5 automake armadillo lapack libmatio gnuradio openssl pugixml protobuf
           pip3 install mako
       - name: configure
         run: cd build && cmake -GNinja ..
@@ -90,8 +89,7 @@ jobs:
           rm /usr/local/bin/python3.1* || true
           export HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK=1
           brew link --overwrite python@3.12
-          brew install ninja pkg-config hdf5 automake armadillo lapack libmatio \
-          gflags glog gnuradio log4cpp openssl pugixml protobuf
+          brew install ninja pkg-config hdf5 automake armadillo lapack libmatio gnuradio openssl pugixml protobuf
           pip3 install mako          
       - name: configure
         run: cd build && cmake -GXcode ..
@@ -142,8 +140,7 @@ jobs:
           rm /usr/local/bin/python3.1* || true
           export HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK=1
           brew link --overwrite python@3.12
-          brew install ninja pkg-config hdf5 automake armadillo lapack libmatio \
-          gflags glog gnuradio log4cpp openssl pugixml protobuf llvm
+          brew install ninja pkg-config hdf5 automake armadillo lapack libmatio gnuradio openssl pugixml protobuf llvm
           pip3 install mako
           ln -s $(brew --prefix llvm)/bin/clang-tidy /usr/local/bin
           ln -s $(brew --prefix llvm)/bin/clang-apply-replacements /usr/local/bin
@@ -151,7 +148,7 @@ jobs:
       - name: Prepare run
         run: cd build && cmake .. && make volk_gnsssdr_module gtest-1.14.0 core_monitor core_libs pvt_libs
       - name: run clang-tidy
-        run: cd build && /usr/local/opt/llvm/bin/run-clang-tidy -fix
+        run: cd build && /opt/homebrew/opt/llvm/bin/run-clang-tidy -fix
       - name: check
         run: |
           git diff > clang_tidy.patch
@@ -243,8 +240,13 @@ jobs:
     runs-on: macos-latest
     steps:
       - uses: actions/checkout@v4
-      - name: install dependencies
-        run: pip3 install mako
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install mako
       - name: configure
         run: cd build && cmake ../src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr
       - name: build
@@ -256,8 +258,13 @@ jobs:
     runs-on: macos-latest
     steps:
       - uses: actions/checkout@v4
-      - name: install dependencies
-        run: pip3 install mako
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install mako
       - name: configure
         run: cd build && cmake -GXcode ../src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr
       - name: build

CMakeLists.txt

@@ -74,9 +74,20 @@ option(ENABLE_PACKAGING "Enable software packaging" OFF)
 
 option(ENABLE_OWN_GLOG "Download glog and link it to gflags" OFF)
 
+option(ENABLE_GLOG_AND_GFLAGS "Force using Google glog and Gflags instead of Abseil" OFF)
+
+option(ENABLE_OWN_ABSEIL "Forces downloading and building of Abseil" OFF)
+if(CMAKE_VERSION VERSION_LESS 3.24)
+    set(ENABLE_OWN_ABSEIL OFF)
+endif()
+if(ENABLE_OWN_ABSEIL)
+    set(ENABLE_OWN_GLOG OFF)
+    set(ENABLE_GLOG_AND_GFLAGS OFF)
+endif()
+
 option(ENABLE_OWN_ARMADILLO "Download and build Armadillo locally" OFF)
 
-option(ENABLE_LOG "Enable logging" ON)
+option(ENABLE_LOG "Enable internal logging" ON)
 
 option(ENABLE_ARMA_NO_DEBUG OFF)
 
@@ -329,6 +340,7 @@ set(GNSSSDR_MATIO_MIN_VERSION "1.5.3")
 set(GNSSSDR_PROTOBUF_MIN_VERSION "3.0.0")
 set(GNSSSDR_PYTHON_MIN_VERSION "2.7")
 set(GNSSSDR_PYTHON3_MIN_VERSION "3.4")
+set(GNSSSDR_ABSEIL_MIN_VERSION "20240116")
 
 
 
@@ -1157,7 +1169,7 @@ if(NOT VOLKGNSSSDR_FOUND)
 
     if(CMAKE_GENERATOR STREQUAL Xcode)
         set(VOLK_GNSSSDR_BUILD_COMMAND "xcodebuild"
-            "-configuration" $<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>$<$<CONFIG:RelWithDebInfo>:RelWithDebInfo>$<$<CONFIG:MinSizeRel>:MinSizeRel>
+            "-configuration" $<$<CONFIG:None>:None>$<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>$<$<CONFIG:RelWithDebInfo>:RelWithDebInfo>$<$<CONFIG:MinSizeRel>:MinSizeRel>$<$<CONFIG:NoOptWithASM>:NoOptWithASM>$<$<CONFIG:Coverage>:Coverage>$<$<CONFIG:O2WithASM>:O2WithASM>$<$<CONFIG:O3WithASM>:O3WithASM>$<$<CONFIG:ASAN>:Debug>:RelWithDebInfo>$<$<CONFIG:ASAN>:Debug>
         )
     endif()
 
@@ -1392,16 +1404,85 @@ endif()
 
 
 ################################################################################
-# gflags - https://github.com/gflags/gflags
+# Abseil C++ - https://abseil.io/docs/cpp/
 ################################################################################
-set(LOCAL_GFLAGS FALSE)
-if(ENABLE_OWN_GLOG)
+if(CMAKE_VERSION VERSION_GREATER 3.13
+    AND NOT (CMAKE_CXX_STANDARD VERSION_LESS 14)
+    AND NOT (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.3.1)
+    AND NOT (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0.0)
+    AND NOT (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 12)
+    AND NOT ENABLE_OWN_GLOG
+    AND NOT ENABLE_GLOG_AND_GFLAGS)
+    # See https://github.com/google/oss-policies-info/blob/main/foundational-cxx-support-matrix.md
+
+    if(ENABLE_OWN_ABSEIL)
+        include(FetchContent)
+        set(ABSEIL_BUILD_COMMAND ${CMAKE_COMMAND}
+            "--build" "${GNSSSDR_BINARY_DIR}/abseil-cpp"
+            "--config" $<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>$<$<CONFIG:RelWithDebInfo>:RelWithDebInfo>$<$<CONFIG:MinSizeRel>:MinSizeRel>$<$<CONFIG:NoOptWithASM>:Debug>$<$<CONFIG:Coverage>:Debug>$<$<CONFIG:O2WithASM>:RelWithDebInfo>$<$<CONFIG:O3WithASM>:RelWithDebInfo>$<$<CONFIG:ASAN>:Debug>
+            "--target" "install"
+        )
+        if(CMAKE_GENERATOR STREQUAL Xcode)
+            set(ABSEIL_BUILD_COMMAND "xcodebuild" "-configuration" $<$<CONFIG:None>:None>$<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>$<$<CONFIG:RelWithDebInfo>:RelWithDebInfo>$<$<CONFIG:MinSizeRel>:MinSizeRel>$<$<CONFIG:NoOptWithASM>:NoOptWithASM>$<$<CONFIG:Coverage>:Coverage>$<$<CONFIG:O2WithASM>:O2WithASM>$<$<CONFIG:O3WithASM>:O3WithASM>$<$<CONFIG:ASAN>:Debug>)
+        endif()
+        if(CMAKE_TOOLCHAIN_FILE)
+            set(ABSEIL_TOOLCHAIN_FILE -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE})
+        endif()
+        set(ABSL_PROPAGATE_CXX_STD ON)
+        FetchContent_Declare(
+            absl
+            GIT_REPOSITORY https://github.com/abseil/abseil-cpp
+            GIT_TAG master # live at head
+            SOURCE_DIR ${GNSSSDR_BINARY_DIR}/thirdparty/abseil-cpp
+            CMAKE_ARGS -DABSL_PROPAGATE_CXX_STD=ON -ABSL_BUILD_TESTING=OFF -DCMAKE_INSTALL_PREFIX=${GNSSSDR_BINARY_DIR}/abseil-cpp ${ABSEIL_TOOLCHAIN_FILE}
+            BINARY_DIR ${GNSSSDR_BINARY_DIR}/abseil-cpp
+            BUILD_COMMAND ${ABSEIL_BUILD_COMMAND}
+            OVERRIDE_FIND_PACKAGE # Requires CMake 3.24
+        )
+        FetchContent_MakeAvailable(absl)
+        set(absl_FOUND TRUE)
+        set(ENABLE_GLOG_AND_GFLAGS OFF)
+    else()
+        find_package(absl)
+        set_package_properties(absl PROPERTIES
+            URL "https://github.com/abseil/abseil-cpp"
+            PURPOSE "Making use of Abseil's log and flags libraries."
+            TYPE OPTIONAL
+        )
+        if(absl_FOUND)
+            set_package_properties(absl PROPERTIES
+                DESCRIPTION "A collection of C++ library code designed to augment the C++ standard library (found: v${absl_VERSION})"
+            )
+        else()
+            set_package_properties(absl PROPERTIES
+                DESCRIPTION "A collection of C++ library code designed to augment the C++ standard library"
+            )
+        endif()
+        if("${absl_VERSION}" VERSION_LESS ${GNSSSDR_ABSEIL_MIN_VERSION})
+            unset(absl_FOUND CACHE)
+            set(absl_FOUND FALSE)
+            set(ENABLE_GLOG_AND_GFLAGS ON)
+            set_package_properties(absl PROPERTIES
+                DESCRIPTION "A collection of C++ library code designed to augment the C++ standard library (found: v${absl_VERSION}, but it is too old and it will not be used)"
+            )
+        endif()
+    endif()
+endif()
+
+
+if(NOT absl_FOUND)
+    set(ENABLE_GLOG_AND_GFLAGS ON)
+    ################################################################################
+    # gflags - https://github.com/gflags/gflags
+    ################################################################################
+    set(LOCAL_GFLAGS FALSE)
+    if(ENABLE_OWN_GLOG)
         unset(Glog::glog CACHE)
         unset(GLOG_FOUND CACHE)
         unset(Gflags::gflags CACHE)
         unset(GLAGS_FOUND CACHE)
         set(GFLAGS_GREATER_20 TRUE)
-else()
+    else()
         unset(Glog::glog CACHE)
         unset(GLOG_FOUND CACHE)
         find_package(GLOG)
@@ -1409,12 +1490,12 @@ else()
             unset(GFLAGS_GREATER_20 CACHE)
             find_package(GFLAGS)
         endif()
-endif()
-set_package_properties(GFLAGS PROPERTIES
+    endif()
+    set_package_properties(GFLAGS PROPERTIES
         PURPOSE "Used for commandline flags management."
         TYPE REQUIRED
-)
-if(NOT GFLAGS_FOUND)
+    )
+    if(NOT GFLAGS_FOUND)
         set(ENABLE_OWN_GLOG ON)
         if(GFLAGS_VERSION)
             message(STATUS " A version of the gflags library equal or higher than v${GNSSSDR_GFLAGS_MIN_VERSION} has not been found.")
@@ -1428,7 +1509,7 @@ if(NOT GFLAGS_FOUND)
             "--config" $<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>$<$<CONFIG:RelWithDebInfo>:RelWithDebInfo>$<$<CONFIG:MinSizeRel>:MinSizeRel>$<$<CONFIG:NoOptWithASM>:Debug>$<$<CONFIG:Coverage>:Debug>$<$<CONFIG:O2WithASM>:RelWithDebInfo>$<$<CONFIG:O3WithASM>:RelWithDebInfo>$<$<CONFIG:ASAN>:Debug>
         )
         if(CMAKE_GENERATOR STREQUAL Xcode)
-        set(GFLAGS_BUILD_COMMAND "xcodebuild" "-configuration" $<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>$<$<CONFIG:RelWithDebInfo>:RelWithDebInfo>$<$<CONFIG:MinSizeRel>:MinSizeRel>)
+            set(GFLAGS_BUILD_COMMAND "xcodebuild" "-configuration" $<$<CONFIG:None>:None>$<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>$<$<CONFIG:RelWithDebInfo>:RelWithDebInfo>$<$<CONFIG:MinSizeRel>:MinSizeRel>$<$<CONFIG:NoOptWithASM>:NoOptWithASM>$<$<CONFIG:Coverage>:Coverage>$<$<CONFIG:O2WithASM>:O2WithASM>$<$<CONFIG:O3WithASM>:O3WithASM>$<$<CONFIG:ASAN>:Debug>)
         endif()
         if(CMAKE_TOOLCHAIN_FILE)
             set(GFLAGS_TOOLCHAIN_FILE -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE})
@@ -1542,18 +1623,18 @@ if(NOT GFLAGS_FOUND)
                 INTERFACE_COMPILE_DEFINITIONS GFLAGS_OLD_NAMESPACE=1
             )
         endif()
-endif()
+    endif()
 
 
 
-################################################################################
-# glog - https://github.com/google/glog
-################################################################################
-set_package_properties(GLOG PROPERTIES
+    ################################################################################
+    # glog - https://github.com/google/glog
+    ################################################################################
+    set_package_properties(GLOG PROPERTIES
         PURPOSE "Used for runtime internal logging."
         TYPE REQUIRED
-)
-if(NOT GLOG_FOUND OR ${LOCAL_GFLAGS})
+    )
+    if(NOT GLOG_FOUND OR ${LOCAL_GFLAGS})
         message(STATUS " glog library has not been found")
         if(NOT GFLAGS_FOUND)
             message(STATUS " or it is likely not linked to gflags.")
@@ -1581,7 +1662,7 @@ if(NOT GLOG_FOUND OR ${LOCAL_GFLAGS})
         )
         if(CMAKE_GENERATOR STREQUAL Xcode)
             set(GLOG_MAKE_PROGRAM "xcodebuild" "-configuration"
-            $<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>$<$<CONFIG:RelWithDebInfo>:RelWithDebInfo>$<$<CONFIG:MinSizeRel>:MinSizeRel>
+                $<$<CONFIG:None>:None>$<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>$<$<CONFIG:RelWithDebInfo>:RelWithDebInfo>$<$<CONFIG:MinSizeRel>:MinSizeRel>$<$<CONFIG:NoOptWithASM>:NoOptWithASM>$<$<CONFIG:Coverage>:Coverage>$<$<CONFIG:O2WithASM>:O2WithASM>$<$<CONFIG:O3WithASM>:O3WithASM>$<$<CONFIG:ASAN>:Debug>
             )
         endif()
         if(CMAKE_TOOLCHAIN_FILE)
@@ -1610,19 +1691,19 @@ if(NOT GLOG_FOUND OR ${LOCAL_GFLAGS})
                     set(GLOG_EXPORT_CXX_COMPILER "export CXX=g++")
                 endif()
                 file(WRITE ${GNSSSDR_BINARY_DIR}/glog-${GNSSSDR_GLOG_LOCAL_VERSION}/tmp/configure_with_gflags
-"#!/bin/sh
-export CPPFLAGS=-I${GFlags_INCLUDE_DIRS}
-export LDFLAGS=-L${GFLAGS_LIBRARY_DIR_TO_LINK}
-export LIBS=\"${GFLAGS_LIBRARIES_TO_LINK}\"
-${GLOG_EXPORT_CXX_LIBRARIES}
-${GLOG_EXPORT_C_COMPILER}
-${GLOG_EXPORT_CXX_COMPILER}
-cd ${GNSSSDR_BINARY_DIR}/thirdparty/glog/glog-${GNSSSDR_GLOG_LOCAL_VERSION}/
-aclocal
-automake --add-missing
-autoreconf -vfi
-cd ${GNSSSDR_BINARY_DIR}/glog-${GNSSSDR_GLOG_LOCAL_VERSION}
-${GNSSSDR_BINARY_DIR}/thirdparty/glog/glog-${GNSSSDR_GLOG_LOCAL_VERSION}/configure --enable-shared=no"
+    "#!/bin/sh
+    export CPPFLAGS=-I${GFlags_INCLUDE_DIRS}
+    export LDFLAGS=-L${GFLAGS_LIBRARY_DIR_TO_LINK}
+    export LIBS=\"${GFLAGS_LIBRARIES_TO_LINK}\"
+    ${GLOG_EXPORT_CXX_LIBRARIES}
+    ${GLOG_EXPORT_C_COMPILER}
+    ${GLOG_EXPORT_CXX_COMPILER}
+    cd ${GNSSSDR_BINARY_DIR}/thirdparty/glog/glog-${GNSSSDR_GLOG_LOCAL_VERSION}/
+    aclocal
+    automake --add-missing
+    autoreconf -vfi
+    cd ${GNSSSDR_BINARY_DIR}/glog-${GNSSSDR_GLOG_LOCAL_VERSION}
+    ${GNSSSDR_BINARY_DIR}/thirdparty/glog/glog-${GNSSSDR_GLOG_LOCAL_VERSION}/configure --enable-shared=no"
                 )
 
                 file(COPY ${GNSSSDR_BINARY_DIR}/glog-${GNSSSDR_GLOG_LOCAL_VERSION}/tmp/configure_with_gflags
@@ -1830,16 +1911,6 @@ ${GNSSSDR_BINARY_DIR}/thirdparty/glog/glog-${GNSSSDR_GLOG_LOCAL_VERSION}/configu
         set_package_properties(GLOG PROPERTIES
             PURPOSE "Glog v${GNSSSDR_GLOG_LOCAL_VERSION} will be downloaded, built, and statically linked when doing '${CMAKE_MAKE_PROGRAM_PRETTY_NAME}'."
         )
-endif()
-
-if(NOT ENABLE_LOG)
-    message(STATUS "Internal logging is not enabled")
-    if(CMAKE_VERSION VERSION_GREATER 3.11.0)
-        target_compile_definitions(Glog::glog INTERFACE -DGOOGLE_STRIP_LOG=1)
-    else()
-        set_property(TARGET Glog::glog APPEND PROPERTY
-            INTERFACE_COMPILE_DEFINITIONS GOOGLE_STRIP_LOG=1
-        )
     endif()
 endif()
 
@@ -2656,12 +2727,6 @@ if((NOT Protobuf_FOUND) OR (NOT Protobuf_PROTOC_EXECUTABLE) OR (${Protobuf_VERSI
         endif()
     else()
         if(CMAKE_VERSION VERSION_GREATER "3.13")
-            find_package(absl)
-            set_package_properties(absl PROPERTIES
-                URL "https://github.com/abseil/abseil-cpp"
-                PURPOSE "Abseil-cpp >= 20230117 required to be installed before building Protocol Buffers >22.x on the fly."
-                TYPE OPTIONAL
-            )
             if(absl_FOUND)
                 if(absl_VERSION)
                     if(${absl_VERSION} VERSION_LESS "20230117")
@@ -3481,8 +3546,10 @@ add_feature_info(ENABLE_FPGA ENABLE_FPGA "Enables building of processing blocks
 add_feature_info(ENABLE_ARMA_NO_DEBUG ENABLE_ARMA_NO_DEBUG "Enables passing the ARMA_NO_DEBUG macro to Armadillo, hence disabling bound checking.")
 add_feature_info(ENABLE_PACKAGING ENABLE_PACKAGING "Enables software packaging.")
 add_feature_info(ENABLE_OWN_GLOG ENABLE_OWN_GLOG "Forces the downloading and building of Google glog.")
+add_feature_info(ENABLE_GLOG_AND_GFLAGS ENABLE_GLOG_AND_GFLAGS "Forces the usage of Google glog and Gflags instead of Abseil")
+add_feature_info(ENABLE_OWN_ABSEIL ENABLE_OWN_ABSEIL "Forces downloading and building Abseil. Supersedes ENABLE_OWN_GLOG")
 add_feature_info(ENABLE_OWN_ARMADILLO ENABLE_OWN_ARMADILLO "Forces the downloading and building of Armadillo.")
-add_feature_info(ENABLE_LOG ENABLE_LOG "Enables runtime internal logging with Google glog.")
+add_feature_info(ENABLE_LOG ENABLE_LOG "Enables runtime internal logging.")
 add_feature_info(ENABLE_ORC ENABLE_ORC "Use the Optimized Inner Loop Runtime Compiler (ORC) for building volk_gnsssdr.")
 add_feature_info(ENABLE_STRIP ENABLE_STRIP "Enables the generation of stripped binaries (without debugging symbols).")
 add_feature_info(ENABLE_UNIT_TESTING ENABLE_UNIT_TESTING "Enables building of Unit Tests.")

README.md

@@ -222,9 +222,9 @@ Once you have installed these packages, you can jump directly to
 If you are using Arch Linux:
 
 ```
-$ pacman -S gcc make cmake pkgconf git boost boost-libs log4cpp libvolk gnuradio \
-       blas lapack gflags google-glog openssl pugixml libmatio protobuf \
-       python-mako libpcap gtest
+$ pacman -S gcc make cmake pkgconf git boost boost-libs libvolk gnuradio \
+       blas lapack hdf5 openssl pugixml libmatio protobuf libpcap gtest \
+       python-mako
 ```
 
 Once you have installed these packages, you can jump directly to
@@ -430,6 +430,10 @@ $ sudo make install
 $ sudo ldconfig
 ```
 
+Please note that GFlags is replaced by the
+[Abseil Flags Library](https://abseil.io/docs/cpp/guides/flags) if Abseil >=
+v20240116 is available in your system.
+
 #### Install [Glog](https://github.com/google/glog "Glog's Homepage"), a library that implements application-level logging
 
 ```
@@ -443,6 +447,10 @@ $ sudo make install
 $ sudo ldconfig
 ```
 
+Please note that Glog is replaced by the
+[Abseil Logging Library](https://abseil.io/docs/cpp/guides/logging) if Abseil >=
+v20240116 is available in your system.
+
 #### Install the GnuTLS or OpenSSL libraries
 
 ```
@@ -832,7 +840,7 @@ $ sudo port selfupdate
 $ sudo port upgrade outdated
 $ sudo port install armadillo cmake pkgconfig protobuf3-cpp pugixml gnutls
 $ sudo port install gnuradio +uhd +grc +zeromq
-$ sudo port install boost matio libad9361-iio libiio google-glog +gflags
+$ sudo port install boost matio libad9361-iio libiio
 $ sudo port install py311-mako
 $ sudo port install doxygen +docs
 ```
@@ -871,8 +879,7 @@ Install the required dependencies:
 
 ```
 $ brew update && brew upgrade
-$ brew install armadillo cmake hdf5 gflags glog gnuradio libmatio log4cpp \
-    openssl pkg-config protobuf pugixml
+$ brew install armadillo cmake hdf5 gnuradio libmatio openssl pkg-config protobuf pugixml
 $ brew install --cask mactex  # when completed, restart Terminal
 $ brew install graphviz doxygen
 ¢ pip3 install mako

docs/CHANGELOG.md

@@ -16,8 +16,37 @@ All notable changes to GNSS-SDR will be documented in this file.
 
 ### Improvements in Portability:
 
-- Fix building against google-glog 0.7.0
+- Fix building against google-glog 0.7.0.
 - Find dependencies in the loongarch64 architecture.
+- Soft transition from [GFlags](https://github.com/gflags/gflags) and
+  [Google Logging (glog)](https://github.com/google/glog) to Abseil
+  [Logging](https://abseil.io/docs/cpp/guides/logging) and
+  [Flags](https://abseil.io/docs/cpp/guides/flags) libraries. While gflags and
+  glog have dutifully served GNSS-SDR for over a decade, they are now showing
+  signs of aging. The latest version of gflags dates back six years now, with
+  its last commit in the master branch occurring two years ago. Glog remains
+  well maintained, with its latest version v0.7.0 released in February 2024, but
+  with no active development of new features and stuck at C++14. Abseil, on the
+  other hand, represents a contemporary evolution in software development,
+  supports C++17 and C++20, and has absorbed the functionalities of flags and
+  logging from its predecessors. Furthermore, as Abseil has become a
+  prerequisite for the latest versions of Protocol Buffers, its eventual
+  inclusion in GNSS-SDR's indirect dependencies is inevitable. Leveraging Abseil
+  allows for eliminating the need for gflags and glog, thereby reducing the
+  number of mandatory dependencies for GNSS-SDR in forthcoming GNU/Linux
+  distributions. For seamless integration, GNSS-SDR requires a quite recent
+  minimum version of Abseil, v20240116. If an older version is detected, the
+  library will not be utilized, and GNSS-SDR will fall back to using gflags and
+  glog, which still can be used and are fully supported. A new CMake
+  configuration option `-DENABLE_GLOG_AND_GFLAGS=ON` is available to force the
+  usage of glog and gflags instead of Abseil, even if a valid version of that
+  library is present. If the Abseil version installed in your system is too old
+  but you still want to try it, you can also force the downloading and building
+  of a recent version with the new CMake configuration flag
+  `-DENABLE_OWN_ABSEIL=ON` (requires CMake >= 3.24, otherwise it has no effect).
+  This change has a downside in maintainability, since the source code becomes
+  plagued with preprocessor directives required to maintain compatibility both
+  with gflags and glog, and with Abseil.
 
 ### Improvements in Usability:
 

src/algorithms/PVT/adapters/CMakeLists.txt

@@ -23,10 +23,16 @@ target_link_libraries(pvt_adapters
         pvt_gr_blocks
     PRIVATE
         gnss_sdr_flags
-        Glog::glog
         pvt_libs
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(pvt_adapters PRIVATE Glog::glog)
+    target_compile_definitions(pvt_adapters PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(pvt_adapters PRIVATE absl::flags absl::log)
+endif()
+
 target_include_directories(pvt_adapters
     PUBLIC
         ${GNSSSDR_SOURCE_DIR}/src/core/interfaces

src/algorithms/PVT/adapters/rtklib_pvt.cc

@@ -26,8 +26,12 @@
 #include "gps_ephemeris.h"             // for Gps_Ephemeris
 #include "pvt_conf.h"                  // for Pvt_Conf
 #include "rtklib_rtkpos.h"             // for rtkfree, rtkinit
-#include <glog/logging.h>              // for LOG
 #include <iostream>                    // for std::cout
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 #if USE_STD_COMMON_FACTOR
 #include <numeric>
 namespace bc = std;
@@ -88,6 +92,7 @@ Rtklib_Pvt::Rtklib_Pvt(const ConfigurationInterface* configuration,
 
     // RINEX version
     pvt_output_parameters.rinex_version = configuration->property(role + ".rinex_version", 3);
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_RINEX_version == "3.01" || FLAGS_RINEX_version == "3.02" || FLAGS_RINEX_version == "3")
         {
             pvt_output_parameters.rinex_version = 3;
@@ -96,13 +101,29 @@ Rtklib_Pvt::Rtklib_Pvt(const ConfigurationInterface* configuration,
         {
             pvt_output_parameters.rinex_version = 2;
         }
+#else
+    if (absl::GetFlag(FLAGS_RINEX_version) == "3.01" || absl::GetFlag(FLAGS_RINEX_version) == "3.02" || absl::GetFlag(FLAGS_RINEX_version) == "3")
+        {
+            pvt_output_parameters.rinex_version = 3;
+        }
+    else if (absl::GetFlag(FLAGS_RINEX_version) == "2.10" || absl::GetFlag(FLAGS_RINEX_version) == "2.11" || absl::GetFlag(FLAGS_RINEX_version) == "2")
+        {
+            pvt_output_parameters.rinex_version = 2;
+        }
+#endif
     pvt_output_parameters.rinexobs_rate_ms = bc::lcm(configuration->property(role + ".rinexobs_rate_ms", 1000), pvt_output_parameters.output_rate_ms);
     pvt_output_parameters.rinex_name = configuration->property(role + ".rinex_name", std::string("-"));
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_RINEX_name != "-")
         {
             pvt_output_parameters.rinex_name = FLAGS_RINEX_name;
         }
-
+#else
+    if (absl::GetFlag(FLAGS_RINEX_name) != "-")
+        {
+            pvt_output_parameters.rinex_name = absl::GetFlag(FLAGS_RINEX_name);
+        }
+#endif
     // RTCM Printer settings
     pvt_output_parameters.flag_rtcm_tty_port = configuration->property(role + ".flag_rtcm_tty_port", false);
     pvt_output_parameters.rtcm_dump_devname = configuration->property(role + ".rtcm_dump_devname", default_rtcm_dump_devname);

src/algorithms/PVT/gnuradio_blocks/CMakeLists.txt

@@ -27,11 +27,16 @@ target_link_libraries(pvt_gr_blocks
     PRIVATE
         algorithms_libs
         pvt_libs
-        Gflags::gflags
-        Glog::glog
         Boost::serialization
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(pvt_gr_blocks PRIVATE Gflags::gflags Glog::glog)
+    target_compile_definitions(pvt_gr_blocks PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(pvt_gr_blocks PRIVATE absl::log)
+endif()
+
 if(GNURADIO_USES_STD_POINTERS)
     target_compile_definitions(pvt_gr_blocks
         PUBLIC -DGNURADIO_USES_STD_POINTERS=1

src/algorithms/PVT/gnuradio_blocks/rtklib_pvt_gs.cc

@@ -64,7 +64,6 @@
 #include <boost/exception/exception.hpp>
 #include <boost/serialization/map.hpp>
 #include <boost/serialization/nvp.hpp>  // for nvp, make_nvp
-#include <glog/logging.h>               // for LOG
 #include <gnuradio/io_signature.h>      // for io_signature
 #include <pmt/pmt_sugar.h>              // for mp
 #include <algorithm>                    // for sort, unique
@@ -82,6 +81,12 @@
 #include <typeinfo>                     // for std::type_info, typeid
 #include <utility>                      // for pair
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_GENERIC_LAMBDA
 #else
 #include <boost/bind/bind.hpp>

src/algorithms/PVT/libs/CMakeLists.txt

@@ -92,11 +92,18 @@ target_link_libraries(pvt_libs
         algorithms_libs_rtklib
     PRIVATE
         algorithms_libs
-        Gflags::gflags
-        Glog::glog
+        gnss_sdr_flags
         Matio::matio
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(pvt_libs PUBLIC Glog::glog)
+
+    target_compile_definitions(pvt_libs PUBLIC -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(pvt_libs PUBLIC absl::log)
+endif()
+
 get_filename_component(PROTO_INCLUDE_HEADERS_DIR ${PROTO_HDRS} DIRECTORY)
 
 # for concurrent_queue.h

src/algorithms/PVT/libs/an_packet_printer.cc

@@ -20,7 +20,6 @@
 
 #include "an_packet_printer.h"
 #include "rtklib_solver.h"  // for Rtklib_Solver
-#include <glog/logging.h>   // for DLOG
 #include <cmath>            // for M_PI
 #include <cstring>          // for memcpy
 #include <fcntl.h>          // for fcntl
@@ -29,6 +28,12 @@
 #include <termios.h>        // values for termios
 #include <unistd.h>         // for write(), read(), close()
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 An_Packet_Printer::An_Packet_Printer(const std::string& an_dump_devname)
     : d_start(std::chrono::system_clock::now()),

src/algorithms/PVT/libs/geohash.cc

@@ -135,7 +135,7 @@ std::array<double, 2> Geohash::decode(std::string geohash) const
 
 std::array<double, 4> Geohash::bounds(std::string geohash) const
 {
-    if (geohash.length() == 0)
+    if (geohash.empty())
         {
             throw std::runtime_error("Invalid geohash");
         }

src/algorithms/PVT/libs/geojson_printer.cc

@@ -20,13 +20,18 @@
 #include "gnss_sdr_filesystem.h"
 #include "pvt_solution.h"
 #include <boost/date_time/posix_time/posix_time.hpp>
-#include <glog/logging.h>
 #include <ctime>      // for tm
 #include <exception>  // for exception
 #include <iomanip>    // for operator<<
 #include <iostream>   // for cout, cerr
 #include <sstream>    // for stringstream
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 GeoJSON_Printer::GeoJSON_Printer(const std::string& base_path) : geojson_base_path(base_path),
                                                                  first_pos(true)

src/algorithms/PVT/libs/gpx_printer.cc

@@ -20,13 +20,17 @@
 #include "gnss_sdr_filesystem.h"
 #include "pvt_solution.h"
 #include <boost/date_time/posix_time/posix_time.hpp>
-#include <glog/logging.h>
 #include <ctime>      // for tm
 #include <exception>  // for exception
 #include <iomanip>    // for operator<<
 #include <iostream>   // for cout, cerr
 #include <sstream>    // for stringstream
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 Gpx_Printer::Gpx_Printer(const std::string& base_path) : indent("  "),
                                                          gpx_base_path(base_path),

src/algorithms/PVT/libs/has_simple_printer.cc

@@ -21,7 +21,6 @@
 #include "galileo_has_data.h"
 #include "gnss_sdr_filesystem.h"
 #include <boost/date_time/posix_time/posix_time.hpp>
-#include <glog/logging.h>
 #include <algorithm>  // for std::find, std::count
 #include <bitset>     // for std::bitset
 #include <cstdint>    // for uint8_t, ...
@@ -32,6 +31,12 @@
 #include <iostream>   // for std::cout, std::cerr
 #include <sstream>    // for std::stringstream
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 Has_Simple_Printer::Has_Simple_Printer(const std::string& base_path,
     const std::string& filename,

src/algorithms/PVT/libs/kml_printer.cc

@@ -20,7 +20,6 @@
 #include "gnss_sdr_filesystem.h"
 #include "pvt_solution.h"
 #include <boost/date_time/posix_time/posix_time.hpp>
-#include <glog/logging.h>
 #include <cstdlib>    // for mkstemp
 #include <ctime>      // for tm
 #include <exception>  // for exception
@@ -30,6 +29,11 @@
 #include <sys/stat.h>   // for S_IXUSR | S_IRWXG | S_IRWXO
 #include <sys/types.h>  // for mode_t
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 Kml_Printer::Kml_Printer(const std::string& base_path) : kml_base_path(base_path),
                                                          indent("  "),

src/algorithms/PVT/libs/nmea_printer.cc

@@ -23,7 +23,6 @@
 #include "gnss_sdr_filesystem.h"
 #include "rtklib_solution.h"
 #include "rtklib_solver.h"
-#include <glog/logging.h>
 #include <array>
 #include <cstdint>
 #include <exception>
@@ -32,6 +31,12 @@
 #include <termios.h>
 #include <utility>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 Nmea_Printer::Nmea_Printer(const std::string& filename,
     bool flag_nmea_output_file,

src/algorithms/PVT/libs/pvt_kf.cc

@@ -16,8 +16,12 @@
  */
 
 #include "pvt_kf.h"
-#include <glog/logging.h>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 void Pvt_Kf::init_Kf(const arma::vec& p,
     const arma::vec& v,

src/algorithms/PVT/libs/pvt_solution.cc

@@ -17,10 +17,14 @@
 
 #include "pvt_solution.h"
 #include "MATH_CONSTANTS.h"
-#include <glog/logging.h>
 #include <cmath>
 #include <cstddef>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 int Pvt_Solution::cart2geo(double X, double Y, double Z, int elipsoid_selection)
 {

src/algorithms/PVT/libs/rinex_printer.cc

@@ -42,7 +42,6 @@
 #include <boost/date_time/gregorian/gregorian.hpp>
 #include <boost/date_time/local_time/local_time.hpp>
 #include <boost/date_time/time_zone_base.hpp>
-#include <glog/logging.h>
 #include <algorithm>  // for min and max
 #include <array>
 #include <cmath>  // for floor
@@ -55,6 +54,11 @@
 #include <utility>
 #include <vector>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 Rinex_Printer::Rinex_Printer(int32_t conf_version,
     const std::string& base_path,

src/algorithms/PVT/libs/rtcm.h

@@ -29,7 +29,6 @@
 #include "gps_ephemeris.h"
 #include <boost/asio.hpp>
 #include <boost/date_time/posix_time/posix_time.hpp>
-#include <glog/logging.h>
 #include <algorithm>  // for std::max, std::min, std::copy_n
 #include <array>
 #include <bitset>
@@ -47,6 +46,12 @@
 #include <utility>
 #include <vector>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 /** \addtogroup PVT
  * \{ */
 /** \addtogroup PVT_libs

src/algorithms/PVT/libs/rtcm_printer.cc

@@ -30,7 +30,6 @@
 #include "rtcm.h"
 #include "rtklib_solver.h"
 #include <boost/exception/diagnostic_information.hpp>
-#include <glog/logging.h>
 #include <ctime>      // for tm
 #include <exception>  // for exception
 #include <fcntl.h>    // for O_RDWR
@@ -39,6 +38,11 @@
 #include <unistd.h>   // for close, write
 #include <vector>     // for std::vector
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 Rtcm_Printer::Rtcm_Printer(const std::string& filename,
     bool flag_rtcm_file_dump,

src/algorithms/PVT/libs/rtklib_solver.cc

@@ -35,7 +35,6 @@
 #include "gnss_sdr_filesystem.h"
 #include "rtklib_rtkpos.h"
 #include "rtklib_solution.h"
-#include <glog/logging.h>
 #include <matio.h>
 #include <algorithm>
 #include <cmath>
@@ -43,6 +42,11 @@
 #include <utility>
 #include <vector>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 Rtklib_Solver::Rtklib_Solver(const rtk_t &rtk,
     const Pvt_Conf &conf,

src/algorithms/acquisition/adapters/CMakeLists.txt

@@ -104,9 +104,15 @@ target_link_libraries(acquisition_adapters
     PRIVATE
         gnss_sdr_flags
         Boost::headers
-        Glog::glog
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(acquisition_adapters PRIVATE Glog::glog)
+    target_compile_definitions(acquisition_adapters PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(acquisition_adapters PRIVATE absl::flags absl::log)
+endif()
+
 if(GNURADIO_USES_STD_POINTERS)
     target_compile_definitions(acquisition_adapters
         PUBLIC -DGNURADIO_USES_STD_POINTERS=1

src/algorithms/acquisition/adapters/beidou_b1i_pcps_acquisition.cc

@@ -23,10 +23,15 @@
 #include "beidou_b1i_signal_replica.h"
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
-#include <glog/logging.h>
 #include <algorithm>
 #include <memory>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -52,10 +57,17 @@ BeidouB1iPcpsAcquisition::BeidouB1iPcpsAcquisition(
 
     LOG(INFO) << "role " << role;
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     fs_in_ = acq_parameters_.fs_in;

src/algorithms/acquisition/adapters/beidou_b3i_pcps_acquisition.cc

@@ -21,9 +21,14 @@
 #include "beidou_b3i_signal_replica.h"
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -48,10 +53,17 @@ BeidouB3iPcpsAcquisition::BeidouB3iPcpsAcquisition(
 
     LOG(INFO) << "role " << role;
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     item_type_ = acq_parameters_.item_type;

src/algorithms/acquisition/adapters/galileo_e1_pcps_8ms_ambiguous_acquisition.cc

@@ -21,9 +21,14 @@
 #include "galileo_e1_signal_replica.h"
 #include "gnss_sdr_flags.h"
 #include <boost/math/distributions/exponential.hpp>
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -58,10 +63,17 @@ GalileoE1Pcps8msAmbiguousAcquisition::GalileoE1Pcps8msAmbiguousAcquisition(
     fs_in_ = configuration_->property("GNSS-SDR.internal_fs_sps", fs_in_deprecated);
     dump_filename_ = configuration_->property(role_ + ".dump_filename", default_dump_filename);
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             doppler_max_ = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            doppler_max_ = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
 
     if (sampled_ms_ % 4 != 0)
         {

src/algorithms/acquisition/adapters/galileo_e1_pcps_ambiguous_acquisition.cc

@@ -22,9 +22,14 @@
 #include "galileo_e1_signal_replica.h"
 #include "gnss_sdr_flags.h"
 #include <boost/math/distributions/exponential.hpp>
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -51,10 +56,17 @@ GalileoE1PcpsAmbiguousAcquisition::GalileoE1PcpsAmbiguousAcquisition(
     acq_parameters_.ms_per_code = 4;
     acq_parameters_.SetFromConfiguration(configuration_, role_, GALILEO_E1_CODE_CHIP_RATE_CPS, GALILEO_E1_OPT_ACQ_FS_SPS);
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     item_type_ = acq_parameters_.item_type;

src/algorithms/acquisition/adapters/galileo_e1_pcps_ambiguous_acquisition_fpga.cc

@@ -21,7 +21,6 @@
 #include "galileo_e1_signal_replica.h"
 #include "gnss_sdr_fft.h"
 #include "gnss_sdr_flags.h"
-#include <glog/logging.h>
 #include <gnuradio/fft/fft.h>     // for fft_complex
 #include <gnuradio/gr_complex.h>  // for gr_complex
 #include <volk/volk.h>            // for volk_32fc_conjugate_32fc
@@ -30,6 +29,12 @@
 #include <cmath>      // for abs, pow, floor
 #include <complex>    // for complex
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 GalileoE1PcpsAmbiguousAcquisitionFpga::GalileoE1PcpsAmbiguousAcquisitionFpga(
     const ConfigurationInterface* configuration,
     const std::string& role,
@@ -46,10 +51,17 @@ GalileoE1PcpsAmbiguousAcquisitionFpga::GalileoE1PcpsAmbiguousAcquisitionFpga(
 {
     acq_parameters_.SetFromConfiguration(configuration, role_, fpga_buff_num, fpga_blk_exp, downsampling_factor_default, GALILEO_E1_CODE_CHIP_RATE_CPS, GALILEO_E1_B_CODE_LENGTH_CHIPS);
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     fs_in_ = acq_parameters_.fs_in;

src/algorithms/acquisition/adapters/galileo_e1_pcps_cccwsr_ambiguous_acquisition.cc

@@ -21,8 +21,12 @@
 #include "galileo_e1_signal_replica.h"
 #include "gnss_sdr_flags.h"
 #include <boost/math/distributions/exponential.hpp>
-#include <glog/logging.h>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 GalileoE1PcpsCccwsrAmbiguousAcquisition::GalileoE1PcpsCccwsrAmbiguousAcquisition(
     const ConfigurationInterface* configuration,
@@ -50,10 +54,17 @@ GalileoE1PcpsCccwsrAmbiguousAcquisition::GalileoE1PcpsCccwsrAmbiguousAcquisition
     fs_in_ = configuration_->property("GNSS-SDR.internal_fs_sps", fs_in_deprecated);
     dump_filename_ = configuration_->property(role_ + ".dump_filename", default_dump_filename);
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             doppler_max_ = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            doppler_max_ = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
 
     if (sampled_ms_ % 4 != 0)
         {

src/algorithms/acquisition/adapters/galileo_e1_pcps_quicksync_ambiguous_acquisition.cc

@@ -21,9 +21,14 @@
 #include "galileo_e1_signal_replica.h"
 #include "gnss_sdr_flags.h"
 #include <boost/math/distributions/exponential.hpp>
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -58,10 +63,17 @@ GalileoE1PcpsQuickSyncAmbiguousAcquisition::GalileoE1PcpsQuickSyncAmbiguousAcqui
     fs_in_ = configuration_->property("GNSS-SDR.internal_fs_sps", fs_in_deprecated);
     dump_filename_ = configuration_->property(role + ".dump_filename", default_dump_filename);
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             doppler_max_ = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            doppler_max_ = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
 
     /* --- Find number of samples per spreading code (4 ms)  -----------------*/
     code_length_ = static_cast<unsigned int>(round(

src/algorithms/acquisition/adapters/galileo_e1_pcps_tong_ambiguous_acquisition.cc

@@ -21,9 +21,14 @@
 #include "galileo_e1_signal_replica.h"
 #include "gnss_sdr_flags.h"
 #include <boost/math/distributions/exponential.hpp>
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -71,10 +76,17 @@ GalileoE1PcpsTongAmbiguousAcquisition::GalileoE1PcpsTongAmbiguousAcquisition(
                          << sampled_ms_ << " ms will be used.";
         }
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             doppler_max_ = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            doppler_max_ = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
 
     bool enable_monitor_output = configuration_->property("AcquisitionMonitor.enable_monitor", false);
 

src/algorithms/acquisition/adapters/galileo_e5a_noncoherent_iq_acquisition_caf.cc

@@ -27,9 +27,14 @@
 #include "galileo_e5_signal_replica.h"
 #include "gnss_sdr_flags.h"
 #include <boost/math/distributions/exponential.hpp>
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -67,10 +72,17 @@ GalileoE5aNoncoherentIQAcquisitionCaf::GalileoE5aNoncoherentIQAcquisitionCaf(
     int64_t fs_in_deprecated = configuration_->property("GNSS-SDR.internal_fs_hz", 32000000);
     fs_in_ = configuration_->property("GNSS-SDR.internal_fs_sps", fs_in_deprecated);
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             doppler_max_ = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            doppler_max_ = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
 
     DLOG(INFO) << "role " << role_;
     if (sampled_ms_ > 3)

src/algorithms/acquisition/adapters/galileo_e5a_pcps_acquisition.cc

@@ -21,10 +21,15 @@
 #include "configuration_interface.h"
 #include "galileo_e5_signal_replica.h"
 #include "gnss_sdr_flags.h"
-#include <glog/logging.h>
 #include <volk_gnsssdr/volk_gnsssdr_complex.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -51,10 +56,17 @@ GalileoE5aPcpsAcquisition::GalileoE5aPcpsAcquisition(
     acq_parameters_.ms_per_code = 1;
     acq_parameters_.SetFromConfiguration(configuration, role_, GALILEO_E5A_CODE_CHIP_RATE_CPS, GALILEO_E5A_OPT_ACQ_FS_SPS);
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     item_type_ = acq_parameters_.item_type;

src/algorithms/acquisition/adapters/galileo_e5a_pcps_acquisition_fpga.cc

@@ -21,7 +21,6 @@
 #include "galileo_e5_signal_replica.h"
 #include "gnss_sdr_fft.h"
 #include "gnss_sdr_flags.h"
-#include <glog/logging.h>
 #include <gnuradio/gr_complex.h>  // for gr_complex
 #include <volk/volk.h>            // for volk_32fc_conjugate_32fc
 #include <volk_gnsssdr/volk_gnsssdr_alloc.h>
@@ -29,6 +28,12 @@
 #include <cmath>      // for abs, pow, floor
 #include <complex>    // for complex
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 GalileoE5aPcpsAcquisitionFpga::GalileoE5aPcpsAcquisitionFpga(
     const ConfigurationInterface* configuration,
     const std::string& role,
@@ -45,10 +50,17 @@ GalileoE5aPcpsAcquisitionFpga::GalileoE5aPcpsAcquisitionFpga(
 {
     acq_parameters_.SetFromConfiguration(configuration, role_, fpga_buff_num, fpga_blk_exp, downsampling_factor_default, GALILEO_E5A_CODE_CHIP_RATE_CPS, GALILEO_E5A_CODE_LENGTH_CHIPS);
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     fs_in_ = acq_parameters_.fs_in;

src/algorithms/acquisition/adapters/galileo_e5b_pcps_acquisition.cc

@@ -22,10 +22,15 @@
 #include "configuration_interface.h"
 #include "galileo_e5_signal_replica.h"
 #include "gnss_sdr_flags.h"
-#include <glog/logging.h>
 #include <volk_gnsssdr/volk_gnsssdr_complex.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -51,10 +56,17 @@ GalileoE5bPcpsAcquisition::GalileoE5bPcpsAcquisition(const ConfigurationInterfac
     acq_parameters_.ms_per_code = 1;
     acq_parameters_.SetFromConfiguration(configuration, role_, GALILEO_E5B_CODE_CHIP_RATE_CPS, GALILEO_E5B_OPT_ACQ_FS_SPS);
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     item_type_ = acq_parameters_.item_type;

src/algorithms/acquisition/adapters/galileo_e5b_pcps_acquisition_fpga.cc

@@ -22,13 +22,18 @@
 #include "galileo_e5_signal_replica.h"
 #include "gnss_sdr_fft.h"
 #include "gnss_sdr_flags.h"
-#include <glog/logging.h>
 #include <gnuradio/gr_complex.h>  // for gr_complex
 #include <volk/volk.h>            // for volk_32fc_conjugate_32fc
 #include <algorithm>              // for copy_n
 #include <cmath>                  // for abs, pow, floor
 #include <complex>                // for complex
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 GalileoE5bPcpsAcquisitionFpga::GalileoE5bPcpsAcquisitionFpga(const ConfigurationInterface* configuration,
     const std::string& role,
     unsigned int in_streams,
@@ -44,10 +49,17 @@ GalileoE5bPcpsAcquisitionFpga::GalileoE5bPcpsAcquisitionFpga(const Configuration
       acq_iq_(configuration->property(role + ".acquire_iq", false))
 {
     acq_parameters_.SetFromConfiguration(configuration, role_, fpga_buff_num, fpga_blk_exp, downsampling_factor_default, GALILEO_E5B_CODE_CHIP_RATE_CPS, GALILEO_E5B_CODE_LENGTH_CHIPS);
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     fs_in_ = acq_parameters_.fs_in;

src/algorithms/acquisition/adapters/galileo_e6_pcps_acquisition.cc

@@ -21,9 +21,14 @@
 #include "configuration_interface.h"
 #include "galileo_e6_signal_replica.h"
 #include "gnss_sdr_flags.h"
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -51,10 +56,17 @@ GalileoE6PcpsAcquisition::GalileoE6PcpsAcquisition(
 
     DLOG(INFO) << "role " << role;
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     item_type_ = acq_parameters_.item_type;

src/algorithms/acquisition/adapters/glonass_l1_ca_pcps_acquisition.cc

@@ -23,9 +23,14 @@
 #include "configuration_interface.h"
 #include "glonass_l1_signal_replica.h"
 #include "gnss_sdr_flags.h"
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -51,10 +56,17 @@ GlonassL1CaPcpsAcquisition::GlonassL1CaPcpsAcquisition(
 
     DLOG(INFO) << "role " << role;
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     item_type_ = acq_parameters_.item_type;

src/algorithms/acquisition/adapters/glonass_l2_ca_pcps_acquisition.cc

@@ -22,9 +22,14 @@
 #include "configuration_interface.h"
 #include "glonass_l2_signal_replica.h"
 #include "gnss_sdr_flags.h"
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -50,10 +55,17 @@ GlonassL2CaPcpsAcquisition::GlonassL2CaPcpsAcquisition(
 
     DLOG(INFO) << "role " << role;
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     item_type_ = acq_parameters_.item_type;

src/algorithms/acquisition/adapters/gps_l1_ca_pcps_acquisition.cc

@@ -25,9 +25,14 @@
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
 #include "gps_sdr_signal_replica.h"
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -54,10 +59,17 @@ GpsL1CaPcpsAcquisition::GpsL1CaPcpsAcquisition(
 
     DLOG(INFO) << "role " << role;
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
 
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);

src/algorithms/acquisition/adapters/gps_l1_ca_pcps_acquisition_fine_doppler.cc

@@ -24,8 +24,12 @@
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
 #include "gps_sdr_signal_replica.h"
-#include <glog/logging.h>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 GpsL1CaPcpsAcquisitionFineDoppler::GpsL1CaPcpsAcquisitionFineDoppler(
     const ConfigurationInterface* configuration,
@@ -57,10 +61,17 @@ GpsL1CaPcpsAcquisitionFineDoppler::GpsL1CaPcpsAcquisitionFineDoppler(
     acq_parameters.dump = dump_;
     dump_filename_ = configuration->property(role_ + ".dump_filename", std::move(default_dump_filename));
     acq_parameters.dump_filename = dump_filename_;
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             doppler_max_ = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            doppler_max_ = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     acq_parameters.doppler_max = doppler_max_;
     acq_parameters.sampled_ms = sampled_ms_;
     acq_parameters.max_dwells = max_dwells_;

src/algorithms/acquisition/adapters/gps_l1_ca_pcps_acquisition_fpga.cc

@@ -24,13 +24,18 @@
 #include "gnss_sdr_fft.h"
 #include "gnss_sdr_flags.h"
 #include "gps_sdr_signal_replica.h"
-#include <glog/logging.h>
 #include <gnuradio/gr_complex.h>  // for gr_complex
 #include <volk/volk.h>            // for volk_32fc_conjugate_32fc
 #include <algorithm>              // for copy_n
 #include <cmath>                  // for abs, pow, floor
 #include <complex>                // for complex
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 GpsL1CaPcpsAcquisitionFpga::GpsL1CaPcpsAcquisitionFpga(
     const ConfigurationInterface* configuration,
     const std::string& role,
@@ -47,10 +52,17 @@ GpsL1CaPcpsAcquisitionFpga::GpsL1CaPcpsAcquisitionFpga(
 
     DLOG(INFO) << "role " << role;
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     fs_in_ = acq_parameters_.fs_in;

src/algorithms/acquisition/adapters/gps_l1_ca_pcps_assisted_acquisition.cc

@@ -23,8 +23,12 @@
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
 #include "gps_sdr_signal_replica.h"
-#include <glog/logging.h>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 GpsL1CaPcpsAssistedAcquisition::GpsL1CaPcpsAssistedAcquisition(
     const ConfigurationInterface* configuration,
@@ -51,10 +55,17 @@ GpsL1CaPcpsAssistedAcquisition::GpsL1CaPcpsAssistedAcquisition(
     int64_t fs_in_deprecated = configuration->property("GNSS-SDR.internal_fs_hz", 2048000);
     fs_in_ = configuration->property("GNSS-SDR.internal_fs_sps", fs_in_deprecated);
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             doppler_max_ = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            doppler_max_ = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_min_ = configuration->property(role_ + ".doppler_min", -doppler_max_);
 
     bool enable_monitor_output = configuration->property("AcquisitionMonitor.enable_monitor", false);

src/algorithms/acquisition/adapters/gps_l1_ca_pcps_opencl_acquisition.cc

@@ -21,9 +21,14 @@
 #include "gnss_sdr_flags.h"
 #include "gps_sdr_signal_replica.h"
 #include <boost/math/distributions/exponential.hpp>
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -58,10 +63,17 @@ GpsL1CaPcpsOpenClAcquisition::GpsL1CaPcpsOpenClAcquisition(
     fs_in_ = configuration->property("GNSS-SDR.internal_fs_sps", fs_in_deprecated);
     dump_ = configuration->property(role + ".dump", false);
     doppler_max_ = configuration->property(role + ".doppler_max", 5000);
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             doppler_max_ = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            doppler_max_ = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     sampled_ms_ = configuration->property(role + ".coherent_integration_time_ms", 1);
 
     bit_transition_flag_ = configuration->property("Acquisition.bit_transition_flag", false);

src/algorithms/acquisition/adapters/gps_l1_ca_pcps_quicksync_acquisition.cc

@@ -22,9 +22,14 @@
 #include "gnss_sdr_flags.h"
 #include "gps_sdr_signal_replica.h"
 #include <boost/math/distributions/exponential.hpp>
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -58,10 +63,17 @@ GpsL1CaPcpsQuickSyncAcquisition::GpsL1CaPcpsQuickSyncAcquisition(
     int64_t fs_in_deprecated = configuration_->property("GNSS-SDR.internal_fs_hz", 2048000);
     fs_in_ = configuration_->property("GNSS-SDR.internal_fs_sps", fs_in_deprecated);
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             doppler_max_ = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            doppler_max_ = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
 
     // -- Find number of samples per spreading code -------------------------
     code_length_ = static_cast<unsigned int>(round(fs_in_ / (GPS_L1_CA_CODE_RATE_CPS / GPS_L1_CA_CODE_LENGTH_CHIPS)));

src/algorithms/acquisition/adapters/gps_l1_ca_pcps_tong_acquisition.cc

@@ -21,9 +21,14 @@
 #include "gnss_sdr_flags.h"
 #include "gps_sdr_signal_replica.h"
 #include <boost/math/distributions/exponential.hpp>
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -63,10 +68,17 @@ GpsL1CaPcpsTongAcquisition::GpsL1CaPcpsTongAcquisition(
     fs_in_ = configuration_->property("GNSS-SDR.internal_fs_sps", fs_in_deprecated);
     dump_filename_ = configuration_->property(role_ + ".dump_filename", std::move(default_dump_filename));
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             doppler_max_ = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            doppler_max_ = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     bool enable_monitor_output = configuration_->property("AcquisitionMonitor.enable_monitor", false);
 
     // -- Find number of samples per spreading code -------------------------

src/algorithms/acquisition/adapters/gps_l2_m_pcps_acquisition.cc

@@ -23,9 +23,14 @@
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
 #include "gps_l2c_signal_replica.h"
-#include <glog/logging.h>
 #include <algorithm>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -52,10 +57,17 @@ GpsL2MPcpsAcquisition::GpsL2MPcpsAcquisition(
 
     DLOG(INFO) << "Role " << role;
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     item_type_ = acq_parameters_.item_type;

src/algorithms/acquisition/adapters/gps_l2_m_pcps_acquisition_fpga.cc

@@ -23,7 +23,6 @@
 #include "gnss_sdr_fft.h"
 #include "gnss_sdr_flags.h"
 #include "gps_l2c_signal_replica.h"
-#include <glog/logging.h>
 #include <gnuradio/gr_complex.h>  // for gr_complex
 #include <volk/volk.h>            // for volk_32fc_conjugate_32fc
 #include <volk_gnsssdr/volk_gnsssdr_alloc.h>
@@ -31,6 +30,12 @@
 #include <cmath>      // for abs, pow, floor
 #include <complex>    // for complex
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 GpsL2MPcpsAcquisitionFpga::GpsL2MPcpsAcquisitionFpga(
     const ConfigurationInterface* configuration,
     const std::string& role,
@@ -47,10 +52,17 @@ GpsL2MPcpsAcquisitionFpga::GpsL2MPcpsAcquisitionFpga(
 
     LOG(INFO) << "role " << role;
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     fs_in_ = acq_parameters_.fs_in;

src/algorithms/acquisition/adapters/gps_l5i_pcps_acquisition.cc

@@ -23,8 +23,14 @@
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
 #include "gps_l5_signal_replica.h"
-#include <glog/logging.h>
 #include <algorithm>
+
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -51,10 +57,17 @@ GpsL5iPcpsAcquisition::GpsL5iPcpsAcquisition(
 
     DLOG(INFO) << "role " << role;
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
 
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);

src/algorithms/acquisition/adapters/gps_l5i_pcps_acquisition_fpga.cc

@@ -24,7 +24,6 @@
 #include "gnss_sdr_fft.h"
 #include "gnss_sdr_flags.h"
 #include "gps_l5_signal_replica.h"
-#include <glog/logging.h>
 #include <gnuradio/gr_complex.h>  // for gr_complex
 #include <volk/volk.h>            // for volk_32fc_conjugate_32fc
 #include <volk_gnsssdr/volk_gnsssdr_alloc.h>
@@ -32,6 +31,12 @@
 #include <cmath>      // for abs, pow, floor
 #include <complex>    // for complex
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 GpsL5iPcpsAcquisitionFpga::GpsL5iPcpsAcquisitionFpga(
     const ConfigurationInterface* configuration,
     const std::string& role,
@@ -48,10 +53,17 @@ GpsL5iPcpsAcquisitionFpga::GpsL5iPcpsAcquisitionFpga(
 
     LOG(INFO) << "role " << role;
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_max != 0)
         {
             acq_parameters_.doppler_max = FLAGS_doppler_max;
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_max) != 0)
+        {
+            acq_parameters_.doppler_max = absl::GetFlag(FLAGS_doppler_max);
+        }
+#endif
     doppler_max_ = acq_parameters_.doppler_max;
     doppler_step_ = static_cast<unsigned int>(acq_parameters_.doppler_step);
     fs_in_ = acq_parameters_.fs_in;

src/algorithms/acquisition/gnuradio_blocks/CMakeLists.txt

@@ -65,11 +65,16 @@ target_link_libraries(acquisition_gr_blocks
         Volk::volk
         Volkgnsssdr::volkgnsssdr
     PRIVATE
-        Gflags::gflags
-        Glog::glog
         Matio::matio
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(acquisition_gr_blocks PRIVATE Gflags::gflags Glog::glog)
+    target_compile_definitions(acquisition_gr_blocks PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(acquisition_gr_blocks PRIVATE absl::flags absl::log)
+endif()
+
 target_include_directories(acquisition_gr_blocks
     PRIVATE
         ${GNSSSDR_SOURCE_DIR}/src/core/receiver

src/algorithms/acquisition/gnuradio_blocks/galileo_e5a_noncoherent_iq_acquisition_caf_cc.cc

@@ -23,7 +23,6 @@
 
 #include "galileo_e5a_noncoherent_iq_acquisition_caf_cc.h"
 #include "MATH_CONSTANTS.h"
-#include <glog/logging.h>
 #include <gnuradio/io_signature.h>
 #include <volk/volk.h>
 #include <volk_gnsssdr/volk_gnsssdr.h>
@@ -32,6 +31,12 @@
 #include <exception>
 #include <sstream>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 galileo_e5a_noncoherentIQ_acquisition_caf_cc_sptr galileo_e5a_noncoherentIQ_make_acquisition_caf_cc(
     unsigned int sampled_ms,

src/algorithms/acquisition/gnuradio_blocks/galileo_pcps_8ms_acquisition_cc.cc

@@ -17,7 +17,6 @@
 
 #include "galileo_pcps_8ms_acquisition_cc.h"
 #include "MATH_CONSTANTS.h"
-#include <glog/logging.h>
 #include <gnuradio/io_signature.h>
 #include <volk/volk.h>
 #include <volk_gnsssdr/volk_gnsssdr.h>
@@ -26,6 +25,11 @@
 #include <exception>
 #include <sstream>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 galileo_pcps_8ms_acquisition_cc_sptr galileo_pcps_8ms_make_acquisition_cc(
     uint32_t sampled_ms,

src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.cc

@@ -39,6 +39,12 @@
 #include <iostream>
 #include <map>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 pcps_acquisition_sptr pcps_make_acquisition(const Acq_Conf& conf_)
 {
@@ -896,6 +902,18 @@ void pcps_acquisition::calculate_threshold()
 }
 
 
+void pcps_acquisition::set_doppler_center(int32_t doppler_center)
+{
+    gr::thread::scoped_lock lock(d_setlock);  // require mutex with work function called by the scheduler
+    if (doppler_center != d_doppler_center)
+        {
+            DLOG(INFO) << " Doppler assistance for Channel: " << d_channel << " => Doppler: " << doppler_center << "[Hz]";
+            d_doppler_center = doppler_center;
+            update_grid_doppler_wipeoffs();
+        }
+}
+
+
 int pcps_acquisition::general_work(int noutput_items __attribute__((unused)),
     gr_vector_int& ninput_items,
     gr_vector_const_void_star& input_items,

src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.h

@@ -46,7 +46,6 @@
 #include "channel_fsm.h"
 #include "gnss_sdr_fft.h"
 #include <armadillo>
-#include <glog/logging.h>
 #include <gnuradio/block.h>
 #include <gnuradio/gr_complex.h>              // for gr_complex
 #include <gnuradio/thread/thread.h>           // for scoped_lock
@@ -60,6 +59,7 @@
 #include <string>
 #include <utility>
 
+
 #if HAS_STD_SPAN
 #include <span>
 namespace own = std;
@@ -196,16 +196,7 @@ public:
      * \brief Set Doppler center frequency for the grid search. It will refresh the Doppler grid.
      * \param doppler_center - Frequency center of the search grid [Hz].
      */
-    inline void set_doppler_center(int32_t doppler_center)
-    {
-        gr::thread::scoped_lock lock(d_setlock);  // require mutex with work function called by the scheduler
-        if (doppler_center != d_doppler_center)
-            {
-                DLOG(INFO) << " Doppler assistance for Channel: " << d_channel << " => Doppler: " << doppler_center << "[Hz]";
-                d_doppler_center = doppler_center;
-                update_grid_doppler_wipeoffs();
-            }
-    }
+    void set_doppler_center(int32_t doppler_center);
 
     /*!
      * \brief Parallel Code Phase Search Acquisition signal processing.

src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_fine_doppler_cc.cc

@@ -21,7 +21,6 @@
 #include "gnss_sdr_create_directory.h"
 #include "gnss_sdr_filesystem.h"
 #include "gps_sdr_signal_replica.h"
-#include <glog/logging.h>
 #include <gnuradio/io_signature.h>
 #include <matio.h>
 #include <volk/volk.h>
@@ -30,6 +29,12 @@
 #include <sstream>
 #include <vector>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 pcps_acquisition_fine_doppler_cc_sptr pcps_make_acquisition_fine_doppler_cc(const Acq_Conf &conf_)
 {

src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_fpga.cc

@@ -21,12 +21,17 @@
 #include "pcps_acquisition_fpga.h"
 #include "gnss_sdr_make_unique.h"  // for std::make_unique in C++11
 #include "gnss_synchro.h"
-#include <glog/logging.h>
 #include <cmath>     // for ceil
 #include <iostream>  // for operator<<
 #include <utility>   // for move
 
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 pcps_acquisition_fpga_sptr pcps_make_acquisition_fpga(Acq_Conf_Fpga& conf_)
 {
     return pcps_acquisition_fpga_sptr(new pcps_acquisition_fpga(conf_));
@@ -288,6 +293,16 @@ void pcps_acquisition_fpga::set_active(bool active)
 }
 
 
+void pcps_acquisition_fpga::set_doppler_center(int32_t doppler_center)
+{
+    if (doppler_center != d_doppler_center)
+        {
+            DLOG(INFO) << " Doppler assistance for Channel: " << d_channel << " => Doppler: " << doppler_center << "[Hz]";
+            d_doppler_center = doppler_center;
+        }
+}
+
+
 void pcps_acquisition_fpga::reset_acquisition()
 {
     // this function triggers a HW reset of the FPGA PL.

src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_fpga.h

@@ -29,7 +29,6 @@
 #include "acq_conf_fpga.h"
 #include "channel_fsm.h"
 #include "fpga_acquisition.h"
-#include <glog/logging.h>
 #include <cstdint>  // for uint32_t
 #include <memory>   // for shared_ptr
 #include <string>   // for string
@@ -156,14 +155,7 @@ public:
      * \brief Set Doppler center frequency for the grid search. It will refresh the Doppler grid.
      * \param doppler_center - Frequency center of the search grid [Hz].
      */
-    inline void set_doppler_center(int32_t doppler_center)
-    {
-        if (doppler_center != d_doppler_center)
-            {
-                DLOG(INFO) << " Doppler assistance for Channel: " << d_channel << " => Doppler: " << doppler_center << "[Hz]";
-                d_doppler_center = doppler_center;
-            }
-    }
+    void set_doppler_center(int32_t doppler_center);
 
     /*!
      * \brief This function triggers a HW reset of the FPGA PL.

src/algorithms/acquisition/gnuradio_blocks/pcps_assisted_acquisition_cc.cc

@@ -20,7 +20,6 @@
 #include "MATH_CONSTANTS.h"
 #include "concurrent_map.h"
 #include "gps_acq_assist.h"
-#include <glog/logging.h>
 #include <gnuradio/io_signature.h>
 #include <volk/volk.h>
 #include <volk_gnsssdr/volk_gnsssdr.h>
@@ -30,6 +29,11 @@
 #include <sstream>
 #include <utility>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 extern Concurrent_Map<Gps_Acq_Assist> global_gps_acq_assist_map;
 

src/algorithms/acquisition/gnuradio_blocks/pcps_cccwsr_acquisition_cc.cc

@@ -22,7 +22,6 @@
 
 #include "pcps_cccwsr_acquisition_cc.h"
 #include "MATH_CONSTANTS.h"  // TWO_PI
-#include <glog/logging.h>
 #include <gnuradio/io_signature.h>
 #include <volk/volk.h>
 #include <volk_gnsssdr/volk_gnsssdr.h>
@@ -32,6 +31,12 @@
 #include <sstream>
 #include <utility>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 pcps_cccwsr_acquisition_cc_sptr pcps_cccwsr_make_acquisition_cc(
     uint32_t sampled_ms,

src/algorithms/acquisition/gnuradio_blocks/pcps_opencl_acquisition_cc.cc

@@ -38,7 +38,6 @@
 #include "MATH_CONSTANTS.h"  // TWO_PI
 #include "opencl/fft_base_kernels.h"
 #include "opencl/fft_internal.h"
-#include <glog/logging.h>
 #include <gnuradio/io_signature.h>
 #include <volk/volk.h>
 #include <volk_gnsssdr/volk_gnsssdr.h>
@@ -50,6 +49,12 @@
 #include <sstream>
 #include <utility>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 pcps_opencl_acquisition_cc_sptr pcps_make_opencl_acquisition_cc(
     uint32_t sampled_ms, uint32_t max_dwells,

src/algorithms/acquisition/gnuradio_blocks/pcps_quicksync_acquisition_cc.cc

@@ -16,7 +16,6 @@
 
 #include "pcps_quicksync_acquisition_cc.h"
 #include "MATH_CONSTANTS.h"
-#include <glog/logging.h>
 #include <gnuradio/io_signature.h>
 #include <volk/volk.h>
 #include <volk_gnsssdr/volk_gnsssdr.h>
@@ -25,6 +24,12 @@
 #include <exception>
 #include <sstream>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 pcps_quicksync_acquisition_cc_sptr pcps_quicksync_make_acquisition_cc(
     uint32_t folding_factor,

src/algorithms/acquisition/gnuradio_blocks/pcps_tong_acquisition_cc.cc

@@ -36,7 +36,6 @@
 
 #include "pcps_tong_acquisition_cc.h"
 #include "MATH_CONSTANTS.h"  // for TWO_PI
-#include <glog/logging.h>
 #include <gnuradio/io_signature.h>
 #include <volk/volk.h>
 #include <volk_gnsssdr/volk_gnsssdr.h>
@@ -45,6 +44,12 @@
 #include <exception>
 #include <sstream>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 pcps_tong_acquisition_cc_sptr pcps_tong_make_acquisition_cc(
     uint32_t sampled_ms,

src/algorithms/acquisition/libs/CMakeLists.txt

@@ -38,12 +38,17 @@ target_link_libraries(acquisition_libs
     INTERFACE
         Gnuradio::runtime
     PRIVATE
-        Gflags::gflags
-        Glog::glog
         algorithms_libs
         core_system_parameters
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(acquisition_libs PRIVATE Gflags::gflags Glog::glog)
+    target_compile_definitions(acquisition_libs PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(acquisition_libs PRIVATE absl::flags absl::log)
+endif()
+
 if(ENABLE_CLANG_TIDY)
     if(CLANG_TIDY_EXE)
         set_target_properties(acquisition_libs

src/algorithms/acquisition/libs/acq_conf.cc

@@ -17,9 +17,14 @@
 
 #include "acq_conf.h"
 #include "item_type_helpers.h"
-#include <glog/logging.h>
 #include <cmath>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 void Acq_Conf::SetFromConfiguration(const ConfigurationInterface *configuration,
     const std::string &role, double chip_rate, double opt_freq)

src/algorithms/acquisition/libs/acq_conf_fpga.cc

@@ -18,11 +18,16 @@
 #include "acq_conf_fpga.h"
 #include "item_type_helpers.h"
 #include "uio_fpga.h"
-#include <glog/logging.h>
 #include <cmath>
 #include <iostream>
 #include <utility>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 void Acq_Conf_Fpga::SetFromConfiguration(const ConfigurationInterface *configuration,
     const std::string &role, uint32_t sel_queue_fpga, uint32_t blk_exp, uint32_t downsampling_factor_default, double chip_rate, double code_length_chips)
 {

src/algorithms/acquisition/libs/fpga_acquisition.cc

@@ -21,7 +21,6 @@
 
 #include "fpga_acquisition.h"
 #include "MATH_CONSTANTS.h"  // for TWO_PI
-#include <glog/logging.h>    // for LOG
 #include <cmath>             // for log2
 #include <fcntl.h>           // libraries used by the GIPO
 #include <iostream>          // for operator<<
@@ -29,6 +28,11 @@
 #include <unistd.h>          // for write, close, read, ssize_t
 #include <utility>           // for move
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 #ifndef TEMP_FAILURE_RETRY
 #define TEMP_FAILURE_RETRY(exp)              \

src/algorithms/channel/adapters/CMakeLists.txt

@@ -26,9 +26,15 @@ target_link_libraries(channel_adapters
         channel_libs
     PRIVATE
         gnss_sdr_flags
-        Glog::glog
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(channel_adapters PRIVATE Glog::glog)
+    target_compile_definitions(channel_adapters PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(channel_adapters PRIVATE absl::flags absl::log)
+endif()
+
 target_include_directories(channel_adapters
     PUBLIC
         ${GNSSSDR_SOURCE_DIR}/src/core/interfaces

src/algorithms/channel/adapters/channel.cc

@@ -22,10 +22,14 @@
 #include "gnss_sdr_flags.h"
 #include "telemetry_decoder_interface.h"
 #include "tracking_interface.h"
-#include <glog/logging.h>
 #include <stdexcept>  // for std::invalid_argument
 #include <utility>    // for std::move
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 Channel::Channel(const ConfigurationInterface* configuration,
     uint32_t channel,
@@ -77,10 +81,17 @@ Channel::Channel(const ConfigurationInterface* configuration,
         {
             doppler_step = configuration->property("Acquisition_" + signal_str + ".doppler_step", 500);
         }
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_doppler_step != 0)
         {
             doppler_step = static_cast<uint32_t>(FLAGS_doppler_step);
         }
+#else
+    if (absl::GetFlag(FLAGS_doppler_step) != 0)
+        {
+            doppler_step = static_cast<uint32_t>(absl::GetFlag(FLAGS_doppler_step));
+        }
+#endif
     DLOG(INFO) << "Channel " << channel_ << " Doppler_step = " << doppler_step;
 
     acq_->set_doppler_step(doppler_step);

src/algorithms/channel/libs/CMakeLists.txt

@@ -39,10 +39,15 @@ target_link_libraries(channel_libs
     PRIVATE
         core_libs
         Boost::headers
-        Gflags::gflags
-        Glog::glog
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(channel_libs PRIVATE Gflags::gflags Glog::glog)
+    target_compile_definitions(channel_libs PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(channel_libs PRIVATE absl::flags absl::log)
+endif()
+
 target_include_directories(channel_libs
     PUBLIC
         ${GNSSSDR_SOURCE_DIR}/src/core/receiver

src/algorithms/channel/libs/channel_fsm.cc

@@ -18,9 +18,14 @@
 
 #include "channel_fsm.h"
 #include "channel_event.h"
-#include <glog/logging.h>
 #include <utility>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 ChannelFsm::ChannelFsm()
     : queue_(nullptr),
       channel_(0U),

src/algorithms/channel/libs/channel_msg_receiver_cc.cc

@@ -17,12 +17,17 @@
 
 
 #include "channel_msg_receiver_cc.h"
-#include <glog/logging.h>
 #include <gnuradio/gr_complex.h>
 #include <gnuradio/io_signature.h>
 #include <cstdint>
 #include <utility>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if PMT_USES_BOOST_ANY
 #include <boost/any.hpp>
 namespace wht = boost;

src/algorithms/conditioner/adapters/CMakeLists.txt

@@ -37,11 +37,15 @@ endif()
 target_link_libraries(conditioner_adapters
     PUBLIC
         Gnuradio::runtime
-    PRIVATE
-        Gflags::gflags
-        Glog::glog
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(conditioner_adapters PRIVATE Gflags::gflags Glog::glog)
+    target_compile_definitions(conditioner_adapters PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(conditioner_adapters PRIVATE absl::flags absl::log)
+endif()
+
 target_include_directories(conditioner_adapters
     PUBLIC
         ${GNSSSDR_SOURCE_DIR}/src/core/interfaces

src/algorithms/conditioner/adapters/array_signal_conditioner.cc

@@ -17,9 +17,13 @@
 
 #include "array_signal_conditioner.h"
 #include "configuration_interface.h"
-#include <glog/logging.h>
 #include <utility>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 // Constructor
 ArraySignalConditioner::ArraySignalConditioner(std::shared_ptr<GNSSBlockInterface> data_type_adapt,

src/algorithms/conditioner/adapters/signal_conditioner.cc

@@ -16,10 +16,14 @@
  */
 
 #include "signal_conditioner.h"
-#include <glog/logging.h>
 #include <stdexcept>
 #include <utility>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 // Constructor
 SignalConditioner::SignalConditioner(std::shared_ptr<GNSSBlockInterface> data_type_adapt,

src/algorithms/data_type_adapter/adapters/CMakeLists.txt

@@ -53,11 +53,16 @@ target_link_libraries(data_type_adapters
         Gnuradio::blocks
         data_type_gr_blocks
     PRIVATE
-        Gflags::gflags
-        Glog::glog
         Volk::volk
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(data_type_adapters PRIVATE Gflags::gflags Glog::glog)
+    target_compile_definitions(data_type_adapters PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(data_type_adapters PRIVATE absl::flags absl::log)
+endif()
+
 if(ENABLE_CLANG_TIDY)
     if(CLANG_TIDY_EXE)
         set_target_properties(data_type_adapters

src/algorithms/data_type_adapter/adapters/byte_to_short.cc

@@ -16,9 +16,14 @@
 
 #include "byte_to_short.h"
 #include "configuration_interface.h"
-#include <glog/logging.h>
 #include <utility>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 ByteToShort::ByteToShort(const ConfigurationInterface* configuration,
     std::string role,

src/algorithms/data_type_adapter/adapters/ibyte_to_cbyte.cc

@@ -17,9 +17,14 @@
 
 #include "ibyte_to_cbyte.h"
 #include "configuration_interface.h"
-#include <glog/logging.h>
 #include <volk/volk.h>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 
 IbyteToCbyte::IbyteToCbyte(const ConfigurationInterface* configuration,
     const std::string& role,

src/algorithms/data_type_adapter/adapters/ibyte_to_complex.cc

@@ -16,7 +16,12 @@
 
 #include "ibyte_to_complex.h"
 #include "configuration_interface.h"
+
+#if USE_GLOG_AND_GFLAGS
 #include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 
 IbyteToComplex::IbyteToComplex(const ConfigurationInterface* configuration, const std::string& role,

src/algorithms/data_type_adapter/adapters/ibyte_to_cshort.cc

@@ -17,9 +17,13 @@
 
 #include "ibyte_to_cshort.h"
 #include "configuration_interface.h"
-#include <glog/logging.h>
 #include <volk/volk.h>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 IbyteToCshort::IbyteToCshort(const ConfigurationInterface* configuration,
     const std::string& role,

src/algorithms/data_type_adapter/adapters/ishort_to_complex.cc

@@ -16,8 +16,12 @@
 
 #include "ishort_to_complex.h"
 #include "configuration_interface.h"
-#include <glog/logging.h>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 IshortToComplex::IshortToComplex(const ConfigurationInterface* configuration,
     const std::string& role,

src/algorithms/data_type_adapter/adapters/ishort_to_cshort.cc

@@ -17,9 +17,13 @@
 
 #include "ishort_to_cshort.h"
 #include "configuration_interface.h"
-#include <glog/logging.h>
 #include <volk/volk.h>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 IshortToCshort::IshortToCshort(const ConfigurationInterface* configuration,
     const std::string& role,

src/algorithms/input_filter/adapters/CMakeLists.txt

@@ -47,11 +47,16 @@ target_link_libraries(input_filter_adapters
         algorithms_libs
         input_filter_gr_blocks
     PRIVATE
-        Gflags::gflags
-        Glog::glog
         Volk::volk
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(input_filter_adapters PRIVATE Gflags::gflags Glog::glog)
+    target_compile_definitions(input_filter_adapters PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(input_filter_adapters PRIVATE absl::flags absl::log)
+endif()
+
 if(GNURADIO_IS_38_OR_GREATER)
     target_compile_definitions(input_filter_adapters PUBLIC -DGR_GREATER_38=1)
 endif()

src/algorithms/input_filter/adapters/beamformer_filter.cc

@@ -17,9 +17,13 @@
 #include "beamformer_filter.h"
 #include "beamformer.h"
 #include "configuration_interface.h"
-#include <glog/logging.h>
 #include <gnuradio/blocks/file_sink.h>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 BeamformerFilter::BeamformerFilter(
     const ConfigurationInterface* configuration, const std::string& role,

src/algorithms/input_filter/adapters/fir_filter.cc

@@ -17,11 +17,15 @@
 
 #include "fir_filter.h"
 #include "configuration_interface.h"
-#include <glog/logging.h>
 #include <gnuradio/filter/pm_remez.h>
 #include <volk/volk.h>
 #include <utility>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 FirFilter::FirFilter(const ConfigurationInterface* configuration,
     std::string role,

src/algorithms/input_filter/adapters/freq_xlating_fir_filter.cc

@@ -17,13 +17,17 @@
 
 #include "freq_xlating_fir_filter.h"
 #include "configuration_interface.h"
-#include <glog/logging.h>
 #include <gnuradio/blocks/file_sink.h>
 #include <gnuradio/filter/firdes.h>
 #include <gnuradio/filter/pm_remez.h>
 #include <volk/volk.h>
 #include <utility>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 FreqXlatingFirFilter::FreqXlatingFirFilter(const ConfigurationInterface* configuration,
     std::string role,

src/algorithms/input_filter/adapters/notch_filter.cc

@@ -19,8 +19,12 @@
 #include "configuration_interface.h"
 #include "notch_cc.h"
 #include <boost/lexical_cast.hpp>
-#include <glog/logging.h>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 NotchFilter::NotchFilter(const ConfigurationInterface* configuration,
     const std::string& role,

src/algorithms/input_filter/adapters/notch_filter_lite.cc

@@ -19,9 +19,13 @@
 #include "configuration_interface.h"
 #include "notch_lite_cc.h"
 #include <boost/lexical_cast.hpp>
-#include <glog/logging.h>
 #include <algorithm>  // for max
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 NotchFilterLite::NotchFilterLite(const ConfigurationInterface* configuration,
     const std::string& role,

src/algorithms/input_filter/adapters/pulse_blanking_filter.cc

@@ -19,12 +19,16 @@
 #include "pulse_blanking_filter.h"
 #include "configuration_interface.h"
 #include <boost/lexical_cast.hpp>
-#include <glog/logging.h>
 #include <gnuradio/filter/firdes.h>
 #include <cmath>
 #include <utility>
 #include <vector>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 PulseBlankingFilter::PulseBlankingFilter(const ConfigurationInterface* configuration,
     std::string role,

src/algorithms/libs/CMakeLists.txt

@@ -109,10 +109,15 @@ target_link_libraries(algorithms_libs
         core_system_parameters
         Volk::volk
         Volkgnsssdr::volkgnsssdr
-        Gflags::gflags
-        Glog::glog
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(algorithms_libs PRIVATE Gflags::gflags Glog::glog)
+    target_compile_definitions(algorithms_libs PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(algorithms_libs PRIVATE absl::flags absl::log)
+endif()
+
 if(GNURADIO_USES_STD_POINTERS)
     target_compile_definitions(algorithms_libs
         PUBLIC -DGNURADIO_USES_STD_POINTERS=1
@@ -208,13 +213,14 @@ else()
     target_link_libraries(gnss_sdr_flags PRIVATE Boost::filesystem Boost::system)
 endif()
 
-target_link_libraries(gnss_sdr_flags
-    PUBLIC
-        Gflags::gflags
-)
-
-if(GFLAGS_GREATER_20 OR ${LOCAL_GFLAGS})
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(gnss_sdr_flags PUBLIC Gflags::gflags)
+    target_compile_definitions(gnss_sdr_flags PUBLIC -DUSE_GLOG_AND_GFLAGS=1)
+    if(GFLAGS_GREATER_20 OR "${LOCAL_GFLAGS}")
         target_compile_definitions(gnss_sdr_flags PRIVATE -DGFLAGS_GREATER_2_0=1)
+    endif()
+else()
+    target_link_libraries(gnss_sdr_flags PUBLIC absl::flags)
 endif()
 
 target_compile_definitions(gnss_sdr_flags

src/algorithms/libs/gnss_sdr_flags.cc

@@ -1,7 +1,7 @@
 /*!
  * \file gnss_sdr_flags.cc
  * \brief Helper file for gnss-sdr commandline flags
- * \author Carles Fernandez-Prades, 2018. cfernandez(at)cttc.es
+ * \author Carles Fernandez-Prades, 2018-2024. cfernandez(at)cttc.es
  *
  *
  * -----------------------------------------------------------------------------
@@ -9,7 +9,7 @@
  * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
  * This file is part of GNSS-SDR.
  *
- * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
+ * Copyright (C) 2010-2024  (see AUTHORS file for a list of contributors)
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
  * -----------------------------------------------------------------------------
@@ -19,9 +19,8 @@
 #include "gnss_sdr_flags.h"
 #include "gnss_sdr_filesystem.h"
 #include <iostream>
-#include <string>
-
 
+#if USE_GLOG_AND_GFLAGS
 DEFINE_string(c, "-", "Path to the configuration file (if set, overrides --config_file).");
 
 DEFINE_string(config_file, std::string(GNSSSDR_INSTALL_DIR "/share/gnss-sdr/conf/default.conf"),
@@ -235,3 +234,26 @@ DEFINE_validator(pll_bw_hz, &ValidatePllBw);
 DEFINE_validator(carrier_smoothing_factor, &ValidateCarrierSmoothingFactor);
 
 #endif
+
+#else
+ABSL_FLAG(std::string, c, "-", "Path to the configuration file (if set, overrides --config_file).");
+ABSL_FLAG(std::string, config_file, std::string(GNSSSDR_INSTALL_DIR "/share/gnss-sdr/conf/default.conf"), "Path to the configuration file.");
+ABSL_FLAG(std::string, log_dir, "", "Directory for log files");
+ABSL_FLAG(std::string, s, "-", "If defined, path to the file containing the signal samples (overrides the configuration file and --signal_source).");
+ABSL_FLAG(std::string, signal_source, "-", "If defined, path to the file containing the signal samples (overrides the configuration file).");
+ABSL_FLAG(std::string, timestamp_source, "-", "If defined, path to the file containing the signal timestamp data (overrides the configuration file).");
+ABSL_FLAG(bool, rf_shutdown, true, "If set to false, AD9361 RF channels are not shut down when exiting the program. Useful to leave the AD9361 configured and running.");
+ABSL_FLAG(int32_t, doppler_max, 0, "If defined, sets the maximum Doppler value in the search grid, in Hz (overrides the configuration file).");
+ABSL_FLAG(int32_t, doppler_step, 0, "If defined, sets the frequency step in the search grid, in Hz (overrides the configuration file).");
+ABSL_FLAG(int32_t, cn0_samples, 20, "Number of correlator outputs used for CN0 estimation.");
+ABSL_FLAG(int32_t, cn0_min, 25, "Minimum valid CN0 (in dB-Hz).");
+ABSL_FLAG(int32_t, max_carrier_lock_fail, 5000, "Maximum number of carrier lock failures before dropping a satellite.");
+ABSL_FLAG(int32_t, max_lock_fail, 50, "Maximum number of code lock failures before dropping a satellite.");
+ABSL_FLAG(double, carrier_lock_th, 0.7, "Carrier lock threshold (in rad).");
+ABSL_FLAG(double, dll_bw_hz, 0.0, "If defined, bandwidth of the DLL low pass filter, in Hz (overrides the configuration file).");
+ABSL_FLAG(double, pll_bw_hz, 0.0, "If defined, bandwidth of the PLL low pass filter, in Hz (overrides the configuration file).");
+ABSL_FLAG(int32_t, carrier_smoothing_factor, DEFAULT_CARRIER_SMOOTHING_FACTOR, "Sets carrier smoothing factor M (overrides the configuration file)");
+ABSL_FLAG(std::string, RINEX_version, "-", "If defined, specifies the RINEX version (2.11 or 3.02). Overrides the configuration file.");
+ABSL_FLAG(std::string, RINEX_name, "-", "If defined, specifies the RINEX files base name");
+ABSL_FLAG(bool, keyboard, true, "If set to false, it disables the keyboard listener (so the receiver cannot be stopped with q+[Enter])");
+#endif

src/algorithms/libs/gnss_sdr_flags.h

@@ -1,7 +1,7 @@
 /*!
  * \file gnss_sdr_flags.h
  * \brief Helper file for gnss-sdr commandline flags
- * \author Carles Fernandez-Prades, 2018. cfernandez(at)cttc.es
+ * \author Carles Fernandez-Prades, 2018-2024. cfernandez(at)cttc.es
  *
  *
  * -----------------------------------------------------------------------------
@@ -9,7 +9,7 @@
  * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
  * This file is part of GNSS-SDR.
  *
- * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
+ * Copyright (C) 2010-2024  (see AUTHORS file for a list of contributors)
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
  * -----------------------------------------------------------------------------
@@ -18,9 +18,20 @@
 #ifndef GNSS_SDR_GNSS_SDR_FLAGS_H
 #define GNSS_SDR_GNSS_SDR_FLAGS_H
 
-
-#include <gflags/gflags.h>
 #include <cstdint>
+#include <string>
+
+#if USE_GLOG_AND_GFLAGS
+#include <gflags/gflags.h>
+#else
+#include <absl/flags/declare.h>
+#include <absl/flags/flag.h>
+#include <cstdlib>
+#include <iostream>
+#include <sys/stat.h>
+#include <vector>
+#endif
+
 
 /** \addtogroup Algorithms_Library
  * \{ */
@@ -28,7 +39,7 @@
  * Library for command-line handling.
  * \{ */
 
-
+#if USE_GLOG_AND_GFLAGS
 DECLARE_string(c);            //!< Path to the configuration file.
 DECLARE_string(config_file);  //!< Path to the configuration file.
 
@@ -62,6 +73,113 @@ DECLARE_string(RINEX_version);  //!< If defined, specifies the RINEX version (2.
 DECLARE_string(RINEX_name);     //!< If defined, specifies the RINEX files base name
 DECLARE_bool(keyboard);         //!< If set to false, disables the keyboard listener. Only for debug purposes (e.g. ASAN mode termination)
 
+#else
+ABSL_DECLARE_FLAG(std::string, c);            //!< Path to the configuration file.
+ABSL_DECLARE_FLAG(std::string, config_file);  //!< Path to the configuration file.
+
+ABSL_DECLARE_FLAG(std::string, log_dir);  //!< Path to the folder in which logging will be stored.
+
+// Declare flags for signal sources
+ABSL_DECLARE_FLAG(std::string, s);                 //!< Path to the file containing the signal samples.
+ABSL_DECLARE_FLAG(std::string, signal_source);     //!< Path to the file containing the signal samples.
+ABSL_DECLARE_FLAG(std::string, timestamp_source);  //!< Path to the file containing the signal samples.
+ABSL_DECLARE_FLAG(bool, rf_shutdown);              //!< Shutdown RF when program exits.
+
+// Declare flags for acquisition blocks
+ABSL_DECLARE_FLAG(int32_t, doppler_max);   //!< If defined, maximum Doppler value in the search grid, in Hz (overrides the configuration file).
+ABSL_DECLARE_FLAG(int32_t, doppler_step);  //!< If defined, sets the frequency step in the search grid, in Hz, in Hz (overrides the configuration file).
+
+// Declare flags for tracking blocks
+ABSL_DECLARE_FLAG(int32_t, cn0_samples);            //!< Number of correlator outputs used for CN0 estimation.
+ABSL_DECLARE_FLAG(int32_t, cn0_min);                //!< Minimum valid CN0 (in dB-Hz).
+ABSL_DECLARE_FLAG(int32_t, max_lock_fail);          //!< Maximum number of code lock failures before dropping a satellite.
+ABSL_DECLARE_FLAG(int32_t, max_carrier_lock_fail);  //!< Maximum number of carrier lock failures before dropping a satellite.
+ABSL_DECLARE_FLAG(double, carrier_lock_th);         //!< Carrier lock threshold (in rad).
+ABSL_DECLARE_FLAG(double, dll_bw_hz);               //!< Bandwidth of the DLL low pass filter, in Hz (overrides the configuration file).
+ABSL_DECLARE_FLAG(double, pll_bw_hz);               //!< Bandwidth of the PLL low pass filter, in Hz (overrides the configuration file).
+
+// Declare flags for observables block
+ABSL_DECLARE_FLAG(int32_t, carrier_smoothing_factor);  //!< Sets carrier smoothing factor M (overrides the configuration file).
+const int32_t DEFAULT_CARRIER_SMOOTHING_FACTOR = 200;
+
+// Declare flags for PVT
+ABSL_DECLARE_FLAG(std::string, RINEX_version);  //!< If defined, specifies the RINEX version (2.11 or 3.02). Overrides the configuration file.
+ABSL_DECLARE_FLAG(std::string, RINEX_name);     //!< If defined, specifies the RINEX files base name
+ABSL_DECLARE_FLAG(bool, keyboard);              //!< If set to false, disables the keyboard listener. Only for debug purposes (e.g. ASAN mode termination)
+
+static inline void GetTempDirectories(std::vector<std::string>& list)
+{
+    list.clear();
+    // Directories, in order of preference. If we find a dir that
+    // exists, we stop adding other less-preferred dirs
+    const char* candidates[] = {
+        // Non-null only during unittest/regtest
+        std::getenv("TEST_TMPDIR"),
+
+        // Explicitly-supplied temp dirs
+        std::getenv("TMPDIR"),
+        std::getenv("TMP"),
+
+        // If all else fails
+        "/tmp",
+    };
+    for (auto d : candidates)
+        {
+            if (!d) continue;  // Empty env var
+
+            // Make sure we don't surprise anyone who's expecting a '/'
+            std::string dstr = d;
+            if (dstr[dstr.size() - 1] != '/')
+                {
+                    dstr += "/";
+                }
+            list.push_back(dstr);
+
+            struct stat statbuf;
+            if (!stat(d, &statbuf) && S_ISDIR(statbuf.st_mode))
+                {
+                    // We found a dir that exists - we're done.
+                    return;
+                }
+        }
+}
+
+
+static inline void GetExistingTempDirectories(std::vector<std::string>& list)
+{
+    GetTempDirectories(list);
+    auto i_dir = list.begin();
+    while (i_dir != list.end())
+        {
+            if (access(i_dir->c_str(), 0))
+                {
+                    i_dir = list.erase(i_dir);
+                }
+            else
+                {
+                    ++i_dir;
+                }
+        };
+}
+
+
+static inline std::string GetTempDir()
+{
+    std::vector<std::string> temp_directories_list;
+    GetExistingTempDirectories(temp_directories_list);
+
+    if (temp_directories_list.empty())
+        {
+            std::cerr << "No temporary directory found\n";
+            exit(EXIT_FAILURE);
+        }
+
+    // Use first directory from list of existing temporary directories.
+    return temp_directories_list.front();
+}
+#endif
+
+
 /** \} */
 /** \} */
 #endif  // GNSS_SDR_GNSS_SDR_FLAGS_H

src/algorithms/libs/pass_through.cc

@@ -18,12 +18,16 @@
 
 #include "pass_through.h"
 #include "configuration_interface.h"
-#include <glog/logging.h>
 #include <gnuradio/gr_complex.h>
 #include <volk/volk_complex.h>
 #include <cstdint>  // for int8_t
 #include <ostream>  // for operator<<
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
 
 Pass_Through::Pass_Through(const ConfigurationInterface* configuration,
     const std::string& role,

src/algorithms/libs/rtklib/CMakeLists.txt

@@ -70,12 +70,17 @@ target_link_libraries(algorithms_libs_rtklib
         core_system_parameters
         algorithms_libs
         Armadillo::armadillo
-        Gflags::gflags
-        Glog::glog
         LAPACK::LAPACK
         BLAS::BLAS
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(algorithms_libs_rtklib PRIVATE Gflags::gflags Glog::glog)
+    target_compile_definitions(algorithms_libs_rtklib PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(algorithms_libs_rtklib PRIVATE absl::flags absl::log)
+endif()
+
 if(ENABLE_ARMA_NO_DEBUG)
     target_compile_definitions(algorithms_libs_rtklib
         PRIVATE -DARMA_NO_BOUND_CHECKING=1

src/algorithms/libs/rtklib/rtklib_rtkcmn.cc

@@ -30,7 +30,6 @@
  *----------------------------------------------------------------------------*/
 
 #include "rtklib_rtkcmn.h"
-#include <glog/logging.h>
 #include <array>
 #include <cassert>
 #include <cstring>
@@ -43,6 +42,12 @@
 #include <sys/types.h>
 #include <vector>
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 const double GPST0[] = {1980, 1, 6, 0, 0, 0}; /* gps time reference */
 const double GST0[] = {1999, 8, 22, 0, 0, 0}; /* galileo system time reference */
 const double BDT0[] = {2006, 1, 1, 0, 0, 0};  /* beidou time reference */

src/algorithms/observables/adapters/CMakeLists.txt

@@ -29,9 +29,15 @@ target_link_libraries(obs_adapters
         core_system_parameters
     PRIVATE
         gnss_sdr_flags
-        Glog::glog
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(obs_adapters PRIVATE Glog::glog)
+    target_compile_definitions(obs_adapters PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(obs_adapters PRIVATE absl::flags absl::log)
+endif()
+
 if(ENABLE_CLANG_TIDY)
     if(CLANG_TIDY_EXE)
         set_target_properties(obs_adapters

src/algorithms/observables/adapters/hybrid_observables.cc

@@ -19,9 +19,14 @@
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
 #include "obs_conf.h"
-#include <glog/logging.h>
 #include <ostream>  // for operator<<
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 HybridObservables::HybridObservables(const ConfigurationInterface* configuration,
     const std::string& role,
     unsigned int in_streams,
@@ -45,7 +50,11 @@ HybridObservables::HybridObservables(const ConfigurationInterface* configuration
     conf.always_output_gs = configuration->property("PVT.an_output_enabled", conf.always_output_gs) || configuration->property(role + ".always_output_gs", conf.always_output_gs);
     conf.enable_E6 = configuration->property("PVT.use_e6_for_pvt", conf.enable_E6);
 
+#if USE_GLOG_AND_GFLAGS
     if (FLAGS_carrier_smoothing_factor == DEFAULT_CARRIER_SMOOTHING_FACTOR)
+#else
+    if (absl::GetFlag(FLAGS_carrier_smoothing_factor) == DEFAULT_CARRIER_SMOOTHING_FACTOR)
+#endif
         {
             conf.smoothing_factor = configuration->property(role + ".smoothing_factor", conf.smoothing_factor);
         }

src/algorithms/observables/gnuradio_blocks/CMakeLists.txt

@@ -31,12 +31,17 @@ target_link_libraries(obs_gr_blocks
     PRIVATE
         algorithms_libs
         core_system_parameters
-        Gflags::gflags
-        Glog::glog
         Matio::matio
         Gnuradio::pmt
 )
 
+if(ENABLE_GLOG_AND_GFLAGS)
+    target_link_libraries(obs_gr_blocks PRIVATE Gflags::gflags Glog::glog)
+    target_compile_definitions(obs_gr_blocks PRIVATE -DUSE_GLOG_AND_GFLAGS=1)
+else()
+    target_link_libraries(obs_gr_blocks PRIVATE absl::flags absl::log)
+endif()
+
 target_include_directories(obs_gr_blocks
     PUBLIC
         ${GNSSSDR_SOURCE_DIR}/src/core/interfaces

src/algorithms/observables/gnuradio_blocks/hybrid_observables_gs.cc

@@ -23,7 +23,6 @@
 #include "gnss_sdr_filesystem.h"
 #include "gnss_sdr_make_unique.h"
 #include "gnss_synchro.h"
-#include <glog/logging.h>
 #include <gnuradio/io_signature.h>
 #include <matio.h>
 #include <pmt/pmt.h>
@@ -36,6 +35,12 @@
 #include <limits>     // for numeric_limits
 #include <utility>    // for move
 
+#if USE_GLOG_AND_GFLAGS
+#include <glog/logging.h>
+#else
+#include <absl/log/log.h>
+#endif
+
 #if PMT_USES_BOOST_ANY
 #include <boost/any.hpp>
 namespace wht = boost;