From 92e9e649459f45a5514f2c27219a25a3aaeeccbf Mon Sep 17 00:00:00 2001
From: Calvin Rose <calsrose@gmail.com>
Date: Sun, 6 Jan 2019 12:32:44 -0500
Subject: [PATCH] Update CONTRIBUTING.md and make valtest

---
 CONTRIBUTING.md | 23 +++++++++++++++++++++++
 Makefile        |  6 +++---
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 0ecfc1f0..4a4911b6 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -33,6 +33,29 @@ may require changes before being merged.
   For janet code, the use lisp indentation with 2 spaces. One can use janet.vim to
   do this indentation, or approximate as close as possible.
 
+## C style
+
+For changes to the VM and Core code, you will probably need to know C. Janet is programmed with
+a subset of C99 that works with Microsoft Visual C++. This means most of C99 but with the following
+omissions.
+
+* No Variable Length Arrays (yes these may work in newer MSVC compilers)
+* No `restrict` 
+* Certain functions in the standard library are not always available
+
+In practice, this means programming for both MSVC on one hand and everything else on the other.
+The code must also build with emscripten, even if some features are not available, although
+this is not a priority.
+
+Code should compile warning free and run valgrind clean. I find that these two criteria are some
+of the easiest ways to protect against a large number of bugs in an unsafe language like C. To check for
+valgrind errors, run `make valtest` and check the output for undefined or flagged behavior.
+
+## Janet style
+
+All janet code in the project should be formatted similar to the code in core.janet.
+The auto formatting from janet.vim will work well.
+
 ## Suggesting Changes
 
 To suggest changes, open an issue on GitHub. Check GitHub for other issues
diff --git a/Makefile b/Makefile
index 0b8c56c7..d298fba4 100644
--- a/Makefile
+++ b/Makefile
@@ -136,15 +136,15 @@ repl: $(JANET_TARGET)
 debug: $(JANET_TARGET)
 	$(DEBUGGER) ./$(JANET_TARGET)
 
+VALGRIND_COMMAND=valgrind --leak-check=full
+
 valgrind: $(JANET_TARGET)
-	valgrind --leak-check=full -v ./$(JANET_TARGET)
+	$(VALGRIND_COMMAND) ./$(JANET_TARGET)
 
 test: $(JANET_TARGET) $(TEST_PROGRAMS)
 	for f in build/*.out; do "$$f" || exit; done
 	for f in test/*.janet; do ./$(JANET_TARGET) "$$f" || exit; done
 
-VALGRIND_COMMAND=valgrind --leak-check=full -v
-
 valtest: $(JANET_TARGET) $(TEST_PROGRAMS)
 	for f in build/*.out; do $(VALGRIND_COMMAND) "$$f" || exit; done
 	for f in test/*.janet; do $(VALGRIND_COMMAND) ./$(JANET_TARGET) "$$f" || exit; done