Check crash arm runner.

macos actually works with 47-bit pointers.

.github/workflows/test.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ ubuntu-latest, macos-latest, macos-14, macos-15-intel ]
+        os: [ ubuntu-latest, ubuntu-24.04-arm, macos-latest, macos-14, macos-15-intel ]
     steps:
       - name: Checkout the repository
         uses: actions/checkout@master

CONTRIBUTING.md

@@ -37,6 +37,12 @@ may require changes before being merged.
   do this indentation, or approximate as close as possible. There is a janet formatter
   in [spork](https://github.com/janet-lang/spork.git) that can be used to format code as well.
 
+Bot pull requests will not be accepted, and anonymous submissions, including
+new accounts, unknown emails, and first time contributors will be subjected
+to greater scrutiny and code reivew. Automatically generated and filed bug
+reports MAY be ok, if they are of consistent and good quality, such as
+OSSFuzz or well constructed CI pipelines.
+
 ## C style
 
 For changes to the VM and Core code, you will probably need to know C. Janet is programmed with
@@ -90,3 +96,18 @@ timely manner. In short, if you want extra functionality now, then build it.
 
 * Include a good description of the problem that is being solved
 * Include descriptions of potential solutions if you have some in mind.
+
+## LLMs, Tool Usage, and Transparency
+
+All usage of Large Language Models (LLMs), Neural Networks, "AI" tools, and
+other tools such as software fuzzers or static analyzers must be disclosed.
+This applies to pull requests, email patches, bug reports, and any other
+meaningful contribution to Janet's source code. Please also refrain from using
+generative AI for code that will be embedded in the Janet runtime, which include
+all C source files as well as boot.janet. All code should be well
+and completely understood by the human author, including test cases. Large and
+obviously AI-driven changes will be rejected. Be mindful and transparent on the
+copyright implications of any submitted code. We will use discretion when
+accepting generated test cases for bug reproductions, one-line bug
+fixes, or typo fixes. Often, these can be trivially rewritten by a human to
+avoid the problem.

examples/error.janet

@@ -3,10 +3,10 @@
 
 (defn bork [x]
 
-  (defn bark [x]
+  (defn bark [y]
     (print "Woof!")
-    (print x)
-    (error x)
+    (print y)
+    (error y)
     (print "Woof!"))
 
   (bark (* 2 x))

examples/iterate-fiber.janet

@@ -7,13 +7,13 @@
 (print "simple yielding")
 (each item f (print "got: " item ", now " (fiber/status f)))
 
-(def f
+(def f2
   (coro
     (for i 0 10
       (yield (string "yield " i))
       (ev/sleep 0))))
 
 (print "complex yielding")
-(each item f (print "got: " item ", now " (fiber/status f)))
+(each item f2 (print "got: " item ", now " (fiber/status f2)))
 
-(print (fiber/status f))
+(print (fiber/status f2))

examples/lazyseqs.janet

@@ -4,7 +4,7 @@
 # that must be called (realizing it), and the memoized.
 # Use with (import "./path/to/this/file" :prefix "seq.")
 
-(defmacro delay
+(defmacro dolazy
   "Lazily evaluate a series of expressions. Returns a function that
   returns the result of the last expression. Will only evaluate the
   body once, and then memoizes the result."
@@ -35,7 +35,7 @@
   (def x (tuple h t))
   (fn [] x))
 
-(defn empty?
+(defn lazy-empty?
   "Check if a sequence is empty."
   [s]
   (not (s)))
@@ -55,14 +55,14 @@
   [start end &]
   (if end
     (if (< start end)
-      (delay (tuple start (lazy-range (+ 1 start) end)))
+      (dolazy (tuple start (lazy-range (+ 1 start) end)))
       empty-seq)
     (lazy-range 0 start)))
 
 (defn lazy-map
   "Return a sequence that is the result of applying f to each value in s."
   [f s]
-  (delay
+  (dolazy
     (def x (s))
     (if x (tuple (f (get x HEAD)) (map f (get x TAIL))))))
 
@@ -76,31 +76,31 @@
   [f s]
   (when (s) (f (head s)) (realize-map f (tail s))))
 
-(defn drop
+(defn lazy-drop
   "Ignores the first n values of the sequence and returns the rest."
   [n s]
-  (delay
+  (dolazy
     (def x (s))
-    (if (and x (pos? n)) ((drop (- n 1) (get x TAIL))))))
+    (if (and x (pos? n)) ((lazy-drop (- n 1) (get x TAIL))))))
 
-(defn take
+(defn lazy-take
   "Returns at most the first n values of s."
   [n s]
-  (delay
+  (dolazy
     (def x (s))
     (if (and x (pos? n))
-      (tuple (get x HEAD) (take (- n 1) (get x TAIL))))))
+      (tuple (get x HEAD) (lazy-take (- n 1) (get x TAIL))))))
 
 (defn randseq
   "Return a sequence of random numbers."
   []
-  (delay (tuple (math/random) (randseq))))
+  (dolazy (tuple (math/random) (randseq))))
 
-(defn take-while
+(defn lazy-take-while
   "Returns a sequence of values until the predicate is false."
   [pred s]
-  (delay
+  (dolazy
     (def x (s))
     (when x
       (def thehead (get HEAD x))
-      (if thehead (tuple thehead (take-while pred (get TAIL x)))))))
+      (if thehead (tuple thehead (lazy-take-while pred (get TAIL x)))))))

examples/life.janet

@@ -16,8 +16,8 @@
   (def cell-set (frequencies state))
   (def neighbor-set (frequencies (mapcat neighbors state)))
   (seq [coord :keys neighbor-set
-         :let [count (get neighbor-set coord)]
-         :when (or (= count 3) (and (get cell-set coord) (= count 2)))]
+         :let [ncount (get neighbor-set coord)]
+         :when (or (= ncount 3) (and (get cell-set coord) (= ncount 2)))]
       coord))
 
 (defn draw

meson.build

@@ -72,6 +72,9 @@ conf.set_quoted('JANET_VERSION', meson.project_version())
 # Use options
 conf.set_quoted('JANET_BUILD', get_option('git_hash'))
 conf.set('JANET_NO_NANBOX', not get_option('nanbox'))
+if get_option('nanbox_pointer_shift') != -1 # -1 is auto-detect
+  conf.set('JANET_NANBOX_64_POINTER_SHIFT', get_option('nanbox_pointer_shift'))
+endif
 conf.set('JANET_SINGLE_THREADED', get_option('single_threaded'))
 conf.set('JANET_NO_DYNAMIC_MODULES', not get_option('dynamic_modules'))
 conf.set('JANET_NO_DOCSTRINGS', not get_option('docstrings'))

meson_options.txt

@@ -2,6 +2,7 @@ option('git_hash', type : 'string', value : 'meson')
 
 option('single_threaded', type : 'boolean', value : false)
 option('nanbox', type : 'boolean', value : true)
+option('nanbox_pointer_shift', type : 'integer', min : -1, max : 4, value : -1)
 option('dynamic_modules', type : 'boolean', value : true)
 option('docstrings', type : 'boolean', value : true)
 option('sourcemaps', type : 'boolean', value : true)

src/boot/boot.janet

@@ -46,7 +46,6 @@
 (defn defmacro :macro :flycheck
   "Define a macro."
   [name & more]
-  (setdyn name @{}) # override old macro definitions in the case of a recursive macro
   (apply defn name :macro more))
 
 (defmacro as-macro
@@ -219,9 +218,9 @@
 
 (defmacro default
   ``Define a default value for an optional argument.
-  Expands to `(def sym (if (= nil sym) val sym))`.``
+  Expands to `(def sym :shadow (if (= nil sym) val sym))`.``
   [sym val]
-  ~(def ,sym (if (,= nil ,sym) ,val ,sym)))
+  ~(def ,sym :shadow (if (,= nil ,sym) ,val ,sym)))
 
 (defmacro comment
   "Ignores the body of the comment."
@@ -2675,17 +2674,17 @@
     (var resumeval nil)
     (def f
       (fiber/new
-        (fn []
+        (fn :compile-and-lint []
           (array/clear lints)
           (def res (compile source env where lints))
-          (unless (empty? lints)
+          (when (next lints)
             # Convert lint levels to numbers.
             (def levels (get env *lint-levels* lint-levels))
             (def lint-error (get env *lint-error*))
             (def lint-warning (get env *lint-warn*))
             (def lint-error (or (get levels lint-error lint-error) 0))
             (def lint-warning (or (get levels lint-warning lint-warning) 2))
-            (each [level line col msg] lints
+            (each [level line col msg] (distinct lints) # some macros might cause code to be duplicated. Avoid repeated messages.
               (def lvl (get lint-levels level 0))
               (cond
                 (<= lvl lint-error) (do

src/conf/janetconf.h

@@ -16,6 +16,7 @@
 /* #define JANET_THREAD_LOCAL _Thread_local */
 /* #define JANET_NO_DYNAMIC_MODULES */
 /* #define JANET_NO_NANBOX */
+/* #define JANET_NANBOX_64_POINTER_SHIFT 0 */
 /* #define JANET_API __attribute__((visibility ("default"))) */
 
 /* These settings should be specified before amalgamation is

src/core/bytecode.c

@@ -29,7 +29,7 @@
 #endif
 
 /* Look up table for instructions */
-enum JanetInstructionType janet_instructions[JOP_INSTRUCTION_COUNT] = {
+const enum JanetInstructionType janet_instructions[JOP_INSTRUCTION_COUNT] = {
     JINT_0, /* JOP_NOOP, */
     JINT_S, /* JOP_ERROR, */
     JINT_ST, /* JOP_TYPECHECK, */

src/core/compile.c

@@ -91,29 +91,38 @@ void janetc_freeslot(JanetCompiler *c, JanetSlot s) {
 }
 
 /* Add a slot to a scope with a symbol associated with it (def or var). */
-void janetc_nameslot(JanetCompiler *c, const uint8_t *sym, JanetSlot s) {
+void janetc_nameslot(JanetCompiler *c, const uint8_t *sym, JanetSlot s, uint32_t flags) {
+    if (!(flags & JANET_DEFFLAG_NO_SHADOWCHECK)) {
+        if (sym[0] != '_') {
+            switch (janetc_shadowcheck(c, sym)) {
+                default:
+                    break;
+                case JANETC_SHADOW_MACRO:
+                    janetc_lintf(c, JANET_C_LINT_NORMAL, "binding %q is shadowing a macro", janet_wrap_symbol(sym));
+                    break;
+                case JANETC_SHADOW_LOCAL_HIDES_LOCAL:
+                    janetc_lintf(c, JANET_C_LINT_STRICT, "binding %q is shadowing a binding", janet_wrap_symbol(sym));
+                    break;
+                case JANETC_SHADOW_LOCAL_HIDES_GLOBAL:
+                    janetc_lintf(c, JANET_C_LINT_STRICT, "binding %q is shadowing a top-level binding", janet_wrap_symbol(sym));
+                    break;
+                case JANETC_SHADOW_GLOBAL_HIDES_GLOBAL:
+                    janetc_lintf(c, JANET_C_LINT_STRICT, "top-level binding %q is shadowing another top-level binding", janet_wrap_symbol(sym));
+                    break;
+            }
+        }
+    }
     SymPair sp;
     int32_t cnt = janet_v_count(c->buffer);
     sp.sym = sym;
     sp.sym2 = sym;
     sp.slot = s;
     sp.keep = 0;
-    sp.referenced = sym[0] == '_'; /* Fake ref if symbol is _ to avoid lints */
-    sp.slot.flags |= JANET_SLOT_NAMED;
-    sp.birth_pc = cnt ? cnt - 1 : 0;
-    sp.death_pc = UINT32_MAX;
-    janet_v_push(c->scope->syms, sp);
-}
-
-/* Same as janetc_nameslot, but don't have a lint for unused bindings. */
-void janetc_nameslot_no_unused(JanetCompiler *c, const uint8_t *sym, JanetSlot s) {
-    SymPair sp;
-    int32_t cnt = janet_v_count(c->buffer);
-    sp.sym = sym;
-    sp.sym2 = sym;
-    sp.slot = s;
-    sp.keep = 0;
-    sp.referenced = 1;
+    if (flags & JANET_DEFFLAG_NO_UNUSED) {
+        sp.referenced = 1;
+    } else {
+        sp.referenced = sym[0] == '_'; /* Fake ref if symbol starts with _ to avoid lints */
+    }
     sp.slot.flags |= JANET_SLOT_NAMED;
     sp.birth_pc = cnt ? cnt - 1 : 0;
     sp.death_pc = UINT32_MAX;
@@ -260,6 +269,38 @@ static int lookup_missing(
     return 1;
 }
 
+/* Check if a binding is defined in an upper scope. This lets us check for
+ * variable shadowing. */
+Shadowing janetc_shadowcheck(JanetCompiler *c, const uint8_t *sym) {
+    /* Check locals */
+    JanetScope *scope = c->scope;
+    int is_global = (scope->flags & JANET_SCOPE_TOP);
+    while (scope) {
+        int32_t len = janet_v_count(scope->syms);
+        for (int32_t i = len - 1; i >= 0; i--) {
+            SymPair *pair = scope->syms + i;
+            if (pair->sym == sym) {
+                janet_assert(!is_global, "shadowing analysis is incorrect. compiler bug");
+                return JANETC_SHADOW_LOCAL_HIDES_LOCAL;
+            }
+        }
+        scope = scope->parent;
+    }
+    /* Check globals */
+    JanetBinding binding = janet_resolve_ext(c->env, sym);
+    if (binding.type == JANET_BINDING_MACRO || binding.type == JANET_BINDING_DYNAMIC_MACRO) {
+        return JANETC_SHADOW_MACRO;
+    } else if (binding.type == JANET_BINDING_NONE) {
+        return JANETC_SHADOW_NONE;
+    } else {
+        if (is_global) {
+            return JANETC_SHADOW_GLOBAL_HIDES_GLOBAL;
+        } else {
+            return JANETC_SHADOW_LOCAL_HIDES_GLOBAL;
+        }
+    }
+}
+
 /* Allow searching for symbols. Return information about the symbol */
 JanetSlot janetc_resolve(
     JanetCompiler *c,
@@ -1103,6 +1144,7 @@ static void janetc_init(JanetCompiler *c, JanetTable *env, const uint8_t *where,
     c->current_mapping.line = -1;
     c->current_mapping.column = -1;
     c->lints = lints;
+    c->is_redef = janet_truthy(janet_table_get_keyword(c->env, "redef"));
     /* Init result */
     c->result.error = NULL;
     c->result.status = JANET_COMPILE_OK;

src/core/compile.h

@@ -36,6 +36,15 @@ typedef enum {
     JANET_C_LINT_STRICT
 } JanetCompileLintLevel;
 
+/* Kinds of variable shadowing for linting */
+typedef enum {
+    JANETC_SHADOW_NONE,
+    JANETC_SHADOW_MACRO,
+    JANETC_SHADOW_GLOBAL_HIDES_GLOBAL,
+    JANETC_SHADOW_LOCAL_HIDES_GLOBAL,
+    JANETC_SHADOW_LOCAL_HIDES_LOCAL
+} Shadowing;
+
 /* Tags for some functions for the prepared inliner */
 #define JANET_FUN_DEBUG 1
 #define JANET_FUN_ERROR 2
@@ -184,6 +193,9 @@ struct JanetCompiler {
 
     /* Collect linting results */
     JanetArray *lints;
+
+    /* Cached version of (dyn *redef*) */
+    int is_redef;
 };
 
 #define JANET_FOPTS_TAIL 0x10000
@@ -221,9 +233,11 @@ const JanetFunOptimizer *janetc_funopt(uint32_t flags);
 /* Get a special. Return NULL if none exists */
 const JanetSpecial *janetc_special(const uint8_t *name);
 
+#define JANET_DEFFLAG_NO_SHADOWCHECK 1
+#define JANET_DEFFLAG_NO_UNUSED 2
+
 void janetc_freeslot(JanetCompiler *c, JanetSlot s);
-void janetc_nameslot(JanetCompiler *c, const uint8_t *sym, JanetSlot s);
-void janetc_nameslot_no_unused(JanetCompiler *c, const uint8_t *sym, JanetSlot s);
+void janetc_nameslot(JanetCompiler *c, const uint8_t *sym, JanetSlot s, uint32_t flags);
 JanetSlot janetc_farslot(JanetCompiler *c);
 
 /* Throw away some code after checking that it is well formed. */
@@ -267,9 +281,12 @@ JanetFuncDef *janetc_pop_funcdef(JanetCompiler *c);
 /* Create a destroy slot */
 JanetSlot janetc_cslot(Janet x);
 
-/* Search for a symbol */
+/* Search for a symbol, and mark any found symbols as "used" for dead code elimination and linting */
 JanetSlot janetc_resolve(JanetCompiler *c, const uint8_t *sym);
 
+/* Check if a symbol is already in scope for shadowing lints */
+Shadowing janetc_shadowcheck(JanetCompiler *c, const uint8_t *sym);
+
 /* Bytecode optimization */
 void janet_bytecode_movopt(JanetFuncDef *def);
 void janet_bytecode_remove_noops(JanetFuncDef *def);

src/core/corelib.c

@@ -70,7 +70,7 @@ JanetModule janet_native(const char *name, const uint8_t **error) {
             host.minor != modconf.minor ||
             host.bits != modconf.bits) {
         char errbuf[128];
-        snprintf(errbuf, sizeof(errbuf), "config mismatch - host %d.%.d.%d(%.4x) vs. module %d.%d.%d(%.4x)",
+        snprintf(errbuf, sizeof(errbuf), "config mismatch - host %d.%.d.%d(%.4x) vs. module %d.%d.%d(%.4x) - native needs to be recompiled!",
                  host.major,
                  host.minor,
                  host.patch,

src/core/inttypes.c

@@ -333,7 +333,7 @@ static int compare_uint64_double(uint64_t x, double y) {
     }
 }
 
-static Janet cfun_it_s64_compare(int32_t argc, Janet *argv) {
+static JANET_CFUNCTION_ALIGN Janet cfun_it_s64_compare(int32_t argc, Janet *argv) {
     janet_fixarity(argc, 2);
     if (janet_is_int(argv[0]) != JANET_INT_S64) {
         janet_panic("compare method requires int/s64 as first argument");
@@ -368,7 +368,7 @@ static Janet cfun_it_s64_compare(int32_t argc, Janet *argv) {
     return janet_wrap_nil();
 }
 
-static Janet cfun_it_u64_compare(int32_t argc, Janet *argv) {
+static JANET_CFUNCTION_ALIGN Janet cfun_it_u64_compare(int32_t argc, Janet *argv) {
     janet_fixarity(argc, 2);
     if (janet_is_int(argv[0]) != JANET_INT_U64) {
         janet_panic("compare method requires int/u64 as first argument");
@@ -416,7 +416,7 @@ static Janet cfun_it_u64_compare(int32_t argc, Janet *argv) {
  * This will not affect the end result (property of twos complement).
  */
 #define OPMETHOD(T, type, name, oper) \
-static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
+static JANET_CFUNCTION_ALIGN Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
     janet_arity(argc, 2, -1); \
     T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
     *box = janet_unwrap_##type(argv[0]); \
@@ -427,7 +427,7 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
 } \
 
 #define OPMETHODINVERT(T, type, name, oper) \
-static Janet cfun_it_##type##_##name##i(int32_t argc, Janet *argv) { \
+static JANET_CFUNCTION_ALIGN Janet cfun_it_##type##_##name##i(int32_t argc, Janet *argv) { \
     janet_fixarity(argc, 2); \
     T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
     *box = janet_unwrap_##type(argv[1]); \
@@ -437,7 +437,7 @@ static Janet cfun_it_##type##_##name##i(int32_t argc, Janet *argv) { \
 } \
 
 #define UNARYMETHOD(T, type, name, oper) \
-static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
+static JANET_CFUNCTION_ALIGN Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
     janet_fixarity(argc, 1); \
     T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
     *box = oper(janet_unwrap_##type(argv[0])); \
@@ -450,7 +450,7 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
 #define DIVZERO_mod return janet_wrap_abstract(box)
 
 #define DIVMETHOD(T, type, name, oper) \
-static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
+static JANET_CFUNCTION_ALIGN Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
     janet_arity(argc, 2, -1);                       \
     T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
     *box = janet_unwrap_##type(argv[0]); \
@@ -463,7 +463,7 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
 } \
 
 #define DIVMETHODINVERT(T, type, name, oper) \
-static Janet cfun_it_##type##_##name##i(int32_t argc, Janet *argv) { \
+static JANET_CFUNCTION_ALIGN Janet cfun_it_##type##_##name##i(int32_t argc, Janet *argv) { \
     janet_fixarity(argc, 2);                       \
     T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
     *box = janet_unwrap_##type(argv[1]); \
@@ -474,7 +474,7 @@ static Janet cfun_it_##type##_##name##i(int32_t argc, Janet *argv) { \
 } \
 
 #define DIVMETHOD_SIGNED(T, type, name, oper) \
-static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
+static JANET_CFUNCTION_ALIGN Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
     janet_arity(argc, 2, -1);                       \
     T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
     *box = janet_unwrap_##type(argv[0]); \
@@ -488,7 +488,7 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
 } \
 
 #define DIVMETHODINVERT_SIGNED(T, type, name, oper) \
-static Janet cfun_it_##type##_##name##i(int32_t argc, Janet *argv) { \
+static JANET_CFUNCTION_ALIGN Janet cfun_it_##type##_##name##i(int32_t argc, Janet *argv) { \
     janet_fixarity(argc, 2);                       \
     T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
     *box = janet_unwrap_##type(argv[1]); \
@@ -499,7 +499,7 @@ static Janet cfun_it_##type##_##name##i(int32_t argc, Janet *argv) { \
     return janet_wrap_abstract(box); \
 } \
 
-static Janet cfun_it_s64_divf(int32_t argc, Janet *argv) {
+static JANET_CFUNCTION_ALIGN Janet cfun_it_s64_divf(int32_t argc, Janet *argv) {
     janet_fixarity(argc, 2);
     int64_t *box = janet_abstract(&janet_s64_type, sizeof(int64_t));
     int64_t op1 = janet_unwrap_s64(argv[0]);
@@ -510,7 +510,7 @@ static Janet cfun_it_s64_divf(int32_t argc, Janet *argv) {
     return janet_wrap_abstract(box);
 }
 
-static Janet cfun_it_s64_divfi(int32_t argc, Janet *argv) {
+static JANET_CFUNCTION_ALIGN Janet cfun_it_s64_divfi(int32_t argc, Janet *argv) {
     janet_fixarity(argc, 2);
     int64_t *box = janet_abstract(&janet_s64_type, sizeof(int64_t));
     int64_t op2 = janet_unwrap_s64(argv[0]);
@@ -521,7 +521,7 @@ static Janet cfun_it_s64_divfi(int32_t argc, Janet *argv) {
     return janet_wrap_abstract(box);
 }
 
-static Janet cfun_it_s64_mod(int32_t argc, Janet *argv) {
+static JANET_CFUNCTION_ALIGN Janet cfun_it_s64_mod(int32_t argc, Janet *argv) {
     janet_fixarity(argc, 2);
     int64_t *box = janet_abstract(&janet_s64_type, sizeof(int64_t));
     int64_t op1 = janet_unwrap_s64(argv[0]);
@@ -535,7 +535,7 @@ static Janet cfun_it_s64_mod(int32_t argc, Janet *argv) {
     return janet_wrap_abstract(box);
 }
 
-static Janet cfun_it_s64_modi(int32_t argc, Janet *argv) {
+static JANET_CFUNCTION_ALIGN Janet cfun_it_s64_modi(int32_t argc, Janet *argv) {
     janet_fixarity(argc, 2);
     int64_t *box = janet_abstract(&janet_s64_type, sizeof(int64_t));
     int64_t op2 = janet_unwrap_s64(argv[0]);

src/core/specials.c

@@ -404,7 +404,7 @@ SlotHeadPair *dohead_destructure(JanetCompiler *c, SlotHeadPair *into, JanetFopt
 }
 
 /* Def or var a symbol in a local scope */
-static int namelocal(JanetCompiler *c, const uint8_t *head, int32_t flags, JanetSlot ret, int no_unused) {
+static int namelocal(JanetCompiler *c, const uint8_t *head, int32_t flags, JanetSlot ret, uint32_t def_flags) {
     int isUnnamedRegister = !(ret.flags & JANET_SLOT_NAMED) &&
                             ret.index > 0 &&
                             ret.envindex >= 0;
@@ -425,11 +425,10 @@ static int namelocal(JanetCompiler *c, const uint8_t *head, int32_t flags, Janet
         ret = localslot;
     }
     ret.flags |= flags;
-    if ((c->scope->flags & JANET_SCOPE_TOP) || no_unused) {
-        janetc_nameslot_no_unused(c, head, ret);
-    } else {
-        janetc_nameslot(c, head, ret);
+    if (c->scope->flags & JANET_SCOPE_TOP) {
+        def_flags |= JANET_DEFFLAG_NO_UNUSED;
     }
+    janetc_nameslot(c, head, ret, def_flags);
     return !isUnnamedRegister;
 }
 
@@ -443,7 +442,7 @@ static int varleaf(
         JanetSlot refslot;
         JanetTable *entry = janet_table_clone(reftab);
 
-        int is_redef = janet_truthy(janet_table_get_keyword(c->env, "redef"));
+        int is_redef = c->is_redef;
 
         JanetArray *ref;
         JanetBinding old_binding;
@@ -464,7 +463,11 @@ static int varleaf(
         return 1;
     } else {
         int no_unused = reftab && reftab->count && janet_truthy(janet_table_get_keyword(reftab, "unused"));
-        return namelocal(c, sym, JANET_SLOT_MUTABLE, s, no_unused);
+        int no_shadow = reftab && reftab->count && janet_truthy(janet_table_get_keyword(reftab, "shadow"));
+        uint32_t def_flags = 0;
+        if (no_unused) def_flags |= JANET_DEFFLAG_NO_UNUSED;
+        if (no_shadow) def_flags |= JANET_DEFFLAG_NO_SHADOWCHECK;
+        return namelocal(c, sym, JANET_SLOT_MUTABLE, s, def_flags);
     }
 }
 
@@ -505,12 +508,14 @@ static int defleaf(
     const uint8_t *sym,
     JanetSlot s,
     JanetTable *tab) {
+    JanetTable *entry = NULL;
+    int is_redef = 0;
     if (c->scope->flags & JANET_SCOPE_TOP) {
-        JanetTable *entry = janet_table_clone(tab);
+        entry = janet_table_clone(tab);
         janet_table_put(entry, janet_ckeywordv("source-map"),
                         janet_wrap_tuple(janetc_make_sourcemap(c)));
 
-        int is_redef = janet_truthy(janet_table_get_keyword(c->env, "redef"));
+        is_redef = c->is_redef;
         if (is_redef) janet_table_put(entry, janet_ckeywordv("redef"), janet_wrap_true());
 
         if (is_redef) {
@@ -530,12 +535,18 @@ static int defleaf(
             JanetSlot tabslot = janetc_cslot(janet_wrap_table(entry));
             janetc_emit_sss(c, JOP_PUT, tabslot, valsym, s, 0);
         }
-
-        /* Add env entry to env */
-        janet_table_put(c->env, janet_wrap_symbol(sym), janet_wrap_table(entry));
     }
     int no_unused = tab && tab->count && janet_truthy(janet_table_get_keyword(tab, "unused"));
-    return namelocal(c, sym, 0, s, no_unused);
+    int no_shadow = is_redef || (tab && tab->count && janet_truthy(janet_table_get_keyword(tab, "shadow")));
+    uint32_t def_flags = 0;
+    if (no_unused) def_flags |= JANET_DEFFLAG_NO_UNUSED;
+    if (no_shadow) def_flags |= JANET_DEFFLAG_NO_SHADOWCHECK;
+    int result = namelocal(c, sym, 0, s, def_flags);
+    if (entry) {
+        /* Add env entry to env AFTER namelocal to avoid the shadowcheck false positive */
+        janet_table_put(c->env, janet_wrap_symbol(sym), janet_wrap_table(entry));
+    }
+    return result;
 }
 
 static JanetSlot janetc_def(JanetFopts opts, int32_t argn, const Janet *argv) {
@@ -1066,10 +1077,10 @@ static JanetSlot janetc_fn(JanetFopts opts, int32_t argn, const Janet *argv) {
                     named_table = janet_table(10);
                     named_slot = janetc_farslot(c);
                 } else {
-                    janetc_nameslot(c, sym, janetc_farslot(c));
+                    janetc_nameslot(c, sym, janetc_farslot(c), 0);
                 }
             } else {
-                janetc_nameslot(c, sym, janetc_farslot(c));
+                janetc_nameslot(c, sym, janetc_farslot(c), 0);
             }
         } else {
             janet_v_push(destructed_params, janetc_farslot(c));
@@ -1118,7 +1129,9 @@ static JanetSlot janetc_fn(JanetFopts opts, int32_t argn, const Janet *argv) {
             JanetSlot slot = janetc_farslot(c);
             slot.flags = JANET_SLOT_NAMED | JANET_FUNCTION;
             janetc_emit_s(c, JOP_LOAD_SELF, slot, 1);
-            janetc_nameslot_no_unused(c, sym, slot);
+            /* We should figure out a better way to avoid `(def x 1) (def x :shadow (fn x [...] ...))` triggering a
+             * shadow lint for the last x */
+            janetc_nameslot(c, sym, slot, JANET_DEFFLAG_NO_UNUSED | JANET_DEFFLAG_NO_SHADOWCHECK);
         }
     }
 

src/core/strtod.c

@@ -49,6 +49,8 @@
 #include <math.h>
 #include <string.h>
 
+#define JANET_NUMBER_LENGTH_RIDICULOUS 0xFFFF
+
 /* Lookup table for getting values of characters when parsing numbers. Handles
  * digits 0-9 and a-z (and A-Z). A-Z have values of 10 to 35. */
 static uint8_t digit_lookup[128] = {
@@ -266,7 +268,7 @@ int janet_scan_number_base(
      * the decimal point, exponent could wrap around and become positive. It's
      * easier to reject ridiculously large inputs than to check for overflows.
      * */
-    if (len > INT32_MAX / 40) goto error;
+    if (len > JANET_NUMBER_LENGTH_RIDICULOUS) goto error;
 
     /* Get sign */
     if (str >= end) goto error;
@@ -410,10 +412,7 @@ static int scan_uint64(
     *neg = 0;
     *out = 0;
     uint64_t accum = 0;
-    /* len max is INT64_MAX in base 2 with _ between each bits */
-    /* '2r' + 64 bits + 63 _  + sign = 130 => 150 for some leading  */
-    /* zeros */
-    if (len > 150) return 0;
+    if (len > JANET_NUMBER_LENGTH_RIDICULOUS) return 0;
     /* Get sign */
     if (str >= end) return 0;
     if (*str == '-') {

src/core/util.c

@@ -573,8 +573,24 @@ static char *namebuf_name(NameBuf *namebuf, const char *suffix) {
     return (char *)(namebuf->buf);
 }
 
+/* Add a little bit of safety when using nanboxing on arm. Instead of inserting run-time checks everywhere, we are
+ * only doing it during registration which has much less cost (1 shift and mask). */
+static void janet_check_pointer_align(void *p) {
+    (void) p;
+#if defined(JANET_NANBOX_64) && JANET_NANBOX_64_POINTER_SHIFT != 0
+    union {
+        void *p;
+        uintptr_t u;
+    } un;
+    un.p = p;
+    janet_assert(!(un.u & (uintptr_t) ((1 << JANET_NANBOX_64_POINTER_SHIFT) - 1)),
+        "unaligned pointer wrap - cfunction pointers and abstract types must be aligned with this nanboxing configuration.");
+#endif
+}
+
 void janet_cfuns(JanetTable *env, const char *regprefix, const JanetReg *cfuns) {
     while (cfuns->name) {
+        janet_check_pointer_align(cfuns->cfun);
         Janet fun = janet_wrap_cfunction(cfuns->cfun);
         if (env) janet_def(env, cfuns->name, fun, cfuns->documentation);
         janet_registry_put(cfuns->cfun, cfuns->name, regprefix, NULL, 0);
@@ -584,6 +600,7 @@ void janet_cfuns(JanetTable *env, const char *regprefix, const JanetReg *cfuns)
 
 void janet_cfuns_ext(JanetTable *env, const char *regprefix, const JanetRegExt *cfuns) {
     while (cfuns->name) {
+        janet_check_pointer_align(cfuns->cfun);
         Janet fun = janet_wrap_cfunction(cfuns->cfun);
         if (env) janet_def_sm(env, cfuns->name, fun, cfuns->documentation, cfuns->source_file, cfuns->source_line);
         janet_registry_put(cfuns->cfun, cfuns->name, regprefix, cfuns->source_file, cfuns->source_line);
@@ -595,6 +612,7 @@ void janet_cfuns_prefix(JanetTable *env, const char *regprefix, const JanetReg *
     NameBuf nb;
     if (env) namebuf_init(&nb, regprefix);
     while (cfuns->name) {
+        janet_check_pointer_align(cfuns->cfun);
         Janet fun = janet_wrap_cfunction(cfuns->cfun);
         if (env) janet_def(env, namebuf_name(&nb, cfuns->name), fun, cfuns->documentation);
         janet_registry_put(cfuns->cfun, cfuns->name, regprefix, NULL, 0);
@@ -607,6 +625,7 @@ void janet_cfuns_ext_prefix(JanetTable *env, const char *regprefix, const JanetR
     NameBuf nb;
     if (env) namebuf_init(&nb, regprefix);
     while (cfuns->name) {
+        janet_check_pointer_align(cfuns->cfun);
         Janet fun = janet_wrap_cfunction(cfuns->cfun);
         if (env) janet_def_sm(env, namebuf_name(&nb, cfuns->name), fun, cfuns->documentation, cfuns->source_file, cfuns->source_line);
         janet_registry_put(cfuns->cfun, cfuns->name, regprefix, cfuns->source_file, cfuns->source_line);
@@ -623,6 +642,7 @@ void janet_register(const char *name, JanetCFunction cfun) {
 /* Abstract type introspection */
 
 void janet_register_abstract_type(const JanetAbstractType *at) {
+    janet_check_pointer_align((void *) at);
     Janet sym = janet_csymbolv(at->name);
     Janet check = janet_table_get(janet_vm.abstract_registry, sym);
     if (!janet_checktype(check, JANET_NIL) && at != janet_unwrap_pointer(check)) {
@@ -655,6 +675,7 @@ void janet_core_def_sm(JanetTable *env, const char *name, Janet x, const void *p
 void janet_core_cfuns_ext(JanetTable *env, const char *regprefix, const JanetRegExt *cfuns) {
     (void) regprefix;
     while (cfuns->name) {
+        janet_check_pointer_align(cfuns->cfun);
         Janet fun = janet_wrap_cfunction(cfuns->cfun);
         janet_table_put(env, janet_csymbolv(cfuns->name), fun);
         janet_registry_put(cfuns->cfun, cfuns->name, regprefix, cfuns->source_file, cfuns->source_line);

src/core/wrap.c

@@ -194,12 +194,18 @@ Janet janet_wrap_number_safe(double d) {
 
 void *janet_nanbox_to_pointer(Janet x) {
     x.i64 &= JANET_NANBOX_PAYLOADBITS;
+    x.u64 <<= JANET_NANBOX_64_POINTER_SHIFT; /* Alignment, usually 0 */
     return x.pointer;
 }
 
 Janet janet_nanbox_from_pointer(void *p, uint64_t tagmask) {
     Janet ret;
     ret.pointer = p;
+    /* Should be noop when pointer shift is 0 */
+    /*
+    janet_assert(!(ret.u64 & (uint64_t) ((1 << JANET_NANBOX_64_POINTER_SHIFT) - 1)), "unaligned pointer wrap");
+    */
+    ret.u64 >>= JANET_NANBOX_64_POINTER_SHIFT; /* Alignment, usually 0 */
     ret.u64 |= tagmask;
     return ret;
 }
@@ -207,6 +213,11 @@ Janet janet_nanbox_from_pointer(void *p, uint64_t tagmask) {
 Janet janet_nanbox_from_cpointer(const void *p, uint64_t tagmask) {
     Janet ret;
     ret.pointer = (void *)p;
+    /* Should be noop when pointer shift is 0 */
+    /*
+    janet_assert(!(ret.u64 & (uint64_t) ((1 << JANET_NANBOX_64_POINTER_SHIFT) - 1)), "unaligned pointer wrap");
+    */
+    ret.u64 >>= JANET_NANBOX_64_POINTER_SHIFT; /* Alignment, usually 0 */
     ret.u64 |= tagmask;
     return ret;
 }

src/include/janet.h

@@ -307,25 +307,38 @@ extern "C" {
  * architectures (Nanboxing only tested on x86 and x64), comment out
  * the JANET_NANBOX define.*/
 
-#if defined(_M_ARM64) || defined(_M_ARM) || defined(__aarch64__)
-#define JANET_NO_NANBOX
-#endif
-
 #ifndef JANET_NO_NANBOX
 #ifdef JANET_32
 #define JANET_NANBOX_32
-#elif defined(__x86_64__) || defined(_WIN64) || defined(__riscv)
+#elif defined(__x86_64__) || defined(_WIN64) || defined(__riscv) || defined(__aarch64__) || defined(_M_ARM64)
 /* We will only enable nanboxing by default on 64 bit systems
- * for x64 and risc-v. This is mainly because the approach is tied to the
+ * for x64, risc-v, and arm64. This is mainly because the approach is tied to the
  * implicit 47 bit address space. Many arches allow/require this, but not all,
- * and it requires cooperation from the OS. ARM should also work in many configurations. */
+ * and it requires cooperation from the OS. ARM should also work in many configurations by taking advantage
+ * of pointer alignment to allow for 48 or 49 bits of address space. */
 #define JANET_NANBOX_64
+
+/* Allow 64-bit nanboxing to assume aligned pointers to get back some extra bits for representation.
+ * This is needed to use nanboxing on systems with larger than 47-bit address spaces, such as many
+ * aarch64 systems. */
+#ifndef JANET_NANBOX_64_POINTER_SHIFT
+#if (defined(_M_ARM64) || defined(__aarch64__)) && !defined(JANET_APPLE)
+/* All pointers, including function pointers, should be 4-byte aligned on aarch64 by default.
+ * The exception is aarch64 macos, as it uses the same 47-bit userland address-space as on amd64. */
+#define JANET_NANBOX_64_POINTER_SHIFT 0 /* TODO - set me back to 2! (trying to trigger crash) */
 #endif
 #endif
+#endif
+#endif
+
+/* Allow for custom pointer alignment as well */
+#if defined(JANET_NANBOX_64) && !defined(JANET_NANBOX_64_POINTER_SHIFT)
+#define JANET_NANBOX_64_POINTER_SHIFT 0
+#endif
 
 /* Runtime config constants */
 #ifdef JANET_NO_NANBOX
-#define JANET_NANBOX_BIT 0
+#define JANET_NANBOX_BIT 0x0
 #else
 #define JANET_NANBOX_BIT 0x1
 #endif
@@ -336,9 +349,16 @@ extern "C" {
 #define JANET_SINGLE_THREADED_BIT 0
 #endif
 
+#ifdef JANET_NANBOX_64_POINTER_SHIFT
+#define JANET_NANBOX_POINTER_SHIFT_BITS (JANET_NANBOX_64_POINTER_SHIFT ? (0x4 << JANET_NANBOX_64_POINTER_SHIFT) : 0)
+#else
+#define JANET_NANBOX_POINTER_SHIFT_BITS 0
+#endif
+
 #define JANET_CURRENT_CONFIG_BITS \
     (JANET_SINGLE_THREADED_BIT | \
-     JANET_NANBOX_BIT)
+     JANET_NANBOX_BIT | \
+     JANET_NANBOX_POINTER_SHIFT_BITS)
 
 /* Represents the settings used to compile Janet, as well as the version */
 typedef struct {
@@ -1415,7 +1435,7 @@ enum JanetOpCode {
 };
 
 /* Info about all instructions */
-extern enum JanetInstructionType janet_instructions[JOP_INSTRUCTION_COUNT];
+extern const enum JanetInstructionType janet_instructions[JOP_INSTRUCTION_COUNT];
 
 /***** END SECTION OPCODES *****/
 
@@ -2063,8 +2083,14 @@ JANET_API Janet janet_resolve_core(const char *name);
  *
  * */
 
+#if defined(JANET_NANBOX_64) && (JANET_NANBOX_64_POINTER_SHIFT != 0) && !defined(JANET_MSVC)
+#define JANET_CFUNCTION_ALIGN __attribute__((aligned(1 << JANET_NANBOX_64_POINTER_SHIFT)))
+#else
+#define JANET_CFUNCTION_ALIGN
+#endif
+
 /* Shorthand for janet C function declarations */
-#define JANET_CFUN(name) Janet name (int32_t argc, Janet *argv)
+#define JANET_CFUN(name) JANET_CFUNCTION_ALIGN Janet name (int32_t argc, Janet *argv)
 
 /* Declare a C function with documentation and source mapping */
 #define JANET_REG_END {NULL, NULL, NULL, NULL, 0}
@@ -2080,7 +2106,7 @@ JANET_API Janet janet_resolve_core(const char *name);
 #define JANET_REG_S(JNAME, CNAME) {JNAME, CNAME, NULL, __FILE__, CNAME##_sourceline_}
 #define JANET_FN_S(CNAME, USAGE, DOCSTRING) \
     static const int32_t CNAME##_sourceline_ = __LINE__; \
-    Janet CNAME (int32_t argc, Janet *argv)
+    Janet JANET_CFUNCTION_ALIGN CNAME (int32_t argc, Janet *argv)
 #define JANET_DEF_S(ENV, JNAME, VAL, DOC) \
     janet_def_sm(ENV, JNAME, VAL, NULL, __FILE__, __LINE__)
 
@@ -2088,7 +2114,7 @@ JANET_API Janet janet_resolve_core(const char *name);
 #define JANET_REG_D(JNAME, CNAME) {JNAME, CNAME, CNAME##_docstring_, NULL, 0}
 #define JANET_FN_D(CNAME, USAGE, DOCSTRING) \
     static const char CNAME##_docstring_[] = USAGE "\n\n" DOCSTRING; \
-    Janet CNAME (int32_t argc, Janet *argv)
+    Janet JANET_CFUNCTION_ALIGN CNAME (int32_t argc, Janet *argv)
 #define JANET_DEF_D(ENV, JNAME, VAL, DOC) \
     janet_def(ENV, JNAME, VAL, DOC)
 
@@ -2097,7 +2123,7 @@ JANET_API Janet janet_resolve_core(const char *name);
 #define JANET_FN_SD(CNAME, USAGE, DOCSTRING) \
     static const int32_t CNAME##_sourceline_ = __LINE__; \
     static const char CNAME##_docstring_[] = USAGE "\n\n" DOCSTRING; \
-    Janet CNAME (int32_t argc, Janet *argv)
+    Janet JANET_CFUNCTION_ALIGN CNAME (int32_t argc, Janet *argv)
 #define JANET_DEF_SD(ENV, JNAME, VAL, DOC) \
     janet_def_sm(ENV, JNAME, VAL, DOC, __FILE__, __LINE__)
 

test/helper.janet

@@ -27,9 +27,11 @@
   (def line-info (string/format "%s:%d"
                               (frame :source) (frame :source-line)))
   (if x
-    (when is-verbose (eprintf "\e[32m✔\e[0m %s: %s: %v" line-info (describe e) x))
+    (when is-verbose
+      (eprintf "\e[32m✔\e[0m %s: %s: %v" line-info (describe e) x)
+      (eflush) (flush))
     (do
-      (eprintf "\e[31m✘\e[0m %s: %s: %v" line-info (describe e) x) (eflush)))
+      (eprintf "\e[31m✘\e[0m %s: %s: %v" line-info (describe e) x) (eflush) (flush)))
   x)
 
 (defn skip-asserts
@@ -38,7 +40,7 @@
   (+= skip-n n)
   nil)
 
-(defmacro assert
+(defmacro assert :shadow
   [x &opt e]
   (def xx (gensym))
   (default e (string/format "%j" x))
@@ -50,12 +52,12 @@
 (defmacro assert-error
   [msg & forms]
   (def errsym (keyword (gensym)))
-  ~(assert (= ,errsym (try (do ,;forms) ([_] ,errsym))) ,msg))
+  ~(as-macro ,assert (= ,errsym (try (do ,;forms) ([_] ,errsym))) ,msg))
 
 (defmacro assert-error-value
   [msg errval & forms]
   (def e (gensym))
-  ~(assert (= ,errval (try (do ,;forms) ([,e] ,e))) ,msg))
+  ~(as-macro ,assert (= ,errval (try (do ,;forms) ([,e] ,e))) ,msg))
 
 (defn check-compile-error
   [form]

test/suite-array.janet

@@ -70,9 +70,9 @@
 (assert (= (array/pop @[]) nil) "array/pop empty")
 
 # Code coverage
-(def a @[1])
-(array/pop a)
-(array/trim a)
+(def a1 @[1])
+(array/pop a1)
+(array/trim a1)
 (array/ensure @[1 1] 6 2)
 
 # array/join

test/suite-buffer.janet

@@ -48,8 +48,8 @@
 
 (assert (deep= (buffer/push @"AA" @"BB") @"AABB") "buffer/push buffer")
 (assert (deep= (buffer/push @"AA" 66 66) @"AABB") "buffer/push int")
-(def b @"AA")
-(assert (deep= (buffer/push b b) @"AAAA") "buffer/push buffer self")
+(def b1 @"AA")
+(assert (deep= (buffer/push b1 b1) @"AAAA") "buffer/push buffer self")
 
 # buffer/push-byte
 (assert (deep= (buffer/push-byte @"AA" 66) @"AAB") "buffer/push-byte")
@@ -145,8 +145,8 @@
 
 # Regression #301
 # a3d4ecddb
-(def b (buffer/new-filled 128 0x78))
-(assert (= 38 (length (buffer/blit @"" b -1 90))) "buffer/blit 1")
+(def b8 (buffer/new-filled 128 0x78))
+(assert (= 38 (length (buffer/blit @"" b8 -1 90))) "buffer/blit 1")
 
 (def a @"abcdefghijklm")
 (assert (deep= @"abcde" (buffer/blit @"" a -1 0 5)) "buffer/blit 2")

test/suite-compile.janet

@@ -84,23 +84,23 @@
 (assert (get result :error) "bad sum3 fuzz issue valgrind")
 
 # Issue #1700
-(def result
+(def result1
   (compile
     '(defn fuzz-case-1
       [start end &]
       (if end
         (if e start (lazy-range (+ 1 start) end)))
       1)))
-(assert (get result :error) "fuzz case issue #1700")
+(assert (get result1 :error) "fuzz case issue #1700")
 
 # Issue #1702 - fuzz case with upvalues
-(def result
+(def result2
   (compile
   '(each item [1 2 3]
     # Generate a lot of upvalues (more than 224)
     (def ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;out-buf @"")
     (with-dyns [:out out-buf] 1))))
-(assert result "bad upvalues fuzz case")
+(assert result2 "bad upvalues fuzz case")
 
 # Named argument linting
 # Enhancement for #1654
@@ -117,14 +117,14 @@
 (defn check-good-compile
   [code msg]
   (def lints @[])
-  (def result (compile code (curenv) "suite-compile.janet" lints))
-  (assert (and (function? result) (empty? lints)) msg))
+  (def result4 (compile code (curenv) "suite-compile.janet" lints))
+  (assert (and (function? result4) (empty? lints)) msg))
 
 (defn check-lint-compile
   [code msg]
   (def lints @[])
-  (def result (compile code (curenv) "suite-compile.janet" lints))
-  (assert (and (function? result) (next lints)) msg))
+  (def result4 (compile code (curenv) "suite-compile.janet" lints))
+  (assert (and (function? result4) (next lints)) msg))
 
 (check-good-compile '(fnamed) "named no args")
 (check-good-compile '(fnamed :x 1 :y 2 :z 3) "named full args")
@@ -150,5 +150,10 @@
 (check-lint-compile '(g 1 2 :z) "g lint 1")
 (check-lint-compile '(g 1 2 :z 4 5) "g lint 2")
 
-(end-suite)
+# Variable shadowing linting
+(def outer1 "a")
+(check-lint-compile '(def outer1 "b") "shadow global-to-global")
+(check-lint-compile '(let [outer1 "b"] outer1) "shadow local-to-global")
+(check-lint-compile '(do (def x "b") (def x "c")) "shadow local-to-local")
 
+(end-suite)

test/suite-ev2.janet

@@ -43,9 +43,9 @@
 (assert (deep= '(:error "deadline expired" nil) (ev/take super)) "deadline expirataion")
 
 # Another variant
-(def thread-channel (ev/thread-chan 100))
-(def super (ev/thread-chan 10))
-(defn worker []
+(def thread-channel :shadow (ev/thread-chan 100))
+(def super :shadow (ev/thread-chan 10))
+(defn worker :shadow []
   (while true
     (def item (ev/take thread-channel))
     (when (= item :deadline)

test/suite-io.janet

@@ -37,7 +37,7 @@
 
 # Printing to functions
 # 4e263b8c3
-(def out-buf @"")
+(def out-buf :shadow @"")
 (defn prepend [x]
   (with-dyns [:out out-buf]
     (prin "> " x)))
@@ -59,8 +59,8 @@
 
 # issue #1055 - 2c927ea76
 (let [b @""]
-  (defn dummy [a b c]
-    (+ a b c))
+  (defn dummy [a bb c]
+    (+ a bb c))
   (trace dummy)
   (defn errout [arg]
     (buffer/push b arg))

test/suite-marsh.janet

@@ -95,11 +95,11 @@
 (do
   (defn f1
     [a]
-    (defn f1 [] (++ (a 0)))
+    (defn f1 :shadow [] (++ (a 0)))
     (defn f2 [] (++ (a 0)))
     (error [f1 f2]))
   (def [_ tup] (protect (f1 @[0])))
-  (def [f1 f2] (unmarshal (marshal tup make-image-dict) load-image-dict))
+  (def [f1 f2] :shadow (unmarshal (marshal tup make-image-dict) load-image-dict))
   (assert (= 1 (f1)) "marshal-non-resumable-closure 1")
   (assert (= 2 (f2)) "marshal-non-resumable-closure 2"))
 
@@ -108,10 +108,10 @@
 (do
   (defn f1
     [a]
-    (defn f1 [] (++ (a 0)))
-    (defn f2 [] (++ (a 0)))
+    (defn f1 :shadow [] (++ (a 0)))
+    (defn f2 :shadow [] (++ (a 0)))
     (marshal [f1 f2] make-image-dict))
-  (def [f1 f2] (unmarshal (f1 @[0]) load-image-dict))
+  (def [f1 f2] :shadow (unmarshal (f1 @[0]) load-image-dict))
   (assert (= 1 (f1)) "marshal-live-closure 1")
   (assert (= 2 (f2)) "marshal-live-closure 2"))
 
@@ -189,11 +189,11 @@ neldb\0\0\0\xD8\x05printG\x01\0\xDE\xDE\xDE'\x03\0marshal_tes/\x02
 (assert (deep= t tclone) "table/weak marsh 7")
 
 # table weak keys
-(def t (table/weak-keys 1))
+(def t :shadow (table/weak-keys 1))
 (put t @"" keep-value)
 (put t :key @"")
 (assert (= 2 (length t)) "table/weak-keys marsh 1")
-(def tclone (-> t marshal unmarshal))
+(def tclone :shadow (-> t marshal unmarshal))
 (assert (= 2 (length tclone)) "table/weak-keys marsh 2")
 (gccollect)
 (assert (= 1 (length tclone)) "table/weak-keys marsh 3")
@@ -201,23 +201,23 @@ neldb\0\0\0\xD8\x05printG\x01\0\xDE\xDE\xDE'\x03\0marshal_tes/\x02
 (assert (deep= t tclone) "table/weak-keys marsh 5")
 
 # table weak values
-(def t (table/weak-values 1))
+(def t :shadow (table/weak-values 1))
 (put t @"" keep-value)
 (put t :key @"")
 (assert (= 2 (length t)) "table/weak-values marsh 1")
-(def tclone (-> t marshal unmarshal))
+(def tclone :shadow (-> t marshal unmarshal))
 (assert (= 2 (length tclone)) "table/weak-values marsh 2")
 (gccollect)
 (assert (= 1 (length t)) "table/weak-value marsh 3")
 (assert (deep= (freeze t) (freeze tclone)) "table/weak-values marsh 4")
 
 # tables with prototypes
-(def t (table/weak-values 1))
+(def t :shadow (table/weak-values 1))
 (table/setproto t @{:abc 123})
 (put t @"" keep-value)
 (put t :key @"")
 (assert (= 2 (length t)) "marsh weak tables with prototypes 1")
-(def tclone (-> t marshal unmarshal))
+(def tclone :shadow (-> t marshal unmarshal))
 (assert (= 2 (length tclone)) "marsh weak tables with prototypes 2")
 (gccollect)
 (assert (= 1 (length t)) "marsh weak tables with prototypes 3")

test/suite-parse.janet

@@ -138,13 +138,13 @@
 
 # Parser clone
 # 43520ac67
-(def p (parser/new))
-(assert (= 7 (parser/consume p "(1 2 3 ")) "parser 1")
-(def p2 (parser/clone p))
+(def p0 (parser/new))
+(assert (= 7 (parser/consume p0 "(1 2 3 ")) "parser 1")
+(def p2 (parser/clone p0))
 (parser/consume p2 ") 1 ")
-(parser/consume p ") 1 ")
-(assert (deep= (parser/status p) (parser/status p2)) "parser 2")
-(assert (deep= (parser/state p) (parser/state p2)) "parser 3")
+(parser/consume p0 ") 1 ")
+(assert (deep= (parser/status p0) (parser/status p2)) "parser 2")
+(assert (deep= (parser/state p0) (parser/state p2)) "parser 3")
 
 # Parser errors
 # 976dfc719
@@ -179,11 +179,11 @@
 (parser/consume p1 step1)
 (loop [_ :iterate (parser/produce p1)])
 (parser/state p1)
-(def p2 (parser/clone p1))
-(parser/state p2)
-(parser/consume p2 step2)
-(loop [_ :iterate (parser/produce p2)])
-(parser/state p2)
+(def p3 (parser/clone p1))
+(parser/state p3)
+(parser/consume p3 step2)
+(loop [_ :iterate (parser/produce p3)])
+(parser/state p3)
 
 # parser delimiter errors
 (defn test-error [delim fmt]
@@ -202,11 +202,11 @@
 (parser/consume p ")")
 (assert (= (parser/produce p) ["hello"]))
 
-(def p (parser/new))
-(parser/consume p `("hel`)
-(parser/insert p `lo`)
-(parser/consume p `")`)
-(assert (= (parser/produce p) ["hello"]))
+(def p4 (parser/new))
+(parser/consume p4 `("hel`)
+(parser/insert p4 `lo`)
+(parser/consume p4 `")`)
+(assert (= (parser/produce p4) ["hello"]))
 
 # Hex floats
 (assert (= math/pi +0x1.921fb54442d18p+0001))

test/suite-peg.janet

@@ -84,10 +84,10 @@
 
 # Substitution test with peg
 # d7626f8c5
-(def grammar '(accumulate (any (+ (/ "dog" "purple panda") (<- 1)))))
+(def grammar1 '(accumulate (any (+ (/ "dog" "purple panda") (<- 1)))))
 (defn try-grammar [text]
   (assert (= (string/replace-all "dog" "purple panda" text)
-             (0 (peg/match grammar text))) text))
+             (0 (peg/match grammar1 text))) text))
 
 (try-grammar "i have a dog called doug the dog. he is good.")
 (try-grammar "i have a dog called doug the dog. he is a good boy.")
@@ -336,7 +336,7 @@
 
 # unref
 # 96513665d
-(def grammar
+(def grammar2
   (peg/compile
     ~{:main (* :tagged -1)
       :tagged (unref (replace (* :open-tag :value :close-tag) ,struct))
@@ -344,9 +344,9 @@
       :value (* (constant :value) (group (any (+ :tagged :untagged))))
       :close-tag (* "</" (backmatch :tag-name) ">")
       :untagged (capture (any (if-not "<" 1)))}))
-(check-deep grammar "<p><em>foobar</em></p>"
+(check-deep grammar2 "<p><em>foobar</em></p>"
             @[{:tag "p" :value @[{:tag "em" :value @["foobar"]}]}])
-(check-deep grammar "<p>foobar</p>" @[{:tag "p" :value @["foobar"]}])
+(check-deep grammar2 "<p>foobar</p>" @[{:tag "p" :value @["foobar"]}])
 
 # Using a large test grammar
 # cf05ff610
@@ -369,7 +369,7 @@
   (def sym (symbol text))
   [(if (or (root-env sym) (specials sym)) :coresym :symbol) text])
 
-(def grammar
+(def grammar3
   ~{:ws (set " \v\t\r\f\n\0")
     :readermac (set "';~,")
     :symchars (+ (range "09" "AZ" "az" "\x80\xFF")
@@ -408,13 +408,13 @@
     :dict (* '"@" :struct)
     :main (+ :root (error ""))})
 
-(def p (peg/compile grammar))
+(def porig (peg/compile grammar3))
 
 # Just make sure is valgrind clean.
-(def p (-> p make-image load-image))
+(def pprime (-> porig make-image load-image))
 
-(assert (peg/match p "abc") "complex peg grammar 1")
-(assert (peg/match p "[1 2 3 4]") "complex peg grammar 2")
+(assert (peg/match pprime "abc") "complex peg grammar 1")
+(assert (peg/match pprime "[1 2 3 4]") "complex peg grammar 2")
 
 ###
 ### Compiling brainfuck to Janet.
@@ -565,8 +565,8 @@
         "peg/replace-all function")
 
 # 9dc7e8ed3
-(defn peg-test [name f peg subst text expected]
-  (assert (= (string (f peg subst text)) expected) name))
+(defn peg-test [name f pegg subst text expected]
+  (assert (= (string (f pegg subst text)) expected) name))
 
 (peg-test "peg/replace has access to captures"
           peg/replace
@@ -602,10 +602,10 @@
 
 # Marshal and unmarshal pegs
 # 446ab037b
-(def p (-> "abcd" peg/compile marshal unmarshal))
-(assert (peg/match p "abcd") "peg marshal 1")
-(assert (peg/match p "abcdefg") "peg marshal 2")
-(assert (not (peg/match p "zabcdefg")) "peg marshal 3")
+(def p3 (-> "abcd" peg/compile marshal unmarshal))
+(assert (peg/match p3 "abcd") "peg marshal 1")
+(assert (peg/match p3 "abcdefg") "peg marshal 2")
+(assert (not (peg/match p3 "zabcdefg")) "peg marshal 3")
 
 # to/thru bug
 # issue #971 - a895219d2
@@ -669,10 +669,10 @@
           (peg/match '(if (not (* (constant 7) "a")) "hello") "hello")
           @[]) "peg if not")
 
-(defn test [name peg input expected]
-  (assert-no-error "compile peg" (peg/compile peg))
-  (assert-no-error "marshal/unmarshal peg" (-> peg marshal unmarshal))
-  (assert (deep= (peg/match peg input) expected) name))
+(defn test [name pegg input expected]
+  (assert-no-error "compile peg" (peg/compile pegg))
+  (assert-no-error "marshal/unmarshal peg" (-> pegg marshal unmarshal))
+  (assert (deep= (peg/match pegg input) expected) name))
 
 (test "sub: matches the same input twice"
       ~(sub "abcd" "abc")
@@ -852,20 +852,20 @@
       @[["b" "b" "b"]])
 
 # Debug and ?? tests.
-(defn test-stderr [name peg input expected-matches expected-stderr]
+(defn test-stderr [name pegg input expected-matches expected-stderr]
   (with-dyns [:err @""]
-    (test name peg input expected-matches))
+    (test name pegg input expected-matches))
   (def actual @"")
   (with-dyns [:err actual *err-color* true]
-    (peg/match peg input))
+    (peg/match pegg input))
   (assert (deep= (string actual) expected-stderr)))
 
-(defn test-stderr-no-color [name peg input expected-matches expected-stderr]
+(defn test-stderr-no-color [name pegg input expected-matches expected-stderr]
   (with-dyns [:err @""]
-    (test name peg input expected-matches))
+    (test name pegg input expected-matches))
   (def actual @"")
   (with-dyns [:err actual *err-color* false]
-    (peg/match peg input))
+    (peg/match pegg input))
   (assert (deep= (string actual) expected-stderr)))
 
 (test-stderr

test/suite-pp.janet

@@ -44,8 +44,8 @@
 (def buftemp @"abcd")
 (assert (= (string (buffer/format buftemp "---%p---" buftemp))
            `abcd---@"abcd"---`) "buffer/format on self 1")
-(def buftemp @"abcd")
-(assert (= (string (buffer/format buftemp "---%p %p---" buftemp buftemp))
+(def buftemp2 @"abcd")
+(assert (= (string (buffer/format buftemp2 "---%p %p---" buftemp2 buftemp2))
            `abcd---@"abcd" @"abcd"---`) "buffer/format on self 2")
 
 # 5c364e0

test/suite-vm.janet

@@ -132,11 +132,11 @@
 
 # Cancel test
 # 28439d822
-(def f (fiber/new (fn [&] (yield 1) (yield 2) (yield 3) 4) :yti))
-(assert (= 1 (resume f)) "cancel resume 1")
-(assert (= 2 (resume f)) "cancel resume 2")
-(assert (= :hi (cancel f :hi)) "cancel resume 3")
-(assert (= :error (fiber/status f)) "cancel resume 4")
+(def fc (fiber/new (fn [&] (yield 1) (yield 2) (yield 3) 4) :yti))
+(assert (= 1 (resume fc)) "cancel resume 1")
+(assert (= 2 (resume fc)) "cancel resume 2")
+(assert (= :hi (cancel fc :hi)) "cancel resume 3")
+(assert (= :error (fiber/status fc)) "cancel resume 4")
 
 (end-suite)