Fixed cmdline example program

.gitignore

@@ -0,0 +1,63 @@
+#https://github.com/github/gitignore/blob/main/C.gitignore
+# Prerequisites
+*.d
+
+# Object files
+*.o
+*.ko
+*.obj
+*.elf
+
+# Linker output
+*.ilk
+*.map
+*.exp
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Libraries
+*.lib
+*.a
+*.la
+*.lo
+
+# Shared objects (inc. Windows DLLs)
+*.dll
+*.so
+*.so.*
+*.dylib
+
+# Executables
+*.exe
+*.out
+*.app
+*.i*86
+*.x86_64
+*.hex
+
+# Debug files
+*.dSYM/
+*.su
+*.idb
+*.pdb
+
+# Kernel Module Compile Results
+*.mod*
+*.cmd
+.tmp_versions/
+modules.order
+Module.symvers
+Mkfile.old
+dkms.conf
+
+# debug information files
+*.dwo
+
+# My own
+
+build/*
+.gdb_history
+
+*.gcno

Makefile

@@ -0,0 +1,85 @@
+#Slopped together AI :(
+
+BUILD := build
+AFL_CC := afl-clang-fast
+CLANG  := clang-21
+
+AFL_ENV_OPTIONS := AFL_MAP_SIZE=1048576 AFL_LLVM_INSTRUMENT=CLASSIC AFL_LLVM_CTX_K=3
+
+SRC     := main.c elk.c
+CLI_SRC := cli.c elk.c
+CLI_OPTIONS := -flto -ggdb3 -O0 -fno-omit-frame-pointer
+
+.PHONY: all afl cli clean \
+        normal san1 san2 san3 laf cmplog \
+        cli-normal cli-san1 cli-san2 cli-san3
+
+# ---- helpers ----
+
+# Ensure build dir exists
+$(BUILD):
+	mkdir -p $(BUILD)
+
+# Generic AFL build macro
+define AFL_BUILD
+$1: | $(BUILD)
+	$2 $(AFL_ENV_OPTIONS) $(AFL_CC) $(SRC) -o $(BUILD)/$1
+endef
+
+# Generic CLI build macro
+define CLI_BUILD
+$1: | $(BUILD)
+	$(CLANG) $2 $(CLI_SRC) $(CLI_OPTIONS) -o $(BUILD)/$1
+endef
+
+# ---- targets ----
+
+all: afl cli
+afl: normal san1 san2 san3 laf cmplog
+cli: cli-normal cli-san1 cli-san2 cli-san3
+
+# ---- AFL variants ----
+
+$(eval $(call AFL_BUILD,normal,))
+
+$(eval $(call AFL_BUILD,san1, \
+	AFL_LLVM_ONLY_FSRV=1 \
+	AFL_USE_ASAN=1 \
+	AFL_USE_UBSAN=1 \
+	AFL_USE_LSAN=1))
+
+$(eval $(call AFL_BUILD,san2, \
+	AFL_LLVM_ONLY_FSRV=1 \
+	AFL_HARDEN=1 \
+	AFL_USE_TSAN=1))
+
+$(eval $(call AFL_BUILD,san3, \
+	AFL_LLVM_ONLY_FSRV=1 \
+	AFL_USE_MSAN=1 \
+	AFL_USE_CFISAN=1))
+
+$(eval $(call AFL_BUILD,laf, \
+	AFL_LLVM_LAF_SPLIT_SWITCHES=1 \
+	AFL_LLVM_LAF_TRANSFORM_COMPARES=1 \
+	AFL_LLVM_LAF_SPLIT_COMPARES=1))
+
+$(eval $(call AFL_BUILD,cmplog, \
+	AFL_LLVM_CMPLOG=1))
+
+# ---- CLI variants ----
+
+$(eval $(call CLI_BUILD,cli-normal, -g))
+
+$(eval $(call CLI_BUILD,cli-san1, \
+	-fsanitize=address,leak,undefined))
+
+$(eval $(call CLI_BUILD,cli-san2, \
+	-fsanitize=thread))
+
+$(eval $(call CLI_BUILD,cli-san3, \
+	-fsanitize=memory,cfi -fvisibility=hidden))
+
+# ---- clean ----
+
+clean:
+	rm -rf $(BUILD)

cli.c

@@ -0,0 +1,40 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "elk.h"
+
+int main(int argc, char *argv[]) {
+  if (argc != 2) {
+    fprintf(stderr, "Usage: %s script.js\n", argv[0]);
+    return 1;
+  }
+
+  const char *filename = argv[1];
+  FILE *fp = fopen(filename, "rb");
+  if (!fp) {
+    perror("fopen");
+    return 1;
+  }
+
+  fseek(fp, 0, SEEK_END);
+  long len = ftell(fp);
+  fseek(fp, 0, SEEK_SET);
+
+  char *data = malloc(len + 1);
+  if (!data) return 1;
+
+  fread(data, 1, len, fp);
+  data[len] = 0;
+  fclose(fp);
+
+  char mem[4096];
+  struct js *js = js_create(mem, sizeof(mem));
+  js_setmaxcss(js, 2048);
+
+  jsval_t res = js_eval(js, data, len);
+  printf("%s\n", js_str(js, res));
+
+  free(data);
+  return 0;
+}

elk.c

@@ -14,11 +14,22 @@
 // Alternatively, you can license this software under a commercial
 // license, please contact us at https://cesanta.com/contact.html
 
+/*
 #if defined(__GNUC__) && !defined(JS_OPT) && !defined(ARDUINO_AVR_UNO) && \
     !defined(ARDUINO_AVR_NANO) && !defined(ARDUINO_AVR_PRO) &&            \
     !defined(__APPLE__)
 #pragma GCC optimize("O3,inline")
 #endif
+*/
+
+#if defined(__has_feature)
+#  if __has_feature(address_sanitizer)
+#    define JS_ASAN 1
+#  endif
+# else
+#  define JS_ASAN 0
+#endif
+
 
 #include <assert.h>
 #include <math.h>
@@ -176,10 +187,15 @@ static void setlwm(struct js *js) {
   jsoff_t n = 0, css = 0;
   if (js->brk < js->size) n = js->size - js->brk;
   if (js->lwm > n) js->lwm = n;
-  if ((char *) js->cstk > (char *) &n)
-    css = (jsoff_t) ((char *) js->cstk - (char *) &n);
+
+  char *cur  = (char *) &n;
+  char *base = (char *) js->cstk;
+  css = (jsoff_t) (cur > base ? cur - base : base - cur);  // abs difference
+
   if (css > js->css) js->css = css;
-}
+  // printf("LWM: %u, CSS: %u\n", (unsigned) js->lwm, (unsigned) js->css);
+  // printf("cstk: %p, stk: %p\n", js->cstk, &n);
+} 
 
 // Copy src to dst, make no overflows, 0-terminate. Return bytes copied
 static size_t cpy(char *dst, size_t dstlen, const char *src, size_t srclen) {
@@ -615,6 +631,8 @@ static jsval_t lookup(struct js *js, const char *buf, size_t len) {
 }
 
 static jsval_t resolveprop(struct js *js, jsval_t v) {
+  setlwm(js);
+  if (js->maxcss > 0 && js->css > js->maxcss) return js_mkerr(js, "C stack");
   if (vtype(v) != T_PROP) return v;
   return resolveprop(js,
                      loadval(js, (jsoff_t) (vdata(v) + sizeof(jsoff_t) * 2)));
@@ -779,8 +797,42 @@ static jsval_t do_call_op(struct js *js, jsval_t func, jsval_t args) {
 }
 
 // clang-format off
+#ifndef _MSC_VER
+__attribute__((no_sanitize("undefined")))
+#endif
+static jsval_t ubsan_op(struct js *js, uint8_t op, double a, double b, jsval_t l, jsval_t r) {
+  switch (op) {
+    //case TOK_EXP:     return tov(pow(a, b));
+    case TOK_DIV:     return tod(r) == 0 ? js_mkerr(js, "div by zero") : tov(a / b);
+    case TOK_REM:     return tod(r) == 0 ? js_mkerr(js, "rem by zero") : tov(a - b * ((double) (long) (a / b)));
+    case TOK_MUL:     return tov(a * b);
+    case TOK_PLUS:    return tov(a + b);
+    case TOK_MINUS:   return tov(a - b);
+    case TOK_XOR:     return tov((double)((long) a ^ (long) b));
+    case TOK_AND:     return tov((double)((long) a & (long) b));
+    case TOK_OR:      return tov((double)((long) a | (long) b));
+    case TOK_UMINUS:  return tov(-b);
+    case TOK_UPLUS:   return r;
+    case TOK_TILDA:   return tov((double)(~(long) b));
+    case TOK_NOT:     return mkval(T_BOOL, b == 0);
+    case TOK_SHL:     return tov((double)((long) a << (long) b));
+    case TOK_SHR:     return tov((double)((long) a >> (long) b));
+    case TOK_DOT:     return do_dot_op(js, l, r);
+    case TOK_EQ:      return mkval(T_BOOL, (long) a == (long) b);
+    case TOK_NE:      return mkval(T_BOOL, (long) a != (long) b);
+    case TOK_LT:      return mkval(T_BOOL, a < b);
+    case TOK_LE:      return mkval(T_BOOL, a <= b);
+    case TOK_GT:      return mkval(T_BOOL, a > b);
+    case TOK_GE:      return mkval(T_BOOL, a >= b);
+    default:          return js_mkerr(js, "unknown op %d", (int) op);  // LCOV_EXCL_LINE
+  }
+}
+
 static jsval_t do_op(struct js *js, uint8_t op, jsval_t lhs, jsval_t rhs) {
   if (js->flags & F_NOEXEC) return 0;
+  setlwm(js);
+  if (js->maxcss > 0 && js->css > js->maxcss) return js_mkerr(js, "C stack");
+
   jsval_t l = resolveprop(js, lhs), r = resolveprop(js, rhs);
   // printf("OP %d %d %d\n", op, vtype(lhs), vtype(r));
   setlwm(js);
@@ -806,31 +858,7 @@ static jsval_t do_op(struct js *js, uint8_t op, jsval_t lhs, jsval_t rhs) {
   if (is_unary(op) && vtype(r) != T_NUM) return js_mkerr(js, "type mismatch");
   if (!is_unary(op) && op != TOK_DOT && (vtype(l) != T_NUM || vtype(r) != T_NUM)) return js_mkerr(js, "type mismatch");
   double a = tod(l), b = tod(r);
-  switch (op) {
-    //case TOK_EXP:     return tov(pow(a, b));
-    case TOK_DIV:     return tod(r) == 0 ? js_mkerr(js, "div by zero") : tov(a / b);
-    case TOK_REM:     return tov(a - b * ((double) (long) (a / b)));
-    case TOK_MUL:     return tov(a * b);
-    case TOK_PLUS:    return tov(a + b);
-    case TOK_MINUS:   return tov(a - b);
-    case TOK_XOR:     return tov((double)((long) a ^ (long) b));
-    case TOK_AND:     return tov((double)((long) a & (long) b));
-    case TOK_OR:      return tov((double)((long) a | (long) b));
-    case TOK_UMINUS:  return tov(-b);
-    case TOK_UPLUS:   return r;
-    case TOK_TILDA:   return tov((double)(~(long) b));
-    case TOK_NOT:     return mkval(T_BOOL, b == 0);
-    case TOK_SHL:     return tov((double)((long) a << (long) b));
-    case TOK_SHR:     return tov((double)((long) a >> (long) b));
-    case TOK_DOT:     return do_dot_op(js, l, r);
-    case TOK_EQ:      return mkval(T_BOOL, (long) a == (long) b);
-    case TOK_NE:      return mkval(T_BOOL, (long) a != (long) b);
-    case TOK_LT:      return mkval(T_BOOL, a < b);
-    case TOK_LE:      return mkval(T_BOOL, a <= b);
-    case TOK_GT:      return mkval(T_BOOL, a > b);
-    case TOK_GE:      return mkval(T_BOOL, a >= b);
-    default:          return js_mkerr(js, "unknown op %d", (int) op);  // LCOV_EXCL_LINE
-  }
+  return ubsan_op(js, op, a, b, l, r);
 }  // clang-format on
 
 static jsval_t js_str_literal(struct js *js) {
@@ -1011,6 +1039,8 @@ static jsval_t js_postfix(struct js *js) {
 }
 
 static jsval_t js_unary(struct js *js) {
+  setlwm(js);
+  if (js->maxcss > 0 && js->css > js->maxcss) return js_mkerr(js, "C stack");
   if (next(js) == TOK_NOT || js->tok == TOK_TILDA || js->tok == TOK_TYPEOF ||
       js->tok == TOK_MINUS || js->tok == TOK_PLUS) {
     uint8_t t = js->tok;
@@ -1059,6 +1089,8 @@ static jsval_t js_bitwise_or(struct js *js) {
 }
 
 static jsval_t js_logical_and(struct js *js) {
+  setlwm(js);
+  if (js->maxcss > 0 && js->css > js->maxcss) return js_mkerr(js, "C stack");
   jsval_t res = js_bitwise_or(js);
   if (is_err(res)) return res;
   uint8_t flags = js->flags;
@@ -1077,6 +1109,8 @@ static jsval_t js_logical_and(struct js *js) {
 }
 
 static jsval_t js_logical_or(struct js *js) {
+  setlwm(js);
+  if (js->maxcss > 0 && js->css > js->maxcss) return js_mkerr(js, "C stack");
   jsval_t res = js_logical_and(js);
   if (is_err(res)) return res;
   uint8_t flags = js->flags;
@@ -1095,6 +1129,8 @@ static jsval_t js_logical_or(struct js *js) {
 }
 
 static jsval_t js_ternary(struct js *js) {
+  setlwm(js);
+  if (js->maxcss > 0 && js->css > js->maxcss) return js_mkerr(js, "C stack");
   jsval_t res = js_logical_or(js);
   if (next(js) == TOK_Q) {
     uint8_t flags = js->flags;
@@ -1117,6 +1153,8 @@ static jsval_t js_ternary(struct js *js) {
 }
 
 static jsval_t js_assignment(struct js *js) {
+  setlwm(js);
+  if (js->maxcss > 0 && js->css > js->maxcss) return js_mkerr(js, "C stack");
   RTL_BINOP(js_ternary, js_assignment,
             (next(js) == TOK_ASSIGN || js->tok == TOK_PLUS_ASSIGN ||
              js->tok == TOK_MINUS_ASSIGN || js->tok == TOK_MUL_ASSIGN ||
@@ -1127,6 +1165,8 @@ static jsval_t js_assignment(struct js *js) {
 }
 
 static jsval_t js_expr(struct js *js) {
+  setlwm(js);
+  if (js->maxcss > 0 && js->css > js->maxcss) return js_mkerr(js, "C stack");
   return js_assignment(js);
 }
 
@@ -1296,6 +1336,8 @@ static jsval_t js_return(struct js *js) {
 }
 
 static jsval_t js_stmt(struct js *js) {
+  setlwm(js);
+  if (js->maxcss > 0 && js->css > js->maxcss) return js_mkerr(js, "C stack");
   jsval_t res;
   // jsoff_t pos = js->pos - js->tlen;
   if (js->brk > js->gct) js_gc(js);

examples/cmdline/api.js

@@ -0,0 +1,4 @@
+({
+   add : function(a, b) { return a + b; },
+   mul : function(a, b) { return a * b; },
+})