Boehm-GC: fix global `const` handling (#9477)

* define global `__v_inside_init`

* unset `__v_inside_init` after `_vinit()`

* define `C.GC_MALLOC_UNCOLLECTABLE()`

* allocate uncollectable memory during `_vinit()`

* ci: run test cases with V copiler that uses GC-Boehm itself

* wrap `__v_inside_init` access into `#ifdef _VGCBOEHM`

.github/workflows/ci.yml

@@ -129,7 +129,9 @@ jobs:
           thirdparty/tcc/tcc.exe -version
           ./v -cg -o v cmd/v # Make sure vtcc can build itself twice
       - name: v self compilation with -gc boehm
-        run: ./v -gc boehm -o v2 cmd/v && ./v2 -gc boehm -o v3 cmd/v && ./v3 -gc boehm -o v4 cmd/v
+        run: |
+          ./v -gc boehm -o v2 cmd/v && ./v2 -gc boehm -o v3 cmd/v && ./v3 -gc boehm -o v4 cmd/v
+          mv v4 v
       - name: v doctor
         run: |
           ./v doctor
@@ -137,8 +139,7 @@ jobs:
         run: |
           ./v -gc boehm cmd/tools/test_if_v_test_system_works.v
           ./cmd/tools/test_if_v_test_system_works
-      - name: Self tests with `-gc boehm`
-        ## The test cases are run with non-gc `v` for now
+      - name: Self tests with `-gc boehm` with V compiler using Boehm-GC itself
         run: ./v -gc boehm -silent test-self
       - name: Test leak detector
         run: |

vlib/builtin/builtin.c.v

@@ -189,7 +189,13 @@ pub fn malloc(n int) byteptr {
 		nr_mallocs++
 	} $else {
 		$if gcboehm ? {
-			res = unsafe { C.GC_MALLOC(n) }
+			unsafe {
+				if C.__v_inside_init == 0 {
+					res = C.GC_MALLOC(n)
+				} else {
+					res = C.GC_MALLOC_UNCOLLECTABLE(n)
+				}
+			}
 		} $else {
 			res = unsafe { C.malloc(n) }
 		}
@@ -282,16 +288,6 @@ pub fn realloc_data(old_data byteptr, old_size int, new_size int) byteptr {
 	return nptr
 }
 
-// v_calloc dynamically allocates a zeroed `n` bytes block of memory on the heap.
-// v_calloc returns a `byteptr` pointing to the memory address of the allocated space.
-pub fn v_calloc(n int) byteptr {
-	$if gcboehm ? {
-		return C.GC_MALLOC(n)
-	} $else {
-		return C.calloc(1, n)
-	}
-}
-
 // vcalloc dynamically allocates a zeroed `n` bytes block of memory on the heap.
 // vcalloc returns a `byteptr` pointing to the memory address of the allocated space.
 // Unlike `v_calloc` vcalloc checks for negative values given in `n`.
@@ -302,7 +298,11 @@ pub fn vcalloc(n int) byteptr {
 		return byteptr(0)
 	}
 	$if gcboehm ? {
-		return C.GC_MALLOC(n)
+		return if C.__v_inside_init == 0 {
+			byteptr(C.GC_MALLOC(n))
+		} else {
+			byteptr(C.GC_MALLOC_UNCOLLECTABLE(n))
+		}
 	} $else {
 		return C.calloc(1, n)
 	}

vlib/builtin/builtin_d_gcboehm.v

@@ -22,6 +22,8 @@ $if gcboehm_leak ? {
 // compiled with `-gc boehm` or `-gc boehm_leak`.
 fn C.GC_MALLOC(n size_t) voidptr
 
+fn C.GC_MALLOC_UNCOLLECTABLE(n size_t) voidptr
+
 fn C.GC_REALLOC(ptr voidptr, n size_t) voidptr
 
 fn C.GC_FREE(ptr voidptr)

vlib/builtin/builtin_notd_gcboehm.v

@@ -6,6 +6,8 @@ module builtin
 
 fn C.GC_MALLOC(n size_t) voidptr
 
+fn C.GC_MALLOC_UNCOLLECTABLE(n size_t) voidptr
+
 fn C.GC_REALLOC(ptr voidptr, n size_t) voidptr
 
 fn C.GC_FREE(ptr voidptr)

vlib/v/gen/c/cheaders.v

@@ -335,6 +335,9 @@ static inline bool _us64_lt(uint64_t a, int64_t b) { return a < INT64_MAX && (in
 #endif
 
 //================================== GLOBALS =================================*/
+#if defined(_VGCBOEHM)
+	int __v_inside_init = 1;
+#endif
 //byte g_str_buf[1024];
 byte* g_str_buf;
 int load_so(byteptr);

vlib/v/gen/c/cmain.v

@@ -76,6 +76,11 @@ fn (mut g Gen) gen_c_main_header() {
 		g.writeln('#endif')
 	}
 	g.writeln('\t_vinit(___argc, (voidptr)___argv);')
+	if g.pref.gc_mode in [.boehm, .boehm_leak] {
+		g.writeln('#if defined(_VGCBOEHM)')
+		g.writeln('\t__v_inside_init = 0;')
+		g.writeln('#endif')
+	}
 	if g.pref.is_prof {
 		g.writeln('')
 		g.writeln('\tatexit(vprint_profile_stats);')
@@ -167,6 +172,11 @@ pub fn (mut g Gen) gen_c_main_for_tests() {
 		g.writeln('#endif')
 	}
 	g.writeln('\t_vinit(___argc, (voidptr)___argv);')
+	if g.pref.gc_mode in [.boehm, .boehm_leak] {
+		g.writeln('#if defined(_VGCBOEHM)')
+		g.writeln('\t__v_inside_init = 0;')
+		g.writeln('#endif')
+	}
 	all_tfuncs := g.get_all_test_function_names()
 	if g.pref.is_stats {
 		g.writeln('\tmain__BenchedTests bt = main__start_testing($all_tfuncs.len, _SLIT("$g.pref.path"));')