all: enable -gc boehm by default (#14577)

vlib/builtin/builtin_d_gcboehm.c.v

@@ -3,16 +3,16 @@ module builtin
 $if dynamic_boehm ? {
 	$if windows {
 		$if tinyc {
-			#flag -I@VEXEROOT/thirdparty/libgc/include
-			#flag -L@VEXEROOT/thirdparty/tcc/lib
+			#flag -I @VEXEROOT/thirdparty/libgc/include
+			#flag -L @VEXEROOT/thirdparty/tcc/lib
 			#flag -lgc
 		} $else $if msvc {
 			#flag -DGC_BUILTIN_ATOMIC=1
-			#flag -I@VEXEROOT/thirdparty/libgc/include
+			#flag -I @VEXEROOT/thirdparty/libgc/include
 		} $else {
 			#flag -DGC_WIN32_THREADS=1
 			#flag -DGC_BUILTIN_ATOMIC=1
-			#flag -I@VEXEROOT/thirdparty/libgc
+			#flag -I @VEXEROOT/thirdparty/libgc
 			#flag @VEXEROOT/thirdparty/libgc/gc.o
 		}
 	} $else {
@@ -31,7 +31,7 @@ $if dynamic_boehm ? {
 	#flag -DGC_BUILTIN_ATOMIC=1
 	$if macos || linux {
 		#flag -DGC_PTHREADS=1
-		#flag -I@VEXEROOT/thirdparty/libgc/include
+		#flag -I @VEXEROOT/thirdparty/libgc/include
 		$if (prod && !tinyc && !debug) || !(amd64 || arm64 || i386 || arm32) {
 			// TODO: replace the architecture check with a `!$exists("@VEXEROOT/thirdparty/tcc/lib/libgc.a")` comptime call
 			#flag @VEXEROOT/thirdparty/libgc/gc.o
@@ -45,7 +45,7 @@ $if dynamic_boehm ? {
 		#flag -DBUS_PAGE_FAULT=T_PAGEFLT
 		#flag -DGC_PTHREADS=1
 		$if !tinyc {
-			#flag -I@VEXEROOT/thirdparty/libgc/include
+			#flag -I @VEXEROOT/thirdparty/libgc/include
 			#flag @VEXEROOT/thirdparty/libgc/gc.o
 		}
 		$if tinyc {
@@ -62,11 +62,11 @@ $if dynamic_boehm ? {
 		#flag -DGC_NOT_DLL=1
 		#flag -DGC_WIN32_THREADS=1
 		$if tinyc {
-			#flag -I@VEXEROOT/thirdparty/libgc/include
+			#flag -I @VEXEROOT/thirdparty/libgc/include
 			#flag @VEXEROOT/thirdparty/tcc/lib/libgc.a
 			#flag -luser32
 		} $else {
-			#flag -I@VEXEROOT/thirdparty/libgc/include
+			#flag -I @VEXEROOT/thirdparty/libgc/include
 			#flag @VEXEROOT/thirdparty/libgc/gc.o
 		}
 	} $else $if $pkgconfig('bdw-gc') {

vlib/v/builder/cc.v

@@ -93,6 +93,13 @@ fn (mut v Builder) post_process_c_compiler_output(res os.Result) {
 		}
 		return
 	}
+	if res.exit_code != 0 && v.pref.gc_mode != .no_gc && res.output.contains('libgc.a') {
+		$if windows {
+			verror(r'Your V installation may be out-of-date. Try removing `thirdparty\tcc\` and running `.\make.bat`')
+		} $else {
+			verror('Your V installation may be out-of-date. Try removing `thirdparty/tcc/` and running `make`')
+		}
+	}
 	for emsg_marker in [builder.c_verror_message_marker, 'error: include file '] {
 		if res.output.contains(emsg_marker) {
 			emessage := res.output.all_after(emsg_marker).all_before('\n').all_before('\r').trim_right('\r\n')

vlib/v/cflag/cflags.v

@@ -117,10 +117,14 @@ pub fn (cflags []CFlag) defines_others_libs() ([]string, []string, []string) {
 	mut others := []string{}
 	mut libs := []string{}
 	for copt in copts_without_obj_files {
-		if copt.starts_with('-l') || copt.ends_with('.a') {
+		if copt.starts_with('-l') {
 			libs << copt
 			continue
 		}
+		if copt.ends_with('.a') {
+			libs << '"$copt"'
+			continue
+		}
 		if copt.starts_with('-D') {
 			defines << copt
 			continue

vlib/v/pref/default.v

@@ -85,6 +85,18 @@ pub fn (mut p Preferences) fill_with_defaults() {
 	}
 	rpath_name := os.file_name(rpath)
 	p.building_v = !p.is_repl && (rpath_name == 'v' || rpath_name == 'vfmt.v')
+	if p.gc_mode == .unknown {
+		if p.backend != .c || p.building_v || p.is_bare || p.ccompiler == 'msvc' {
+			p.gc_mode = .no_gc
+			p.build_options << ['-gc', 'none']
+		} else {
+			// enable the GC by default
+			p.gc_mode = .boehm_full_opt
+			p.parse_define('gcboehm')
+			p.parse_define('gcboehm_full')
+			p.parse_define('gcboehm_opt')
+		}
+	}
 	if p.os == ._auto {
 		// No OS specifed? Use current system
 		p.os = get_host_os()

vlib/v/pref/pref.v

@@ -24,6 +24,7 @@ pub enum AssertFailureMode {
 }
 
 pub enum GarbageCollectionMode {
+	unknown
 	no_gc
 	boehm_full // full garbage collection mode
 	boehm_incr // incremental garbage colletion mode
@@ -204,7 +205,7 @@ pub mut:
 	cleanup_files       []string    // list of temporary *.tmp.c and *.tmp.c.rsp files. Cleaned up on successfull builds.
 	build_options       []string    // list of options, that should be passed down to `build-module`, if needed for -usecache
 	cache_manager       vcache.CacheManager
-	gc_mode             GarbageCollectionMode = .no_gc // .no_gc, .boehm, .boehm_leak, ...
+	gc_mode             GarbageCollectionMode = .unknown // .no_gc, .boehm, .boehm_leak, ...
 	assert_failure_mode AssertFailureMode     // whether to call abort() or print_backtrace() after an assertion failure
 	message_limit       int = 100 // the maximum amount of warnings/errors/notices that will be accumulated
 	nofloat             bool // for low level code, like kernels: replaces f32 with u32 and f64 with u64
@@ -327,9 +328,15 @@ pub fn parse_args_and_show_errors(known_external_commands []string, args []strin
 			'-gc' {
 				gc_mode := cmdline.option(current_args, '-gc', '')
 				match gc_mode {
-					'', 'none' {
+					'none' {
 						res.gc_mode = .no_gc
 					}
+					'', 'boehm' {
+						res.gc_mode = .boehm_full_opt // default mode
+						res.parse_define('gcboehm')
+						res.parse_define('gcboehm_full')
+						res.parse_define('gcboehm_opt')
+					}
 					'boehm_full' {
 						res.gc_mode = .boehm_full
 						res.parse_define('gcboehm')
@@ -352,12 +359,6 @@ pub fn parse_args_and_show_errors(known_external_commands []string, args []strin
 						res.parse_define('gcboehm_incr')
 						res.parse_define('gcboehm_opt')
 					}
-					'boehm' {
-						res.gc_mode = .boehm_full_opt // default mode
-						res.parse_define('gcboehm')
-						res.parse_define('gcboehm_full')
-						res.parse_define('gcboehm_opt')
-					}
 					'boehm_leak' {
 						res.gc_mode = .boehm_leak
 						res.parse_define('gcboehm')

vlib/v/tests/valgrind/valgrind_test.v

@@ -86,7 +86,7 @@ fn test_all() {
 		base_filename := os.file_name(test).replace('.v', '')
 		exe_filename := '$wrkdir/$base_filename'
 		full_path_to_source_file := os.join_path(vroot, test)
-		compile_cmd := '${os.quoted_path(vexe)} -o ${os.quoted_path(exe_filename)} -cg -cflags "-w" -experimental -autofree ${os.quoted_path(full_path_to_source_file)}'
+		compile_cmd := '${os.quoted_path(vexe)} -o ${os.quoted_path(exe_filename)} -cg -cflags "-w" -experimental -gc none -autofree ${os.quoted_path(full_path_to_source_file)}'
 		vprintln('compile cmd: ${bold(compile_cmd)}')
 		res := os.execute(compile_cmd)
 		if res.exit_code != 0 {

vlib/v/vcache/vcache.v

@@ -55,7 +55,14 @@ pub fn new_cache_manager(opts []string) CacheManager {
 		os.write_file(readme_file, readme_content) or { panic(err) }
 		dlog(@FN, 'created readme_file:\n    $readme_file')
 	}
-	original_vopts := opts.join('|')
+	mut deduped_opts := map[string]bool{}
+	for o in opts {
+		deduped_opts[o] = true
+	}
+	deduped_opts_keys := deduped_opts.keys().filter(it != '' && !it.starts_with("['gcboehm', "))
+	// TODO: do not filter the gcboehm options here, instead just start `v build-module vlib/builtin` without the -d gcboehm etc.
+	// Note: the current approach of filtering the gcboehm keys may interfere with (potential) other gc modes.
+	original_vopts := deduped_opts_keys.join('|')
 	return CacheManager{
 		basepath: vcache_basepath
 		vopts: original_vopts