markused: cleanup the generated c code (#25210)

cmd/tools/vast/vast.v

@@ -596,6 +596,7 @@ fn (t Tree) fn_decl(node ast.FnDecl) &Node {
 	obj.add_terse('is_variadic', t.bool_node(node.is_variadic))
 	obj.add('is_anon', t.bool_node(node.is_anon))
 	obj.add_terse('is_noreturn', t.bool_node(node.is_noreturn))
+	obj.add_terse('is_weak', t.bool_node(node.is_weak))
 	obj.add_terse('is_manualfree', t.bool_node(node.is_manualfree))
 	obj.add('is_main', t.bool_node(node.is_main))
 	obj.add('is_test', t.bool_node(node.is_test))
@@ -840,6 +841,8 @@ fn (t Tree) global_field(node ast.GlobalField) &Node {
 	obj.add_terse('typ', t.type_node(node.typ))
 	obj.add_terse('has_expr', t.bool_node(node.has_expr))
 	obj.add_terse('is_markused', t.bool_node(node.is_markused))
+	obj.add_terse('is_weak', t.bool_node(node.is_weak))
+	obj.add_terse('is_hidden', t.bool_node(node.is_hidden))
 	obj.add('comments', t.array_node_comment(node.comments))
 	obj.add('pos', t.pos(node.pos))
 	obj.add('typ_pos', t.pos(node.typ_pos))

vlib/v/ast/ast.v

@@ -446,6 +446,7 @@ pub:
 	module_pos       int = -1 // module:
 	is_union         bool
 	is_option        bool
+	is_aligned       bool
 	attrs            []Attr
 	pre_comments     []Comment
 	end_comments     []Comment
@@ -593,6 +594,7 @@ pub:
 	is_c_extern           bool
 	is_variadic           bool
 	is_anon               bool
+	is_weak               bool
 	is_noreturn           bool        // true, when @[noreturn] is used on a fn
 	is_manualfree         bool        // true, when @[manualfree] is used on a fn
 	is_main               bool        // true for `fn main()`
@@ -967,6 +969,8 @@ pub:
 	is_markused bool // an explicit `@[markused]` tag; the global will NOT be removed by `-skip-unused`
 	is_volatile bool
 	is_exported bool // an explicit `@[export]` tag; the global will NOT be removed by `-skip-unused`
+	is_weak     bool
+	is_hidden   bool
 pub mut:
 	expr     Expr
 	typ      Type

vlib/v/ast/table.v

@@ -38,6 +38,10 @@ pub mut:
 	// json             bool            // json is imported
 	comptime_calls map[string]bool // resolved name to call on comptime
 	comptime_syms  map[Type]bool   // resolved syms (generic)
+	//
+	used_attr_noreturn bool // @[noreturn]
+	used_attr_hidden   bool // @[hidden]
+	used_attr_weak     bool // @[weak]
 }
 
 @[unsafe]

vlib/v/gen/c/cgen.v

@@ -1001,6 +1001,16 @@ pub fn (mut g Gen) init() {
 		} else {
 			g.cheaders.writeln(c_headers)
 		}
+		if !g.pref.skip_unused || g.table.used_features.used_attr_weak {
+			g.cheaders.writeln(c_common_weak_attr)
+		}
+		if !g.pref.skip_unused || g.table.used_features.used_attr_hidden {
+			g.cheaders.writeln(c_common_hidden_attr)
+		}
+		if !g.pref.skip_unused || g.table.used_features.used_attr_noreturn {
+			g.cheaders.writeln(c_common_noreturn_attr)
+			g.cheaders.writeln(c_common_unreachable_attr)
+		}
 		if !g.pref.skip_unused || g.table.used_features.used_maps > 0 {
 			g.cheaders.writeln(c_wyhash_headers)
 		}

vlib/v/gen/c/cheaders.v

@@ -180,8 +180,6 @@ const c_common_macros = '
 #endif
 #endif
 
-#define OPTION_CAST(x) (x)
-
 #if defined(_WIN32) || defined(__CYGWIN__)
 	#define VV_EXP extern __declspec(dllexport)
 	#define VV_LOC static
@@ -220,7 +218,17 @@ const c_common_macros = '
 #undef __has_include
 #endif
 
+//likely and unlikely macros
+#if defined(__GNUC__) || defined(__INTEL_COMPILER) || defined(__clang__)
+	#define _likely_(x)  __builtin_expect(x,1)
+	#define _unlikely_(x)  __builtin_expect(x,0)
+#else
+	#define _likely_(x) (x)
+	#define _unlikely_(x) (x)
+#endif
+'
 
+const c_common_weak_attr = '
 #if !defined(VWEAK)
 	#define VWEAK __attribute__((weak))
 	#ifdef _MSC_VER
@@ -232,7 +240,9 @@ const c_common_macros = '
 		#define VWEAK
 	#endif
 #endif
+'
 
+const c_common_hidden_attr = '
 #if !defined(VHIDDEN)
 	#define VHIDDEN __attribute__((visibility("hidden")))
 	#ifdef _MSC_VER
@@ -244,7 +254,9 @@ const c_common_macros = '
 		#define VHIDDEN
 	#endif
 #endif
+'
 
+const c_common_noreturn_attr = '
 #if !defined(VNORETURN)
 	#if defined(__TINYC__)
 		#include <stdnoreturn.h>
@@ -259,7 +271,9 @@ const c_common_macros = '
 		#define VNORETURN
 	#endif
 #endif
+'
 
+const c_common_unreachable_attr = '
 #if !defined(VUNREACHABLE)
 	#if defined(__GNUC__) && !defined(__clang__)
 		#define V_GCC_VERSION  (__GNUC__ * 10000L + __GNUC_MINOR__ * 100L + __GNUC_PATCHLEVEL__)
@@ -276,16 +290,6 @@ const c_common_macros = '
 		#define VUNREACHABLE() do { } while (0)
 	#endif
 #endif
-
-//likely and unlikely macros
-#if defined(__GNUC__) || defined(__INTEL_COMPILER) || defined(__clang__)
-	#define _likely_(x)  __builtin_expect(x,1)
-	#define _unlikely_(x)  __builtin_expect(x,0)
-#else
-	#define _likely_(x) (x)
-	#define _unlikely_(x) (x)
-#endif
-
 '
 
 const c_unsigned_comparison_functions = '
@@ -433,8 +437,6 @@ void v_free(voidptr ptr);
 		#define _Atomic volatile
 
 		// MSVC cannot parse some things properly
-		#undef OPTION_CAST
-		#define OPTION_CAST(x)
 		#undef __NOINLINE
 		#undef __IRQHANDLER
 		#define __NOINLINE __declspec(noinline)
@@ -451,9 +453,6 @@ void v_free(voidptr ptr);
 	#endif
 #endif
 
-// g_live_info is used by live.info()
-static void* g_live_info = NULL;
-
 #if defined(__MINGW32__) || defined(__MINGW64__) || (defined(_WIN32) && defined(__TINYC__))
 	#undef PRId64
 	#undef PRIi64
@@ -711,5 +710,4 @@ static inline uint64_t wy2u0k(uint64_t r, uint64_t k){ _wymum(&r,&k); return k;
 #endif
 
 #define _IN_MAP(val, m) map_exists(m, val)
-
 '

vlib/v/gen/c/consts_and_globals.v

@@ -437,13 +437,14 @@ fn (mut g Gen) global_decl(node ast.GlobalDecl) {
 	should_init := (!g.pref.use_cache && g.pref.build_mode != .build_module)
 		|| (g.pref.build_mode == .build_module && g.module_built == node.mod)
 	mut attributes := ''
-	if node.attrs.contains('weak') {
+	first_field := node.fields[0]
+	if first_field.is_weak {
 		attributes += 'VWEAK '
 	}
-	if node.attrs.contains('hidden') {
+	if first_field.is_hidden {
 		attributes += 'VHIDDEN '
 	}
-	if node.attrs.contains('export') {
+	if first_field.is_exported {
 		attributes += 'VV_EXP '
 	}
 	if attr := node.attrs.find_first('_linker_section') {

vlib/v/gen/c/fn.v

@@ -532,9 +532,9 @@ fn (mut g Gen) gen_fn_decl(node &ast.FnDecl, skip bool) {
 	if g.pref.printfn_list.len > 0 && g.last_fn_c_name in g.pref.printfn_list {
 		println(g.out.after(fn_start_pos))
 	}
+	weak := if node.is_weak { 'VWEAK ' } else { '' }
 	for attr in node.attrs {
 		if attr.name == 'export' {
-			weak := if node.attrs.any(it.name == 'weak') { 'VWEAK ' } else { '' }
 			g.writeln('// export alias: ${attr.arg} -> ${name}')
 			g.export_funcs << attr.arg
 			export_alias := '${weak}${type_name} ${fn_attrs}${attr.arg}(${arg_str})'

vlib/v/markused/walker.v

@@ -142,6 +142,9 @@ pub fn (mut w Walker) mark_global_as_used(ckey string) {
 	}
 	w.used_globals[ckey] = true
 	gfield := w.all_globals[ckey] or { return }
+	w.table.used_features.used_attr_weak = w.table.used_features.used_attr_weak || gfield.is_weak
+	w.table.used_features.used_attr_hidden = w.table.used_features.used_attr_hidden
+		|| gfield.is_hidden || gfield.is_hidden
 	w.expr(gfield.expr)
 	if !gfield.has_expr {
 		w.mark_by_type(gfield.typ)
@@ -355,9 +358,7 @@ pub fn (mut w Walker) stmt(node_ ast.Stmt) {
 				w.mark_by_type(typ.typ)
 			}
 			w.struct_fields(node.fields)
-			if !w.uses_mem_align {
+			w.uses_mem_align = w.uses_mem_align || node.is_aligned
-				w.uses_mem_align = node.attrs.contains('aligned')
-			}
 		}
 		ast.DeferStmt {
 			w.stmts(node.stmts)
@@ -894,6 +895,9 @@ pub fn (mut w Walker) fn_decl(mut node ast.FnDecl) {
 			w.is_builtin_mod = last_is_builtin_mod
 		}
 	}
+	w.table.used_features.used_attr_weak = w.table.used_features.used_attr_weak || node.is_weak
+	w.table.used_features.used_attr_noreturn = w.table.used_features.used_attr_noreturn
+		|| node.is_noreturn
 	if node.language == .c {
 		w.mark_fn_as_used(node.fkey())
 		w.mark_fn_ret_and_params(node.return_type, node.params)
@@ -1153,9 +1157,7 @@ pub fn (mut w Walker) mark_by_sym(isym ast.TypeSymbol) {
 			}
 			if decl := w.all_structs[isym.name] {
 				w.struct_fields(decl.fields)
-				if !w.uses_mem_align {
+				w.uses_mem_align = w.uses_mem_align || decl.is_aligned
-					w.uses_mem_align = decl.attrs.contains('aligned')
-				}
 				for iface_typ in decl.implements_types {
 					w.mark_by_type(iface_typ.typ)
 				}

vlib/v/parser/fn.v

@@ -213,6 +213,7 @@ fn (mut p Parser) fn_decl() ast.FnDecl {
 	mut is_c2v_variadic := false
 	mut is_c_extern := false
 	mut is_markused := false
+	mut is_weak := false
 	mut is_expand_simple_interpolation := false
 	mut comments := []ast.Comment{}
 	fn_attrs := p.attrs
@@ -254,6 +255,9 @@ fn (mut p Parser) fn_decl() ast.FnDecl {
 			'c2v_variadic' {
 				is_c2v_variadic = true
 			}
+			'weak' {
+				is_weak = true
+			}
 			'use_new' {
 				is_ctor_new = true
 			}
@@ -706,6 +710,7 @@ run them via `v file.v` instead',
 		is_unsafe:          is_unsafe
 		is_must_use:        is_must_use
 		is_markused:        is_markused
+		is_weak:            is_weak
 		is_file_translated: p.is_translated
 		//
 		attrs:          fn_attrs

vlib/v/parser/parser.v

@@ -2599,10 +2599,14 @@ fn (mut p Parser) global_decl() ast.GlobalDecl {
 
 	mut is_markused := false
 	mut is_exported := false
+	mut is_weak := false
+	mut is_hidden := false
 	for ga in attrs {
 		match ga.name {
 			'export' { is_exported = true }
 			'markused' { is_markused = true }
+			'weak' { is_weak = true }
+			'hidden' { is_hidden = true }
 			else {}
 		}
 	}
@@ -2687,6 +2691,8 @@ fn (mut p Parser) global_decl() ast.GlobalDecl {
 			is_markused: is_markused
 			is_volatile: is_volatile
 			is_exported: is_exported
+			is_weak:     is_weak
+			is_hidden:   is_hidden
 		}
 		fields << field
 		if name !in ast.global_reserved_type_names {

vlib/v/parser/struct.v

@@ -480,6 +480,7 @@ fn (mut p Parser) struct_decl(is_anon bool) ast.StructDecl {
 		language:         language
 		is_union:         is_union
 		is_option:        is_option
+		is_aligned:       attrs.contains('aligned')
 		attrs:            if is_anon { []ast.Attr{} } else { attrs } // anon structs can't have attributes
 		pre_comments:     pre_comments
 		end_comments:     end_comments