Make Windows use wWinMain always. Support /SUBSYSTEM:WINDOWS

lib/std/core/private/main_stub.c3

@@ -0,0 +1,156 @@
+module std::core::main_stub;
+
+private macro usz _strlen(ptr)
+{
+	usz len = 0;
+	while (ptr[len]) len++;
+	return len;
+}
+
+macro int @main_to_err_main(#m, int, char**) => catch(#m()) ? 1 : 0;
+macro int @main_to_int_main(#m, int, char**) => #m();
+macro int @main_to_void_main(#m, int, char**)
+{
+	#m();
+	return 0;
+}
+
+private macro String[] args_to_strings(int argc, char** argv)
+{
+	String *list = malloc(String.sizeof * argc);
+	for (int i = 0; i < argc; i++)
+	{
+		char* arg = argv[i];
+		usz len = 0;
+		list[i] = arg[:_strlen(arg)];
+	}
+	return list[:argc];
+}
+
+
+macro int @main_to_err_main_args(#m, int argc, char** argv)
+{
+	String[] list = args_to_strings(argc, argv);
+	defer free(list.ptr);
+	return catch(#m(list)) ? 1 : 0;
+}
+
+macro int @main_to_int_main_args(#m, int argc, char** argv)
+{
+	String[] list = args_to_strings(argc, argv);
+	defer free(list.ptr);
+	return #m(list);
+}
+
+macro int @main_to_void_main_args(#m, int argc, char** argv)
+{
+	String[] list = args_to_strings(argc, argv);
+	defer free(list.ptr);
+	#m(list);
+	return 0;
+}
+
+$if (env::OS_TYPE == OsType.WIN32):
+
+extern fn Char16** _win_command_line_to_argv_w(ushort* cmd_line, int* argc_ptr) @extname("CommandLineToArgvW");
+
+private macro String[] win_command_line_to_strings(ushort* cmd_line)
+{
+	int argc;
+	Char16** argv = _win_command_line_to_argv_w(cmd_line, &argc);
+	return wargs_strings(argc, argv);
+}
+
+private macro String[] wargs_strings(int argc, Char16** argv)
+{
+	String *list = malloc(String.sizeof * argc);
+	for (int i = 0; i < argc; i++)
+	{
+		Char16* arg = argv[i];
+		Char16[] argstring = arg[:_strlen(arg)];
+		list[i] = str::utf16to8(argstring) ?? str::copy("?");
+	}
+	return list[:argc];
+}
+
+private macro void release_wargs(String[] list)
+{
+	foreach (s : list) free(s.ptr);
+	free(list.ptr);
+}
+
+macro int @win_to_err_main_noargs(#m, void* handle, Char16* cmd_line, int show_cmd) => catch(#m()) ? 1 : 0;
+macro int @win_to_int_main_noargs(#m, void* handle, Char16* cmd_line, int show_cmd) => #m();
+macro int @win_to_void_main_noargs(#m, void* handle, Char16* cmd_line, int show_cmd)
+{
+	#m();
+	return 0;
+}
+
+macro int @win_to_err_main_args(#m, void* handle, Char16* cmd_line, int show_cmd)
+{
+	String[] args = win_command_line_to_strings(cmd_line);
+	defer release_wargs(args);
+    return catch(#m(args)) ? 1 : 0;
+}
+
+macro int @win_to_int_main_args(#m, void* handle, Char16* cmd_line, int show_cmd)
+{
+	String[] args = win_command_line_to_strings(cmd_line);
+	defer release_wargs(args);
+    return #m(args);
+}
+
+macro int @win_to_void_main_args(#m, void* handle, Char16* cmd_line, int show_cmd)
+{
+	String[] args = win_command_line_to_strings(cmd_line);
+	defer release_wargs(args);
+	#m(args);
+	return 0;
+}
+
+macro int @win_to_err_main(#m, void* handle, Char16* cmd_line, int show_cmd)
+{
+	String[] args = win_command_line_to_strings(cmd_line);
+	defer release_wargs(args);
+    return catch(#m(handle, args, show_cmd)) ? 1 : 0;
+}
+
+macro int @win_to_int_main(#m, void* handle, Char16* cmd_line, int show_cmd)
+{
+	String[] args = win_command_line_to_strings(cmd_line);
+	defer release_wargs(args);
+    return #m(handle, args, show_cmd);
+}
+
+macro int @win_to_void_main(#m, void* handle, Char16* cmd_line, int show_cmd)
+{
+	String[] args = win_command_line_to_strings(cmd_line);
+	defer release_wargs(args);
+	#m(handle, args, show_cmd);
+	return 0;
+}
+
+macro int @wmain_to_err_main_args(#m, int argc, Char16** argv)
+{
+	String[] args = wargs_strings(argc, argv);
+	defer release_wargs(args);
+    return catch(#m(args)) ? 1 : 0;
+}
+
+macro int @wmain_to_int_main_args(#m, int argc, Char16** argv)
+{
+	String[] args = wargs_strings(argc, argv);
+	defer release_wargs(args);
+    return #m(args);
+}
+
+macro int @wmain_to_void_main_args(#m, int argc, Char16** argv)
+{
+	String[] args = wargs_strings(argc, argv);
+	defer release_wargs(args);
+	#m(args);
+	return 0;
+}
+
+$endif;

lib/std/core/runtime.c3

@@ -1,7 +1,7 @@
 // Copyright (c) 2021 Christoffer Lerno. All rights reserved.
 // Use of this source code is governed by the MIT license
 // a copy of which can be found in the LICENSE_STDLIB file.
-module std::runtime;
+module std::core::runtime;
 
 struct VirtualAny
 {

resources/examples/fasta.c3

@@ -87,7 +87,7 @@ fn void random_fasta(String symb, double[] probability, int n)
 	if (i % LINELEN != 0) io::putchar('\n');
 }
 
-fn void main(int argc, char **argv)
+fn int main(int argc, char **argv)
 {
 	int n = 1000;
 	if (argc > 1) n = libc::atoi(argv[1]);
@@ -101,4 +101,5 @@ fn void main(int argc, char **argv)
 	io::printf(">THREE Homo sapiens frequency\n");
 	random_fasta(homosapiens, homosapiens_p, n * 5);
 
+	return 0;
 }

resources/examples/mandelbrot.c3

@@ -4,7 +4,7 @@ extern fn int atoi(char *s);
 extern fn int printf(char *s, ...);
 extern fn void putchar(int c);
 
-fn void main(int argc, char **argv)
+fn int main(int argc, char **argv)
 {
 	int w = atoi(argv[1]);
 	int h = w;
@@ -55,4 +55,5 @@ fn void main(int argc, char **argv)
 			}
 		}
 	}
+	return 0;
 }

src/build/build_options.c

@@ -129,6 +129,7 @@ static void usage(void)
 	OUTPUT("  -z <argument>             - Send the <argument> as a parameter to the linker.");
 	OUTPUT("  --forcelinker             - Force built in linker usage when doing non-cross linking.");
 	OUTPUT("");
+	OUTPUT("  --gui                     - Build a 'gui' variant of the executable (e.g. '/SUBSYSTEM:WINDOWS' on Win32).");
 	OUTPUT("  --reloc=<option>          - Relocation model: none, pic, PIC, pie, PIE.");
 	OUTPUT("  --x86vec=<option>         - Set max level of vector instructions: none, native, mmx, sse, avx, avx512.");
 	OUTPUT("  --memory-env=<option>     - Set the memory environment: normal, small, tiny, none.");
@@ -532,6 +533,11 @@ static void parse_option(BuildOptions *options)
 				options->symtab_size = next_highest_power_of_2(symtab);
 				return;
 			}
+			if (match_longopt("gui"))
+			{
+				options->gui = true;
+				return;
+			}
 			if (match_longopt("forcelinker"))
 			{
 				options->force_linker = true;

src/build/build_options.h

@@ -290,6 +290,7 @@ typedef struct BuildOptions_
 	bool no_stdlib;
 	bool no_entry;
 	bool no_libc;
+	bool gui;
 	bool force_linker;
 	bool read_stdin;
 	bool print_output;
@@ -374,6 +375,7 @@ typedef struct
 	bool emit_asm;
 	bool no_stdlib;
 	bool no_libc;
+	bool gui;
 	bool emit_object_files;
 	bool force_linker;
 	bool benchmarking;

src/build/builder.c

@@ -233,6 +233,7 @@ static void update_build_target_from_options(BuildTarget *target, BuildOptions *
 	target->panicfn = options->panicfn;
 	target->benchmarking = options->benchmarking;
 	target->testing = options->testing;
+	if (options->gui) target->gui = true;
 	if (options->macos.sdk) target->macos.sdk = options->macos.sdk;
 	if (options->win.sdk) target->win.sdk = options->win.sdk;
 	if (options->macos.min_version) target->macos.min_version = options->macos.min_version;

src/build/project.c

@@ -362,6 +362,9 @@ static void load_into_build_target(JSONObject *json, const char *type, BuildTarg
 	// nolibc
 	target->no_libc = get_valid_bool(json, "nolibc", type, target->no_libc);
 
+	// gui
+	target->gui = get_valid_bool(json, "gui", type, target->gui);
+
 	// no-entry
 	target->no_entry = get_valid_bool(json, "no-entry", type, target->no_entry);
 

src/compiler/compiler_internal.h

@@ -1902,6 +1902,8 @@ extern const char *kw_pure;
 extern const char *kw_return;
 extern const char *kw_std;
 extern const char *kw_type;
+extern const char *kw_winmain;
+extern const char *kw_wmain;
 extern ArchOsTarget default_target;
 
 ARENA_DEF(chars, char)

src/compiler/enums.h

@@ -992,3 +992,13 @@ typedef enum
 	COND_TYPE_UNWRAP,
 	COND_TYPE_EVALTYPE_VALUE,
 } CondType;
+
+
+typedef enum
+{
+	MAIN_TYPE_ERROR,
+	MAIN_TYPE_RAW,
+	MAIN_TYPE_NO_ARGS,
+	MAIN_TYPE_ARGS,
+	MAIN_TYPE_WIN,
+} MainType;

src/compiler/linker.c

@@ -77,6 +77,7 @@ static const char *string_esc(const char *str)
 }
 static void linker_setup_windows(const char ***args_ref, LinkerType linker_type)
 {
+	add_arg(active_target.gui ? "/SUBSYSTEM:WINDOWS" : "/SUBSYSTEM:CONSOLE");
 	if (linker_type == LINKER_CC) return;
 	//add_arg("/MACHINE:X64");
 	bool is_debug = false;
@@ -145,6 +146,7 @@ static void linker_setup_windows(const char ***args_ref, LinkerType linker_type)
 	add_arg("kernel32.lib");
 	add_arg("ntdll.lib");
 	add_arg("user32.lib");
+	add_arg("shell32.lib");
 	add_arg("legacy_stdio_definitions.lib");
 
 	if (active_target.win.crt_linking == WIN_CRT_STATIC)

src/compiler/sema_decls.c

@@ -1881,6 +1881,285 @@ ADDED:;
 	return true;
 }
 
+static inline MainType sema_find_main_type(SemaContext *context, Signature *sig)
+{
+	Decl **params = sig->params;
+	unsigned param_count = vec_size(params);
+	bool is_win32 = platform_target.os == OS_TYPE_WIN32;
+	Type *arg_type, *arg_type2;
+	switch (param_count)
+	{
+		case 0:
+			return MAIN_TYPE_NO_ARGS;
+			break;
+		case 1:
+			arg_type = type_flatten_distinct(params[0]->type);
+			if (arg_type == type_get_subarray(type_get_subarray(type_char))) return MAIN_TYPE_ARGS;
+			SEMA_ERROR(params[0], "Expected a parameter of type 'String[]'.");
+			return MAIN_TYPE_ERROR;
+		case 2:
+			arg_type = type_flatten_distinct(params[0]->type);
+			arg_type2 = type_flatten_distinct(params[1]->type);
+			if (arg_type != type_cint)
+			{
+				SEMA_ERROR(params[0],
+				           "Expected a parameter of type %s for a C-style main.",
+				           type_quoted_error_string(type_cint));
+				return MAIN_TYPE_ERROR;
+			}
+			if (arg_type2 != type_get_ptr(type_get_ptr(type_char)))
+			{
+				SEMA_ERROR(params[1], "Expected a parameter of type 'char**' for a C-style main.");
+				return MAIN_TYPE_ERROR;
+			}
+			return MAIN_TYPE_RAW;
+		case 3:
+			if (!is_win32) break;
+			arg_type = type_flatten_distinct(params[0]->type);
+			arg_type2 = type_flatten_distinct(params[1]->type);
+			if (arg_type != type_voidptr)
+			{
+				SEMA_ERROR(params[0], "Expected a parameter of type 'void*' (HINSTANCE)");
+				return MAIN_TYPE_ERROR;
+			}
+			if (arg_type2 != type_get_subarray(type_get_subarray(type_char)))
+			{
+				SEMA_ERROR(params[1], "Expected a parameter of type 'String[]'.");
+				return MAIN_TYPE_ERROR;
+			}
+			if (type_flatten_distinct(params[2]->type) != type_cint)
+			{
+				SEMA_ERROR(params[2], "Expected a parameter of type %s for the 'showCmd' parameter.",
+				           type_quoted_error_string(type_cint));
+				return MAIN_TYPE_ERROR;
+			}
+			return MAIN_TYPE_WIN;
+		default:
+			break;
+	}
+	SEMA_ERROR(params[0], is_win32
+		? "Expected zero, 1 or 3 parameters for main."
+		: "Expected zero or 1 parameters for main.");
+	return MAIN_TYPE_ERROR;
+
+}
+
+static inline Decl *sema_create_synthetic_main(SemaContext *context, Decl *decl, MainType main, bool int_return, bool err_return)
+{
+	Decl *function = decl_new(DECL_FUNC, NULL, decl->span, VISIBLE_EXTERN);
+	function->name = kw_mainstub;
+	function->unit = decl->unit;
+	function->extname = kw_main;
+	function->has_extname = true;
+	function->func_decl.signature.rtype = type_infoid(type_info_new_base(type_cint, decl->span));
+	function->func_decl.signature.vararg_index = 2;
+	Decl *param1 = decl_new_generated_var(type_cint, VARDECL_PARAM, decl->span);
+	Decl *param2 = decl_new_generated_var(type_get_ptr(type_get_ptr(type_char)), VARDECL_PARAM, decl->span);
+	Decl **main_params = NULL;
+	vec_add(main_params, param1);
+	vec_add(main_params, param2);
+	function->func_decl.signature.params = main_params;
+	Ast *body = new_ast(AST_COMPOUND_STMT, decl->span);
+	AstId *next = &body->compound_stmt.first_stmt;
+	Ast *ret_stmt = new_ast(AST_RETURN_STMT, decl->span);
+	int type = int_return ? 1 : (err_return ? 2 : 0);
+	const char *main_invoker;
+	switch (main)
+	{
+		case MAIN_TYPE_ARGS:
+			switch (type)
+			{
+				case 0 : main_invoker = "@main_to_void_main_args"; goto NEXT;
+				case 1 : main_invoker = "@main_to_int_main_args"; goto NEXT;
+				case 2 : main_invoker = "@main_to_err_main_args"; goto NEXT;
+				default: UNREACHABLE
+			}
+		case MAIN_TYPE_NO_ARGS:
+			switch (type)
+			{
+				case 0 : main_invoker = "@main_to_void_main"; goto NEXT;
+				case 1 : main_invoker = "@main_to_int_main"; goto NEXT;
+				case 2 : main_invoker = "@main_to_err_main"; goto NEXT;
+				default: UNREACHABLE
+			}
+		default:
+			UNREACHABLE;
+	}
+NEXT:;
+	const char *kw_main_invoker = symtab_preset(main_invoker, TOKEN_AT_IDENT);
+	Decl *d = sema_find_symbol(context, kw_main_invoker);
+	if (!d)
+	{
+		SEMA_ERROR(decl, "Missing main forwarding function '%s'.", kw_main_invoker);
+		return poisoned_decl;
+	}
+	Expr *invoker = expr_new(EXPR_IDENTIFIER, decl->span);
+	invoker->identifier_expr.decl = d;
+	invoker->resolve_status = RESOLVE_DONE;
+	invoker->type = decl->type;
+	Expr *call = expr_new(EXPR_CALL, decl->span);
+	Expr *fn_ref = expr_variable(decl);
+	vec_add(call->call_expr.arguments, fn_ref);
+	vec_add(call->call_expr.arguments, expr_variable(param1));
+	vec_add(call->call_expr.arguments, expr_variable(param2));
+	call->call_expr.function = exprid(invoker);
+	param1->resolve_status = RESOLVE_NOT_DONE;
+	param2->resolve_status = RESOLVE_NOT_DONE;
+	ast_append(&next, ret_stmt);
+	ret_stmt->return_stmt.expr = call;
+	function->func_decl.body = astid(body);
+	function->is_synthetic = true;
+	return function;
+}
+
+static inline Decl *sema_create_synthetic_wmain(SemaContext *context, Decl *decl, MainType main, bool int_return, bool err_return)
+{
+	Decl *function = decl_new(DECL_FUNC, NULL, decl->span, VISIBLE_EXTERN);
+	function->name = kw_mainstub;
+	function->unit = decl->unit;
+	function->extname = kw_wmain;
+	function->has_extname = true;
+	function->func_decl.signature.rtype = type_infoid(type_info_new_base(type_cint, decl->span));
+	function->func_decl.signature.vararg_index = 2;
+	Decl *param1 = decl_new_generated_var(type_cint, VARDECL_PARAM, decl->span);
+	Decl *param2 = decl_new_generated_var(type_get_ptr(type_get_ptr(type_ushort)), VARDECL_PARAM, decl->span);
+	Decl **main_params = NULL;
+	vec_add(main_params, param1);
+	vec_add(main_params, param2);
+	function->func_decl.signature.params = main_params;
+	Ast *body = new_ast(AST_COMPOUND_STMT, decl->span);
+	AstId *next = &body->compound_stmt.first_stmt;
+	Ast *ret_stmt = new_ast(AST_RETURN_STMT, decl->span);
+	int type = int_return ? 1 : (err_return ? 2 : 0);
+	const char *main_invoker;
+	switch (main)
+	{
+		case MAIN_TYPE_ARGS:
+			switch (type)
+			{
+				case 0 : main_invoker = "@wmain_to_void_main_args"; goto NEXT;
+				case 1 : main_invoker = "@wmain_to_int_main_args"; goto NEXT;
+				case 2 : main_invoker = "@wmain_to_err_main_args"; goto NEXT;
+				default: UNREACHABLE
+			}
+		case MAIN_TYPE_NO_ARGS:
+			switch (type)
+			{
+				case 0 : main_invoker = "@main_to_void_main"; goto NEXT;
+				case 1 : main_invoker = "@main_to_int_main"; goto NEXT;
+				case 2 : main_invoker = "@main_to_err_main"; goto NEXT;
+				default: UNREACHABLE
+			}
+		default:
+			UNREACHABLE;
+	}
+	NEXT:;
+	const char *kw_main_invoker = symtab_preset(main_invoker, TOKEN_AT_IDENT);
+	Decl *d = sema_find_symbol(context, kw_main_invoker);
+	if (!d)
+	{
+		SEMA_ERROR(decl, "Missing main forwarding function '%s'.", kw_main_invoker);
+		return poisoned_decl;
+	}
+	Expr *invoker = expr_new(EXPR_IDENTIFIER, decl->span);
+	invoker->identifier_expr.decl = d;
+	invoker->resolve_status = RESOLVE_DONE;
+	invoker->type = decl->type;
+	Expr *call = expr_new(EXPR_CALL, decl->span);
+	Expr *fn_ref = expr_variable(decl);
+	vec_add(call->call_expr.arguments, fn_ref);
+	vec_add(call->call_expr.arguments, expr_variable(param1));
+	vec_add(call->call_expr.arguments, expr_variable(param2));
+	call->call_expr.function = exprid(invoker);
+	param1->resolve_status = RESOLVE_NOT_DONE;
+	param2->resolve_status = RESOLVE_NOT_DONE;
+	ast_append(&next, ret_stmt);
+	ret_stmt->return_stmt.expr = call;
+	function->func_decl.body = astid(body);
+	function->is_synthetic = true;
+	return function;
+}
+
+static inline Decl *sema_create_synthetic_win_main(SemaContext *context, Decl *decl, MainType main, bool int_return, bool err_return)
+{
+	Decl *function = decl_new(DECL_FUNC, NULL, decl->span, VISIBLE_EXTERN);
+	function->name = kw_mainstub;
+	function->unit = decl->unit;
+	function->extname = kw_winmain;
+	function->has_extname = true;
+	function->func_decl.signature.rtype = type_infoid(type_info_new_base(type_cint, decl->span));
+	function->func_decl.signature.vararg_index = 3;
+	Decl *param1 = decl_new_generated_var(type_voidptr, VARDECL_PARAM, decl->span);
+	Decl *param2 = decl_new_generated_var(type_get_ptr(type_ushort), VARDECL_PARAM, decl->span);
+	Decl *param3 = decl_new_generated_var(type_cint, VARDECL_PARAM, decl->span);
+	Decl **main_params = NULL;
+	vec_add(main_params, param1);
+	vec_add(main_params, param2);
+	vec_add(main_params, param3);
+	function->func_decl.signature.params = main_params;
+	Ast *body = new_ast(AST_COMPOUND_STMT, decl->span);
+	AstId *next = &body->compound_stmt.first_stmt;
+	Ast *ret_stmt = new_ast(AST_RETURN_STMT, decl->span);
+	int type = int_return ? 1 : (err_return ? 2 : 0);
+	const char *main_invoker;
+	switch (main)
+	{
+		case MAIN_TYPE_ARGS:
+			switch (type)
+			{
+				case 0 : main_invoker = "@win_to_void_main_args"; goto NEXT;
+				case 1 : main_invoker = "@win_to_int_main_args"; goto NEXT;
+				case 2 : main_invoker = "@win_to_err_main_args"; goto NEXT;
+				default: UNREACHABLE
+			}
+		case MAIN_TYPE_NO_ARGS:
+			switch (type)
+			{
+				case 0 : main_invoker = "@win_to_void_main_noargs"; goto NEXT;
+				case 1 : main_invoker = "@win_to_int_main_noargs"; goto NEXT;
+				case 2 : main_invoker = "@win_to_err_main_noargs"; goto NEXT;
+				default: UNREACHABLE
+			}
+		case MAIN_TYPE_WIN:
+			switch (type)
+			{
+				case 0 : main_invoker = "@win_to_void_main"; goto NEXT;
+				case 1 : main_invoker = "@win_to_int_main"; goto NEXT;
+				case 2 : main_invoker = "@win_to_err_main"; goto NEXT;
+				default: UNREACHABLE
+			}
+		default:
+			UNREACHABLE;
+	}
+NEXT:;
+	const char *kw_main_invoker = symtab_preset(main_invoker, TOKEN_AT_IDENT);
+	Decl *d = sema_find_symbol(context, kw_main_invoker);
+	if (!d)
+	{
+		SEMA_ERROR(decl, "Missing main forwarding macro '%s'.", kw_main_invoker);
+		return poisoned_decl;
+	}
+	Expr *invoker = expr_new(EXPR_IDENTIFIER, decl->span);
+	invoker->identifier_expr.decl = d;
+	invoker->resolve_status = RESOLVE_DONE;
+	invoker->type = decl->type;
+	Expr *call = expr_new(EXPR_CALL, decl->span);
+	Expr *fn_ref = expr_variable(decl);
+	vec_add(call->call_expr.arguments, fn_ref);
+	vec_add(call->call_expr.arguments, expr_variable(param1));
+	vec_add(call->call_expr.arguments, expr_variable(param2));
+	vec_add(call->call_expr.arguments, expr_variable(param3));
+	call->call_expr.function = exprid(invoker);
+	param1->resolve_status = RESOLVE_NOT_DONE;
+	param2->resolve_status = RESOLVE_NOT_DONE;
+	param3->resolve_status = RESOLVE_NOT_DONE;
+	ast_append(&next, ret_stmt);
+	ret_stmt->return_stmt.expr = call;
+	function->func_decl.body = astid(body);
+	function->is_synthetic = true;
+	return function;
+}
+
 static inline bool sema_analyse_main_function(SemaContext *context, Decl *decl)
 {
 	assert(decl != context->unit->main_function);
@@ -1914,40 +2193,8 @@ static inline bool sema_analyse_main_function(SemaContext *context, Decl *decl)
 		return false;
 	}
 	// At this point the style is either MAIN_INT_VOID, MAIN_VOID_VOID or MAIN_ERR_VOID
-	Decl **params = signature->params;
-	unsigned param_count = vec_size(params);
-	bool subarray_param = false;
-	bool cparam = false;
-	switch (param_count)
-	{
-		case 0:
-			// This is the default style already set
-			break;
-		case 1:
-			if (type_flatten_distinct(params[0]->type) != type_get_subarray(type_get_subarray(type_char)))
-			{
-				SEMA_ERROR(params[0], "Expected a parameter of type 'char[][]'");
-				return false;
-			}
-			subarray_param = true;
-			break;
-		case 2:
-			if (type_flatten_distinct(params[0]->type) != type_cint)
-			{
-				SEMA_ERROR(params[0], "Expected a parameter of type %s for a C-style main.", type_quoted_error_string(type_cint));
-				return false;
-			}
-			if (type_flatten_distinct(params[1]->type) != type_get_ptr(type_get_ptr(type_char)))
-			{
-				SEMA_ERROR(params[1], "Expected a parameter of type 'char**' for a C-style main.");
-				return false;
-			}
-			cparam = true;
-			break;
-		default:
-			SEMA_ERROR(params[0], "Expected zero, 1 or 2 parameters for main.");
-			return false;
-	}
+	MainType type = sema_find_main_type(context, signature);
+	if (type == MAIN_TYPE_ERROR) return false;
 	if (active_target.type == TARGET_TYPE_TEST) return true;
 	Decl *function;
 	if (active_target.no_entry)
@@ -1955,73 +2202,29 @@ static inline bool sema_analyse_main_function(SemaContext *context, Decl *decl)
 		function = decl;
 		goto REGISTER_MAIN;
 	}
-	if (!subarray_param && is_int_return)
+	if (type == MAIN_TYPE_RAW && !is_int_return)
+	{
+		SEMA_ERROR(rtype_info, "Int return is required for C style main.");
+		return false;
+	}
+	if ((type == MAIN_TYPE_RAW || type == MAIN_TYPE_NO_ARGS) && is_int_return && !active_target.gui)
 	{
 		// Int return is pass-through at the moment.
 		decl->visibility = VISIBLE_EXTERN;
 		function = decl;
 		goto REGISTER_MAIN;
 	}
-	function = decl_new(DECL_FUNC, NULL, decl->span, VISIBLE_EXTERN);
-	function->name = kw_mainstub;
-	function->unit = decl->unit;
-	function->extname = kw_main;
-	function->has_extname = true;
-	function->func_decl.signature.rtype = type_infoid(type_info_new_base(type_cint, decl->span));
-	function->func_decl.signature.vararg_index = 2;
-	Decl *param1 = decl_new_generated_var(type_cint, VARDECL_PARAM, decl->span);
-	Decl *param2 = decl_new_generated_var(type_get_ptr(type_get_ptr(type_char)), VARDECL_PARAM, decl->span);
-	Decl **main_params = NULL;
-	vec_add(main_params, param1);
-	vec_add(main_params, param2);
-	function->func_decl.signature.params = main_params;
-	Ast *body = new_ast(AST_COMPOUND_STMT, decl->span);
-	AstId *next = &body->compound_stmt.first_stmt;
-	Ast *ret_stmt = new_ast(AST_RETURN_STMT, decl->span);
-	Expr *call = expr_new(EXPR_CALL, decl->span);
-	call->call_expr.function = exprid(expr_variable(decl));
-	if (subarray_param)
+	if (platform_target.os == OS_TYPE_WIN32)
 	{
-		Expr *subarray = expr_new(EXPR_ARGV_TO_SUBARRAY, decl->span);
-		subarray->argv_expr.argc = param1;
-		subarray->argv_expr.argv = param2;
-		vec_add(call->call_expr.arguments, subarray);
-	}
-	else if (cparam)
-	{
-		vec_add(call->call_expr.arguments, expr_variable(param1));
-		vec_add(call->call_expr.arguments, expr_variable(param2));
-	}
-	// Unresolve them or the params cannot be resolved later.
-	param1->resolve_status = RESOLVE_NOT_DONE;
-	param2->resolve_status = RESOLVE_NOT_DONE;
-	if (is_int_return)
-	{
-		ret_stmt->return_stmt.expr = call;
-	}
-	else if (is_err_return)
-	{
-		Expr *try_expr = expr_new(EXPR_TRY, decl->span);
-		try_expr->inner_expr = call;
-		Expr *not_expr = expr_new(EXPR_UNARY, decl->span);
-		not_expr->unary_expr.expr = try_expr;
-		not_expr->unary_expr.operator = UNARYOP_NOT;
-		Expr *cast_expr = expr_new(EXPR_CAST, decl->span);
-		cast_expr->cast_expr.expr = exprid(not_expr);
-		cast_expr->cast_expr.type_info = type_infoid(type_info_new_base(type_cint, decl->span));
-		ret_stmt->return_stmt.expr = cast_expr;
+		function = active_target.gui
+				? sema_create_synthetic_win_main(context, decl, type, is_int_return, is_err_return)
+				: sema_create_synthetic_wmain(context, decl, type, is_int_return, is_err_return);
 	}
 	else
 	{
-		Ast *stmt = new_ast(AST_EXPR_STMT, decl->span);
-		stmt->expr_stmt = call;
-		ast_append(&next, stmt);
-		ret_stmt->expr_stmt = expr_new_const_int(decl->span, type_cint, 0, true);
+		function = sema_create_synthetic_main(context, decl, type, is_int_return, is_err_return);
 	}
-	ast_append(&next, ret_stmt);
-	assert(body);
-	function->func_decl.body = astid(body);
-	function->is_synthetic = true;
+	if (!decl_ok(function)) return false;
 REGISTER_MAIN:
 	context->unit->main_function = function;
 	if (global_context.main)

src/compiler/symtab.c

@@ -82,6 +82,8 @@ const char *kw_std__core__types;
 const char *kw___run_default_test_runner;
 const char *kw_type;
 const char *kw_typekind;
+const char *kw_winmain;
+const char *kw_wmain;
 
 void symtab_destroy()
 {
@@ -162,6 +164,8 @@ void symtab_init(uint32_t capacity)
 	kw_std__core__types = KW_DEF("std::core::types");
 	kw___run_default_test_runner = KW_DEF("__run_default_test_runner");
 	kw_type = KW_DEF("type");
+	kw_winmain = KW_DEF("wWinMain");
+	kw_wmain = KW_DEF("wmain");
 
 	type_property_list[TYPE_PROPERTY_MAX] = builtin_list[BUILTIN_MAX] = KW_DEF("max");
 	type_property_list[TYPE_PROPERTY_MIN] = builtin_list[BUILTIN_MIN] = KW_DEF("min");

src/version.h

@@ -1 +1 @@
-#define COMPILER_VERSION "0.4.28"
+#define COMPILER_VERSION "0.4.29"

test/test_suite/initializer_lists/fasta.c3t

@@ -89,7 +89,7 @@ fn void random_fasta(char[] symb, double[] probability, int n)
 	if (i % LINELEN != 0) putchar('\n');
 }
 
-fn void main(int argc, char **argv)
+fn int main(int argc, char **argv)
 {
 	int n = 1000;
 	if (argc > 1) n = atoi(argv[1]);
@@ -103,6 +103,7 @@ fn void main(int argc, char **argv)
 	printf(">THREE Homo sapiens frequency\n");
 	random_fasta(homosapiens, homosapiens_p, n * 5);
 
+	return 0;
 }
 
 /* #expect: fasta.ll
@@ -326,7 +327,7 @@ if.exit14:                                        ; preds = %if.then13, %loop.ex
 }
 
 ; Function Attrs: nounwind
-define void @fasta_main(i32 %0, ptr %1) #0 {
+define i32 @main(i32 %0, ptr %1) #0 {
 entry:
   %n = alloca i32, align 4
   store i32 1000, ptr %n, align 4
@@ -363,11 +364,5 @@ if.exit:                                          ; preds = %if.then, %entry
   %9 = load i32, ptr %n, align 4
   %mul10 = mul i32 %9, 5
   call void @fasta_random_fasta(ptr %lo6, i64 %hi7, ptr %lo8, i64 %hi9, i32 %mul10)
-  ret void
-}
-
-define i32 @main(i32 %0, ptr %1) #0 {
-entry:
-  call void @fasta_main(i32 %0, ptr %1)
   ret i32 0
 }

test/test_suite/macros/macro_body_defer.c3t

@@ -106,21 +106,18 @@ define i32 @main(i32 %0, ptr %1) #0 {
 entry:
   %2 = call i64 @foo_main()
   %not_err = icmp eq i64 %2, 0
-  br i1 %not_err, label %after_check, label %error_block
+  br i1 %not_err, label %after_check, label %assign_optional
+
+assign_optional:                                  ; preds = %entry
+  store i64 %2, ptr %error_var, align 8
+  br label %noerr_block
 
 after_check:                                      ; preds = %entry
   br label %noerr_block
 
-noerr_block:                                      ; preds = %after_check
-  br label %phi_trycatch_block
-
-error_block:                                      ; preds = %entry
-  br label %phi_trycatch_block
-
-phi_trycatch_block:                               ; preds = %error_block, %noerr_block
-  %val = phi i8 [ 1, %noerr_block ], [ 0, %error_block ]
-  %3 = trunc i8 %val to i1
-  %not = xor i1 %3, true
-  %boolsi = zext i1 %not to i32
-  ret i32 %boolsi
-}
+noerr_block:                                      ; preds = %after_check, %assign_optional
+  %3 = load i64, ptr %error_var, align 8
+  %neq = icmp ne i64 %3, 0
+  %ternary = select i1 %neq, i32 1, i32 0
+  ret i32 %ternary
+}

test/test_suite14/initializer_lists/fasta.c3t

@@ -89,7 +89,7 @@ fn void random_fasta(char[] symb, double[] probability, int n)
 	if (i % LINELEN != 0) putchar('\n');
 }
 
-fn void main(int argc, char **argv)
+fn int main(int argc, char **argv)
 {
 	int n = 1000;
 	if (argc > 1) n = atoi(argv[1]);
@@ -102,7 +102,7 @@ fn void main(int argc, char **argv)
 
 	printf(">THREE Homo sapiens frequency\n");
 	random_fasta(homosapiens, homosapiens_p, n * 5);
-
+	return 0;
 }
 
 /* #expect: fasta.ll
@@ -329,7 +329,7 @@ if.exit15:                                        ; preds = %if.then14, %loop.ex
 }
 
 ; Function Attrs: nounwind
-define void @fasta_main(i32 %0, i8** %1) #0 {
+define i32 @main(i32 %0, i8** %1) #0 {
 entry:
   %n = alloca i32, align 4
   store i32 1000, i32* %n, align 4
@@ -366,11 +366,5 @@ if.exit:                                          ; preds = %if.then, %entry
   %9 = load i32, i32* %n, align 4
   %mul10 = mul i32 %9, 5
   call void @fasta_random_fasta(i8* %lo6, i64 %hi7, i8* %lo8, i64 %hi9, i32 %mul10)
-  ret void
-}
-
-define i32 @main(i32 %0, i8** %1) #0 {
-entry:
-  call void @fasta_main(i32 %0, i8** %1)
   ret i32 0
 }

test/test_suite14/macros/macro_body_defer.c3t

@@ -106,21 +106,18 @@ define i32 @main(i32 %0, i8** %1) #0 {
 entry:
   %2 = call i64 @foo_main()
   %not_err = icmp eq i64 %2, 0
-  br i1 %not_err, label %after_check, label %error_block
+  br i1 %not_err, label %after_check, label %assign_optional
+
+assign_optional:                                  ; preds = %entry
+  store i64 %2, i64* %error_var, align 8
+  br label %noerr_block
 
 after_check:                                      ; preds = %entry
   br label %noerr_block
 
-noerr_block:                                      ; preds = %after_check
-  br label %phi_trycatch_block
-
-error_block:                                      ; preds = %entry
-  br label %phi_trycatch_block
-
-phi_trycatch_block:                               ; preds = %error_block, %noerr_block
-  %val = phi i8 [ 1, %noerr_block ], [ 0, %error_block ]
-  %3 = trunc i8 %val to i1
-  %not = xor i1 %3, true
-  %boolsi = zext i1 %not to i32
-  ret i32 %boolsi
+noerr_block:                                      ; preds = %after_check, %assign_optional
+  %3 = load i64, i64* %error_var, align 8
+  %neq = icmp ne i64 %3, 0
+  %ternary = select i1 %neq, i32 1, i32 0
+  ret i32 %ternary
 }