Commit 1273bc277f7274683db5041d8b41d91903e3045e | zig

Use a `defer` statement to implement the C __cleanup__ attribute.

See https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html

6 files changed, 60 insertions(+), 0 deletions(-)

src/clang.zig+3

...	...	@@ -976,6 +976,9 @@ pub const VarDecl = opaque {
976	976	pub const getAlignedAttribute = ZigClangVarDecl_getAlignedAttribute;
977	977	extern fn ZigClangVarDecl_getAlignedAttribute(const VarDecl, const ASTContext) c_uint;
978	978
	979	pub const getCleanupAttribute = ZigClangVarDecl_getCleanupAttribute;
	980	extern fn ZigClangVarDecl_getCleanupAttribute(const VarDecl) ?const FunctionDecl;
	981
979	982	pub const getTypeSourceInfo_getType = ZigClangVarDecl_getTypeSourceInfo_getType;
980	983	extern fn ZigClangVarDecl_getTypeSourceInfo_getType(*const VarDecl) QualType;
981	984	};

src/translate_c.zig+16

...	...	@@ -1656,6 +1656,22 @@ fn transDeclStmtOne(
1656	1656	.init = init_node,
1657	1657	});
1658	1658	try block_scope.statements.append(node);
	1659
	1660	const cleanup_attr = var_decl.getCleanupAttribute();
	1661	if (cleanup_attr) \|fn_decl\| {
	1662	const cleanup_fn_name = try c.str(@ptrCast(*const clang.NamedDecl, fn_decl).getName_bytes_begin());
	1663	const fn_id = try Tag.identifier.create(c.arena, cleanup_fn_name);
	1664
	1665	const varname = try Tag.identifier.create(c.arena, mangled_name);
	1666	const args = try c.arena.alloc(Node, 1);
	1667	args[0] = try Tag.address_of.create(c.arena, varname);
	1668
	1669	const cleanup_call = try Tag.call.create(c.arena, .{ .lhs = fn_id, .args = args });
	1670	const discard = try Tag.discard.create(c.arena, cleanup_call);
	1671	const deferred_cleanup = try Tag.@"defer".create(c.arena, discard);
	1672
	1673	try block_scope.statements.append(deferred_cleanup);
	1674	}
1659	1675	},
1660	1676	.Typedef => {
1661	1677	try transTypeDef(c, scope, @ptrCast(*const clang.TypedefNameDecl, decl));

src/translate_c/ast.zig+14

...	...	@@ -67,6 +67,7 @@ pub const Node = extern union {
67	67	@"struct",
68	68	@"union",
69	69	@"comptime",
	70	@"defer",
70	71	array_init,
71	72	tuple,
72	73	container_init,
...	...	@@ -247,6 +248,7 @@ pub const Node = extern union {
247	248	.std_mem_zeroes,
248	249	.@"return",
249	250	.@"comptime",
	251	.@"defer",
250	252	.asm_simple,
251	253	.discard,
252	254	.std_math_Log2Int,
...	...	@@ -1020,6 +1022,17 @@ fn renderNode(c: *Context, node: Node) Allocator.Error!NodeIndex {
1020	1022	},
1021	1023	});
1022	1024	},
	1025	.@"defer" => {
	1026	const payload = node.castTag(.@"defer").?.data;
	1027	return c.addNode(.{
	1028	.tag = .@"defer",
	1029	.main_token = try c.addToken(.keyword_defer, "defer"),
	1030	.data = .{
	1031	.lhs = undefined,
	1032	.rhs = try renderNode(c, payload),
	1033	},
	1034	});
	1035	},
1023	1036	.asm_simple => {
1024	1037	const payload = node.castTag(.asm_simple).?.data;
1025	1038	const asm_token = try c.addToken(.keyword_asm, "asm");
...	...	@@ -2273,6 +2286,7 @@ fn renderNodeGrouped(c: *Context, node: Node) !NodeIndex {
2273	2286	.@"continue",
2274	2287	.@"return",
2275	2288	.@"comptime",
	2289	.@"defer",
2276	2290	.asm_simple,
2277	2291	.usingnamespace_builtins,
2278	2292	.while_true,

src/zig_clang.cpp+8

...	...	@@ -1784,6 +1784,14 @@ unsigned ZigClangVarDecl_getAlignedAttribute(const struct ZigClangVarDecl *self,
1784	1784	return 0;
1785	1785	}
1786	1786
	1787	const struct ZigClangFunctionDecl ZigClangVarDecl_getCleanupAttribute(const struct ZigClangVarDecl self) {
	1788	auto casted_self = reinterpret_cast<const clang::VarDecl *>(self);
	1789	if (const clang::CleanupAttr *CA = casted_self->getAttr<clang::CleanupAttr>()) {
	1790	return reinterpret_cast<const ZigClangFunctionDecl *>(CA->getFunctionDecl());
	1791	}
	1792	return nullptr;
	1793	}
	1794
1787	1795	unsigned ZigClangFieldDecl_getAlignedAttribute(const struct ZigClangFieldDecl self, const ZigClangASTContext ctx) {
1788	1796	auto casted_self = reinterpret_cast<const clang::FieldDecl *>(self);
1789	1797	auto casted_ctx = const_cast<clang::ASTContext >(reinterpret_cast<const clang::ASTContext >(ctx));

src/zig_clang.h+1

...	...	@@ -997,6 +997,7 @@ ZIG_EXTERN_C const struct ZigClangTypedefNameDecl *ZigClangTypedefNameDecl_getCa
997	997	ZIG_EXTERN_C const struct ZigClangFunctionDecl ZigClangFunctionDecl_getCanonicalDecl(const ZigClangFunctionDecl self);
998	998	ZIG_EXTERN_C const struct ZigClangVarDecl ZigClangVarDecl_getCanonicalDecl(const ZigClangVarDecl self);
999	999	ZIG_EXTERN_C const char* ZigClangVarDecl_getSectionAttribute(const struct ZigClangVarDecl self, size_t len);
	1000	ZIG_EXTERN_C const struct ZigClangFunctionDecl ZigClangVarDecl_getCleanupAttribute(const struct ZigClangVarDecl self);
1000	1001	ZIG_EXTERN_C unsigned ZigClangVarDecl_getAlignedAttribute(const struct ZigClangVarDecl self, const ZigClangASTContext ctx);
1001	1002	ZIG_EXTERN_C unsigned ZigClangFunctionDecl_getAlignedAttribute(const struct ZigClangFunctionDecl self, const ZigClangASTContext ctx);
1002	1003	ZIG_EXTERN_C unsigned ZigClangFieldDecl_getAlignedAttribute(const struct ZigClangFieldDecl self, const ZigClangASTContext ctx);

test/run_translated_c.zig+18

...	...	@@ -1490,4 +1490,22 @@ pub fn addCases(cases: *tests.RunTranslatedCContext) void {
1490	1490	\\ return 0;
1491	1491	\\}
1492	1492	, "");
	1493
	1494	cases.add("__cleanup__ attribute",
	1495	\\#include <stdlib.h>
	1496	\\static int cleanup_count = 0;
	1497	\\void clean_up(int *final_value) {
	1498	\\ if (*final_value != cleanup_count++) abort();
	1499	\\}
	1500	\\void doit(void) {
	1501	\\ int a __attribute__ ((__cleanup__(clean_up))) __attribute__ ((unused)) = 2;
	1502	\\ int b __attribute__ ((__cleanup__(clean_up))) __attribute__ ((unused)) = 1;
	1503	\\ int c __attribute__ ((__cleanup__(clean_up))) __attribute__ ((unused)) = 0;
	1504	\\}
	1505	\\int main(void) {
	1506	\\ doit();
	1507	\\ if (cleanup_count != 3) abort();
	1508	\\ return 0;
	1509	\\}
	1510	, "");
1493	1511	}