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Sema: perform codegen for anon decl created by @extern

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This fixes a bug where, at least with the LLVM backend, `@extern` calls
which had the same name as a normal `extern` in the same Zcu would
result in the `@extern` incorrectly suffixing the identifier `.2`.
Usually, the LLVM backend has a system to change the generated globals
to "collapse" them all together, but it only works if `updateDecl` is
called!
This commit is contained in:
mlugg
2024-03-08 21:42:45 +00:00
committed by Matthew Lugg
parent 9cf28d1e9b
commit e2cbbd0c26
2 changed files with 43 additions and 31 deletions
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56
src/Sema.zig
View File

@@ -25989,41 +25989,35 @@ fn zirBuiltinExtern(
}
const ptr_info = ty.ptrInfo(mod);
// TODO check duplicate extern
const new_decl_index = try mod.allocateNewDecl(sema.owner_decl.src_namespace, sema.owner_decl.src_node);
errdefer mod.destroyDecl(new_decl_index);
const new_decl = mod.declPtr(new_decl_index);
new_decl.name = options.name;
new_decl.src_line = sema.owner_decl.src_line;
new_decl.ty = Type.fromInterned(ptr_info.child);
new_decl.val = Value.fromInterned(
if (Type.fromInterned(ptr_info.child).zigTypeTag(mod) == .Fn)
try ip.getExternFunc(sema.gpa, .{
.ty = ptr_info.child,
.decl = new_decl_index,
.lib_name = options.library_name,
})
else
try mod.intern(.{ .variable = .{
.ty = ptr_info.child,
.init = .none,
.decl = new_decl_index,
.lib_name = options.library_name,
.is_extern = true,
.is_const = ptr_info.flags.is_const,
.is_threadlocal = options.is_thread_local,
.is_weak_linkage = options.linkage == .Weak,
} }),
);
new_decl.alignment = .none;
new_decl.@"linksection" = .none;
new_decl.has_tv = true;
try mod.initNewAnonDecl(new_decl_index, sema.owner_decl.src_line, .{
.ty = Type.fromInterned(ptr_info.child),
.val = Value.fromInterned(
if (Type.fromInterned(ptr_info.child).zigTypeTag(mod) == .Fn)
try ip.getExternFunc(sema.gpa, .{
.ty = ptr_info.child,
.decl = new_decl_index,
.lib_name = options.library_name,
})
else
try mod.intern(.{ .variable = .{
.ty = ptr_info.child,
.init = .none,
.decl = new_decl_index,
.lib_name = options.library_name,
.is_extern = true,
.is_const = ptr_info.flags.is_const,
.is_threadlocal = options.is_thread_local,
.is_weak_linkage = options.linkage == .Weak,
} }),
),
}, options.name);
new_decl.owns_tv = true;
new_decl.analysis = .complete;
try sema.ensureDeclAnalyzed(new_decl_index);
// Note that this will queue the anon decl for codegen, so that the backend can
// correctly handle the extern, including duplicate detection.
try mod.finalizeAnonDecl(new_decl_index);
return Air.internedToRef((try mod.getCoerced(Value.fromInterned((try mod.intern(.{ .ptr = .{
.ty = switch (ip.indexToKey(ty.toIntern())) {

18
test/behavior/extern.zig
View File

@@ -27,3 +27,21 @@ test "function extern symbol" {
export fn a_mystery_function() i32 {
return 4567;
}
test "function extern symbol matches extern decl" {
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_x86_64 and builtin.target.ofmt != .elf and builtin.target.ofmt != .macho) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
const S = struct {
extern fn another_mystery_function() u32;
const same_thing = @extern(*const fn () callconv(.C) u32, .{ .name = "another_mystery_function" });
};
try expect(S.another_mystery_function() == 12345);
try expect(S.same_thing() == 12345);
}
export fn another_mystery_function() u32 {
return 12345;
}