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Sema: fix memcpy with C pointers #23174

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Merged
merged 1 commit into from
Apr 28, 2025
Merged

Sema: fix memcpy with C pointers #23174

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5 changes: 4 additions & 1 deletion src/Sema.zig
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Original file line number Diff line number Diff line change
Expand Up @@ -3669,7 +3669,10 @@ fn indexablePtrLenOrNone(
const zcu = pt.zcu;
const operand_ty = sema.typeOf(operand);
try checkMemOperand(sema, block, src, operand_ty);
if (operand_ty.ptrSize(zcu) == .many) return .none;
switch (operand_ty.ptrSize(zcu)) {
.many, .c => return .none,
.one, .slice => {},
}
const field_name = try zcu.intern_pool.getOrPutString(sema.gpa, pt.tid, "len", .no_embedded_nulls);
return sema.fieldVal(block, src, operand, field_name, src);
}
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21 changes: 21 additions & 0 deletions test/behavior/memcpy.zig
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Original file line number Diff line number Diff line change
Expand Up @@ -69,6 +69,27 @@ fn testMemcpyDestManyPtr() !void {
try expect(buf[4] == 'o');
}

test "@memcpy C pointer" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;

try testMemcpyCPointer();
try comptime testMemcpyCPointer();
}

fn testMemcpyCPointer() !void {
const src = "hello";
var buf: [5]u8 = undefined;
@memcpy(@as([*c]u8, &buf), src);
try expect(buf[0] == 'h');
try expect(buf[1] == 'e');
try expect(buf[2] == 'l');
try expect(buf[3] == 'l');
try expect(buf[4] == 'o');
}

test "@memcpy slice" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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