Commit a859f94644cb362d84d3f9d72bc02b00a75fc32a | zig

author	Mitchell Hashimoto <mitchell.hashimoto@gmail.com> 2022-03-14 16:21:11-07:00
committer	Mitchell Hashimoto <mitchell.hashimoto@gmail.com> 2022-03-14 17:41:12-07:00
log	a859f94644cb362d84d3f9d72bc02b00a75fc32a
tree	e3f4d09b74fb4bca327b192d311bb5bbe950d161
parent	5ea94e7715607e986298908536cdd3d9dfdd0ce9
signature	Commit is signed but in an unrecognized format.

stage2: LLVM codegen of arrays should use type length, not value length

It is possible for the value length to be longer than the type because
we allow in-memory coercing of types such as `[5:0]u8` to `[5]u8`. In
such a case, the value length is 6 but the type length if 5.

The `.repeated` value type already got this right, so this is extending
similar logic out to `.aggregate` and `.bytes`. Both scenarios are
tested in behavior tests.

Fixes #11165

3 files changed, 47 insertions(+), 3 deletions(-)

src
- codegen
  - llvm.zig
test
- behavior.zig
- behavior
  - bugs
    11165.zig

src/codegen/llvm.zig+4-3

 @@ -1507,7 +1507,7 @@ pub const DeclGen = struct {
                     const bytes = tv.val.castTag(.bytes).?.data;
                     return dg.context.constString(
                         bytes.ptr,
-                        @intCast(c_uint, bytes.len),
+                        @intCast(c_uint, tv.ty.arrayLenIncludingSentinel()),
                         .True, // don't null terminate. bytes has the sentinel, if any.
                     );
                 },
 @@ -1515,10 +1515,11 @@ pub const DeclGen = struct {
                     const elem_vals = tv.val.castTag(.aggregate).?.data;
                     const elem_ty = tv.ty.elemType();
                     const gpa = dg.gpa;
-                    const llvm_elems = try gpa.alloc(*const llvm.Value, elem_vals.len);
+                    const len = @intCast(usize, tv.ty.arrayLenIncludingSentinel());
+                    const llvm_elems = try gpa.alloc(*const llvm.Value, len);
                     defer gpa.free(llvm_elems);
                     var need_unnamed = false;
-                    for (elem_vals) |elem_val, i| {
+                    for (elem_vals[0..len]) |elem_val, i| {
                         llvm_elems[i] = try dg.genTypedValue(.{ .ty = elem_ty, .val = elem_val });
                         need_unnamed = need_unnamed or dg.isUnnamedType(elem_ty, llvm_elems[i]);
                     }

test/behavior.zig+1

...	@@ -62,6 +62,7 @@ test {	...	@@ -62,6 +62,7 @@ test {
62	_ = @import("behavior/bugs/11100.zig");	62	_ = @import("behavior/bugs/11100.zig");
63	_ = @import("behavior/bugs/10970.zig");	63	_ = @import("behavior/bugs/10970.zig");
64	_ = @import("behavior/bugs/11046.zig");	64	_ = @import("behavior/bugs/11046.zig");
		65	_ = @import("behavior/bugs/11165.zig");
65	_ = @import("behavior/call.zig");	66	_ = @import("behavior/call.zig");
66	_ = @import("behavior/cast.zig");	67	_ = @import("behavior/cast.zig");
67	_ = @import("behavior/comptime_memory.zig");	68	_ = @import("behavior/comptime_memory.zig");

test/behavior/bugs/11165.zig created+42

...	@@ -0,0 +1,42 @@
1	const builtin = @import("builtin");
2
3	test "bytes" {
4	const S = struct {
5	a: u32,
6	c: [5]u8,
7	};
8
9	const U = union {
10	s: S,
11	};
12
13	const s_1 = S{
14	.a = undefined,
15	.c = "12345".*, // this caused problems
16	};
17	_ = s_1;
18
19	const u_2 = U{ .s = s_1 };
20	_ = u_2;
21	}
22
23	test "aggregate" {
24	const S = struct {
25	a: u32,
26	c: [5]u8,
27	};
28
29	const U = union {
30	s: S,
31	};
32
33	const c = [5:0]u8{ 1, 2, 3, 4, 5 };
34	const s_1 = S{
35	.a = undefined,
36	.c = c, // this caused problems
37	};
38	_ = s_1;
39
40	const u_2 = U{ .s = s_1 };
41	_ = u_2;
42	}