Commit 2a25398c869fcdefe8b6508974a5c463ca833520 | zig

author	Andrew Kelley <andrew@ziglang.org> 2017-12-24 04:10:26-05:00
committer	Andrew Kelley <andrew@ziglang.org> 2017-12-24 04:11:58-05:00
log	2a25398c869fcdefe8b6508974a5c463ca833520
tree	cab802b768a4b2559a234c2a29c301435678bac3
parent	86397a532ec3c6699c39c8eeb966cd56b66c6c96

fix segfault when passing union enum with sub byte...

...field to const slice parameter

we use a packed struct internally to represent a const array
of disparate union values, and needed to update the internal
getelementptr instruction to recognize that.

closes #664

3 files changed, 35 insertions(+), 8 deletions(-)

src
- codegen.cpp
std
- debug
  - index.zig
test
- cases
  - union.zig

src/codegen.cpp+19-7

 @@ -3705,12 +3705,24 @@ static LLVMValueRef gen_const_ptr_array_recursive(CodeGen *g, ConstExprValue *ar
     ConstParent *parent = &array_const_val->data.x_array.s_none.parent;
     LLVMValueRef base_ptr = gen_parent_ptr(g, array_const_val, parent);
-    TypeTableEntry *usize = g->builtin_types.entry_usize;
+    LLVMTypeKind el_type = LLVMGetTypeKind(LLVMGetElementType(LLVMTypeOf(base_ptr)));
-    LLVMValueRef indices[] = {
+    if (el_type == LLVMArrayTypeKind) {
-        LLVMConstNull(usize->type_ref),
+        TypeTableEntry *usize = g->builtin_types.entry_usize;
-        LLVMConstInt(usize->type_ref, index, false),
+        LLVMValueRef indices[] = {
-    };
+            LLVMConstNull(usize->type_ref),
-    return LLVMConstInBoundsGEP(base_ptr, indices, 2);
+            LLVMConstInt(usize->type_ref, index, false),
+        };
+        return LLVMConstInBoundsGEP(base_ptr, indices, 2);
+    } else if (el_type == LLVMStructTypeKind) {
+        TypeTableEntry *u32 = g->builtin_types.entry_u32;
+        LLVMValueRef indices[] = {
+            LLVMConstNull(u32->type_ref),
+            LLVMConstInt(u32->type_ref, index, false),
+        };
+        return LLVMConstInBoundsGEP(base_ptr, indices, 2);
+    } else {
+        zig_unreachable();
+    }
 }
 static LLVMValueRef gen_const_ptr_struct_recursive(CodeGen *g, ConstExprValue *struct_const_val, size_t field_index) {
 @@ -3732,7 +3744,7 @@ static LLVMValueRef gen_const_ptr_union_recursive(CodeGen *g, ConstExprValue *un
     TypeTableEntry *u32 = g->builtin_types.entry_u32;
     LLVMValueRef indices[] = {
         LLVMConstNull(u32->type_ref),
-        LLVMConstInt(u32->type_ref, 0, false),
+        LLVMConstInt(u32->type_ref, 0, false), // TODO test const union with more aligned tag type than payload
     };
     return LLVMConstInBoundsGEP(base_ptr, indices, 2);
 }

std/debug/index.zig+1-1

...	@@ -8,7 +8,7 @@ const DW = std.dwarf;	...	@@ -8,7 +8,7 @@ const DW = std.dwarf;
8	const ArrayList = std.ArrayList;	8	const ArrayList = std.ArrayList;
9	const builtin = @import("builtin");	9	const builtin = @import("builtin");
10		10
11	pub use @import("./failing_allocator.zig");	11	pub const FailingAllocator = @import("failing_allocator.zig").FailingAllocator;
12		12
13	error MissingDebugInfo;	13	error MissingDebugInfo;
14	error InvalidDebugInfo;	14	error InvalidDebugInfo;

test/cases/union.zig+15

...	@@ -220,3 +220,18 @@ fn assertIsTheUnion2Item1(value: &const TheUnion2) {	...	@@ -220,3 +220,18 @@ fn assertIsTheUnion2Item1(value: &const TheUnion2) {
220	assert(*value == TheUnion2.Item1);	220	assert(*value == TheUnion2.Item1);
221	}	221	}
222		222
		223
		224	pub const PackThis = union(enum) {
		225	Invalid: bool,
		226	StringLiteral: u2,
		227	};
		228
		229	test "constant packed union" {
		230	testConstPackedUnion([]PackThis {
		231	PackThis { .StringLiteral = 1 },
		232	});
		233	}
		234
		235	fn testConstPackedUnion(expected_tokens: []const PackThis) {
		236	assert(expected_tokens[0].StringLiteral == 1);
		237	}