Commit 4ad4cd26541258a84faf97e9fe07a69fadc57c66 | zig

author	Andrew Kelley <andrew@ziglang.org> 2018-07-06 17:27:44-04:00
committer	Andrew Kelley <andrew@ziglang.org> 2018-07-06 17:27:44-04:00
log	4ad4cd26541258a84faf97e9fe07a69fadc57c66
tree	a74e48ba9e5af6bf20a216478ffea20049c7c9cb
parent	1cf7511dc9d449473748675a5e734e81ea7c85c2

fix iterating over a void slice

closes #1203

2 files changed, 30 insertions(+), 6 deletions(-)

src
- codegen.cpp
test
- cases
  - void.zig

src/codegen.cpp+18-6

 @@ -2992,18 +2992,26 @@ static LLVMValueRef ir_render_elem_ptr(CodeGen *g, IrExecutable *executable, IrI
         return LLVMBuildInBoundsGEP(g->builder, array_ptr, indices, 1, "");
     } else if (array_type->id == TypeTableEntryIdStruct) {
         assert(array_type->data.structure.is_slice);
+        if (!type_has_bits(instruction->base.value.type)) {
+            if (safety_check_on) {
+                assert(LLVMGetTypeKind(LLVMTypeOf(array_ptr)) == LLVMIntegerTypeKind);
+                add_bounds_check(g, subscript_value, LLVMIntEQ, nullptr, LLVMIntULT, array_ptr);
+            }
+            return nullptr;
+        }
         assert(LLVMGetTypeKind(LLVMTypeOf(array_ptr)) == LLVMPointerTypeKind);
         assert(LLVMGetTypeKind(LLVMGetElementType(LLVMTypeOf(array_ptr))) == LLVMStructTypeKind);
         if (safety_check_on) {
-            size_t len_index = array_type->data.structure.fields[1].gen_index;
+            size_t len_index = array_type->data.structure.fields[slice_len_index].gen_index;
             assert(len_index != SIZE_MAX);
             LLVMValueRef len_ptr = LLVMBuildStructGEP(g->builder, array_ptr, (unsigned)len_index, "");
             LLVMValueRef len = gen_load_untyped(g, len_ptr, 0, false, "");
             add_bounds_check(g, subscript_value, LLVMIntEQ, nullptr, LLVMIntULT, len);
         }
-        size_t ptr_index = array_type->data.structure.fields[0].gen_index;
+        size_t ptr_index = array_type->data.structure.fields[slice_ptr_index].gen_index;
         assert(ptr_index != SIZE_MAX);
         LLVMValueRef ptr_ptr = LLVMBuildStructGEP(g->builder, array_ptr, (unsigned)ptr_index, "");
         LLVMValueRef ptr = gen_load_untyped(g, ptr_ptr, 0, false, "");
 @@ -3983,11 +3991,15 @@ static LLVMValueRef ir_render_slice(CodeGen *g, IrExecutable *executable, IrInst
             add_bounds_check(g, start_val, LLVMIntEQ, nullptr, LLVMIntULE, end_val);
         }
-        LLVMValueRef ptr_field_ptr = LLVMBuildStructGEP(g->builder, tmp_struct_ptr, slice_ptr_index, "");
+        if (type_has_bits(array_type)) {
-        LLVMValueRef slice_start_ptr = LLVMBuildInBoundsGEP(g->builder, array_ptr, &start_val, 1, "");
+            size_t gen_ptr_index = instruction->base.value.type->data.structure.fields[slice_ptr_index].gen_index;
-        gen_store_untyped(g, slice_start_ptr, ptr_field_ptr, 0, false);
+            LLVMValueRef ptr_field_ptr = LLVMBuildStructGEP(g->builder, tmp_struct_ptr, gen_ptr_index, "");
+            LLVMValueRef slice_start_ptr = LLVMBuildInBoundsGEP(g->builder, array_ptr, &start_val, 1, "");
+            gen_store_untyped(g, slice_start_ptr, ptr_field_ptr, 0, false);
+        }
-        LLVMValueRef len_field_ptr = LLVMBuildStructGEP(g->builder, tmp_struct_ptr, slice_len_index, "");
+        size_t gen_len_index = instruction->base.value.type->data.structure.fields[slice_len_index].gen_index;
+        LLVMValueRef len_field_ptr = LLVMBuildStructGEP(g->builder, tmp_struct_ptr, gen_len_index, "");
         LLVMValueRef len_value = LLVMBuildNSWSub(g->builder, end_val, start_val, "");
         gen_store_untyped(g, len_value, len_field_ptr, 0, false);

test/cases/void.zig+12

...	@@ -16,3 +16,15 @@ test "compare void with void compile time known" {	...	@@ -16,3 +16,15 @@ test "compare void with void compile time known" {
16	assert(foo.a == {});	16	assert(foo.a == {});
17	}	17	}
18	}	18	}
		19
		20	test "iterate over a void slice" {
		21	var j: usize = 0;
		22	for (times(10)) \|_, i\| {
		23	assert(i == j);
		24	j += 1;
		25	}
		26	}
		27
		28	fn times(n: usize) []const void {
		29	return ([*]void)(undefined)[0..n];
		30	}