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-rw-r--r-- | clang/test/C/C2y/n3254.c | 149 | ||||
-rw-r--r-- | clang/www/c_status.html | 2 |
2 files changed, 150 insertions, 1 deletions
diff --git a/clang/test/C/C2y/n3254.c b/clang/test/C/C2y/n3254.c new file mode 100644 index 0000000..e08659cf --- /dev/null +++ b/clang/test/C/C2y/n3254.c @@ -0,0 +1,149 @@ +// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 5 +// RUN: %clang_cc1 -triple=x86_64 -std=c2y %s -emit-llvm -o - | FileCheck %s + +/* WG14 N3254: Yes + * Accessing byte arrays + * + * NB: this basically boils down to how LLVM handles TBAA, so the best we can + * do for a Clang test is to test that the LLVM IR we pass is reasonable and we + * presume that LLVM has the test coverage to ensure that this behavior isn't + * regressed. + */ + +struct S { + int x; + char c; + float f; +}; + +#define DECL_BUFFER(Ty, Name) alignas(Ty) unsigned char Name[sizeof(Ty)] + +// CHECK-LABEL: define dso_local i32 @foo( +// CHECK-SAME: ) #[[ATTR0:[0-9]+]] { +// CHECK-NEXT: [[ENTRY:.*:]] +// CHECK-NEXT: [[BUFFER:%.*]] = alloca [12 x i8], align 1 +// CHECK-NEXT: [[S_PTR:%.*]] = alloca ptr, align 8 +// CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 1 [[BUFFER]], i8 0, i64 12, i1 false) +// CHECK-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [12 x i8], ptr [[BUFFER]], i64 0, i64 0 +// CHECK-NEXT: store ptr [[ARRAYDECAY]], ptr [[S_PTR]], align 8 +// CHECK-NEXT: [[TMP0:%.*]] = load ptr, ptr [[S_PTR]], align 8 +// CHECK-NEXT: [[X:%.*]] = getelementptr inbounds [[STRUCT_S:%.*]], ptr [[TMP0]], i32 0, i32 0 +// CHECK-NEXT: [[TMP1:%.*]] = load i32, ptr [[X]], align 4 +// CHECK-NEXT: ret i32 [[TMP1]] +// +int foo() { + DECL_BUFFER(struct S, buffer) = {}; + struct S *s_ptr = (struct S *)buffer; + return s_ptr->x; +} + +// CHECK-LABEL: define dso_local signext i8 @bar( +// CHECK-SAME: ) #[[ATTR0]] { +// CHECK-NEXT: [[ENTRY:.*:]] +// CHECK-NEXT: [[BUFFER:%.*]] = alloca [12 x i8], align 1 +// CHECK-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [12 x i8], ptr [[BUFFER]], i64 0, i64 0 +// CHECK-NEXT: [[C:%.*]] = getelementptr inbounds [[STRUCT_S:%.*]], ptr [[ARRAYDECAY]], i32 0, i32 1 +// CHECK-NEXT: store i8 97, ptr [[C]], align 1 +// CHECK-NEXT: [[ARRAYDECAY1:%.*]] = getelementptr inbounds [12 x i8], ptr [[BUFFER]], i64 0, i64 0 +// CHECK-NEXT: [[C2:%.*]] = getelementptr inbounds [[STRUCT_S]], ptr [[ARRAYDECAY1]], i32 0, i32 1 +// CHECK-NEXT: [[TMP0:%.*]] = load i8, ptr [[C2]], align 1 +// CHECK-NEXT: ret i8 [[TMP0]] +// +char bar() { + DECL_BUFFER(struct S, buffer); + ((struct S *)buffer)->c = 'a'; + return ((struct S *)buffer)->c; +} + +// CHECK-LABEL: define dso_local float @baz( +// CHECK-SAME: ) #[[ATTR0]] { +// CHECK-NEXT: [[ENTRY:.*:]] +// CHECK-NEXT: [[BUFFER:%.*]] = alloca [12 x i8], align 1 +// CHECK-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [12 x i8], ptr [[BUFFER]], i64 0, i64 0 +// CHECK-NEXT: [[F:%.*]] = getelementptr inbounds [[STRUCT_S:%.*]], ptr [[ARRAYDECAY]], i32 0, i32 2 +// CHECK-NEXT: store float 3.000000e+00, ptr [[F]], align 1 +// CHECK-NEXT: [[ARRAYDECAY1:%.*]] = getelementptr inbounds [12 x i8], ptr [[BUFFER]], i64 0, i64 0 +// CHECK-NEXT: [[F2:%.*]] = getelementptr inbounds [[STRUCT_S]], ptr [[ARRAYDECAY1]], i32 0, i32 2 +// CHECK-NEXT: [[TMP0:%.*]] = load float, ptr [[F2]], align 1 +// CHECK-NEXT: ret float [[TMP0]] +// +float baz() { + DECL_BUFFER(struct S, buffer); + ((struct S *)buffer)->f = 3.0f; + return ((const struct S *)buffer)->f; +} + +struct T { + DECL_BUFFER(struct S, buffer); +}; + +// CHECK-LABEL: define dso_local signext i8 @quux( +// CHECK-SAME: ) #[[ATTR0]] { +// CHECK-NEXT: [[ENTRY:.*:]] +// CHECK-NEXT: [[T:%.*]] = alloca [[STRUCT_T:%.*]], align 1 +// CHECK-NEXT: [[S_PTR:%.*]] = alloca ptr, align 8 +// CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 1 [[T]], i8 0, i64 12, i1 false) +// CHECK-NEXT: [[BUFFER:%.*]] = getelementptr inbounds [[STRUCT_T]], ptr [[T]], i32 0, i32 0 +// CHECK-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [12 x i8], ptr [[BUFFER]], i64 0, i64 0 +// CHECK-NEXT: store ptr [[ARRAYDECAY]], ptr [[S_PTR]], align 8 +// CHECK-NEXT: [[TMP0:%.*]] = load ptr, ptr [[S_PTR]], align 8 +// CHECK-NEXT: [[C:%.*]] = getelementptr inbounds [[STRUCT_S:%.*]], ptr [[TMP0]], i32 0, i32 1 +// CHECK-NEXT: [[TMP1:%.*]] = load i8, ptr [[C]], align 4 +// CHECK-NEXT: ret i8 [[TMP1]] +// +char quux() { + struct T t = {}; + struct S *s_ptr = (struct S *)t.buffer; + return s_ptr->c; +} + +// CHECK-LABEL: define dso_local float @quibble( +// CHECK-SAME: ) #[[ATTR0]] { +// CHECK-NEXT: [[ENTRY:.*:]] +// CHECK-NEXT: [[BUFFER:%.*]] = alloca [12 x i8], align 1 +// CHECK-NEXT: [[T_PTR:%.*]] = alloca ptr, align 8 +// CHECK-NEXT: [[S_PTR:%.*]] = alloca ptr, align 8 +// CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 1 [[BUFFER]], i8 0, i64 12, i1 false) +// CHECK-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [12 x i8], ptr [[BUFFER]], i64 0, i64 0 +// CHECK-NEXT: store ptr [[ARRAYDECAY]], ptr [[T_PTR]], align 8 +// CHECK-NEXT: [[TMP0:%.*]] = load ptr, ptr [[T_PTR]], align 8 +// CHECK-NEXT: [[BUFFER1:%.*]] = getelementptr inbounds [[STRUCT_T:%.*]], ptr [[TMP0]], i32 0, i32 0 +// CHECK-NEXT: [[ARRAYDECAY2:%.*]] = getelementptr inbounds [12 x i8], ptr [[BUFFER1]], i64 0, i64 0 +// CHECK-NEXT: store ptr [[ARRAYDECAY2]], ptr [[S_PTR]], align 8 +// CHECK-NEXT: [[TMP1:%.*]] = load ptr, ptr [[S_PTR]], align 8 +// CHECK-NEXT: [[F:%.*]] = getelementptr inbounds [[STRUCT_S:%.*]], ptr [[TMP1]], i32 0, i32 2 +// CHECK-NEXT: [[TMP2:%.*]] = load float, ptr [[F]], align 4 +// CHECK-NEXT: ret float [[TMP2]] +// +float quibble() { + DECL_BUFFER(struct T, buffer) = {}; + const struct T *t_ptr = (struct T *)buffer; + const struct S *s_ptr = (struct S *)t_ptr->buffer; + return s_ptr->f; +} + +// CHECK-LABEL: define dso_local i32 @quorble( +// CHECK-SAME: ) #[[ATTR0]] { +// CHECK-NEXT: [[ENTRY:.*:]] +// CHECK-NEXT: [[BUFFER:%.*]] = alloca [12 x i8], align 1 +// CHECK-NEXT: [[S_PTR:%.*]] = alloca ptr, align 8 +// CHECK-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [12 x i8], ptr [[BUFFER]], i64 0, i64 0 +// CHECK-NEXT: [[BUFFER1:%.*]] = getelementptr inbounds [[STRUCT_T:%.*]], ptr [[ARRAYDECAY]], i32 0, i32 0 +// CHECK-NEXT: [[ARRAYDECAY2:%.*]] = getelementptr inbounds [12 x i8], ptr [[BUFFER1]], i64 0, i64 0 +// CHECK-NEXT: [[X:%.*]] = getelementptr inbounds [[STRUCT_S:%.*]], ptr [[ARRAYDECAY2]], i32 0, i32 0 +// CHECK-NEXT: store i32 12, ptr [[X]], align 1 +// CHECK-NEXT: [[ARRAYDECAY3:%.*]] = getelementptr inbounds [12 x i8], ptr [[BUFFER]], i64 0, i64 0 +// CHECK-NEXT: [[BUFFER4:%.*]] = getelementptr inbounds [[STRUCT_T]], ptr [[ARRAYDECAY3]], i32 0, i32 0 +// CHECK-NEXT: [[ARRAYDECAY5:%.*]] = getelementptr inbounds [12 x i8], ptr [[BUFFER4]], i64 0, i64 0 +// CHECK-NEXT: store ptr [[ARRAYDECAY5]], ptr [[S_PTR]], align 8 +// CHECK-NEXT: [[TMP0:%.*]] = load ptr, ptr [[S_PTR]], align 8 +// CHECK-NEXT: [[X6:%.*]] = getelementptr inbounds [[STRUCT_S]], ptr [[TMP0]], i32 0, i32 0 +// CHECK-NEXT: [[TMP1:%.*]] = load i32, ptr [[X6]], align 4 +// CHECK-NEXT: ret i32 [[TMP1]] +// +int quorble() { + DECL_BUFFER(struct T, buffer); + ((struct S *)((struct T *)buffer)->buffer)->x = 12; + const struct S *s_ptr = (struct S *)((struct T *)buffer)->buffer; + return s_ptr->x; +} diff --git a/clang/www/c_status.html b/clang/www/c_status.html index 3fb1efc..2030e1e 100644 --- a/clang/www/c_status.html +++ b/clang/www/c_status.html @@ -1260,7 +1260,7 @@ conforms by not defining the <code>__STDC_IEC_559_COMPLEX__</code> macro. <tr> <td>Accessing byte arrays</td> <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3254.pdf">N3254</a></td> - <td class="unknown" align="center">Unknown</td> + <td class="full" align="center">Yes</td> </tr> <tr> <td>Slay some earthly demons I</td> |