[clang] [CodeGen][counted_by] See past parentheses and no-op casts (PR #151266)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Bill Wendling (bwendling)

<details>
<summary>Changes</summary>

Parentheses and no-op casts don't change the value. Skip past them to get to a MemberExpr.

Fixes #<!-- -->151236

---
Full diff: https://github.com/llvm/llvm-project/pull/151266.diff


2 Files Affected:

- (modified) clang/lib/CodeGen/CGBuiltin.cpp (+2-1) 
- (modified) clang/test/CodeGen/attr-counted-by-for-pointers.c (+77) 


``````````diff
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 3f784fc8e798f..e1f7ea08837c5 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1148,7 +1148,8 @@ llvm::Value *CodeGenFunction::emitCountedByPointerSize(
   assert(E->getCastKind() == CK_LValueToRValue &&
          "must be an LValue to RValue cast");
 
-  const MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr());
+  const MemberExpr *ME =
+      dyn_cast<MemberExpr>(E->getSubExpr()->IgnoreParenNoopCasts(getContext()));
   if (!ME)
     return nullptr;
 
diff --git a/clang/test/CodeGen/attr-counted-by-for-pointers.c b/clang/test/CodeGen/attr-counted-by-for-pointers.c
index 24076541168d4..e939e49a61d4d 100644
--- a/clang/test/CodeGen/attr-counted-by-for-pointers.c
+++ b/clang/test/CodeGen/attr-counted-by-for-pointers.c
@@ -471,3 +471,80 @@ size_t test9(struct annotated_sized_ptr *p, int index) {
 size_t test10(struct annotated_sized_ptr *p, int index) {
   return __bdos(&((unsigned int *) p->buf)[index]);
 }
+
+struct pr151236_struct {
+        int *a __counted_by(a_count);
+        short a_count;
+};
+
+// SANITIZE-WITH-ATTR-LABEL: define dso_local range(i64 -262144, 262137) i64 @test11(
+// SANITIZE-WITH-ATTR-SAME: ptr noundef [[P:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITH-ATTR-NEXT:  entry:
+// SANITIZE-WITH-ATTR-NEXT:    [[COUNTED_BY_GEP:%.*]] = getelementptr inbounds nuw i8, ptr [[P]], i64 8
+// SANITIZE-WITH-ATTR-NEXT:    [[COUNTED_BY_LOAD:%.*]] = load i16, ptr [[COUNTED_BY_GEP]], align 4
+// SANITIZE-WITH-ATTR-NEXT:    [[TMP0:%.*]] = icmp sgt i16 [[COUNTED_BY_LOAD]], -1
+// SANITIZE-WITH-ATTR-NEXT:    [[COUNT:%.*]] = sext i16 [[COUNTED_BY_LOAD]] to i64
+// SANITIZE-WITH-ATTR-NEXT:    [[ARRAY_SIZE:%.*]] = shl nsw i64 [[COUNT]], 3
+// SANITIZE-WITH-ATTR-NEXT:    [[TMP1:%.*]] = select i1 [[TMP0]], i64 [[ARRAY_SIZE]], i64 0
+// SANITIZE-WITH-ATTR-NEXT:    ret i64 [[TMP1]]
+//
+// NO-SANITIZE-WITH-ATTR-LABEL: define dso_local range(i64 -262144, 262137) i64 @test11(
+// NO-SANITIZE-WITH-ATTR-SAME: ptr noundef readonly captures(none) [[P:%.*]]) local_unnamed_addr #[[ATTR1]] {
+// NO-SANITIZE-WITH-ATTR-NEXT:  entry:
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[COUNTED_BY_GEP:%.*]] = getelementptr inbounds nuw i8, ptr [[P]], i64 8
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[COUNTED_BY_LOAD:%.*]] = load i16, ptr [[COUNTED_BY_GEP]], align 4
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[COUNT:%.*]] = sext i16 [[COUNTED_BY_LOAD]] to i64
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[ARRAY_SIZE:%.*]] = shl nsw i64 [[COUNT]], 3
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[TMP0:%.*]] = icmp sgt i16 [[COUNTED_BY_LOAD]], -1
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[TMP1:%.*]] = select i1 [[TMP0]], i64 [[ARRAY_SIZE]], i64 0
+// NO-SANITIZE-WITH-ATTR-NEXT:    ret i64 [[TMP1]]
+//
+// SANITIZE-WITHOUT-ATTR-LABEL: define dso_local range(i64 0, -1) i64 @test11(
+// SANITIZE-WITHOUT-ATTR-SAME: ptr noundef [[P:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITHOUT-ATTR-NEXT:  entry:
+// SANITIZE-WITHOUT-ATTR-NEXT:    ret i64 -2
+//
+// NO-SANITIZE-WITHOUT-ATTR-LABEL: define dso_local range(i64 0, -1) i64 @test11(
+// NO-SANITIZE-WITHOUT-ATTR-SAME: ptr noundef readonly captures(none) [[P:%.*]]) local_unnamed_addr #[[ATTR1]] {
+// NO-SANITIZE-WITHOUT-ATTR-NEXT:  entry:
+// NO-SANITIZE-WITHOUT-ATTR-NEXT:    ret i64 -2
+//
+size_t test11(struct pr151236_struct *p) {
+  return __bdos(p->a) + __bdos((p->a));
+}
+
+// SANITIZE-WITH-ATTR-LABEL: define dso_local range(i64 -262144, 262137) i64 @test12(
+// SANITIZE-WITH-ATTR-SAME: ptr noundef [[P:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITH-ATTR-NEXT:  entry:
+// SANITIZE-WITH-ATTR-NEXT:    [[COUNTED_BY_GEP:%.*]] = getelementptr inbounds nuw i8, ptr [[P]], i64 8
+// SANITIZE-WITH-ATTR-NEXT:    [[COUNTED_BY_LOAD:%.*]] = load i16, ptr [[COUNTED_BY_GEP]], align 4
+// SANITIZE-WITH-ATTR-NEXT:    [[TMP0:%.*]] = icmp sgt i16 [[COUNTED_BY_LOAD]], -1
+// SANITIZE-WITH-ATTR-NEXT:    [[COUNT:%.*]] = sext i16 [[COUNTED_BY_LOAD]] to i64
+// SANITIZE-WITH-ATTR-NEXT:    [[ARRAY_SIZE:%.*]] = shl nsw i64 [[COUNT]], 3
+// SANITIZE-WITH-ATTR-NEXT:    [[TMP1:%.*]] = select i1 [[TMP0]], i64 [[ARRAY_SIZE]], i64 0
+// SANITIZE-WITH-ATTR-NEXT:    ret i64 [[TMP1]]
+//
+// NO-SANITIZE-WITH-ATTR-LABEL: define dso_local range(i64 -262144, 262137) i64 @test12(
+// NO-SANITIZE-WITH-ATTR-SAME: ptr noundef readonly captures(none) [[P:%.*]]) local_unnamed_addr #[[ATTR1]] {
+// NO-SANITIZE-WITH-ATTR-NEXT:  entry:
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[COUNTED_BY_GEP:%.*]] = getelementptr inbounds nuw i8, ptr [[P]], i64 8
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[COUNTED_BY_LOAD:%.*]] = load i16, ptr [[COUNTED_BY_GEP]], align 4
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[COUNT:%.*]] = sext i16 [[COUNTED_BY_LOAD]] to i64
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[ARRAY_SIZE:%.*]] = shl nsw i64 [[COUNT]], 3
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[TMP0:%.*]] = icmp sgt i16 [[COUNTED_BY_LOAD]], -1
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[TMP1:%.*]] = select i1 [[TMP0]], i64 [[ARRAY_SIZE]], i64 0
+// NO-SANITIZE-WITH-ATTR-NEXT:    ret i64 [[TMP1]]
+//
+// SANITIZE-WITHOUT-ATTR-LABEL: define dso_local range(i64 0, -1) i64 @test12(
+// SANITIZE-WITHOUT-ATTR-SAME: ptr noundef [[P:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITHOUT-ATTR-NEXT:  entry:
+// SANITIZE-WITHOUT-ATTR-NEXT:    ret i64 -2
+//
+// NO-SANITIZE-WITHOUT-ATTR-LABEL: define dso_local range(i64 0, -1) i64 @test12(
+// NO-SANITIZE-WITHOUT-ATTR-SAME: ptr noundef readonly captures(none) [[P:%.*]]) local_unnamed_addr #[[ATTR1]] {
+// NO-SANITIZE-WITHOUT-ATTR-NEXT:  entry:
+// NO-SANITIZE-WITHOUT-ATTR-NEXT:    ret i64 -2
+//
+size_t test12(struct pr151236_struct *p) {
+  return __bdos(p->a) + __bdos(((int *)p->a));
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/151266