fhahn updated this revision to Diff 469329.
fhahn added a comment.
Rebased on current main
In D122573#3630767 <https://reviews.llvm.org/D122573#3630767>, @rui.zhang wrote:
> I like the direction where this change is leading to and hope there is some
> way to land it incrementally. Since BuiltinType has the above mentioned
> concern on `void *`, how about we focus on `RecordType` pointers as a first
> step instead? Are there any pitfalls if we distinguish `RecordType` pointers
> by depth?
An initial restriction like that sounds reasonable to me. @jcranmer-intel
@efriedma @rjmccall WDYT?
I also updated the type sanitizer patches and posted
https://discourse.llvm.org/t/reviving-typesanitizer-a-sanitizer-to-catch-type-based-aliasing-violations/66092
to discuss ways to move forward with the sanitizer.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D122573/new/
https://reviews.llvm.org/D122573
Files:
clang/lib/CodeGen/CodeGenTBAA.cpp
clang/test/CodeGen/tbaa-pointers.c
Index: clang/test/CodeGen/tbaa-pointers.c
===================================================================
--- clang/test/CodeGen/tbaa-pointers.c
+++ clang/test/CodeGen/tbaa-pointers.c
@@ -1,12 +1,12 @@
// RUN: %clang_cc1 -triple x86_64-apple-darwin -O1 -disable-llvm-passes %s -emit-llvm -o - | FileCheck %s
-void p2unsigned(unsigned **ptr) {
+void p2unsigned(unsigned** ptr) {
// CHECK-LABEL: define void @p2unsigned(ptr noundef %ptr)
// CHECK-NEXT: entry:
// CHECK-NEXT: %ptr.addr = alloca ptr, align 8
- // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0:!.+]]
- // CHECK-NEXT: [[BASE:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: store ptr null, ptr [[BASE]], align 8, !tbaa [[ANY_POINTER_0]]
+ // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[P2INT_0:!.+]]
+ // CHECK-NEXT: [[BASE:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[P2INT_0]]
+ // CHECK-NEXT: store ptr null, ptr [[BASE]], align 8, !tbaa [[P1INT_0:!.+]]
// CHECK-NEXT: ret void
//
*ptr = 0;
@@ -16,9 +16,9 @@
// CHECK-LABEL: define void @p2unsigned_volatile(ptr noundef %ptr)
// CHECK-NEXT: entry:
// CHECK-NEXT: %ptr.addr = alloca ptr, align 8
- // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: [[BASE:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: store volatile ptr null, ptr [[BASE]], align 8, !tbaa [[ANY_POINTER_0]]
+ // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[P2INT_0]]
+ // CHECK-NEXT: [[BASE:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[P2INT_0]]
+ // CHECK-NEXT: store volatile ptr null, ptr [[BASE]], align 8, !tbaa [[P1INT_0]]
// CHECK-NEXT: ret void
//
*ptr = 0;
@@ -28,10 +28,10 @@
// CHECK-LABEL: define void @p3int(ptr noundef %ptr)
// CHECK-NEXT: entry:
// CHECK-NEXT: %ptr.addr = alloca ptr, align 8
- // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: [[BASE_0:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: [[BASE_1:%.+]] = load ptr, ptr [[BASE_0]], align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: store ptr null, ptr [[BASE_1]], align 8, !tbaa [[ANY_POINTER_0]]
+ // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[P3INT_0:!.+]]
+ // CHECK-NEXT: [[BASE_0:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[P3INT_0]]
+ // CHECK-NEXT: [[BASE_1:%.+]] = load ptr, ptr [[BASE_0]], align 8, !tbaa [[P2INT_0]]
+ // CHECK-NEXT: store ptr null, ptr [[BASE_1]], align 8, !tbaa [[P1INT_0]]
// CHECK-NEXT: ret void
//
**ptr = 0;
@@ -41,11 +41,11 @@
// CHECK-LABEL: define void @p4char(ptr noundef %ptr)
// CHECK-NEXT: entry:
// CHECK-NEXT: %ptr.addr = alloca ptr, align 8
- // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: [[BASE_0:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: [[BASE_1:%.+]] = load ptr, ptr [[BASE_0]], align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: [[BASE_2:%.+]] = load ptr, ptr [[BASE_1]], align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: store ptr null, ptr [[BASE_2]], align 8, !tbaa [[ANY_POINTER_0]]
+ // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[P4CHAR_0:!.+]]
+ // CHECK-NEXT: [[BASE_0:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[P4CHAR_0]]
+ // CHECK-NEXT: [[BASE_1:%.+]] = load ptr, ptr [[BASE_0]], align 8, !tbaa [[P3CHAR_0:!.+]]
+ // CHECK-NEXT: [[BASE_2:%.+]] = load ptr, ptr [[BASE_1]], align 8, !tbaa [[P2CHAR_0:!.+]]
+ // CHECK-NEXT: store ptr null, ptr [[BASE_2]], align 8, !tbaa [[P1CHAR_0:!.+]]
// CHECK-NEXT: ret void
//
***ptr = 0;
@@ -55,11 +55,11 @@
// CHECK-LABEL: define void @p4char_const1(ptr noundef %ptr)
// CHECK-NEXT: entry:
// CHECK-NEXT: %ptr.addr = alloca ptr, align 8
- // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: [[BASE_0:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: [[BASE_1:%.+]] = load ptr, ptr [[BASE_0]], align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: [[BASE_2:%.+]] = load ptr, ptr [[BASE_1]], align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: store ptr null, ptr [[BASE_2]], align 8, !tbaa [[ANY_POINTER_0]]
+ // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[P4CHAR_0]]
+ // CHECK-NEXT: [[BASE_0:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[P4CHAR_0]]
+ // CHECK-NEXT: [[BASE_1:%.+]] = load ptr, ptr [[BASE_0]], align 8, !tbaa [[P3CHAR_0]]
+ // CHECK-NEXT: [[BASE_2:%.+]] = load ptr, ptr [[BASE_1]], align 8, !tbaa [[P2CHAR_0]]
+ // CHECK-NEXT: store ptr null, ptr [[BASE_2]], align 8, !tbaa [[P1CHAR_0]]
// CHECK-NEXT: ret void
//
***ptr = 0;
@@ -69,11 +69,11 @@
// CHECK-LABEL: define void @p4char_const2(ptr noundef %ptr)
// CHECK-NEXT: entry:
// CHECK-NEXT: %ptr.addr = alloca ptr, align 8
- // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: [[BASE_0:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: [[BASE_1:%.+]] = load ptr, ptr [[BASE_0]], align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: [[BASE_2:%.+]] = load ptr, ptr [[BASE_1]], align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: store ptr null, ptr [[BASE_2]], align 8, !tbaa [[ANY_POINTER_0]]
+ // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[P4CHAR_0]]
+ // CHECK-NEXT: [[BASE_0:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[P4CHAR_0]]
+ // CHECK-NEXT: [[BASE_1:%.+]] = load ptr, ptr [[BASE_0]], align 8, !tbaa [[P3CHAR_0]]
+ // CHECK-NEXT: [[BASE_2:%.+]] = load ptr, ptr [[BASE_1]], align 8, !tbaa [[P2CHAR_0]]
+ // CHECK-NEXT: store ptr null, ptr [[BASE_2]], align 8, !tbaa [[P1CHAR_0]]
// CHECK-NEXT: ret void
//
***ptr = 0;
@@ -88,16 +88,28 @@
// CHECK-LABEL: define void @p2struct(ptr noundef %ptr)
// CHECK-NEXT: entry:
// CHECK-NEXT: %ptr.addr = alloca ptr, align 8
- // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: [[BASE:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[ANY_POINTER_0]]
- // CHECK-NEXT: store ptr null, ptr [[BASE]], align 8, !tbaa [[ANY_POINTER_0]]
+ // CHECK-NEXT: store ptr %ptr, ptr %ptr.addr, align 8, !tbaa [[P2S1_0:!.+]]
+ // CHECK-NEXT: [[BASE:%.+]] = load ptr, ptr %ptr.addr, align 8, !tbaa [[P2S1_0]]
+ // CHECK-NEXT: store ptr null, ptr [[BASE]], align 8, !tbaa [[P1S1_:!.+]]
// CHECK-NEXT: ret void
//
*ptr = 0;
}
-// CHECK: [[ANY_POINTER_0]] = !{[[ANY_POINTER:!.+]], [[ANY_POINTER]], i64 0}
+// CHECK: [[P2INT_0]] = !{[[P2INT:!.+]], [[P2INT]], i64 0}
+// CHECK: [[P2INT]] = !{!"p2 int", [[ANY_POINTER:!.+]], i64 0}
// CHECK: [[ANY_POINTER]] = !{!"any pointer", [[CHAR:!.+]], i64 0}
// CHECK: [[CHAR]] = !{!"omnipotent char", [[TBAA_ROOT:!.+]], i64 0}
// CHECK: [[TBAA_ROOT]] = !{!"Simple C/C++ TBAA"}
-//
+// CHECK: [[P1INT_0]] = !{[[P1INT:!.+]], [[P1INT]], i64 0}
+// CHECK: [[P1INT]] = !{!"p1 int", [[ANY_POINTER]], i64 0}
+// CHECK: [[P3INT_0]] = !{[[P3INT:!.+]], [[P3INT]], i64 0}
+// CHECK: [[P3INT]] = !{!"p3 int", [[ANY_POINTER]], i64 0}
+// CHECK: [[P4CHAR_0]] = !{[[P4CHAR:!.+]], [[P4CHAR]], i64 0}
+// CHECK: [[P4CHAR]] = !{!"p4 omnipotent char", [[ANY_POINTER]], i64 0}
+// CHECK: [[P3CHAR_0]] = !{[[P3CHAR:!.+]], [[P3CHAR]], i64 0}
+// CHECK: [[P3CHAR]] = !{!"p3 omnipotent char", [[ANY_POINTER]], i64 0}
+// CHECK: [[P2CHAR_0]] = !{[[P2CHAR:!.+]], [[P2CHAR]], i64 0}
+// CHECK: [[P2CHAR]] = !{!"p2 omnipotent char", [[ANY_POINTER]], i64 0}
+// CHECK: [[P1CHAR_0]] = !{[[P1CHAR:!.+]], [[P1CHAR]], i64 0}
+// CHECK: [[P1CHAR]] = !{!"p1 omnipotent char", [[ANY_POINTER]], i64 0}
Index: clang/lib/CodeGen/CodeGenTBAA.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenTBAA.cpp
+++ clang/lib/CodeGen/CodeGenTBAA.cpp
@@ -184,10 +184,31 @@
return getChar();
// Handle pointers and references.
- // TODO: Implement C++'s type "similarity" and consider dis-"similar"
- // pointers distinct.
- if (Ty->isPointerType() || Ty->isReferenceType())
- return createScalarTypeNode("any pointer", getChar(), Size);
+ if (Ty->isPointerType() || Ty->isReferenceType()) {
+ llvm::MDNode *AnyPtr = createScalarTypeNode("any pointer", getChar(), Size);
+ // Compute the depth of the pointer and generate a tag of the form "p<depth>
+ // <base type tag>".
+ unsigned PtrDepth = 0;
+ do {
+ PtrDepth++;
+ Ty = Ty->getPointeeType().getTypePtr();
+ } while (Ty->isPointerType() || Ty->isReferenceType());
+ // TODO: Implement C++'s type "similarity" and consider dis-"similar"
+ // pointers distinct for non-builtin types.
+ if (isa<BuiltinType>(Ty)) {
+ llvm::MDNode *ScalarMD = getTypeInfoHelper(Ty);
+ StringRef Name =
+ cast<llvm::MDString>(
+ ScalarMD->getOperand(CodeGenOpts.NewStructPathTBAA ? 2 : 0))
+ ->getString();
+ SmallString<256> OutName("p");
+ OutName += std::to_string(PtrDepth);
+ OutName += " ";
+ OutName += Name;
+ return createScalarTypeNode(OutName, AnyPtr, Size);
+ }
+ return AnyPtr;
+ }
// Accesses to arrays are accesses to objects of their element types.
if (CodeGenOpts.NewStructPathTBAA && Ty->isArrayType())
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