[clang] 8392f1c - Fix __builtin_assume_aligned incorrect type descriptor and C++ object polymorphic address
Aaron Ballman via cfe-commits
cfe-commits at lists.llvm.org
Tue Sep 20 09:35:56 PDT 2022
Author: yronglin
Date: 2022-09-20T12:35:18-04:00
New Revision: 8392f1cc78270c7039970b413dfd836bf4def602
URL: https://github.com/llvm/llvm-project/commit/8392f1cc78270c7039970b413dfd836bf4def602
DIFF: https://github.com/llvm/llvm-project/commit/8392f1cc78270c7039970b413dfd836bf4def602.diff
LOG: Fix __builtin_assume_aligned incorrect type descriptor and C++ object polymorphic address
Fix __builtin_assume_aligned incorrect type descriptor
example from @rsmith
struct A { int n; };
struct B { int n; };
struct C : A, B {};
void *f(C *c) {
// Incorrectly returns `c` rather than the address of the B base class.
return __builtin_assume_aligned((B*)c, 8);
}
Differential Revision: https://reviews.llvm.org/D133583
Added:
clang/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-polymorphism.cpp
Modified:
clang/include/clang/Basic/Builtins.def
clang/lib/Basic/Builtins.cpp
clang/lib/Sema/SemaChecking.cpp
clang/test/Sema/builtin-redecl.cpp
Removed:
################################################################################
diff --git a/clang/include/clang/Basic/Builtins.def b/clang/include/clang/Basic/Builtins.def
index 249a3913dc0b6..dc7671ed16cec 100644
--- a/clang/include/clang/Basic/Builtins.def
+++ b/clang/include/clang/Basic/Builtins.def
@@ -546,7 +546,7 @@ BUILTIN(__builtin_va_start, "vA.", "nt")
BUILTIN(__builtin_va_end, "vA", "n")
BUILTIN(__builtin_va_copy, "vAA", "n")
BUILTIN(__builtin_stdarg_start, "vA.", "nt")
-BUILTIN(__builtin_assume_aligned, "v*vC*z.", "nc")
+BUILTIN(__builtin_assume_aligned, "v*vC*z.", "nct")
BUILTIN(__builtin_bcmp, "ivC*vC*z", "Fn")
BUILTIN(__builtin_bcopy, "vv*v*z", "n")
BUILTIN(__builtin_bzero, "vv*z", "nF")
diff --git a/clang/lib/Basic/Builtins.cpp b/clang/lib/Basic/Builtins.cpp
index b42e8f416cfca..0e0566878c30c 100644
--- a/clang/lib/Basic/Builtins.cpp
+++ b/clang/lib/Basic/Builtins.cpp
@@ -209,6 +209,7 @@ bool Builtin::Context::performsCallback(unsigned ID,
bool Builtin::Context::canBeRedeclared(unsigned ID) const {
return ID == Builtin::NotBuiltin || ID == Builtin::BI__va_start ||
+ ID == Builtin::BI__builtin_assume_aligned ||
(!hasReferenceArgsOrResult(ID) && !hasCustomTypechecking(ID)) ||
isInStdNamespace(ID);
}
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index e419287014893..1b74b091dd270 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -141,6 +141,15 @@ static bool checkArgCountAtMost(Sema &S, CallExpr *Call, unsigned MaxArgCount) {
<< Call->getSourceRange();
}
+/// Checks that a call expression's argument count is in the desired range. This
+/// is useful when doing custom type-checking on a variadic function. Returns
+/// true on error.
+static bool checkArgCountRange(Sema &S, CallExpr *Call, unsigned MinArgCount,
+ unsigned MaxArgCount) {
+ return checkArgCountAtLeast(S, Call, MinArgCount) ||
+ checkArgCountAtMost(S, Call, MaxArgCount);
+}
+
/// Checks that a call expression's argument count is the desired number.
/// This is useful when doing custom type-checking. Returns true on error.
static bool checkArgCount(Sema &S, CallExpr *Call, unsigned DesiredArgCount) {
@@ -7651,17 +7660,15 @@ bool Sema::SemaBuiltinAllocaWithAlign(CallExpr *TheCall) {
/// Handle __builtin_assume_aligned. This is declared
/// as (const void*, size_t, ...) and can take one optional constant int arg.
bool Sema::SemaBuiltinAssumeAligned(CallExpr *TheCall) {
- if (checkArgCountAtMost(*this, TheCall, 3))
+ if (checkArgCountRange(*this, TheCall, 2, 3))
return true;
unsigned NumArgs = TheCall->getNumArgs();
Expr *FirstArg = TheCall->getArg(0);
- if (auto *CE = dyn_cast<CastExpr>(FirstArg))
- FirstArg = CE->getSubExprAsWritten();
{
ExprResult FirstArgResult =
- DefaultFunctionArrayLvalueConversion(FirstArg, /*Diagnose=*/false);
+ DefaultFunctionArrayLvalueConversion(FirstArg);
if (FirstArgResult.isInvalid())
return true;
TheCall->setArg(0, FirstArgResult.get());
diff --git a/clang/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-polymorphism.cpp b/clang/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-polymorphism.cpp
new file mode 100644
index 0000000000000..2206a73472f1b
--- /dev/null
+++ b/clang/test/CodeGen/catch-alignment-assumption-builtin_assume_aligned-polymorphism.cpp
@@ -0,0 +1,64 @@
+// RUN: %clang_cc1 -no-opaque-pointers -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s
+// RUN: %clang_cc1 -no-opaque-pointers -fsanitize=alignment -fno-sanitize-recover=alignment -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s -implicit-check-not="call void @__ubsan_handle_alignment_assumption" --check-prefixes=CHECK,CHECK-SANITIZE,CHECK-SANITIZE-ANYRECOVER,CHECK-SANITIZE-NORECOVER,CHECK-SANITIZE-UNREACHABLE
+// RUN: %clang_cc1 -no-opaque-pointers -fsanitize=alignment -fsanitize-recover=alignment -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s -implicit-check-not="call void @__ubsan_handle_alignment_assumption" --check-prefixes=CHECK,CHECK-SANITIZE,CHECK-SANITIZE-ANYRECOVER,CHECK-SANITIZE-RECOVER
+// RUN: %clang_cc1 -no-opaque-pointers -fsanitize=alignment -fsanitize-trap=alignment -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s -implicit-check-not="call void @__ubsan_handle_alignment_assumption" --check-prefixes=CHECK,CHECK-SANITIZE,CHECK-SANITIZE-TRAP,CHECK-SANITIZE-UNREACHABLE
+
+// CHECK-SANITIZE-ANYRECOVER: @[[CHAR:.*]] = {{.*}} c"'B *'\00" }
+// CHECK-SANITIZE-ANYRECOVER: @[[LINE_100_ALIGNMENT_ASSUMPTION:.*]] = {{.*}}, i32 100, i32 35 }, {{.*}}* @[[CHAR]] }
+
+struct A { int n; };
+struct B { int n; };
+struct C : A, B {};
+
+void *f(C *c) {
+ // CHECK: define {{.*}} i8* @{{.*}}(%struct.C* noundef %[[C:.*]]) {{.*}} {
+ // CHECK-NEXT: [[ENTRY:.*]]:
+ // CHECK-NEXT: %[[C_ADDR:.*]] = alloca %struct.C*
+ // CHECK-NEXT: store %struct.C* %[[C]], %struct.C** %[[C_ADDR]]
+ // CHECK-NEXT: %[[C_RELOAD:.*]] = load %struct.C*, %struct.C** %[[C_ADDR]]
+ // CHECK-NEXT: %[[IS_NULL:.*]] = icmp eq %struct.C* %[[C_RELOAD]], null
+ // CHECK-NEXT: br i1 %[[IS_NULL]], label %[[CAST_END:[^,]+]], label %[[CAST_NOT_NULL:[^,]+]]
+ // CHECK: [[CAST_NOT_NULL]]:
+ // CHECK-NOSANITIZE-NEXT: %[[BITCAST:.*]] = bitcast %struct.C* %[[C_RELOAD]] to i8*
+ // CHECK-NOSANITIZE-NEXT: %[[ADD_PTR:.*]] = getelementptr inbounds i8, i8* %[[BITCAST]], i64 4
+ // CHECK-NOSANITIZE-NEXT: %[[BITCAST2:.*]] = bitcast i8* %[[ADD_PTR]] to %struct.B*
+ // CHECK-NOSANITIZE-NEXT: br label %[[CAST_END]]
+ // CHECK-SANITIZE-NEXT: %[[PTRTOINT:.*]] = ptrtoint %struct.C* %[[C_RELOAD]] to i64, !nosanitize
+ // CHECK-SANITIZE-NEXT: %[[MASKEDPTR:.*]] = and i64 %[[PTRTOINT]], 3, !nosanitize
+ // CHECK-SANITIZE-NEXT: %[[MASKCOND:.*]] = icmp eq i64 %[[MASKEDPTR]], 0, !nosanitize
+ // CHECK-SANITIZE-NEXT: br i1 %[[MASKCOND]], label %[[CONT:[^,]+]], label %[[HANDLER_TYPE_MISMATCH:[^,]+]]
+ // CHECK-SANITIZE: [[HANDLER_TYPE_MISMATCH]]:
+ // CHECK-SANITIZE-NORECOVER-NEXT: call void @__ubsan_handle_type_mismatch_v1_abort(
+ // CHECK-SANITIZE-RECOVER-NEXT: call void @__ubsan_handle_type_mismatch_v1(
+ // CHECK-SANITIZE-TRAP-NEXT: call void @llvm.ubsantrap(
+ // CHECK-SANITIZE-UNREACHABLE-NEXT: unreachable, !nosanitize
+ // CHECK-SANITIZE: [[CONT]]:
+ // CHECK-SANITIZE-NEXT: %[[BITCAST:.*]] = bitcast %struct.C* %[[C_RELOAD]] to i8*
+ // CHECK-SANITIZE-NEXT: %[[ADD_PTR:.*]] = getelementptr inbounds i8, i8* %[[BITCAST]], i64 4
+ // CHECK-SANITIZE-NEXT: %[[BITCAST2:.*]] = bitcast i8* %[[ADD_PTR]] to %struct.B*
+ // CHECK-SANITIZE-NEXT: br label %[[CAST_END]]
+ // CHECK: [[CAST_END]]:
+ // CHECK-NOSANITIZE-NEXT: %[[CAST_RESULT:.*]] = phi %struct.B* [ %[[BITCAST2]], %[[CAST_NOT_NULL]] ], [ null, %[[ENTRY]] ]
+ // CHECK-NOSANITIZE-NEXT: %[[CAST_END_BITCAST:.*]] = bitcast %struct.B* %[[CAST_RESULT]] to i8*
+ // CHECK-NOSANITIZE-NEXT: call void @llvm.assume(i1 true) [ "align"(i8* %[[CAST_END_BITCAST]], i64 8) ]
+ // CHECK-NOSANITIZE-NEXT: ret i8* %[[CAST_END_BITCAST]]
+ // CHECK-NOSANITIZE-NEXT: }
+ // CHECK-SANITIZE-NEXT: %[[CAST_RESULT:.*]] = phi %struct.B* [ %[[BITCAST2]], %[[CONT]] ], [ null, %[[ENTRY]] ]
+ // CHECK-SANITIZE-NEXT: %[[CAST_END_BITCAST:.*]] = bitcast %struct.B* %[[CAST_RESULT]] to i8*
+ // CHECK-SANITIZE-NEXT: %[[PTRINT:.*]] = ptrtoint i8* %[[CAST_END_BITCAST]] to i64
+ // CHECK-SANITIZE-NEXT: %[[MASKEDPTR:.*]] = and i64 %[[PTRINT]], 7
+ // CHECK-SANITIZE-NEXT: %[[MASKCOND:.*]] = icmp eq i64 %[[MASKEDPTR]], 0
+ // CHECK-SANITIZE-NEXT: %[[PTRINT_DUP:.*]] = ptrtoint i8* %[[CAST_END_BITCAST]] to i64, !nosanitize
+ // CHECK-SANITIZE-NEXT: br i1 %[[MASKCOND]], label %[[CONT1:.*]], label %[[HANDLER_ALIGNMENT_ASSUMPTION:[^,]+]],{{.*}} !nosanitize
+ // CHECK-SANITIZE: [[HANDLER_ALIGNMENT_ASSUMPTION]]:
+ // CHECK-SANITIZE-NORECOVER-NEXT: call void @__ubsan_handle_alignment_assumption_abort(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 8, i64 0){{.*}}, !nosanitize
+ // CHECK-SANITIZE-RECOVER-NEXT: call void @__ubsan_handle_alignment_assumption(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 8, i64 0){{.*}}, !nosanitize
+ // CHECK-SANITIZE-TRAP-NEXT: call void @llvm.ubsantrap(i8 23){{.*}}, !nosanitize
+ // CHECK-SANITIZE-UNREACHABLE-NEXT: unreachable, !nosanitize
+ // CHECK-SANITIZE: [[CONT1]]:
+ // CHECK-SANITIZE-NEXT: call void @llvm.assume(i1 true) [ "align"(i8* %[[CAST_END_BITCAST]], i64 8) ]
+ // CHECK-SANITIZE-NEXT: ret i8* %[[CAST_END_BITCAST]]
+ // CHECK-SANITIZE-NEXT: }
+#line 100
+ return __builtin_assume_aligned((B*)c, 8);
+}
diff --git a/clang/test/Sema/builtin-redecl.cpp b/clang/test/Sema/builtin-redecl.cpp
index 9d1a7fff02321..323c63e202883 100644
--- a/clang/test/Sema/builtin-redecl.cpp
+++ b/clang/test/Sema/builtin-redecl.cpp
@@ -2,6 +2,8 @@
// RUN: %clang_cc1 %s -fsyntax-only -verify -x c
// RUN: %clang_cc1 %s -fsyntax-only -verify -fms-compatibility
+typedef __typeof__(sizeof(0)) size_t;
+
// Redeclaring library builtins is OK.
void exit(int);
@@ -16,3 +18,9 @@ void __builtin_va_end(__builtin_va_list);
// RUN: %clang_cc1 %s -fsyntax-only -verify -x c
void __va_start(__builtin_va_list*, ...);
+
+#ifdef __cplusplus
+void *__builtin_assume_aligned(const void *, size_t, ...) noexcept;
+#else
+void *__builtin_assume_aligned(const void *, size_t, ...);
+#endif
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