Ensure we pass the right alignment to the error, and fixing failing tests

Author: gbMattN

clang/lib/CodeGen/CGExprCXX.cpp

@@ -17,6 +17,7 @@
 #include "CodeGenFunction.h"
 #include "ConstantEmitter.h"
 #include "TargetInfo.h"
+#include "clang/AST/CharUnits.h"
 #include "clang/Basic/CodeGenOptions.h"
 #include "clang/Basic/Sanitizers.h"
 #include "clang/Basic/SourceLocation.h"
@@ -1756,12 +1757,15 @@ llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
   // return misaligned memory from a replaced operator new without knowing
   // about default alignment.
   TypeCheckKind checkKind = CodeGenFunction::TCK_ConstructorCall;
+  CharUnits checkAlignment = result.getAlignment();
   const TargetInfo &TI = getContext().getTargetInfo();
   unsigned DefaultTargetAlignment = TI.getNewAlign() / TI.getCharWidth();
   if (SanOpts.has(SanitizerKind::Alignment) &&
       (DefaultTargetAlignment >
-       CGM.getContext().getTypeAlignInChars(allocType).getQuantity()))
+       CGM.getContext().getTypeAlignInChars(allocType).getQuantity())){
     checkKind = CodeGenFunction::TCK_ConstructorCallMinimumAlign;
+    checkAlignment = CharUnits::fromQuantity(DefaultTargetAlignment);
+  }
 
   // Emit sanitizer checks for pointer value now, so that in the case of an
   // array it was checked only once and not at each constructor call. We may
@@ -1772,7 +1776,7 @@ llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
   SkippedChecks.set(SanitizerKind::Null, nullCheck);
   EmitTypeCheck(
       checkKind, E->getAllocatedTypeSourceInfo()->getTypeLoc().getBeginLoc(),
-      result, allocType, result.getAlignment(), SkippedChecks, numElements);
+      result, allocType, checkAlignment, SkippedChecks, numElements);
 
   EmitNewInitializer(*this, E, allocType, elementTy, result, numElements,
                      allocSizeWithoutCookie);

clang/test/CodeGenCXX/ubsan-new-checks.cpp

@@ -75,7 +75,7 @@ S3 *func_07() {
   // CHECK-LABEL: define {{.*}} @_Z7func_07v
   // CHECK:       and i64 %{{.*}}, 31, !nosanitize
   // CHECK:       icmp eq i64 %{{.*}}, 0, !nosanitize
-  // CHECK:       and i64 %{{.*}}, 3, !nosanitize
+  // CHECK:       and i64 %{{.*}}, 15, !nosanitize
   // CHECK:       icmp eq i64 %{{.*}}, 0, !nosanitize
   // CHECK:       ret ptr
   return new S3;
@@ -85,7 +85,7 @@ S3 *func_08() {
   // CHECK-LABEL: define {{.*}} @_Z7func_08v
   // CHECK:       and i64 %{{.*}}, 31, !nosanitize
   // CHECK:       icmp eq i64 %{{.*}}, 0, !nosanitize
-  // CHECK:       and i64 %{{.*}}, 3, !nosanitize
+  // CHECK:       and i64 %{{.*}}, 15, !nosanitize
   // CHECK:       icmp eq i64 %{{.*}}, 0, !nosanitize
   // CHECK:       ret ptr
   return new S3[10];

compiler-rt/test/ubsan/TestCases/TypeCheck/minimum-alignment.cpp

@@ -1,7 +1,7 @@
-// RUN: %clangxx %gmlt -fsanitize=alignment %s -o %t
+// RUN: %clangxx %gmlt -std=c++17 -m64 -fsanitize=alignment %s -o %t
 // RUN: %run %t 2>&1 | FileCheck %s
 
-// UNSUPPORTED: i386
+// UNSUPPORTED: i386, i686
 // UNSUPPORTED: armv7l
 
 // These sanitizers already overload the new operator so won't compile this test
@@ -10,6 +10,7 @@
 
 #include <cassert>
 #include <cstdlib>
+#include <cstddef>
 
 void *operator new(std::size_t count) {
   constexpr const size_t offset = 8;

compiler-rt/test/ubsan/TestCases/TypeCheck/misaligned.cpp

@@ -101,7 +101,7 @@ int main(int, char **argv) {
     return s->f() && 0;
 
   case 'n':
-    // CHECK-NEW: misaligned.cpp:[[@LINE+4]]{{(:21)?}}: runtime error: constructor call with pointer from operator new on misaligned address [[PTR:0x[0-9a-f]*]] for type 'S', which requires target minimum assumed 4 byte alignment
+    // CHECK-NEW: misaligned.cpp:[[@LINE+4]]{{(:21)?}}: runtime error: constructor call{{( with pointer from operator new)?}} on misaligned address [[PTR:0x[0-9a-f]*]] for type 'S', which requires {{(4|(target minimum assumed (8|(16))))}} byte alignment
     // CHECK-NEW-NEXT: [[PTR]]: note: pointer points here
     // CHECK-NEW-NEXT: {{^ 00 00 00 01 02 03 04  05}}
     // CHECK-NEW-NEXT: {{^             \^}}