[clang] [compiler-rt] [Sanitizer] add signed-integer-wrap sanitizer (PR #80089)

[Thorsten Schütt via llvm-commits]

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@@ -0,0 +1,66 @@
+// Check that -fsanitize=signed-integer-wrap instruments with -fwrapv
+// RUN: %clang_cc1 -fwrapv -triple x86_64-apple-darwin -emit-llvm -o - %s -fsanitize=signed-integer-wrap | FileCheck %s --check-prefix=CHECK
+
+// Check that -fsanitize=signed-integer-overflow doesn't instrument with -fwrapv
+// RUN: %clang_cc1 -fwrapv -triple x86_64-apple-darwin -emit-llvm -o - %s -fsanitize=signed-integer-overflow | FileCheck %s --check-prefix=CHECKSIO
+
+extern volatile int a, b, c;
+
+// CHECK-LABEL: define void @test_add_overflow
+void test_add_overflow(void) {
+  // CHECK: [[ADD0:%.*]] = load {{.*}} i32
+  // CHECK-NEXT: [[ADD1:%.*]] = load {{.*}} i32
+  // CHECK-NEXT: {{%.*}} = call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[ADD0]], i32 [[ADD1]])
+  // CHECK: call void @__ubsan_handle_add_overflow
+
+  // CHECKSIO-NOT: call void @__ubsan_handle_add_overflow
+  a = b + c;
+}
+
+// CHECK-LABEL: define void @test_inc_overflow
+void test_inc_overflow(void) {
+  // This decays and gets handled by __ubsan_handle_add_overflow...
+  // CHECK: [[INC0:%.*]] = load {{.*}} i32
+  // CHECK-NEXT: call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[INC0]], i32 1)
+  // CHECK: br {{.*}} %handler.add_overflow
+
+  // CHECKSIO-NOT: br {{.*}} %handler.add_overflow
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tschuett wrote:

In some tests the branch on the overflow bit is not visible. It gives you more confidence, if there is always a branch on the overflow bit.

https://github.com/llvm/llvm-project/pull/80089