[NFC][clang] Add ubsan-trap-merge.c test to show absence of nomerge (#117649)

This test (copied from #83470)
demonstrates that UBSan does not add the nomerge annotation. This is
significant because it can result in them being merged by the backend,
even when -ubsan-unique-traps is enabled.

N.B. #65972 (continuation of
https://reviews.llvm.org/D148654) had considered adding nomerge to
ubsantrap, but did not proceed with that because of
#53011.
#101549 fixed that limitation
("It sets nomerge flag for the node if the instruction has nomerge
arrtibute."); planned upcoming work
(#117651) will add nomerge for
ubsan.

Author: thurstond

clang/test/CodeGen/ubsan-trap-merge.c

@@ -0,0 +1,105 @@
+// NOTE: Assertions have mostly been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 5
+// The most important assertion is the attributes at the end of the file, which
+// shows that ubsan does not currently attach 'nomerge'.
+//
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -fsanitize=signed-integer-overflow -fsanitize-trap=signed-integer-overflow -O3 -mllvm -ubsan-unique-traps %s -o - \
+// RUN:     | FileCheck %s
+//
+// REQUIRES: x86-registered-target
+
+// CHECK-LABEL: define dso_local noundef i32 @f(
+// CHECK-SAME: i32 noundef [[X:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  [[ENTRY:.*:]]
+// CHECK-NEXT:    [[TMP0:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[X]], i32 125), !nosanitize [[META2:![0-9]+]]
+// CHECK-NEXT:    [[TMP1:%.*]] = extractvalue { i32, i1 } [[TMP0]], 1, !nosanitize [[META2]]
+// CHECK-NEXT:    br i1 [[TMP1]], label %[[TRAP:.*]], label %[[CONT:.*]], !nosanitize [[META2]]
+// CHECK:       [[TRAP]]:
+// CHECK-NEXT:    tail call void @llvm.ubsantrap(i8 2) #[[ATTR4:[0-9]+]], !nosanitize [[META2]]
+// CHECK-NEXT:    unreachable, !nosanitize [[META2]]
+// CHECK:       [[CONT]]:
+// CHECK-NEXT:    [[TMP2:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0, !nosanitize [[META2]]
+// CHECK-NEXT:    ret i32 [[TMP2]]
+//
+int f(int x) {
+  return x + 125;
+}
+
+// CHECK-LABEL: define dso_local noundef i32 @g(
+// CHECK-SAME: i32 noundef [[X:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// CHECK-NEXT:  [[ENTRY:.*:]]
+// CHECK-NEXT:    [[TMP0:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[X]], i32 127), !nosanitize [[META2]]
+// CHECK-NEXT:    [[TMP1:%.*]] = extractvalue { i32, i1 } [[TMP0]], 1, !nosanitize [[META2]]
+// CHECK-NEXT:    br i1 [[TMP1]], label %[[TRAP:.*]], label %[[CONT:.*]], !nosanitize [[META2]]
+// CHECK:       [[TRAP]]:
+// CHECK-NEXT:    tail call void @llvm.ubsantrap(i8 2) #[[ATTR4]], !nosanitize [[META2]]
+// CHECK-NEXT:    unreachable, !nosanitize [[META2]]
+// CHECK:       [[CONT]]:
+// CHECK-NEXT:    [[TMP2:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0, !nosanitize [[META2]]
+// CHECK-NEXT:    ret i32 [[TMP2]]
+//
+int g(int x) {
+  return x + 127;
+}
+
+// CHECK-LABEL: define dso_local noundef i32 @h(
+// CHECK-SAME: i32 noundef [[X:%.*]], i32 noundef [[Y:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// CHECK-NEXT:  [[ENTRY:.*:]]
+// CHECK-NEXT:    [[TMP0:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[X]], i32 127), !nosanitize [[META2]]
+// CHECK-NEXT:    [[TMP1:%.*]] = extractvalue { i32, i1 } [[TMP0]], 1, !nosanitize [[META2]]
+// CHECK-NEXT:    br i1 [[TMP1]], label %[[TRAP:.*]], label %[[CONT:.*]], !nosanitize [[META2]]
+// CHECK:       [[TRAP]]:
+// CHECK-NEXT:    tail call void @llvm.ubsantrap(i8 2) #[[ATTR4]], !nosanitize [[META2]]
+// CHECK-NEXT:    unreachable, !nosanitize [[META2]]
+// CHECK:       [[CONT]]:
+// CHECK-NEXT:    [[TMP2:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[Y]], i32 129), !nosanitize [[META2]]
+// CHECK-NEXT:    [[TMP3:%.*]] = extractvalue { i32, i1 } [[TMP2]], 1, !nosanitize [[META2]]
+// CHECK-NEXT:    br i1 [[TMP3]], label %[[TRAP1:.*]], label %[[CONT2:.*]], !nosanitize [[META2]]
+// CHECK:       [[TRAP1]]:
+// CHECK-NEXT:    tail call void @llvm.ubsantrap(i8 4) #[[ATTR4]], !nosanitize [[META2]]
+// CHECK-NEXT:    unreachable, !nosanitize [[META2]]
+// CHECK:       [[CONT2]]:
+// CHECK-NEXT:    [[TMP4:%.*]] = extractvalue { i32, i1 } [[TMP2]], 0, !nosanitize [[META2]]
+// CHECK-NEXT:    [[TMP5:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0, !nosanitize [[META2]]
+// CHECK-NEXT:    [[COND:%.*]] = tail call i32 @llvm.smin.i32(i32 [[TMP5]], i32 [[TMP4]])
+// CHECK-NEXT:    ret i32 [[COND]]
+//
+int h(int x, int y) {
+  x += 127;
+  y += 129;
+  return x < y ? x : y;
+}
+
+// CHECK-LABEL: define dso_local noundef i32 @m(
+// CHECK-SAME: i32 noundef [[X:%.*]], i32 noundef [[Y:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// CHECK-NEXT:  [[ENTRY:.*:]]
+// CHECK-NEXT:    [[TMP0:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[X]], i32 125), !nosanitize [[META2]]
+// CHECK-NEXT:    [[TMP1:%.*]] = extractvalue { i32, i1 } [[TMP0]], 1, !nosanitize [[META2]]
+// CHECK-NEXT:    br i1 [[TMP1]], label %[[TRAP_I:.*]], label %[[F_EXIT:.*]], !nosanitize [[META2]]
+// CHECK:       [[TRAP_I]]:
+// CHECK-NEXT:    tail call void @llvm.ubsantrap(i8 2) #[[ATTR4]], !nosanitize [[META2]]
+// CHECK-NEXT:    unreachable, !nosanitize [[META2]]
+// CHECK:       [[F_EXIT]]:
+// CHECK-NEXT:    [[TMP2:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[Y]], i32 127), !nosanitize [[META2]]
+// CHECK-NEXT:    [[TMP3:%.*]] = extractvalue { i32, i1 } [[TMP2]], 1, !nosanitize [[META2]]
+// CHECK-NEXT:    br i1 [[TMP3]], label %[[TRAP_I2:.*]], label %[[G_EXIT:.*]], !nosanitize [[META2]]
+// CHECK:       [[TRAP_I2]]:
+// CHECK-NEXT:    tail call void @llvm.ubsantrap(i8 2) #[[ATTR4]], !nosanitize [[META2]]
+// CHECK-NEXT:    unreachable, !nosanitize [[META2]]
+// CHECK:       [[G_EXIT]]:
+// CHECK-NEXT:    [[TMP4:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0, !nosanitize [[META2]]
+// CHECK-NEXT:    [[TMP5:%.*]] = extractvalue { i32, i1 } [[TMP2]], 0, !nosanitize [[META2]]
+// CHECK-NEXT:    [[TMP6:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[TMP4]], i32 [[TMP5]]), !nosanitize [[META2]]
+// CHECK-NEXT:    [[TMP7:%.*]] = extractvalue { i32, i1 } [[TMP6]], 1, !nosanitize [[META2]]
+// CHECK-NEXT:    br i1 [[TMP7]], label %[[TRAP:.*]], label %[[CONT:.*]], !nosanitize [[META2]]
+// CHECK:       [[TRAP]]:
+// CHECK-NEXT:    tail call void @llvm.ubsantrap(i8 2) #[[ATTR4]], !nosanitize [[META2]]
+// CHECK-NEXT:    unreachable, !nosanitize [[META2]]
+// CHECK:       [[CONT]]:
+// CHECK-NEXT:    [[TMP8:%.*]] = extractvalue { i32, i1 } [[TMP6]], 0, !nosanitize [[META2]]
+// CHECK-NEXT:    ret i32 [[TMP8]]
+//
+int m(int x, int y) {
+  return f(x) + g(y);
+}
+//.
+// CHECK: attributes #[[ATTR4]] = { noreturn nounwind }