[clang] [ubsan] Add -fsanitize-merge (and -fno-sanitize-merge) (PR #120464)

Wed Dec 18 16:11:53 PST 2024

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-aarch64-darwin` running on `doug-worker-5` while building `clang` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/11649

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang :: CodeGen/ubsan-trap-debugloc.c' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/clang -cc1 -internal-isystem /Users/buildbot/buildbot-root/aarch64-darwin/build/lib/clang/20/include -nostdsysteminc -emit-llvm -disable-llvm-passes -O -fsanitize=signed-integer-overflow -fsanitize-trap=signed-integer-overflow /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/CodeGen/ubsan-trap-debugloc.c -o - -debug-info-kind=line-tables-only | /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/CodeGen/ubsan-trap-debugloc.c
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/clang -cc1 -internal-isystem /Users/buildbot/buildbot-root/aarch64-darwin/build/lib/clang/20/include -nostdsysteminc -emit-llvm -disable-llvm-passes -O -fsanitize=signed-integer-overflow -fsanitize-trap=signed-integer-overflow /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/CodeGen/ubsan-trap-debugloc.c -o - -debug-info-kind=line-tables-only
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/CodeGen/ubsan-trap-debugloc.c
[1m/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/CodeGen/ubsan-trap-debugloc.c:20:11: [0m[0;1;31merror: [0m[1mCHECK: expected string not found in input
[0m// CHECK: [[LOC]] = !DILocation(line: 0
[0;1;32m          ^
[0m[1m<stdin>:75:46: [0m[0;1;30mnote: [0m[1mscanning from here
[0m call void @llvm.ubsantrap(i8 0) #4, !dbg !25, !nosanitize !8
[0;1;32m                                             ^
[0m[1m<stdin>:75:46: [0m[0;1;30mnote: [0m[1mwith "LOC" equal to "!14"
[0m call void @llvm.ubsantrap(i8 0) #4, !dbg !25, !nosanitize !8
[0;1;32m                                             ^
[0m[1m<stdin>:106:3: [0m[0;1;30mnote: [0m[1mpossible intended match here
[0m!13 = !DILocation(line: 7, column: 7, scope: !5)
[0;1;32m  ^
[0m
Input file: <stdin>
Check file: /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/CodeGen/ubsan-trap-debugloc.c

-dump-input=help explains the following input dump.

Input was:
<<<<<<
[1m[0m[0;1;30m            1: [0m[1m[0;1;46m; ModuleID = '/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/CodeGen/ubsan-trap-debugloc.c' [0m
[0;1;30m            2: [0m[1m[0;1;46msource_filename = "/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/CodeGen/ubsan-trap-debugloc.c" [0m
[0;1;30m            3: [0m[1m[0;1;46mtarget datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-n32:64-S128-Fn32" [0m
[0;1;30m            4: [0m[1m[0;1;46mtarget triple = "arm64-apple-darwin23.6.0" [0m
[0;1;30m            5: [0m[1m[0;1;46m [0m
[0;1;30m            6: [0m[1m[0;1;46m at .src = private unnamed_addr constant [99 x i8] c"/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/CodeGen/ubsan-trap-debugloc.c\00", align 1 [0m
[0;1;30m            7: [0m[1m[0;1;46m at 0 = private unnamed_addr constant { i16, i16, [6 x i8] } { i16 0, i16 11, [6 x i8] c"'int'\00" } [0m
[0;1;30m            8: [0m[1m[0;1;46m [0m
[0;1;30m            9: [0m[1m[0;1;46m; Function Attrs: nounwind [0m
[0;1;30m           10: [0m[1m[0;1;46mdefine void [0m at foo[0;1;46m(i32 noundef %a) #0 !dbg !5 { [0m
[0;1;32mlabel:5'0                  ^~~~
[0m[0;1;32mlabel:5'1                  ^~~~
[0m[0;1;30m           11: [0m[1m[0;1;46mentry: [0m
[0;1;30m           12: [0m[1m[0;1;46m %a.addr = alloca i32, align 4 [0m
[0;1;30m           13: [0m[1m[0;1;46m store volatile i32 %a, ptr %a.addr, align 4, !tbaa !9 [0m
[0;1;30m           14: [0m[1m[0;1;46m %0 = load volatile i32, ptr %a.addr, align 4, !dbg !13, !tbaa !9 [0m
[0;1;30m           15: [0m[1m[0;1;46m %1 = call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %0, i32 1), !dbg !14, !nosanitize !8 [0m
[0;1;30m           16: [0m[1m[0;1;46m %2 = extractvalue { i32, i1 } %1, 0, !dbg !14, !nosanitize !8 [0m
[0;1;30m           17: [0m[1m[0;1;46m %3 = extractvalue { i32, i1 } %1, 1, !dbg !14, !nosanitize !8 [0m
[0;1;30m           18: [0m[1m[0;1;46m %4 = xor i1 %3, true, !dbg !14, !nosanitize !8 [0m
[0;1;30m           19: [0m[1m[0;1;46m br i1 %4, label %cont, label %trap, !dbg !14, !nosanitize !8 [0m
[0;1;30m           20: [0m[1m[0;1;46m [0m
...

```

</details>

https://github.com/llvm/llvm-project/pull/120464