[llvm] [Transforms] LoopIdiomRecognize recognize strlen and wcslen (PR #108985)

Fri Mar 14 16:05:21 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-gcc-ubuntu` running on `sie-linux-worker3` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/174/builds/14565

<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)
...
0.037 [1/7/5] Building CXX object compiler-rt/lib/nsan/CMakeFiles/RTNsan_dynamic_version_script_dummy.x86_64.dir/dummy.cpp.o
0.082 [0/7/6] Linking CXX shared library /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/clang/21/lib/x86_64-unknown-linux-gnu/libclang_rt.ubsan_standalone.so
0.085 [0/6/7] Linking CXX shared library /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/clang/21/lib/x86_64-unknown-linux-gnu/libclang_rt.nsan.so
0.092 [0/5/8] Linking CXX shared library /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/clang/21/lib/x86_64-unknown-linux-gnu/libclang_rt.hwasan_aliases.so
0.092 [0/4/9] Linking CXX shared library /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/clang/21/lib/x86_64-unknown-linux-gnu/libclang_rt.hwasan.so
0.095 [0/3/10] Linking CXX shared library /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/clang/21/lib/x86_64-unknown-linux-gnu/libclang_rt.memprof.so
0.107 [0/2/11] Linking CXX shared library /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/clang/21/lib/x86_64-unknown-linux-gnu/libclang_rt.asan.so
0.396 [0/1/12] Generating /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/compile_commands.json
2.062 [3/1/14] cd /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins && /usr/bin/cmake/bin/cmake --build /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/ --target runtimes-test-depends --config Release
5.717 [0/1/1] Checking TSan Go runtime...
FAILED: compiler-rt/lib/tsan/rtl/CMakeFiles/GotsanRuntimeCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/lib/tsan/rtl/CMakeFiles/GotsanRuntimeCheck 
cd /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/lib/tsan/go && env "CC=/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang " EXTRA_CFLAGS= IN_TMPDIR=1 SILENT=1 /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/lib/tsan/rtl/../go/buildgo.sh
clang: /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp:1788: bool {anonymous}::LoopIdiomRecognize::recognizeAndInsertStrLen(): Assertion `StrLenFunc && "Failed to emit strlen function."' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.	Program arguments: /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang /tmp/gotsan.tZUhJHrlUb/gotsan.cpp -c -o /tmp/gotsan.tZUhJHrlUb/race_linux_amd64.syso -I../rtl -I../.. -I../../sanitizer_common -I../../../include -std=c++17 -Wall -fno-exceptions -fno-rtti -DSANITIZER_GO=1 -DSANITIZER_DEADLOCK_DETECTOR_VERSION=2 -fPIC -Wno-maybe-uninitialized -ffreestanding -Wno-unused-const-variable -Wno-unknown-warning-option -m64 -msse3 -DSANITIZER_DEBUG=0 -O3 -fomit-frame-pointer
1.	<eof> parser at end of file
2.	Optimizer
3.	Running pass "require<globals-aa>,function(invalidate<aa>),require<profile-summary>,cgscc(devirt<4>(inline,function-attrs<skip-non-recursive-function-attrs>,argpromotion,openmp-opt-cgscc,function<eager-inv;no-rerun>(sroa<modify-cfg>,early-cse<memssa>,speculative-execution<only-if-divergent-target>,jump-threading,correlated-propagation,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>,aggressive-instcombine,libcalls-shrinkwrap,tailcallelim,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,reassociate,constraint-elimination,loop-mssa(loop-instsimplify,loop-simplifycfg,licm<no-allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<nontrivial;trivial>),simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>,loop(loop-idiom,indvars,extra-simple-loop-unswitch-passes,loop-deletion,loop-unroll-full),sroa<modify-cfg>,vector-combine,mldst-motion<no-split-footer-bb>,gvn<>,sccp,bdce,instcombine<max-iterations=1;no-verify-fixpoint>,jump-threading,correlated-propagation,adce,memcpyopt,dse,move-auto-init,loop-mssa(licm<allowspeculation>),coro-elide,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>),function-attrs,function(require<should-not-run-function-passes>),coro-split,coro-annotation-elide)),function(invalidate<should-not-run-function-passes>),cgscc(devirt<4>())" on module "/tmp/gotsan.tZUhJHrlUb/gotsan.cpp"
4.	Running pass "cgscc(devirt<4>(inline,function-attrs<skip-non-recursive-function-attrs>,argpromotion,openmp-opt-cgscc,function<eager-inv;no-rerun>(sroa<modify-cfg>,early-cse<memssa>,speculative-execution<only-if-divergent-target>,jump-threading,correlated-propagation,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>,aggressive-instcombine,libcalls-shrinkwrap,tailcallelim,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,reassociate,constraint-elimination,loop-mssa(loop-instsimplify,loop-simplifycfg,licm<no-allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<nontrivial;trivial>),simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>,loop(loop-idiom,indvars,extra-simple-loop-unswitch-passes,loop-deletion,loop-unroll-full),sroa<modify-cfg>,vector-combine,mldst-motion<no-split-footer-bb>,gvn<>,sccp,bdce,instcombine<max-iterations=1;no-verify-fixpoint>,jump-threading,correlated-propagation,adce,memcpyopt,dse,move-auto-init,loop-mssa(licm<allowspeculation>),coro-elide,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>),function-attrs,function(require<should-not-run-function-passes>),coro-split,coro-annotation-elide))" on module "/tmp/gotsan.tZUhJHrlUb/gotsan.cpp"
5.	Running pass "loop(loop-idiom,indvars,extra-simple-loop-unswitch-passes,loop-deletion,loop-unroll-full)" on function "_ZN11__sanitizer15internal_wcslenEPKw"
 #0 0x000055bdb5a55a5f llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang+0x4597a5f)
 #1 0x000055bdb5a53554 llvm::sys::CleanupOnSignal(unsigned long) (/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang+0x4595554)
 #2 0x000055bdb59929e8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007f6ee2eb0420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
 #4 0x00007f6ee297d00b raise /build/glibc-LcI20x/glibc-2.31/signal/../sysdeps/unix/sysv/linux/raise.c:51:1
 #5 0x00007f6ee295c859 abort /build/glibc-LcI20x/glibc-2.31/stdlib/abort.c:81:7
 #6 0x00007f6ee295c729 get_sysdep_segment_value /build/glibc-LcI20x/glibc-2.31/intl/loadmsgcat.c:509:8
 #7 0x00007f6ee295c729 _nl_load_domain /build/glibc-LcI20x/glibc-2.31/intl/loadmsgcat.c:970:34
 #8 0x00007f6ee296dfd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
 #9 0x000055bdb9985df0 (anonymous namespace)::LoopIdiomRecognize::recognizeAndInsertStrLen() LoopIdiomRecognize.cpp:0:0
#10 0x000055bdb998ffc6 llvm::LoopIdiomRecognizePass::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang+0x84d1fc6)
#11 0x000055bdb7049c36 llvm::detail::PassModel<llvm::Loop, llvm::LoopIdiomRecognizePass, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) crtstuff.c:0:0
#12 0x000055bdb585844f std::optional<llvm::PreservedAnalyses> llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::runSinglePass<llvm::Loop, std::unique_ptr<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, std::default_delete<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>>>>(llvm::Loop&, std::unique_ptr<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, std::default_delete<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>>>&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&, llvm::PassInstrumentation&) (/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang+0x439a44f)
#13 0x000055bdb585860e llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::runWithoutLoopNestPasses(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang+0x439a60e)
#14 0x000055bdb585997c llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang+0x439b97c)
#15 0x000055bdb585a4e0 llvm::FunctionToLoopPassAdaptor::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang+0x439c4e0)
#16 0x000055bdb2ca7646 llvm::detail::PassModel<llvm::Function, llvm::FunctionToLoopPassAdaptor, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) crtstuff.c:0:0
#17 0x000055bdb53c8a29 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang+0x3f0aa29)
#18 0x000055bdb2ca9206 llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) crtstuff.c:0:0
#19 0x000055bdb4848f7a llvm::CGSCCToFunctionPassAdaptor::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang+0x338af7a)
#20 0x000055bdb2ca9c86 llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::CGSCCToFunctionPassAdaptor, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) crtstuff.c:0:0
#21 0x000055bdb48402f2 llvm::PassManager<llvm::LazyCallGraph::SCC, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang+0x33822f2)
#22 0x000055bdb70468c6 llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::PassManager<llvm::LazyCallGraph::SCC, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) crtstuff.c:0:0
#23 0x000055bdb4845b9d llvm::DevirtSCCRepeatedPass::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang+0x3387b9d)
#24 0x000055bdb7046916 llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::DevirtSCCRepeatedPass, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) crtstuff.c:0:0
#25 0x000055bdb4843958 llvm::ModuleToPostOrderCGSCCPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang+0x3385958)
#26 0x000055bdb7046876 llvm::detail::PassModel<llvm::Module, llvm::ModuleToPostOrderCGSCCPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) crtstuff.c:0:0
#27 0x000055bdb53c6cc1 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang+0x3f08cc1)

```

</details>

https://github.com/llvm/llvm-project/pull/108985