clang segfault

[Quuxplusone]

Bugzilla Link	PR12536
Status	RESOLVED FIXED
Importance	P enhancement
Reported by	John Regehr (regehr@cs.utah.edu)
Reported on	2012-04-12 11:03:35 -0700
Last modified on	2012-10-19 12:54:11 -0700
Version	trunk
Hardware	PC Linux
CC	benny.kra@gmail.com, chenyang@cs.utah.edu, llvm-bugs@lists.llvm.org
Fixed by commit(s)
Attachments
Blocks
Blocked by
See also

[regehr@dyson r24]$ clang -c -O1 small.c
0  clang           0x0000000001ae00ff
1  clang           0x0000000001ae0619
2  libpthread.so.0 0x00007ffff7bcf8f0
3  clang           0x0000000001a604ab llvm::Instruction::eraseFromParent() + 43
4  clang           0x0000000001881587
llvm::RecursivelyDeleteTriviallyDeadInstructions(llvm::Value*) + 343
5  clang           0x0000000001796098
6  clang           0x000000000191645b
llvm::LPPassManager::runOnFunction(llvm::Function&) + 1019
7  clang           0x0000000001a8224b
llvm::FPPassManager::runOnFunction(llvm::Function&) + 331
8  clang           0x00000000018b25d6
9  clang           0x0000000001a8271a
llvm::MPPassManager::runOnModule(llvm::Module&) + 282
10 clang           0x0000000001a82cfb llvm::PassManagerImpl::run(llvm::Module&)
+ 427
11 clang           0x0000000001a82e4a llvm::PassManager::run(llvm::Module&) + 10
12 clang           0x000000000075c3ce
clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::CodeGenOptions
const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::Module*,
clang::BackendAction, llvm::raw_ostream*) + 5038
13 clang           0x000000000075a341
14 clang           0x000000000087ff45 clang::ParseAST(clang::Sema&, bool, bool)
+ 389
15 clang           0x000000000075974d clang::CodeGenAction::ExecuteAction() +
1053
16 clang           0x0000000000632c7d
clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) + 957
17 clang           0x000000000061b9b3
clang::ExecuteCompilerInvocation(clang::CompilerInstance*) + 3299
18 clang           0x0000000000611b46 cc1_main(char const**, char const**, char
const*, void*) + 2950
19 clang           0x00000000006179e8 main + 728
20 libc.so.6       0x00007ffff6ea9c4d __libc_start_main + 253
21 clang           0x0000000000610ef9
Stack dump:
0.  Program arguments: /uusoc/exports/scratch/regehr/z/compiler-install/llvm-gcc-
r154589-install/bin/clang -cc1 -triple x86_64-unknown-linux-gnu -emit-obj -
disable-free -main-file-name small.c -mrelocation-model static -masm-verbose -
mconstructor-aliases -munwind-tables -target-cpu x86-64 -momit-leaf-frame-
pointer -coverage-file small.o -resource-dir
/uusoc/exports/scratch/regehr/z/compiler-install/llvm-gcc-r154589-
install/bin/../lib/clang/3.1 -fmodule-cache-path /var/tmp/clang-module-cache -
internal-isystem /usr/local/include -internal-isystem
/uusoc/exports/scratch/regehr/z/compiler-install/llvm-gcc-r154589-
install/bin/../lib/clang/3.1/include -internal-externc-isystem /include -
internal-externc-isystem /usr/include -O1 -fdebug-compilation-dir
/home/regehr/z/reduce/r24 -ferror-limit 19 -fmessage-length 95 -mstackrealign -
fgnu-runtime -fobjc-runtime-has-arc -fobjc-runtime-has-weak -fobjc-fragile-abi -
fdiagnostics-show-option -fcolor-diagnostics -o small.o -x c small.c
1.  <eof> parser at end of file
2.  Per-module optimization passes
3.  Running pass 'CallGraph Pass Manager' on module 'small.c'.
4.  Running pass 'Loop Pass Manager' on function '@fn1'
5.  Running pass 'Induction Variable Simplification' on basic block '%for.cond1'
clang: error: unable to execute command: Segmentation fault
clang: error: clang frontend command failed due to signal (use -v to see
invocation)
clang: note: diagnostic msg: Please submit a bug report to
http://llvm.org/bugs/ and include command line arguments and all diagnostic
information.
clang: note: diagnostic msg: Preprocessed source(s) and associated run
script(s) are located at:
clang: note: diagnostic msg: /tmp/small-AFQFm3.i
clang: note: diagnostic msg: /tmp/small-AFQFm3.sh
[regehr@dyson r24]$ cat small.c
unsigned a;
void
fn1 ()
{
    int b;
    for (;;)
    {
        int c = 0;
        a = 1;
        for (; a <= 0;)
            c = b;
        b = 0 >= c;
    }
}
[regehr@dyson r24]$ clang -v
clang version 3.1 (trunk 154589)
Target: x86_64-unknown-linux-gnu
Thread model: posix

[Quuxplusone]

Valgrind coughs up a lung on this one, looks like mainly use-after-frees.

[Quuxplusone]

Fixed in r166291.