Compiling the following testcase causes a crash:
struct A {
~A() {}
};
int fred(char *p, int *q) {
if (p != 0) {
goto bail;
}
thread_local A a;
*q = 0;
bail:
return 0;
}The crash is caused by CFGBuilder thinking that the variable a is local (in terms of storage scope), and trying to perform some sort of a lifetime analysis on it. The problem is that the program would not have been legal if a was actually local, and the problem would have been diagnosed earlier, preventing CFGBuilder from running in the first place.
This fix recognizes locally declared C++11 thread_local variables as static.
Assertion failed: (F != const_iterator() && "L iterator is not reachable from F iterator."), function distance, file /w/src/llvm.org/clang/lib/Analysis/CFG.cpp, line 334. 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: /w/c/org/bin/clang++ -c dd.cc 1. <eof> parser at end of file 2. dd.cc:5:27: parsing function body 'fred' #0 0x000000000561c8aa llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/w/c/org/bin/clang+++0x561c8aa) #1 0x000000000561a788 llvm::sys::RunSignalHandlers() (/w/c/org/bin/clang+++0x561a788) #2 0x000000000557edd4 (anonymous namespace)::CrashRecoveryContextImpl::HandleCrash(int, unsigned long) CrashRecoveryContext.cpp:0:0 #3 0x000000000557efa0 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0 #4 0x00000008091f35b0 handle_signal /usr/src/lib/libthr/thread/thr_sig.c:0:3 #5 0x00000008091f2b6f thr_sighandler /usr/src/lib/libthr/thread/thr_sig.c:247:1 #6 0x00007ffffffff2d3 ([vdso]+0x2d3) #7 0x000000080950f14a thr_kill /usr/obj/usr/src/amd64.amd64/lib/libc/thr_kill.S:4:0 #8 0x0000000809487c34 _raise /usr/src/lib/libc/gen/raise.c:0:10 #9 0x0000000809538e99 abort /usr/src/lib/libc/stdlib/abort.c:73:17 #10 0x000000080946a9d1 (/lib/libc.so.7+0x929d1) #11 0x0000000007f2fa66 (anonymous namespace)::CFGBuilder::addAutomaticObjHandling((anonymous namespace)::LocalScope::const_iterator, (anonymous namespace)::LocalScope::const_iterator, clang::Stmt*) CFG.cpp:0:0 #12 0x0000000007f2adc7 (anonymous namespace)::CFGBuilder::VisitGotoStmt(clang::GotoStmt*) CFG.cpp:0:0 #13 0x0000000007f2866f (anonymous namespace)::CFGBuilder::VisitCompoundStmt(clang::CompoundStmt*, bool) CFG.cpp:0:0 #14 0x0000000007f2b612 (anonymous namespace)::CFGBuilder::VisitIfStmt(clang::IfStmt*) CFG.cpp:0:0 #15 0x0000000007f2866f (anonymous namespace)::CFGBuilder::VisitCompoundStmt(clang::CompoundStmt*, bool) CFG.cpp:0:0 #16 0x0000000007f211e4 clang::CFG::buildCFG(clang::Decl const*, clang::Stmt*, clang::ASTContext*, clang::CFG::BuildOptions const&) (/w/c/org/bin/clang+++0x7f211e4) #17 0x0000000007ef12ab clang::AnalysisDeclContext::getCFG() (/w/c/org/bin/clang+++0x7ef12ab) #18 0x00000000076bb654 clang::sema::AnalysisBasedWarnings::IssueWarnings(clang::sema::AnalysisBasedWarnings::Policy, clang::sema::FunctionScopeInfo*, clang::Decl const*, clang::QualType) (/w/c/org/bin/clang+++0x76bb654) #19 0x00000000076b05f7 clang::Sema::PopFunctionScopeInfo(clang::sema::AnalysisBasedWarnings::Policy const*, clang::Decl const*, clang::QualType) (/w/c/org/bin/clang+++0x76b05f7) #20 0x0000000007817aa2 clang::Sema::ActOnFinishFunctionBody(clang::Decl*, clang::Stmt*, bool) (/w/c/org/bin/clang+++0x7817aa2) #21 0x00000000075bb3f3 clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/w/c/org/bin/clang+++0x75bb3f3) #22 0x0000000007590e34 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) (/w/c/org/bin/clang+++0x7590e34) #23 0x0000000007615d7d clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/w/c/org/bin/clang+++0x7615d7d) #24 0x000000000758f681 clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/w/c/org/bin/clang+++0x758f681) #25 0x000000000758f0a2 clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (/w/c/org/bin/clang+++0x758f0a2) #26 0x000000000758de8b clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/w/c/org/bin/clang+++0x758de8b) #27 0x000000000758bdcd clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/w/c/org/bin/clang+++0x758bdcd) #28 0x0000000007585f7e clang::ParseAST(clang::Sema&, bool, bool) (/w/c/org/bin/clang+++0x7585f7e) #29 0x0000000006082523 clang::FrontendAction::Execute() (/w/c/org/bin/clang+++0x6082523) #30 0x000000000600aeef clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/w/c/org/bin/clang+++0x600aeef) #31 0x000000000614c4b5 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/w/c/org/bin/clang+++0x614c4b5) #32 0x0000000003244afc cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/w/c/org/bin/clang+++0x3244afc) #33 0x00000000032421ea ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0 #34 0x0000000005eb48e7 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef> >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >*, bool*) const::$_1>(long) Job.cpp:0:0 #35 0x000000000557ecf0 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/w/c/org/bin/clang+++0x557ecf0) #36 0x0000000005eb43f2 clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef> >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >*, bool*) const (/w/c/org/bin/clang+++0x5eb43f2) #37 0x0000000005e7dba4 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&) const (/w/c/org/bin/clang+++0x5e7dba4) #38 0x0000000005e7dfd9 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::__1::pair<int, clang::driver::Command const*> >&) const (/w/c/org/bin/clang+++0x5e7dfd9) #39 0x0000000005e953ac clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::__1::pair<int, clang::driver::Command const*> >&) (/w/c/org/bin/clang+++0x5e953ac) clang-15: error: clang frontend command failed with exit code 134 (use -v to see invocation) clang version 15.0.0 (https://github.com/llvm/llvm-project.git 0b2a2620b883cef1dac63f3ea4c839aba0e4d80e) Target: x86_64-unknown-freebsd13.0 Thread model: posix InstalledDir: /w/c/org/bin clang-15: note: diagnostic msg: ******************** PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT: Preprocessed source(s) and associated run script(s) are located at: clang-15: note: diagnostic msg: /tmp/dd-48e7c6.cpp clang-15: note: diagnostic msg: /tmp/dd-48e7c6.sh clang-15: note: diagnostic msg: ********************