[clang] Assertion `CachedLexPos != 0' failed.

[yijan4845]

This testcase is generated by a fuzzer.

Compiler Explorer: https://godbolt.org/z/Khfrbeqc9

This code will crash on Clang Assertion Trunk.

#define ID(X) X
extern int ID(decltype);

It seems that this is a regression for the trunk version.

Stack dump:

clang++: /root/llvm-project/clang/include/clang/Lex/Preprocessor.h:1893: clang::SourceLocation clang::Preprocessor::getLastCachedTokenLocation() const: Assertion `CachedLexPos != 0' 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: /opt/compiler-explorer/clang-assertions-trunk/bin/clang++ -gdwarf-4 -g -o /app/output.s -mllvm --x86-asm-syntax=intel -fno-verbose-asm -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics <source>
1.	<source>:2:24: current parser token ';'
 #0 0x0000000003be87b8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3be87b8)
 #1 0x0000000003be64bc llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3be64bc)
 #2 0x0000000003b33df8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007032aa642520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x00007032aa6969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x00007032aa642476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x00007032aa6287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x00007032aa62871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #8 0x00007032aa639e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #9 0x000000000673be99 clang::Parser::AnnotateExistingDecltypeSpecifier(clang::DeclSpec const&, clang::SourceLocation, clang::SourceLocation) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x673be99)
#10 0x0000000006776957 clang::Parser::ParseOptionalCXXScopeSpecifier(clang::CXXScopeSpec&, clang::OpaquePtr<clang::QualType>, bool, bool, bool*, bool, clang::IdentifierInfo const**, bool, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6776957)
#11 0x0000000006723a7b clang::Parser::ParseDeclaratorInternal(clang::Declarator&, void (clang::Parser::*)(clang::Declarator&)) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6723a7b)
#12 0x00000000081be4d1 clang::StackExhaustionHandler::runWithSufficientStackSpace(clang::SourceLocation, llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x81be4d1)
#13 0x0000000006726857 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6726857)
#14 0x00000000066e6fae clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66e6fae)
#15 0x00000000066e776e clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66e776e)
#16 0x00000000066eef03 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66eef03)
#17 0x00000000066efded clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66efded)
#18 0x00000000066f0290 clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66f0290)
#19 0x00000000066e22d2 clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66e22d2)
#20 0x0000000004560df8 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4560df8)
#21 0x000000000481b949 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x481b949)
#22 0x000000000479abbe clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x479abbe)
#23 0x00000000049016de clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49016de)
#24 0x0000000000ce5b8f cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xce5b8f)
#25 0x0000000000cdd84a ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#26 0x00000000045a3f79 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#27 0x0000000003b342a4 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3b342a4)
#28 0x00000000045a456f clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (.part.0) Job.cpp:0:0
#29 0x000000000456a8dd clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x456a8dd)
#30 0x000000000456b9cd clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x456b9cd)
#31 0x0000000004572d85 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4572d85)
#32 0x0000000000ce2a29 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xce2a29)
#33 0x0000000000bafbc4 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xbafbc4)
#34 0x00007032aa629d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#35 0x00007032aa629e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#36 0x0000000000cdd2fe _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xcdd2fe)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Yihan Yang (yijan4845)

**This testcase is generated by a fuzzer.**

Compiler Explorer: https://godbolt.org/z/Khfrbeqc9

This code will crash on Clang Assertion Trunk.

#define ID(X) X
extern int ID(decltype);

It seems that this is a regression for the trunk version.

Stack dump:

clang++: /root/llvm-project/clang/include/clang/Lex/Preprocessor.h:1893: clang::SourceLocation clang::Preprocessor::getLastCachedTokenLocation() const: Assertion `CachedLexPos != 0' 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: /opt/compiler-explorer/clang-assertions-trunk/bin/clang++ -gdwarf-4 -g -o /app/output.s -mllvm --x86-asm-syntax=intel -fno-verbose-asm -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics <source>
1.	<source>:2:24: current parser token ';'
 #<!-- -->0 0x0000000003be87b8 llvm::sys::PrintStackTrace(llvm::raw_ostream&amp;, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3be87b8)
 #<!-- -->1 0x0000000003be64bc llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3be64bc)
 #<!-- -->2 0x0000000003b33df8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #<!-- -->3 0x00007032aa642520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #<!-- -->4 0x00007032aa6969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #<!-- -->5 0x00007032aa642476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #<!-- -->6 0x00007032aa6287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #<!-- -->7 0x00007032aa62871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #<!-- -->8 0x00007032aa639e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #<!-- -->9 0x000000000673be99 clang::Parser::AnnotateExistingDecltypeSpecifier(clang::DeclSpec const&amp;, clang::SourceLocation, clang::SourceLocation) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x673be99)
#<!-- -->10 0x0000000006776957 clang::Parser::ParseOptionalCXXScopeSpecifier(clang::CXXScopeSpec&amp;, clang::OpaquePtr&lt;clang::QualType&gt;, bool, bool, bool*, bool, clang::IdentifierInfo const**, bool, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6776957)
#<!-- -->11 0x0000000006723a7b clang::Parser::ParseDeclaratorInternal(clang::Declarator&amp;, void (clang::Parser::*)(clang::Declarator&amp;)) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6723a7b)
#<!-- -->12 0x00000000081be4d1 clang::StackExhaustionHandler::runWithSufficientStackSpace(clang::SourceLocation, llvm::function_ref&lt;void ()&gt;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x81be4d1)
#<!-- -->13 0x0000000006726857 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&amp;, clang::DeclaratorContext, clang::ParsedAttributes&amp;, clang::Parser::ParsedTemplateInfo&amp;, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6726857)
#<!-- -->14 0x00000000066e6fae clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&amp;, clang::ParsedAttributes&amp;, clang::ParsingDeclSpec&amp;, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66e6fae)
#<!-- -->15 0x00000000066e776e clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&amp;, clang::ParsedAttributes&amp;, clang::ParsingDeclSpec*, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66e776e)
#<!-- -->16 0x00000000066eef03 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&amp;, clang::ParsedAttributes&amp;, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66eef03)
#<!-- -->17 0x00000000066efded clang::Parser::ParseTopLevelDecl(clang::OpaquePtr&lt;clang::DeclGroupRef&gt;&amp;, clang::Sema::ModuleImportState&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66efded)
#<!-- -->18 0x00000000066f0290 clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr&lt;clang::DeclGroupRef&gt;&amp;, clang::Sema::ModuleImportState&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66f0290)
#<!-- -->19 0x00000000066e22d2 clang::ParseAST(clang::Sema&amp;, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66e22d2)
#<!-- -->20 0x0000000004560df8 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4560df8)
#<!-- -->21 0x000000000481b949 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x481b949)
#<!-- -->22 0x000000000479abbe clang::CompilerInstance::ExecuteAction(clang::FrontendAction&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x479abbe)
#<!-- -->23 0x00000000049016de clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49016de)
#<!-- -->24 0x0000000000ce5b8f cc1_main(llvm::ArrayRef&lt;char const*&gt;, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xce5b8f)
#<!-- -->25 0x0000000000cdd84a ExecuteCC1Tool(llvm::SmallVectorImpl&lt;char const*&gt;&amp;, llvm::ToolContext const&amp;) driver.cpp:0:0
#<!-- -->26 0x00000000045a3f79 void llvm::function_ref&lt;void ()&gt;::callback_fn&lt;clang::driver::CC1Command::Execute(llvm::ArrayRef&lt;std::optional&lt;llvm::StringRef&gt;&gt;, std::__cxx11::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt;&gt;*, bool*) const::'lambda'()&gt;(long) Job.cpp:0:0
#<!-- -->27 0x0000000003b342a4 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref&lt;void ()&gt;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3b342a4)
#<!-- -->28 0x00000000045a456f clang::driver::CC1Command::Execute(llvm::ArrayRef&lt;std::optional&lt;llvm::StringRef&gt;&gt;, std::__cxx11::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt;&gt;*, bool*) const (.part.0) Job.cpp:0:0
#<!-- -->29 0x000000000456a8dd clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&amp;, clang::driver::Command const*&amp;, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x456a8dd)
#<!-- -->30 0x000000000456b9cd clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&amp;, llvm::SmallVectorImpl&lt;std::pair&lt;int, clang::driver::Command const*&gt;&gt;&amp;, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x456b9cd)
#<!-- -->31 0x0000000004572d85 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&amp;, llvm::SmallVectorImpl&lt;std::pair&lt;int, clang::driver::Command const*&gt;&gt;&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4572d85)
#<!-- -->32 0x0000000000ce2a29 clang_main(int, char**, llvm::ToolContext const&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xce2a29)
#<!-- -->33 0x0000000000bafbc4 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xbafbc4)
#<!-- -->34 0x00007032aa629d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#<!-- -->35 0x00007032aa629e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#<!-- -->36 0x0000000000cdd2fe _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xcdd2fe)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134