| Issue |
173493
|
| Summary |
Clang ICE: assertion failure in ItaniumRecordLayoutBuilder when using __attribute__((mode(QI))) on a 32-bit C bit-field
|
| Labels |
clang:codegen,
crash-on-invalid
|
| Assignees |
|
| Reporter |
AbyssStaror
|
### Link for quick verification: https://godbolt.org/z/bMx1MTd6P
```c
struct S {
int f1 : 32 __attribute__ ((mode (QI)));
};
int main() {
struct S d;
}
```
Go back to `clang 2.8.0 (assertions)`.
Clang crashes with an assertion failure when compiling a C source that applies `__attribute__((mode(QI)))` to a 32-bit bit-field while `mode(QI)` is 8-bit machine mode. The compiler incorrectly treats the field as a wide bit-field, triggering a assertion in `ItaniumRecordLayoutBuilder`.
## Stack dump:
```console
clang++: /root/llvm-project/llvm/tools/clang/lib/AST/RecordLayoutBuilder.cpp:1462: void {anonymous}::ItaniumRecordLayoutBuilder::LayoutWideBitField(uint64_t, uint64_t, bool, const clang::FieldDecl*): Assertion `Context.getLangOpts().CPlusPlus && "Can only have wide bit-fields in C++!"' 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++ -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 -x c <source>
1. <eof> parser at end of file
2. <source>:6:5: LLVM IR generation of declaration 'main'
3. <source>:6:5: Generating code for declaration 'main'
#0 0x00000000042ebc28 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x42ebc28)
#1 0x00000000042e9054 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x42e9054)
#2 0x000000000422de38 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
#3 0x00007c20bea42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
#4 0x00007c20bea969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
#5 0x00007c20bea42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
#6 0x00007c20bea287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
#7 0x00007c20bea2871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
#8 0x00007c20bea39e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
#9 0x00000000080a8477 (anonymous namespace)::ItaniumRecordLayoutBuilder::LayoutField(clang::FieldDecl const*, bool) RecordLayoutBuilder.cpp:0:0
#10 0x00000000080a8532 (anonymous namespace)::ItaniumRecordLayoutBuilder::LayoutFields(clang::RecordDecl const*) RecordLayoutBuilder.cpp:0:0
#11 0x00000000080a26dd clang::ASTContext::getASTRecordLayout(clang::RecordDecl const*) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x80a26dd)
#12 0x0000000007980227 clang::ASTContext::getTypeInfoImpl(clang::Type const*) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7980227)
#13 0x000000000797d2d7 clang::ASTContext::getTypeInfo(clang::Type const*) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x797d2d7)
#14 0x000000000798214b clang::ASTContext::getPreferredTypeAlign(clang::Type const*) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x798214b)
#15 0x0000000007982dab clang::ASTContext::getDeclAlign(clang::Decl const*, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7982dab)
#16 0x0000000004ba43f9 clang::CodeGen::CodeGenFunction::EmitAutoVarAlloca(clang::VarDecl const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4ba43f9)
#17 0x0000000004baadfb clang::CodeGen::CodeGenFunction::EmitVarDecl(clang::VarDecl const&) (.part.0) CGDecl.cpp:0:0
#18 0x0000000004bab4d7 clang::CodeGen::CodeGenFunction::EmitDecl(clang::Decl const&, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4bab4d7)
#19 0x00000000047e7c2c clang::CodeGen::CodeGenFunction::EmitDeclStmt(clang::DeclStmt const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x47e7c2c)
#20 0x00000000047fea9d clang::CodeGen::CodeGenFunction::EmitSimpleStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x47fea9d)
#21 0x00000000047f6001 clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x47f6001)
#22 0x00000000047fe5fb clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope(clang::CompoundStmt const&, bool, clang::CodeGen::AggValueSlot) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x47fe5fb)
#23 0x000000000486663e clang::CodeGen::CodeGenFunction::EmitFunctionBody(clang::Stmt const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x486663e)
#24 0x0000000004877a94 clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl, llvm::Function*, clang::CodeGen::CGFunctionInfo const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4877a94)
#25 0x00000000048e5980 clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x48e5980)
#26 0x00000000048e0624 clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x48e0624)
#27 0x00000000048e0e03 clang::CodeGen::CodeGenModule::EmitGlobal(clang::GlobalDecl) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x48e0e03)
#28 0x00000000048ec393 clang::CodeGen::CodeGenModule::EmitTopLevelDecl(clang::Decl*) (.part.0) CodeGenModule.cpp:0:0
#29 0x0000000004c4fba9 (anonymous namespace)::CodeGeneratorImpl::HandleTopLevelDecl(clang::DeclGroupRef) ModuleBuilder.cpp:0:0
#30 0x0000000004c406d4 clang::BackendConsumer::HandleTopLevelDecl(clang::DeclGroupRef) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c406d4)
#31 0x0000000006a06f74 clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6a06f74)
#32 0x0000000004c4cfb8 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c4cfb8)
#33 0x0000000004f438b5 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4f438b5)
#34 0x0000000004ec3b4e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4ec3b4e)
#35 0x000000000503dc3d clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x503dc3d)
#36 0x0000000000de5a6c cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xde5a6c)
#37 0x0000000000ddc4ba ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>) driver.cpp:0:0
#38 0x0000000000ddc63d int llvm::function_ref<int (llvm::SmallVectorImpl<char const*>&)>::callback_fn<clang_main(int, char**, llvm::ToolContext const&)::'lambda'(llvm::SmallVectorImpl<char const*>&)>(long, llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#39 0x0000000004cbf909 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
#40 0x000000000422e2d4 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x422e2d4)
#41 0x0000000004cbff1f 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
#42 0x0000000004c80a02 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c80a02)
#43 0x0000000004c819ae 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+++0x4c819ae)
#44 0x0000000004c88e05 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c88e05)
#45 0x0000000000de1e61 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xde1e61)
#46 0x0000000000c8ceb4 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc8ceb4)
#47 0x00007c20bea29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#48 0x00007c20bea29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#49 0x0000000000ddbf55 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xddbf55)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134
```
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