Clang segfault while compiling some SIMD code with -Wcast-align

[audiovention]

I'm having trouble compiling the xsimd library (https://github.com/xtensor-stack/xsimd) with Clang. I've reproduced the issue in my codebase both on Linux (Ubuntu Clang version 15.0.7) and macOS (Apple Clang version 14.0.3 (clang-1403.0.22.14.1)).
Interesting enough on macOS I get the segfault only on Apple Silicon, not on an Intel machine, although it was segfaulting on the Intel machine with the previous version of XCode.

I've manage to create a minimum example, and narrowed down the issue to enabling the warning -Wcast-align (i.e. with the warning enabled I get a segfault during compilation, with the warning disabled the code compiles and runs fine). The code compiles and runs fine in GCC.

Here's the stack trace:

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: /usr/bin/clang++ -I/home/momchil/Desktop/AVxtensor/src -I/home/momchil/Desktop/AVxtensor/externals/xsimd/include -g -Wcast-align -std=gnu++20 -MD -MT CMakeFiles/ExampleProblemProject.dir/src/ExampleProblem.cpp.o -MF CMakeFiles/ExampleProblemProject.dir/src/ExampleProblem.cpp.o.d -o CMakeFiles/ExampleProblemProject.dir/src/ExampleProblem.cpp.o -c /home/momchil/Desktop/AVxtensor/src/ExampleProblem.cpp
1.	/home/momchil/Desktop/AVxtensor/externals/xsimd/include/xsimd/arch/./xsimd_sse2.hpp:672:77: current parser token ')'
2.	/home/momchil/Desktop/AVxtensor/externals/xsimd/include/xsimd/arch/./xsimd_sse2.hpp:21:1: parsing namespace 'xsimd'
3.	/home/momchil/Desktop/AVxtensor/externals/xsimd/include/xsimd/arch/./xsimd_sse2.hpp:32:5: parsing namespace 'xsimd::kernel'
4.	/home/momchil/Desktop/AVxtensor/externals/xsimd/include/xsimd/arch/./xsimd_sse2.hpp:652:9: parsing function body 'xsimd::kernel::from_mask'
5.	/home/momchil/Desktop/AVxtensor/externals/xsimd/include/xsimd/arch/./xsimd_sse2.hpp:652:9: in compound statement ('{}')
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
/usr/lib/llvm-15/bin/../lib/libLLVM-15.so.1(_ZN4llvm3sys15PrintStackTraceERNS_11raw_ostreamEi+0x31)[0x7fc0c4b07281]
/usr/lib/llvm-15/bin/../lib/libLLVM-15.so.1(_ZN4llvm3sys17RunSignalHandlersEv+0xee)[0x7fc0c4b04f9e]
/usr/lib/llvm-15/bin/../lib/libLLVM-15.so.1(_ZN4llvm3sys15CleanupOnSignalEm+0x101)[0x7fc0c4b06641]
/usr/lib/llvm-15/bin/../lib/libLLVM-15.so.1(+0xe2954f)[0x7fc0c4a2954f]
/lib/x86_64-linux-gnu/libc.so.6(+0x3bcf0)[0x7fc0c343bcf0]
/lib/x86_64-linux-gnu/libc.so.6(+0x171b81)[0x7fc0c3571b81]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZNK5clang4Expr21EvaluateKnownConstIntERKNS_10ASTContextEPN4llvm15SmallVectorImplISt4pairINS_14SourceLocationENS_17PartialDiagnosticEEEE+0x277)[0x7fc0cbb794b7]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZNK5clang11AlignedAttr12getAlignmentERNS_10ASTContextE+0x3a)[0x7fc0cba4f10a]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZNK5clang4Decl15getMaxAlignmentEv+0x1b7)[0x7fc0cbaffa17]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZNK5clang10ASTContext12getDeclAlignEPKNS_4DeclEb+0x1e)[0x7fc0cb973e1e]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(+0x12844ed)[0x7fc0cc0844ed]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(+0x12841a8)[0x7fc0cc0841a8]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(+0x12848fe)[0x7fc0cc0848fe]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(+0x12846a8)[0x7fc0cc0846a8]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(+0x12841a8)[0x7fc0cc0841a8]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(+0x1268c0c)[0x7fc0cc068c0c]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang4Sema14CheckCastAlignEPNS_4ExprENS_8QualTypeENS_11SourceRangeE+0x130)[0x7fc0cc068b10]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(+0x123d1f2)[0x7fc0cc03d1f2]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang4Sema19BuildCStyleCastExprENS_14SourceLocationEPNS_14TypeSourceInfoES1_PNS_4ExprE+0x12d)[0x7fc0cc03ac4d]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang4Sema13ActOnCastExprEPNS_5ScopeENS_14SourceLocationERNS_10DeclaratorERNS_9OpaquePtrINS_8QualTypeEEES3_PNS_4ExprE+0x31f)[0x7fc0cc27a2cf]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser20ParseParenExpressionERNS0_16ParenParseOptionEbbRNS_9OpaquePtrINS_8QualTypeEEERNS_14SourceLocationE+0x1628)[0x7fc0cb8db838]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser19ParseCastExpressionENS0_13CastParseKindEbRbNS0_13TypeCastStateEbPb+0x17ee)[0x7fc0cb8d885e]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser25ParseAssignmentExpressionENS0_13TypeCastStateE+0xe1)[0x7fc0cb8d3091]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser19ParseExpressionListERN4llvm15SmallVectorImplIPNS_4ExprEEERNS2_INS_14SourceLocationEEENS1_12function_refIFvvEEEbb+0x10a)[0x7fc0cb8df03a]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser28ParsePostfixExpressionSuffixENS_12ActionResultIPNS_4ExprELb1EEE+0x14f4)[0x7fc0cb8d60b4]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser19ParseCastExpressionENS0_13CastParseKindEbRbNS0_13TypeCastStateEbPb+0xdf)[0x7fc0cb8d714f]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser25ParseAssignmentExpressionENS0_13TypeCastStateE+0xe1)[0x7fc0cb8d3091]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser19ParseExpressionListERN4llvm15SmallVectorImplIPNS_4ExprEEERNS2_INS_14SourceLocationEEENS1_12function_refIFvvEEEbb+0x10a)[0x7fc0cb8df03a]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser28ParsePostfixExpressionSuffixENS_12ActionResultIPNS_4ExprELb1EEE+0x14f4)[0x7fc0cb8d60b4]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser19ParseCastExpressionENS0_13CastParseKindEbRbNS0_13TypeCastStateEbPb+0xdf)[0x7fc0cb8d714f]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser25ParseAssignmentExpressionENS0_13TypeCastStateE+0xe1)[0x7fc0cb8d3091]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser15ParseExpressionENS0_13TypeCastStateE+0x9)[0x7fc0cb8d2f99]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser20ParseReturnStatementEv+0x107)[0x7fc0cb936d97]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser42ParseStatementOrDeclarationAfterAttributesERN4llvm11SmallVectorIPNS_4StmtELj32EEENS0_17ParsedStmtContextEPNS_14SourceLocationERNS_16ParsedAttributesESB_+0xa0d)[0x7fc0cb930bdd]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser27ParseStatementOrDeclarationERN4llvm11SmallVectorIPNS_4StmtELj32EEENS0_17ParsedStmtContextEPNS_14SourceLocationE+0x15f)[0x7fc0cb92ffbf]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser26ParseCompoundStatementBodyEb+0x7a0)[0x7fc0cb938c90]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser26ParseFunctionStatementBodyEPNS_4DeclERNS0_10ParseScopeE+0xb5)[0x7fc0cb939cc5]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser23ParseFunctionDefinitionERNS_17ParsingDeclaratorERKNS0_18ParsedTemplateInfoEPNS0_18LateParsedAttrListE+0xe12)[0x7fc0cb953ec2]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser35ParseSingleDeclarationAfterTemplateENS_17DeclaratorContextERKNS0_18ParsedTemplateInfoERNS_21ParsingDeclRAIIObjectERNS_14SourceLocationERNS_16ParsedAttributesENS_15AccessSpecifierE+0x1043)[0x7fc0cb942273]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser40ParseTemplateDeclarationOrSpecializationENS_17DeclaratorContextERNS_14SourceLocationERNS_16ParsedAttributesENS_15AccessSpecifierE+0x512)[0x7fc0cb9408c2]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser36ParseDeclarationStartingWithTemplateENS_17DeclaratorContextERNS_14SourceLocationERNS_16ParsedAttributesENS_15AccessSpecifierE+0xdc)[0x7fc0cb94023c]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser16ParseDeclarationENS_17DeclaratorContextERNS_14SourceLocationERNS_16ParsedAttributesES5_PS2_+0x1c5)[0x7fc0cb8a1cd5]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser24ParseExternalDeclarationERNS_16ParsedAttributesEPNS_15ParsingDeclSpecE+0x11b)[0x7fc0cb95157b]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser19ParseInnerNamespaceERKN4llvm11SmallVectorINS0_18InnerNamespaceInfoELj4EEEjRNS_14SourceLocationERNS_16ParsedAttributesERNS_24BalancedDelimiterTrackerE+0xd2)[0x7fc0cb8bcd72]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser14ParseNamespaceENS_17DeclaratorContextERNS_14SourceLocationES2_+0x12e6)[0x7fc0cb8bc6b6]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser16ParseDeclarationENS_17DeclaratorContextERNS_14SourceLocationERNS_16ParsedAttributesES5_PS2_+0x3c7)[0x7fc0cb8a1ed7]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser24ParseExternalDeclarationERNS_16ParsedAttributesEPNS_15ParsingDeclSpecE+0x11b)[0x7fc0cb95157b]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser19ParseInnerNamespaceERKN4llvm11SmallVectorINS0_18InnerNamespaceInfoELj4EEEjRNS_14SourceLocationERNS_16ParsedAttributesERNS_24BalancedDelimiterTrackerE+0xd2)[0x7fc0cb8bcd72]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser14ParseNamespaceENS_17DeclaratorContextERNS_14SourceLocationES2_+0x12e6)[0x7fc0cb8bc6b6]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser16ParseDeclarationENS_17DeclaratorContextERNS_14SourceLocationERNS_16ParsedAttributesES5_PS2_+0x3c7)[0x7fc0cb8a1ed7]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser24ParseExternalDeclarationERNS_16ParsedAttributesEPNS_15ParsingDeclSpecE+0x11b)[0x7fc0cb95157b]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6Parser17ParseTopLevelDeclERNS_9OpaquePtrINS_12DeclGroupRefEEERNS_4Sema17ModuleImportStateE+0x453)[0x7fc0cb94ff33]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang8ParseASTERNS_4SemaEbb+0x2ee)[0x7fc0cb88e82e]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang13CodeGenAction13ExecuteActionEv+0xd5)[0x7fc0cca81785]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang14FrontendAction7ExecuteEv+0x67)[0x7fc0cd4be4b7]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang16CompilerInstance13ExecuteActionERNS_14FrontendActionE+0x336)[0x7fc0cd42f606]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang25ExecuteCompilerInvocationEPNS_16CompilerInstanceE+0x29a)[0x7fc0cd53ca6a]
/usr/bin/clang++(_Z8cc1_mainN4llvm8ArrayRefIPKcEES2_Pv+0x968)[0x55c345685598]
/usr/bin/clang++(+0x1169b)[0x55c34568369b]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(+0x228fbd2)[0x7fc0cd08fbd2]
/usr/lib/llvm-15/bin/../lib/libLLVM-15.so.1(_ZN4llvm20CrashRecoveryContext9RunSafelyENS_12function_refIFvvEEE+0xde)[0x7fc0c4a292ae]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZNK5clang6driver10CC1Command7ExecuteEN4llvm8ArrayRefINS2_8OptionalINS2_9StringRefEEEEEPNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEPb+0x138)[0x7fc0cd08f6a8]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZNK5clang6driver11Compilation14ExecuteCommandERKNS0_7CommandERPS3_b+0x44a)[0x7fc0cd05171a]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZNK5clang6driver11Compilation11ExecuteJobsERKNS0_7JobListERN4llvm15SmallVectorImplISt4pairIiPKNS0_7CommandEEEEb+0x8e)[0x7fc0cd05196e]
/usr/lib/llvm-15/bin/../lib/libclang-cpp.so.15(_ZN5clang6driver6Driver18ExecuteCompilationERNS0_11CompilationERN4llvm15SmallVectorImplISt4pairIiPKNS0_7CommandEEEE+0x39f)[0x7fc0cd06e99f]
/usr/bin/clang++(_Z10clang_mainiPPc+0x27ef)[0x55c345682e1f]
/lib/x86_64-linux-gnu/libc.so.6(+0x23510)[0x7fc0c3423510]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x89)[0x7fc0c34235c9]
/usr/bin/clang++(_start+0x25)[0x55c3456802e5]
clang: error: clang frontend command failed with exit code 139 (use -v to see invocation)
Ubuntu clang version 15.0.7
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
clang: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: /tmp/ExampleProblem-999383.cpp
clang: note: diagnostic msg: /tmp/ExampleProblem-999383.sh
clang: note: diagnostic msg: 

********************

I'm attaching the Clang generated preprocessed file and compile script, as well as a zip of a minimum example CMake project to repro.

ExampleProblem.zip
ExampleProblem-999383.zip

[audiovention]

Here's the issue I created in the repo of the project I'm compiling:
xtensor-stack/xsimd#932

[Fznamznon]

Reproduced with trunk and ExampleProblem-999383.zip. Assertion message:

clang: /source/llorg/llvm-project/clang/lib/AST/AttrImpl.cpp:243: unsigned int clang::AlignedAttr::getAlignment(clang::ASTContext&) const: Assertion `!isAlignmentDependent()' failed.

Backtrace:

0.      Program arguments: clang -cc1 -triple x86_64-pc-linux-gnu -emit-obj -mrelax-all -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names
-main-file-name ExampleProblem.cpp -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-alias$
s -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -mllvm -treat-scalable-fixed-error-as-warning -debug-info-kind=constructor -dwarf-version=5 -debugger-tuning=gdb -$
ys-header-deps -Wcast-align -std=gnu++20 -fdeprecated-macro -ferror-limit 19 -fgnuc-version=4.2.1 -fcxx-exceptions -fexceptions -fcolor-diagnostics -faddrsig -D__GCC_HAVE_$
WARF2_CFI_ASM=1 -x c++ ExampleProblem-999383.cpp
1.      /home/momchil/Desktop/AVxtensor/externals/xsimd/include/xsimd/arch/./xsimd_sse2.hpp:672:77: current parser token ')'
2.      /home/momchil/Desktop/AVxtensor/externals/xsimd/include/xsimd/arch/./xsimd_sse2.hpp:21:1: parsing namespace 'xsimd'
3.      /home/momchil/Desktop/AVxtensor/externals/xsimd/include/xsimd/arch/./xsimd_sse2.hpp:32:5: parsing namespace 'xsimd::kernel'
4.      /home/momchil/Desktop/AVxtensor/externals/xsimd/include/xsimd/arch/./xsimd_sse2.hpp:652:9: parsing function body 'xsimd::kernel::from_mask'
5.      /home/momchil/Desktop/AVxtensor/externals/xsimd/include/xsimd/arch/./xsimd_sse2.hpp:652:9: in compound statement ('{}')
 #0 0x0000000003313a08 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (source/llorg/llvm-project/build/bin/clang-17+0x3313a08)
 #1 0x00000000033112ec SignalHandler(int) Signals.cpp:0:0
 #2 0x00007f797c138b20 __restore_rt sigaction.c:0:0
 #3 0x00007f797a97537f raise (/lib64/libc.so.6+0x3737f)
 #4 0x00007f797a95fdb5 abort (/lib64/libc.so.6+0x21db5)
 #5 0x00007f797a95fc89 _nl_load_domain.cold.0 loadmsgcat.c:0:0
 #6 0x00007f797a96da76 .annobin___GI___assert_fail.end assert.c:0:0
 #7 0x0000000005f3edb3 clang::AlignedAttr::getAlignment(clang::ASTContext&) const (source/llorg/llvm-project/build/bin/clang-17+0x5f3edb3)
 #8 0x0000000005ff48ce clang::Decl::getMaxAlignment() const (source/llorg/llvm-project/build/bin/clang-17+0x5ff48ce)
 #9 0x0000000005e7fcdf clang::ASTContext::getDeclAlign(clang::Decl const*, bool) const (source/llorg/llvm-project/build/bin/clang-17+0x5e7fcdf)
#10 0x000000000539fa0e getBaseAlignmentAndOffsetFromLValue(clang::Expr const*, clang::ASTContext&) (.part.2511) SemaChecking.cpp:0:0
#11 0x000000000539fbeb getBaseAlignmentAndOffsetFromPtr(clang::Expr const*, clang::ASTContext&) (.part.2509) SemaChecking.cpp:0:0
#12 0x000000000539fdc8 getAlignmentAndOffsetFromBinAddOrSub(clang::Expr const*, clang::Expr const*, bool, clang::ASTContext&) SemaChecking.cpp:0:0
#13 0x000000000539f99e getBaseAlignmentAndOffsetFromLValue(clang::Expr const*, clang::ASTContext&) (.part.2511) SemaChecking.cpp:0:0
#14 0x000000000539fbeb getBaseAlignmentAndOffsetFromPtr(clang::Expr const*, clang::ASTContext&) (.part.2509) SemaChecking.cpp:0:0
#15 0x00000000053ab5b8 clang::Sema::CheckCastAlign(clang::Expr*, clang::QualType, clang::SourceRange) (source/llorg/llvm-project/build/bin/clang-17+0x5
3ab5b8)
#16 0x00000000053834ff (anonymous namespace)::CastOperation::CheckCXXCStyleCast(bool, bool) SemaCast.cpp:0:0
#17 0x00000000053856fe clang::Sema::BuildCStyleCastExpr(clang::SourceLocation, clang::TypeSourceInfo*, clang::SourceLocation, clang::Expr*) (source/llo
rg/llvm-project/build/bin/clang-17+0x53856fe)
#18 0x00000000056af4d6 clang::Sema::ActOnCastExpr(clang::Scope*, clang::SourceLocation, clang::Declarator&, clang::OpaquePtr<clang::QualType>&, clang::SourceLocation, clang
::Expr*) (source/llorg/llvm-project/build/bin/clang-17+0x56af4d6)
#19 0x0000000005276e16 clang::Parser::ParseParenExpression(clang::Parser::ParenParseOption&, bool, bool, clang::OpaquePtr<clang::QualType>&, clang::SourceLocation&) (/local
disk2/mpodchis/source/llorg/llvm-project/build/bin/clang-17+0x5276e16)
#20 0x000000000526dee8 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, bool&, clang::Parser::TypeCastState, bool, bool*) (source
/llorg/llvm-project/build/bin/clang-17+0x526dee8)
#21 0x0000000005270966 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, clang::Parser::TypeCastState, bool, bool*) (source/llorg/
llvm-project/build/bin/clang-17+0x5270966)
#22 0x00000000052709f8 clang::Parser::ParseAssignmentExpression(clang::Parser::TypeCastState) (source/llorg/llvm-project/build/bin/clang-17+0x52709f8)
#23 0x0000000005270d1f clang::Parser::ParseExpressionList(llvm::SmallVectorImpl<clang::Expr*>&, llvm::function_ref<void ()>, bool, bool) (source/llorg/
llvm-project/build/bin/clang-17+0x5270d1f)
#24 0x0000000005272a05 clang::Parser::ParsePostfixExpressionSuffix(clang::ActionResult<clang::Expr*, true>) (source/llorg/llvm-project/build/bin/clang-
17+0x5272a05)
#25 0x000000000526d2c9 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, bool&, clang::Parser::TypeCastState, bool, bool*) (source
/llorg/llvm-project/build/bin/clang-17+0x526d2c9)
#26 0x0000000005270966 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, clang::Parser::TypeCastState, bool, bool*) (source/llorg$
#27 0x00000000052709f8 clang::Parser::ParseAssignmentExpression(clang::Parser::TypeCastState) (source/llorg/llvm-project/build/bin/clang-17+0x52709f8)
#28 0x0000000005270d1f clang::Parser::ParseExpressionList(llvm::SmallVectorImpl<clang::Expr*>&, llvm::function_ref<void ()>, bool, bool) (source/llorg/
llvm-project/build/bin/clang-17+0x5270d1f)
#29 0x0000000005272a05 clang::Parser::ParsePostfixExpressionSuffix(clang::ActionResult<clang::Expr*, true>) (source/llorg/llvm-project/build/bin/clang-
17+0x5272a05)
#30 0x000000000526d2c9 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, bool&, clang::Parser::TypeCastState, bool, bool*) (source
/llorg/llvm-project/build/bin/clang-17+0x526d2c9)
#31 0x0000000005270966 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, clang::Parser::TypeCastState, bool, bool*) (source/llorg/
llvm-project/build/bin/clang-17+0x5270966)
#32 0x00000000052709f8 clang::Parser::ParseAssignmentExpression(clang::Parser::TypeCastState) (source/llorg/llvm-project/build/bin/clang-17+0x52709f8)
#33 0x00000000052726e9 clang::Parser::ParseExpression(clang::Parser::TypeCastState) (source/llorg/llvm-project/build/bin/clang-17+0x52726e9)
#34 0x00000000052d2fee clang::Parser::ParseReturnStatement() (source/llorg/llvm-project/build/bin/clang-17+0x52d2fee)
#35 0x00000000052d763f clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocat
ion*, clang::ParsedAttributes&, clang::ParsedAttributes&) (source/llorg/llvm-project/build/bin/clang-17+0x52d763f)
#36 0x00000000052d8d3c clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/localdi
sk2/mpodchis/source/llorg/llvm-project/build/bin/clang-17+0x52d8d3c)
#37 0x00000000052d4cb8 clang::Parser::ParseCompoundStatementBody(bool) (source/llorg/llvm-project/build/bin/clang-17+0x52d4cb8)
#38 0x00000000052d533b clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (source/llorg/llvm-project/build/bin/clang-1
7+0x52d533b)
#39 0x0000000005225f93 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) (/loc
aldisk2/mpodchis/source/llorg/llvm-project/build/bin/clang-17+0x5225f93)
#40 0x00000000052e9bd3 clang::Parser::ParseSingleDeclarationAfterTemplate(clang::DeclaratorContext, clang::Parser::ParsedTemplateInfo const&, clang::ParsingDeclRAIIObject&,
 clang::SourceLocation&, clang::ParsedAttributes&, clang::AccessSpecifier) (source/llorg/llvm-project/build/bin/clang-17+0x52e9bd3)
#41 0x00000000052f4823 clang::Parser::ParseTemplateDeclarationOrSpecialization(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::AccessSpec
ifier) (.part.348) ParseTemplate.cpp:0:0
#42 0x00000000052f4ad4 clang::Parser::ParseDeclarationStartingWithTemplate(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::AccessSpecifie
r) (source/llorg/llvm-project/build/bin/clang-17+0x52f4ad4)
#43 0x000000000524d368 clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLo
cation*) (source/llorg/llvm-project/build/bin/clang-17+0x524d368)
#44 0x0000000005227090 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (source/llo
rg/llvm-project/build/bin/clang-17+0x5227090)
#45 0x000000000525ce64 clang::Parser::ParseInnerNamespace(llvm::SmallVector<clang::Parser::InnerNamespaceInfo, 4u> const&, unsigned int, clang::SourceLocation&, clang::Pars
edAttributes&, clang::BalancedDelimiterTracker&) (source/llorg/llvm-project/build/bin/clang-17+0x525ce64)
#46 0x000000000525fe1a clang::Parser::ParseNamespace(clang::DeclaratorContext, clang::SourceLocation&, clang::SourceLocation) (source/llorg/llvm-projec
t/build/bin/clang-17+0x525fe1a)
#47 0x000000000524d226 clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLo
cation*) (source/llorg/llvm-project/build/bin/clang-17+0x524d226)
#48 0x0000000005227090 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (source/llo
rg/llvm-project/build/bin/clang-17+0x5227090)
#49 0x000000000525ce64 clang::Parser::ParseInnerNamespace(llvm::SmallVector<clang::Parser::InnerNamespaceInfo, 4u> const&, unsigned int, clang::SourceLocation&, clang::Pars
edAttributes&, clang::BalancedDelimiterTracker&) (source/llorg/llvm-project/build/bin/clang-17+0x525ce64)
#50 0x000000000525fe1a clang::Parser::ParseNamespace(clang::DeclaratorContext, clang::SourceLocation&, clang::SourceLocation) (source/llorg/llvm-projec
t/build/bin/clang-17+0x525fe1a)
#51 0x000000000524d226 clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceL$
#52 0x0000000005227090 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (source/llo
rg/llvm-project/build/bin/clang-17+0x5227090)
#53 0x00000000052286c9 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (source/llorg/llvm-pro
ject/build/bin/clang-17+0x52286c9)
#54 0x000000000521ae0a clang::ParseAST(clang::Sema&, bool, bool) (source/llorg/llvm-project/build/bin/clang-17+0x521ae0a)
#55 0x0000000004357cf8 clang::CodeGenAction::ExecuteAction() (source/llorg/llvm-project/build/bin/clang-17+0x4357cf8)
#56 0x0000000003c98809 clang::FrontendAction::Execute() (source/llorg/llvm-project/build/bin/clang-17+0x3c98809)
#57 0x0000000003c2dcf9 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (source/llorg/llvm-project/build/bin/clang-17+0x3c2dcf9)
#58 0x0000000003d65a82 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (source/llorg/llvm-project/build/bin/clang-17+0x3d65a82)
#59 0x0000000000aeb938 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (source/llorg/llvm-project/build/bin/clang-17+0xaeb938)
#60 0x0000000000ae6d24 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#61 0x0000000000ae862f clang_main(int, char**, llvm::ToolContext const&) (source/llorg/llvm-project/build/bin/clang-17+0xae862f)
#62 0x0000000000a206b1 main (source/llorg/llvm-project/build/bin/clang-17+0xa206b1)
#63 0x00007f797a961493 __libc_start_main (/lib64/libc.so.6+0x23493)
#64 0x0000000000ae202e _start (source/llorg/llvm-project/build/bin/clang-17+0xae202e)

[llvmbot]

@llvm/issue-subscribers-clang-frontend

[DimitryAndric]

Reduced:

// clang -cc1 -triple x86_64-- -S -Wcast-align ExampleProblem-min.cpp
template <class A> void from_mask() {
  alignas(A) int lut[]{};
  (long *)lut;
}

[serge-sans-paille]

Potential patch: https://reviews.llvm.org/D151753

[DimitryAndric]

Thanks Serge!