clangd 19 crashing when using C++20 Modules

[ilobilo]

clangd crashes if a .cppm file contains #include <fmt/ranges.h>

PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	<eof> parser at end of file
V[11:52:59.010] indexed preamble AST for /home/ilobilo/Desktop/projects/visualsort/source/visualsort.cppm version 1:
  symbol slab: 7292 symbols, 1986776 bytes
  ref slab: 0 symbols, 0 refs, 128 bytes
  relations slab: 375 relations, 8728 bytes
V[11:52:59.027] Build dynamic index for header symbols with estimated memory usage of 6386280 bytes
 #0 0x00007e70b46acc2f llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/usr/lib/llvm-19/bin/../lib/libLLVM.so.19.0+0xeacc2f)
 #1 0x00007e70b46aa929 llvm::sys::RunSignalHandlers() (/usr/lib/llvm-19/bin/../lib/libLLVM.so.19.0+0xeaa929)
 #2 0x00007e70b46ad380 (/usr/lib/llvm-19/bin/../lib/libLLVM.so.19.0+0xead380)
 #3 0x00007e70b2645320 (/lib/x86_64-linux-gnu/libc.so.6+0x45320)
 #4 0x00007e70bc61ef63 clang::StmtIteratorBase::HandleDecl(clang::Decl*) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x121ef63)
 #5 0x00007e70bc61f07b clang::StmtIteratorBase::StmtIteratorBase(clang::Decl**, clang::Decl**) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x121f07b)
 #6 0x00007e70bc616d65 (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x1216d65)
 #7 0x00007e70bc6169ba clang::Stmt::children() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x12169ba)
 #8 0x00007e70bc66e329 (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x126e329)
 #9 0x00007e70bc66dda5 (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x126dda5)
#10 0x00007e70bc66e3af (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x126e3af)
#11 0x00007e70bc66a451 clang::Stmt::ProcessODRHash(llvm::FoldingSetNodeID&, clang::ODRHash&) const (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x126a451)
#12 0x00007e70bc5de2c9 clang::ODRHash::AddFunctionDecl(clang::FunctionDecl const*, bool) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x11de2c9)
#13 0x00007e70bc2f8779 clang::FunctionDecl::getODRHash() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0xef8779)
#14 0x00007e70bdec4adf clang::ASTReader::finishPendingActions() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2ac4adf)
#15 0x00007e70bdec7b3b clang::ASTReader::FinishedDeserializing() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2ac7b3b)
#16 0x00007e70bc30c7ec clang::DeclContext::LoadLexicalDeclsFromExternalStorage() const (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0xf0c7ec)
#17 0x00007e70bc30cf1b clang::DeclContext::decls_begin() const (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0xf0cf1b)
#18 0x00007e70bdec5577 clang::ASTReader::diagnoseOdrViolations() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2ac5577)
#19 0x00007e70bdec7b72 clang::ASTReader::FinishedDeserializing() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2ac7b72)
#20 0x00007e70bdf10586 clang::ASTReader::ReadDeclRecord(clang::GlobalDeclID) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2b10586)
#21 0x00007e70bdeb2ec7 clang::ASTReader::GetDecl(clang::GlobalDeclID) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2ab2ec7)
#22 0x00007e70bc608ab5 clang::ASTContext::getCurrentKeyFunction(clang::CXXRecordDecl const*) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x1208ab5)
#23 0x00007e70bcbe97a0 clang::Sema::DefineUsedVTables() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x17e97a0)
#24 0x00007e70bc980b8a clang::Sema::ActOnEndOfTranslationUnitFragment(clang::Sema::TUFragmentKind) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x1580b8a)
#25 0x00007e70bc981320 clang::Sema::ActOnEndOfTranslationUnit() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x1581320)
#26 0x00007e70bc109144 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0xd09144)
#27 0x00007e70bc0380ae clang::ParseAST(clang::Sema&, bool, bool) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0xc380ae)
#28 0x00007e70be10140c clang::FrontendAction::Execute() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2d0140c)
#29 0x000059b5f0856813 (/usr/bin/clangd+0x3e7813)
#30 0x000059b5f08f51e4 (/usr/bin/clangd+0x4861e4)
#31 0x000059b5f08f4c3a (/usr/bin/clangd+0x485c3a)
#32 0x000059b5f08f1400 (/usr/bin/clangd+0x482400)
#33 0x000059b5f08f0f76 (/usr/bin/clangd+0x481f76)
#34 0x000059b5f0a571d1 (/usr/bin/clangd+0x5e81d1)
#35 0x00007e70b269ca94 start_thread ./nptl/pthread_create.c:447:8
#36 0x00007e70b2729c3c clone3 ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:80:0
Signalled during AST worker action: Build AST
  Filename: source/visualsort.cppm
  Directory: /home/ilobilo/Desktop/projects/visualsort
  Command Line: /usr/lib/llvm-19/bin/clang -c -Qunused-arguments -m64 -fvisibility=hidden -fvisibility-inlines-hidden -Wall -Werror -O3 -std=c++23 -stdlib=libc++ -cxx-isystem/usr/lib/llvm-19/include/c++/v1 -I /home/ilobilo/.xmake/packages/f/ftxui/v5.0.0/bfd210310c974f0bbb9fbb748ac7aae4/include -I /home/ilobilo/.xmake/packages/f/fmt/11.0.0/920a4073dd28420f9c79ca3b805f8e91/include -DNDEBUG -fmodule-file=visualsort:bubblesort=build/.gens/visualsort/linux/x86_64/release/rules/bmi/cache/modules/40bb7f91/visualsort-bubblesort.pcm -fmodule-file=std=build/.gens/visualsort/linux/x86_64/release/rules/bmi/cache/modules/40bb7f91/std.pcm -fmodule-file=visualsort:sorter=build/.gens/visualsort/linux/x86_64/release/rules/bmi/cache/modules/40bb7f91/visualsort-sorter.pcm -x c++-module -fmodule-output=build/.gens/visualsort/linux/x86_64/release/rules/bmi/cache/modules/40bb7f91/visualsort.pcm -o build/.objs/visualsort/linux/x86_64/release/source/visualsort.cppm.o -resource-dir=/usr/lib/llvm-19/lib/clang/19 -- /home/ilobilo/Desktop/projects/visualsort/source/visualsort.cppm
  Version: 1

[llvmbot]

@llvm/issue-subscribers-clangd

Author: ilobilo (ilobilo)

clangd crashes if a ``.cppm`` file contains ``#include <fmt/ranges.h>`` ``` PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace. Stack dump: 0. <eof> parser at end of file V[11:52:59.010] indexed preamble AST for /home/ilobilo/Desktop/projects/visualsort/source/visualsort.cppm version 1: symbol slab: 7292 symbols, 1986776 bytes ref slab: 0 symbols, 0 refs, 128 bytes relations slab: 375 relations, 8728 bytes V[11:52:59.027] Build dynamic index for header symbols with estimated memory usage of 6386280 bytes #0 0x00007e70b46acc2f llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/usr/lib/llvm-19/bin/../lib/libLLVM.so.19.0+0xeacc2f) #1 0x00007e70b46aa929 llvm::sys::RunSignalHandlers() (/usr/lib/llvm-19/bin/../lib/libLLVM.so.19.0+0xeaa929) #2 0x00007e70b46ad380 (/usr/lib/llvm-19/bin/../lib/libLLVM.so.19.0+0xead380) #3 0x00007e70b2645320 (/lib/x86_64-linux-gnu/libc.so.6+0x45320) #4 0x00007e70bc61ef63 clang::StmtIteratorBase::HandleDecl(clang::Decl*) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x121ef63) #5 0x00007e70bc61f07b clang::StmtIteratorBase::StmtIteratorBase(clang::Decl**, clang::Decl**) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x121f07b) #6 0x00007e70bc616d65 (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x1216d65) #7 0x00007e70bc6169ba clang::Stmt::children() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x12169ba) #8 0x00007e70bc66e329 (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x126e329) #9 0x00007e70bc66dda5 (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x126dda5) #10 0x00007e70bc66e3af (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x126e3af) #11 0x00007e70bc66a451 clang::Stmt::ProcessODRHash(llvm::FoldingSetNodeID&, clang::ODRHash&) const (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x126a451) #12 0x00007e70bc5de2c9 clang::ODRHash::AddFunctionDecl(clang::FunctionDecl const*, bool) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x11de2c9) #13 0x00007e70bc2f8779 clang::FunctionDecl::getODRHash() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0xef8779) #14 0x00007e70bdec4adf clang::ASTReader::finishPendingActions() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2ac4adf) #15 0x00007e70bdec7b3b clang::ASTReader::FinishedDeserializing() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2ac7b3b) #16 0x00007e70bc30c7ec clang::DeclContext::LoadLexicalDeclsFromExternalStorage() const (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0xf0c7ec) #17 0x00007e70bc30cf1b clang::DeclContext::decls_begin() const (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0xf0cf1b) #18 0x00007e70bdec5577 clang::ASTReader::diagnoseOdrViolations() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2ac5577) #19 0x00007e70bdec7b72 clang::ASTReader::FinishedDeserializing() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2ac7b72) #20 0x00007e70bdf10586 clang::ASTReader::ReadDeclRecord(clang::GlobalDeclID) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2b10586) #21 0x00007e70bdeb2ec7 clang::ASTReader::GetDecl(clang::GlobalDeclID) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2ab2ec7) #22 0x00007e70bc608ab5 clang::ASTContext::getCurrentKeyFunction(clang::CXXRecordDecl const*) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x1208ab5) #23 0x00007e70bcbe97a0 clang::Sema::DefineUsedVTables() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x17e97a0) #24 0x00007e70bc980b8a clang::Sema::ActOnEndOfTranslationUnitFragment(clang::Sema::TUFragmentKind) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x1580b8a) #25 0x00007e70bc981320 clang::Sema::ActOnEndOfTranslationUnit() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x1581320) #26 0x00007e70bc109144 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0xd09144) #27 0x00007e70bc0380ae clang::ParseAST(clang::Sema&, bool, bool) (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0xc380ae) #28 0x00007e70be10140c clang::FrontendAction::Execute() (/usr/lib/llvm-19/bin/../lib/libclang-cpp.so.19.0+0x2d0140c) #29 0x000059b5f0856813 (/usr/bin/clangd+0x3e7813) #30 0x000059b5f08f51e4 (/usr/bin/clangd+0x4861e4) #31 0x000059b5f08f4c3a (/usr/bin/clangd+0x485c3a) #32 0x000059b5f08f1400 (/usr/bin/clangd+0x482400) #33 0x000059b5f08f0f76 (/usr/bin/clangd+0x481f76) #34 0x000059b5f0a571d1 (/usr/bin/clangd+0x5e81d1) #35 0x00007e70b269ca94 start_thread ./nptl/pthread_create.c:447:8 #36 0x00007e70b2729c3c clone3 ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:80:0 Signalled during AST worker action: Build AST Filename: source/visualsort.cppm Directory: /home/ilobilo/Desktop/projects/visualsort Command Line: /usr/lib/llvm-19/bin/clang -c -Qunused-arguments -m64 -fvisibility=hidden -fvisibility-inlines-hidden -Wall -Werror -O3 -std=c++23 -stdlib=libc++ -cxx-isystem/usr/lib/llvm-19/include/c++/v1 -I /home/ilobilo/.xmake/packages/f/ftxui/v5.0.0/bfd210310c974f0bbb9fbb748ac7aae4/include -I /home/ilobilo/.xmake/packages/f/fmt/11.0.0/920a4073dd28420f9c79ca3b805f8e91/include -DNDEBUG -fmodule-file=visualsort:bubblesort=build/.gens/visualsort/linux/x86_64/release/rules/bmi/cache/modules/40bb7f91/visualsort-bubblesort.pcm -fmodule-file=std=build/.gens/visualsort/linux/x86_64/release/rules/bmi/cache/modules/40bb7f91/std.pcm -fmodule-file=visualsort:sorter=build/.gens/visualsort/linux/x86_64/release/rules/bmi/cache/modules/40bb7f91/visualsort-sorter.pcm -x c++-module -fmodule-output=build/.gens/visualsort/linux/x86_64/release/rules/bmi/cache/modules/40bb7f91/visualsort.pcm -o build/.objs/visualsort/linux/x86_64/release/source/visualsort.cppm.o -resource-dir=/usr/lib/llvm-19/lib/clang/19 -- /home/ilobilo/Desktop/projects/visualsort/source/visualsort.cppm Version: 1 ```

[HighCommander4]

First thing to do here is probably to wait for #66462 to merge and see if that fixes it.