Crash happens when I use 'the scanset' in scanf (VSCode Extension)

[swkfk]

The clangd will crash when I type the following code:

#include <stdio.h>

int main() {
    scanf("%512[\\]")
}

As soon as I put the \\ in the [], the crash will occure.

Logs

Part of the logs:

I[17:56:32.790] <-- textDocument/codeAction(1)
V[17:56:32.846] Driver produced command: cc1 -cc1 -triple x86_64-pc-linux-gnu -fsyntax-only -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name broken.c -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -mllvm -treat-scalable-fixed-error-as-warning -debugger-tuning=gdb -fcoverage-compilation-dir=/home/swkfk/data-struct/final -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/11/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdebug-compilation-dir=/home/swkfk/data-struct/final -ferror-limit 19 -fgnuc-version=4.2.1 -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -x c /home/swkfk/data-struct/final/broken.c
I[17:56:32.846] --> textDocument/clangd.fileStatus
V[17:56:32.846] >>> {"jsonrpc":"2.0","method":"textDocument/clangd.fileStatus","params":{"state":"parsing includes, running Update (1)","uri":"file:///home/swkfk/data-struct/final/broken.c"}}

V[17:56:32.846] Building first preamble for /home/swkfk/data-struct/final/broken.c version 1
V[17:56:32.858] indexed preamble AST for /home/swkfk/data-struct/final/broken.c version 1:
symbol slab: 363 symbols, 104816 bytes
ref slab: 0 symbols, 0 refs, 128 bytes
relations slab: 0 relations, 24 bytes
V[17:56:32.861] Build dynamic index for header symbols with estimated memory usage of 539748 bytes
V[17:56:32.861] Built preamble of size 288608 for file /home/swkfk/data-struct/final/broken.c version 1
I[17:56:32.861] --> workspace/semanticTokens/refresh(0)
V[17:56:32.861] >>> {"id":0,"jsonrpc":"2.0","method":"workspace/semanticTokens/refresh","params":null}

I[17:56:32.861] --> textDocument/clangd.fileStatus
V[17:56:32.861] >>> {"jsonrpc":"2.0","method":"textDocument/clangd.fileStatus","params":{"state":"parsing includes, running Build AST","uri":"file:///home/swkfk/data-struct/final/broken.c"}}

I[17:56:32.861] --> textDocument/clangd.fileStatus
V[17:56:32.861] >>> {"jsonrpc":"2.0","method":"textDocument/clangd.fileStatus","params":{"state":"parsing includes, parsing main file","uri":"file:///home/swkfk/data-struct/final/broken.c"}}

V[17:56:32.862] <<< {"id":0,"jsonrpc":"2.0","result":null}

I[17:56:32.862] <-- reply(0)
/lib/x86_64-linux-gnu/libLLVM-14.so.1(_ZN4llvm3sys15PrintStackTraceERNS_11raw_ostreamEi+0x31)[0x7f01d1effd01]
/lib/x86_64-linux-gnu/libLLVM-14.so.1(_ZN4llvm3sys17RunSignalHandlersEv+0xbc)[0x7f01d1efda0c]
/lib/x86_64-linux-gnu/libLLVM-14.so.1(+0xe40236)[0x7f01d1f00236]
/lib/x86_64-linux-gnu/libc.so.6(+0x42520)[0x7f01d0ba7520]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZNK5clang4Expr21tryEvaluateObjectSizeERmRNS_10ASTContextEj+0x1e)[0x7f01d89b630e]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(+0x11a044d)[0x7f01d8e6d44d]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(+0x11df185)[0x7f01d8eac185]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(+0x11c8458)[0x7f01d8e95458]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang21analyze_format_string16ParseScanfStringERNS0_19FormatStringHandlerEPKcS4_RKNS_11LangOptionsERKNS_10TargetInfoE+0x658)[0x7f01d8b02458]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang4Sema35checkFortifiedBuiltinMemoryFunctionEPNS_12FunctionDeclEPNS_8CallExprE+0xaed)[0x7f01d8e6cf6d]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang4Sema21BuildResolvedCallExprEPNS_4ExprEPNS_9NamedDeclENS_14SourceLocationEN4llvm8ArrayRefIS2_EES5_S2_bNS_8CallExpr11ADLCallKindE+0xf71)[0x7f01d9093731]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang4Sema13BuildCallExprEPNS_5ScopeEPNS_4ExprENS_14SourceLocationEN4llvm15MutableArrayRefIS4_EES5_S4_bb+0xa6c)[0x7f01d907b1fc]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(ZN5clang4Sema13ActOnCallExprEPNS_5ScopeEPNS_4ExprENS_14SourceLocationEN4llvm15MutableArrayRefIS4_EES5_S4+0x47)[0x7f01d9091e47]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser28ParsePostfixExpressionSuffixENS_12ActionResultIPNS_4ExprELb1EEE+0x18ab)[0x7f01d8717d3b]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser19ParseCastExpressionENS0_13CastParseKindEbRbNS0_13TypeCastStateEbPb+0xd8)[0x7f01d8718908]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser25ParseAssignmentExpressionENS0_13TypeCastStateE+0xe6)[0x7f01d8714936]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser15ParseExpressionENS0_13TypeCastStateE+0x9)[0x7f01d8714839]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser18ParseExprStatementENS0_17ParsedStmtContextE+0x46)[0x7f01d8771146]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser42ParseStatementOrDeclarationAfterAttributesERN4llvm11SmallVectorIPNS_4StmtELj32EEENS0_17ParsedStmtContextEPNS_14SourceLocationERNS_25ParsedAttributesWithRangeE+0x1b5b)[0x7f01d8770c8b]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser27ParseStatementOrDeclarationERN4llvm11SmallVectorIPNS_4StmtELj32EEENS0_17ParsedStmtContextEPNS_14SourceLocationE+0xcf)[0x7f01d876ef9f]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser26ParseCompoundStatementBodyEb+0x771)[0x7f01d87778f1]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser26ParseFunctionStatementBodyEPNS_4DeclERNS0_10ParseScopeE+0xb8)[0x7f01d8778818]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser23ParseFunctionDefinitionERNS_17ParsingDeclaratorERKNS0_18ParsedTemplateInfoEPNS0_18LateParsedAttrListE+0xddf)[0x7f01d879259f]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser14ParseDeclGroupERNS_15ParsingDeclSpecENS_17DeclaratorContextEPNS_14SourceLocationEPNS0_12ForRangeInitE+0x1210)[0x7f01d86eacc0]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser30ParseDeclOrFunctionDefInternalERNS_25ParsedAttributesWithRangeERNS_15ParsingDeclSpecENS_15AccessSpecifierE+0x35b)[0x7f01d87915ab]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser36ParseDeclarationOrFunctionDefinitionERNS_25ParsedAttributesWithRangeEPNS_15ParsingDeclSpecENS_15AccessSpecifierE+0x190)[0x7f01d8791060]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser24ParseExternalDeclarationERNS_25ParsedAttributesWithRangeEPNS_15ParsingDeclSpecE+0x92a)[0x7f01d87904da]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser17ParseTopLevelDeclERNS_9OpaquePtrINS_12DeclGroupRefEEEb+0x3ad)[0x7f01d878eb1d]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang6Parser22ParseFirstTopLevelDeclERNS_9OpaquePtrINS_12DeclGroupRefEEE+0x27)[0x7f01d878e687]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang8ParseASTERNS_4SemaEbb+0x1e6)[0x7f01d86d17d6]
/lib/x86_64-linux-gnu/libclang-cpp.so.14(_ZN5clang14FrontendAction7ExecuteEv+0x67)[0x7f01da1e1b57]
/usr/bin/clangd[0x70c05d]
/usr/bin/clangd[0x78d6e7]
/usr/bin/clangd[0x788ed9]
/usr/bin/clangd[0x788ab1]
/usr/bin/clangd[0x926e0a]
/lib/x86_64-linux-gnu/libc.so.6(+0x94b43)[0x7f01d0bf9b43]
/lib/x86_64-linux-gnu/libc.so.6(+0x126a00)[0x7f01d0c8ba00]
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):
Signalled during AST worker action: Build AST
Filename: broken.c
Directory: /home/swkfk/data-struct/final
Command Line: /usr/lib/llvm-14/bin/clang -resource-dir=/usr/lib/llvm-14/lib/clang/14.0.0 -- /home/swkfk/data-struct/final/broken.c
Version: 1
[Error - 5:56:33 PM] The Clang Language Server server crashed 5 times in the last 3 minutes. The server will not be restarted. See the output for more information.
[Error - 5:56:33 PM] Request textDocument/codeAction failed.
[object Object]

System information

The version of the clangd extension for VSCode is 0.1.24.
The version of VSCode is 1.79.2

clangd --version
Ubuntu clangd version 14.0.0-1ubuntu1
Features: linux+grpc
Platform: x86_64-pc-linux-gnu

cat /proc/version
Linux version 5.10.16.3-microsoft-standard-WSL2 (oe-user@oe-host) (x86_64-msft-linux-gcc (GCC) 9.3.0, GNU ld (GNU Binutils) 2.34.0.20200220) #1 SMP Fri Apr 2 22:23:49 UTC 2021

lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 22.04.1 LTS
Release: 22.04
Codename: jammy

[HighCommander4]

I can reproduce the crash with clangd 14 and clangd 15, but it seems to be fixed in clangd 16.

[zyn0217]

Perhaps llvm/llvm-project#57517

[HighCommander4]

Perhaps llvm/llvm-project#57517

Yep, that seems likely based on the issue description and timing of the fix. Nice find!

I will close this a a duplicate.