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clang: 18: Assertion `getType(Base)->isPointerType() || getType(Base)->isArrayType()' failed. #69468

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wierton opened this issue Oct 18, 2023 · 6 comments · May be fixed by #75130 or #77893
Open

clang: 18: Assertion `getType(Base)->isPointerType() || getType(Base)->isArrayType()' failed. #69468

wierton opened this issue Oct 18, 2023 · 6 comments · May be fixed by #75130 or #77893
Labels
clang:frontend Language frontend issues, e.g. anything involving "Sema" confirmed Verified by a second party crash Prefer [crash-on-valid] or [crash-on-invalid]

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@wierton
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wierton commented Oct 18, 2023

Compiler Explorer: https://gcc.godbolt.org/z/9Yz4fTevr

When compile this program with clang (version 5a56f00), clang crashes:

a[i] = b[i];
extern char b[];
extern char a[];

void foo(int j) {
  a[j] = b[j];
}

Stack dump:

<source>:1:3: error: use of undeclared identifier 'i'
    1 | a[i] = b[i];
      |   ^
<source>:1:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
    1 | a[i] = b[i];
      | ^
      | int
<source>:1:8: error: use of undeclared identifier 'b'
    1 | a[i] = b[i];
      |        ^
<source>:1:10: error: use of undeclared identifier 'i'
    1 | a[i] = b[i];
      |          ^
clang: /root/llvm-project/clang/lib/AST/ExprConstant.cpp:1704: void {anonymous}::LValue::addUnsizedArray({anonymous}::EvalInfo&, const clang::Expr*, clang::QualType): Assertion `getType(Base)->isPointerType() || getType(Base)->isArrayType()' 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 -S --gcc-toolchain=/opt/compiler-explorer/gcc-9.2.0 -fcolor-diagnostics -fno-crash-diagnostics -O0 <source>
1.	<source>:7:1: current parser token '}'
2.	<source>:5:17: parsing function body 'foo'
3.	<source>:5:17: in compound statement ('{}')
 #0 0x00000000037346b8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x37346b8)
 #1 0x000000000373237c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x373237c)
 #2 0x000000000367ac28 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007f29190b5420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
 #4 0x00007f2918b7800b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4300b)
 #5 0x00007f2918b57859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22859)
 #6 0x00007f2918b57729 (/lib/x86_64-linux-gnu/libc.so.6+0x22729)
 #7 0x00007f2918b68fd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
 #8 0x0000000006fbc65f (anonymous namespace)::LValue::addUnsizedArray((anonymous namespace)::EvalInfo&, clang::Expr const*, clang::QualType) ExprConstant.cpp:0:0
 #9 0x000000000703f7a2 (anonymous namespace)::PointerExprEvaluator::VisitCastExpr(clang::CastExpr const*) ExprConstant.cpp:0:0
#10 0x0000000006ff69c1 clang::StmtVisitorBase<llvm::make_const_ptr, (anonymous namespace)::PointerExprEvaluator, bool>::Visit(clang::Stmt const*) ExprConstant.cpp:0:0
#11 0x0000000006ff7c8b EvaluatePointer(clang::Expr const*, (anonymous namespace)::LValue&, (anonymous namespace)::EvalInfo&, bool) ExprConstant.cpp:0:0
#12 0x0000000006ff93ad (anonymous namespace)::LValueExprEvaluator::VisitArraySubscriptExpr(clang::ArraySubscriptExpr const*) ExprConstant.cpp:0:0
#13 0x000000000700792e clang::StmtVisitorBase<llvm::make_const_ptr, (anonymous namespace)::LValueExprEvaluator, bool>::Visit(clang::Stmt const*) ExprConstant.cpp:0:0
#14 0x00000000070094dd EvaluateLValue(clang::Expr const*, (anonymous namespace)::LValue&, (anonymous namespace)::EvalInfo&, bool) ExprConstant.cpp:0:0
#15 0x0000000006fdddfe Evaluate(clang::APValue&, (anonymous namespace)::EvalInfo&, clang::Expr const*) ExprConstant.cpp:0:0
#16 0x0000000006fe0bce (anonymous namespace)::DataRecursiveIntBinOpEvaluator::process((anonymous namespace)::DataRecursiveIntBinOpEvaluator::EvalResult&) ExprConstant.cpp:0:0
#17 0x0000000007040633 (anonymous namespace)::IntExprEvaluator::VisitBinaryOperator(clang::BinaryOperator const*) ExprConstant.cpp:0:0
#18 0x0000000006fefa4d clang::StmtVisitorBase<llvm::make_const_ptr, (anonymous namespace)::IntExprEvaluator, bool>::Visit(clang::Stmt const*) ExprConstant.cpp:0:0
#19 0x0000000006fde22e Evaluate(clang::APValue&, (anonymous namespace)::EvalInfo&, clang::Expr const*) ExprConstant.cpp:0:0
#20 0x0000000006fe84b9 EvaluateAsRValue((anonymous namespace)::EvalInfo&, clang::Expr const*, clang::APValue&) ExprConstant.cpp:0:0
#21 0x0000000006fe912f clang::Expr::EvaluateForOverflow(clang::ASTContext const&) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x6fe912f)
#22 0x000000000606fa85 clang::Sema::CheckForIntOverflow(clang::Expr const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x606fa85)
#23 0x00000000060c8a0d clang::Sema::CheckCompletedExpr(clang::Expr*, clang::SourceLocation, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x60c8a0d)
#24 0x000000000654f4c4 clang::Sema::ActOnFinishFullExpr(clang::Expr*, clang::SourceLocation, bool, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x654f4c4)
#25 0x00000000067c9eae clang::Sema::ActOnExprStmt(clang::ActionResult<clang::Expr*, true>, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x67c9eae)
#26 0x0000000005f904e4 clang::Parser::ParseExprStatement(clang::Parser::ParsedStmtContext) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5f904e4)
#27 0x0000000005f86aed clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5f86aed)
#28 0x0000000005f87928 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5f87928)
#29 0x0000000005f88869 clang::Parser::ParseCompoundStatementBody(bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5f88869)
#30 0x0000000005f8a18a clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5f8a18a)
#31 0x0000000005eb7ea1 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5eb7ea1)
#32 0x0000000005edf3b8 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5edf3b8)
#33 0x0000000005eac30b clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5eac30b)
#34 0x0000000005eaca3f clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (.part.0) Parser.cpp:0:0
#35 0x0000000005eb43e4 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5eb43e4)
#36 0x0000000005eb4c0d clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5eb4c0d)
#37 0x0000000005ea7cba clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5ea7cba)
#38 0x00000000049a0c78 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x49a0c78)
#39 0x00000000042046a9 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x42046a9)
#40 0x0000000004185b4e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4185b4e)
#41 0x00000000042e382e clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x42e382e)
#42 0x0000000000bf0b06 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xbf0b06)
#43 0x0000000000be83ca ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#44 0x0000000003fe1d39 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
#45 0x000000000367b0d4 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x367b0d4)
#46 0x0000000003fe232f 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
#47 0x0000000003faa4f5 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3faa4f5)
#48 0x0000000003faaf5d 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+0x3faaf5d)
#49 0x0000000003fb2e85 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3fb2e85)
#50 0x0000000000bedfac clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xbedfac)
#51 0x0000000000ae8141 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xae8141)
#52 0x00007f2918b59083 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24083)
#53 0x0000000000be7eae _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xbe7eae)
clang: error: clang frontend command failed with exit code 134 (use -v to see invocation)
@github-actions github-actions bot added the clang Clang issues not falling into any other category label Oct 18, 2023
@EugeneZelenko EugeneZelenko added clang:frontend Language frontend issues, e.g. anything involving "Sema" crash Prefer [crash-on-valid] or [crash-on-invalid] and removed clang Clang issues not falling into any other category labels Oct 18, 2023
@llvmbot
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llvmbot commented Oct 18, 2023

@llvm/issue-subscribers-clang-frontend

Author: wt.cc (wierton)

Compiler Explorer: https://gcc.godbolt.org/z/9Yz4fTevr

When compile this program with clang (version 5a56f00), clang crashes:

a[i] = b[i];
extern char b[];
extern char a[];

void foo(int j) {
  a[j] = b[j];
}

Stack dump:

&lt;source&gt;:1:3: error: use of undeclared identifier 'i'
    1 | a[i] = b[i];
      |   ^
&lt;source&gt;:1:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
    1 | a[i] = b[i];
      | ^
      | int
&lt;source&gt;:1:8: error: use of undeclared identifier 'b'
    1 | a[i] = b[i];
      |        ^
&lt;source&gt;:1:10: error: use of undeclared identifier 'i'
    1 | a[i] = b[i];
      |          ^
clang: /root/llvm-project/clang/lib/AST/ExprConstant.cpp:1704: void {anonymous}::LValue::addUnsizedArray({anonymous}::EvalInfo&amp;, const clang::Expr*, clang::QualType): Assertion `getType(Base)-&gt;isPointerType() || getType(Base)-&gt;isArrayType()' 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 -S --gcc-toolchain=/opt/compiler-explorer/gcc-9.2.0 -fcolor-diagnostics -fno-crash-diagnostics -O0 &lt;source&gt;
1.	&lt;source&gt;:7:1: current parser token '}'
2.	&lt;source&gt;:5:17: parsing function body 'foo'
3.	&lt;source&gt;:5:17: in compound statement ('{}')
 #<!-- -->0 0x00000000037346b8 llvm::sys::PrintStackTrace(llvm::raw_ostream&amp;, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x37346b8)
 #<!-- -->1 0x000000000373237c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x373237c)
 #<!-- -->2 0x000000000367ac28 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #<!-- -->3 0x00007f29190b5420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
 #<!-- -->4 0x00007f2918b7800b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4300b)
 #<!-- -->5 0x00007f2918b57859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22859)
 #<!-- -->6 0x00007f2918b57729 (/lib/x86_64-linux-gnu/libc.so.6+0x22729)
 #<!-- -->7 0x00007f2918b68fd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
 #<!-- -->8 0x0000000006fbc65f (anonymous namespace)::LValue::addUnsizedArray((anonymous namespace)::EvalInfo&amp;, clang::Expr const*, clang::QualType) ExprConstant.cpp:0:0
 #<!-- -->9 0x000000000703f7a2 (anonymous namespace)::PointerExprEvaluator::VisitCastExpr(clang::CastExpr const*) ExprConstant.cpp:0:0
#<!-- -->10 0x0000000006ff69c1 clang::StmtVisitorBase&lt;llvm::make_const_ptr, (anonymous namespace)::PointerExprEvaluator, bool&gt;::Visit(clang::Stmt const*) ExprConstant.cpp:0:0
#<!-- -->11 0x0000000006ff7c8b EvaluatePointer(clang::Expr const*, (anonymous namespace)::LValue&amp;, (anonymous namespace)::EvalInfo&amp;, bool) ExprConstant.cpp:0:0
#<!-- -->12 0x0000000006ff93ad (anonymous namespace)::LValueExprEvaluator::VisitArraySubscriptExpr(clang::ArraySubscriptExpr const*) ExprConstant.cpp:0:0
#<!-- -->13 0x000000000700792e clang::StmtVisitorBase&lt;llvm::make_const_ptr, (anonymous namespace)::LValueExprEvaluator, bool&gt;::Visit(clang::Stmt const*) ExprConstant.cpp:0:0
#<!-- -->14 0x00000000070094dd EvaluateLValue(clang::Expr const*, (anonymous namespace)::LValue&amp;, (anonymous namespace)::EvalInfo&amp;, bool) ExprConstant.cpp:0:0
#<!-- -->15 0x0000000006fdddfe Evaluate(clang::APValue&amp;, (anonymous namespace)::EvalInfo&amp;, clang::Expr const*) ExprConstant.cpp:0:0
#<!-- -->16 0x0000000006fe0bce (anonymous namespace)::DataRecursiveIntBinOpEvaluator::process((anonymous namespace)::DataRecursiveIntBinOpEvaluator::EvalResult&amp;) ExprConstant.cpp:0:0
#<!-- -->17 0x0000000007040633 (anonymous namespace)::IntExprEvaluator::VisitBinaryOperator(clang::BinaryOperator const*) ExprConstant.cpp:0:0
#<!-- -->18 0x0000000006fefa4d clang::StmtVisitorBase&lt;llvm::make_const_ptr, (anonymous namespace)::IntExprEvaluator, bool&gt;::Visit(clang::Stmt const*) ExprConstant.cpp:0:0
#<!-- -->19 0x0000000006fde22e Evaluate(clang::APValue&amp;, (anonymous namespace)::EvalInfo&amp;, clang::Expr const*) ExprConstant.cpp:0:0
#<!-- -->20 0x0000000006fe84b9 EvaluateAsRValue((anonymous namespace)::EvalInfo&amp;, clang::Expr const*, clang::APValue&amp;) ExprConstant.cpp:0:0
#<!-- -->21 0x0000000006fe912f clang::Expr::EvaluateForOverflow(clang::ASTContext const&amp;) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x6fe912f)
#<!-- -->22 0x000000000606fa85 clang::Sema::CheckForIntOverflow(clang::Expr const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x606fa85)
#<!-- -->23 0x00000000060c8a0d clang::Sema::CheckCompletedExpr(clang::Expr*, clang::SourceLocation, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x60c8a0d)
#<!-- -->24 0x000000000654f4c4 clang::Sema::ActOnFinishFullExpr(clang::Expr*, clang::SourceLocation, bool, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x654f4c4)
#<!-- -->25 0x00000000067c9eae clang::Sema::ActOnExprStmt(clang::ActionResult&lt;clang::Expr*, true&gt;, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x67c9eae)
#<!-- -->26 0x0000000005f904e4 clang::Parser::ParseExprStatement(clang::Parser::ParsedStmtContext) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5f904e4)
#<!-- -->27 0x0000000005f86aed clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector&lt;clang::Stmt*, 32u&gt;&amp;, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&amp;, clang::ParsedAttributes&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5f86aed)
#<!-- -->28 0x0000000005f87928 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector&lt;clang::Stmt*, 32u&gt;&amp;, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5f87928)
#<!-- -->29 0x0000000005f88869 clang::Parser::ParseCompoundStatementBody(bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5f88869)
#<!-- -->30 0x0000000005f8a18a clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5f8a18a)
#<!-- -->31 0x0000000005eb7ea1 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&amp;, clang::Parser::ParsedTemplateInfo const&amp;, clang::Parser::LateParsedAttrList*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5eb7ea1)
#<!-- -->32 0x0000000005edf3b8 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&amp;, clang::DeclaratorContext, clang::ParsedAttributes&amp;, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5edf3b8)
#<!-- -->33 0x0000000005eac30b clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&amp;, clang::ParsedAttributes&amp;, clang::ParsingDeclSpec&amp;, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5eac30b)
#<!-- -->34 0x0000000005eaca3f clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&amp;, clang::ParsedAttributes&amp;, clang::ParsingDeclSpec*, clang::AccessSpecifier) (.part.0) Parser.cpp:0:0
#<!-- -->35 0x0000000005eb43e4 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&amp;, clang::ParsedAttributes&amp;, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5eb43e4)
#<!-- -->36 0x0000000005eb4c0d clang::Parser::ParseTopLevelDecl(clang::OpaquePtr&lt;clang::DeclGroupRef&gt;&amp;, clang::Sema::ModuleImportState&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5eb4c0d)
#<!-- -->37 0x0000000005ea7cba clang::ParseAST(clang::Sema&amp;, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x5ea7cba)
#<!-- -->38 0x00000000049a0c78 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x49a0c78)
#<!-- -->39 0x00000000042046a9 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x42046a9)
#<!-- -->40 0x0000000004185b4e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4185b4e)
#<!-- -->41 0x00000000042e382e clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x42e382e)
#<!-- -->42 0x0000000000bf0b06 cc1_main(llvm::ArrayRef&lt;char const*&gt;, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xbf0b06)
#<!-- -->43 0x0000000000be83ca ExecuteCC1Tool(llvm::SmallVectorImpl&lt;char const*&gt;&amp;, llvm::ToolContext const&amp;) driver.cpp:0:0
#<!-- -->44 0x0000000003fe1d39 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
#<!-- -->45 0x000000000367b0d4 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref&lt;void ()&gt;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x367b0d4)
#<!-- -->46 0x0000000003fe232f 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
#<!-- -->47 0x0000000003faa4f5 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&amp;, clang::driver::Command const*&amp;, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3faa4f5)
#<!-- -->48 0x0000000003faaf5d 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+0x3faaf5d)
#<!-- -->49 0x0000000003fb2e85 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+0x3fb2e85)
#<!-- -->50 0x0000000000bedfac clang_main(int, char**, llvm::ToolContext const&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xbedfac)
#<!-- -->51 0x0000000000ae8141 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xae8141)
#<!-- -->52 0x00007f2918b59083 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24083)
#<!-- -->53 0x0000000000be7eae _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xbe7eae)
clang: error: clang frontend command failed with exit code 134 (use -v to see invocation)

@shafik shafik added the confirmed Verified by a second party label Oct 25, 2023
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cygao90 commented Dec 11, 2023

69cf59e is the first bad commit

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cygao90 commented Dec 11, 2023

In the first line, a will be marked implicitly as int.

<source>:1:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
    1 | a[i] = b[i];
      | ^
      | int

extern char a[]; declares a as an imcomplete type. getType(Base) will find the fist complete type so it will return int which is neither a pointer type nor an array type. Consequently, the assertion fails.

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shafik commented Dec 11, 2023

This is not particular to C: https://gcc.godbolt.org/z/v6TbP3WGs

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shafik commented Dec 11, 2023 •
edited

If we look before it asserts in the call to APValue::LValueBase::getType() in the assert, we see that before the loop here:

llvm-project/clang/lib/AST/APValue.cpp

Lines 73 to 80 in f2afd10

for (auto *Redecl = cast<ValueDecl>(D->getMostRecentDecl()); Redecl;
Redecl = cast_or_null<ValueDecl>(Redecl->getPreviousDecl())) {
QualType T = Redecl->getType();
if (!T->isIncompleteArrayType())
return T;
}
return D->getType();
}

That D is an invalid decl:

expr D->isInvalidDecl()

(bool) $1 = true

the first iteration through the loop Redecl is valid and look like what we want:

IncompleteArrayType 0x14a8e28e0 'char[]' 
`-BuiltinType 0x14a831eb0 'char'

The next iteration gets us back to int and:

expr Redecl->isInvalidDecl())

(bool) $2 = true

I think the logic needs to be adjusted slightly so that D gets reset to Redecl each iteration and we modify the stop condition for the loop to also check !Redecl->isInvalidDecl().

I verified this fixes the problem and does not break check-clang but I am not sure it covers all possible cases.

CC @zygoloid @erichkeane

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Yeah, bailing out if we see any invalid declaration seems reasonable to me.

@shafik shafik linked a pull request Dec 12, 2023 that will close this issue
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@cygao90 cygao90 mentioned this issue Dec 12, 2023
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shafik added a commit to shafik/llvm-project that referenced this issue Dec 15, 2023
@shafik
[Clang][AST] Fix crash in APValue::LValueBase::getType when we have i…
fb0ea87 
…nvalid decl

In some cases when calling APValue::LValueBase::getType() when we have a
ValueDecl in some cases we don't handle invalid decls. We iterating over
redeclarations we reset the current decl to the current most recent decl and
we check the next redeclaration to ensure it is not invalid.

Fixes: llvm#69468
@jcsxky jcsxky linked a pull request Jan 12, 2024 that will close this issue
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clang:frontend Language frontend issues, e.g. anything involving "Sema" confirmed Verified by a second party crash Prefer [crash-on-valid] or [crash-on-invalid]
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