[Diffusion] rG0e3a48778408: PR12350: Handle remaining cases permitted by CWG DR 244.

Wed Feb 12 12:52:32 PST 2020

lebedev.ri added subscribers: cfe-commits, rsmith, vsk, lebedev.ri.
lebedev.ri added a comment.

Post-commit review, although i'm not sure this is the commit that is the problem.

BRANCHES
  master

/clang/lib/AST/NestedNameSpecifier.cpp:485-487 Was this change intentional? 
It seems, http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap-ubsan/builds/17720/steps/annotate/logs/stdio is pointing at this line/change with:
```
FAIL: Clang :: AST/ast-dump-expr.cpp (136 of 16826)
******************** TEST 'Clang :: AST/ast-dump-expr.cpp' FAILED ********************
Script:
--
: 'RUN: at line 1';   /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/clang -cc1 -internal-isystem /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/lib/clang/11.0.0/include -nostdsysteminc -triple x86_64-unknown-unknown -Wno-unused-value -fcxx-exceptions -std=gnu++17 -ast-dump /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/AST/ast-dump-expr.cpp | /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/FileCheck -strict-whitespace /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/AST/ast-dump-expr.cpp
--
Exit Code: 2

Command Output (stderr):
--
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/AST/NestedNameSpecifier.cpp:485:23: runtime error: null pointer passed as argument 2, which is declared to never be null
/usr/include/string.h:43:28: note: nonnull attribute specified here
    #0 0x5f80492 in Append(char*, char*, char*&, unsigned int&, unsigned int&) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/AST/NestedNameSpecifier.cpp:485:5
    #1 0x5f808ca in SaveSourceLocation(clang::SourceLocation, char*&, unsigned int&, unsigned int&) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/AST/NestedNameSpecifier.cpp:500:3
    #2 0x5f80a68 in clang::NestedNameSpecifierLocBuilder::Extend(clang::ASTContext&, clang::NamespaceDecl*, clang::SourceLocation, clang::SourceLocation) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/AST/NestedNameSpecifier.cpp:603:3
    #3 0x4f5f84a in clang::CXXScopeSpec::Extend(clang::ASTContext&, clang::NamespaceDecl*, clang::SourceLocation, clang::SourceLocation) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Sema/DeclSpec.cpp:73:11
    #4 0x4fc1af9 in clang::Sema::BuildCXXNestedNameSpecifier(clang::Scope*, clang::Sema::NestedNameSpecInfo&, bool, clang::CXXScopeSpec&, clang::NamedDecl*, bool, bool*, bool) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Sema/SemaCXXScopeSpec.cpp:714:10
    #5 0x4fc32b4 in clang::Sema::ActOnCXXNestedNameSpecifier(clang::Scope*, clang::Sema::NestedNameSpecInfo&, bool, clang::CXXScopeSpec&, bool, bool*, bool) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Sema/SemaCXXScopeSpec.cpp:841:10
    #6 0x4efb997 in clang::Parser::ParseOptionalCXXScopeSpecifier(clang::CXXScopeSpec&, clang::OpaquePtr<clang::QualType>, bool, bool*, bool, clang::IdentifierInfo**, bool, bool) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/ParseExprCXX.cpp:455:19
    #7 0x4ea7c72 in clang::Parser::TryAnnotateCXXScopeToken(bool) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/Parser.cpp:2045:7
    #8 0x4ebd1d5 in clang::Parser::ParseDeclarationSpecifiers(clang::DeclSpec&, clang::Parser::ParsedTemplateInfo const&, clang::AccessSpecifier, clang::Parser::DeclSpecContext, clang::Parser::LateParsedAttrList*) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/ParseDecl.cpp:3359:13
    #9 0x4ed0326 in clang::Parser::ParseParameterDeclarationClause(clang::DeclaratorContext, clang::ParsedAttributes&, llvm::SmallVectorImpl<clang::DeclaratorChunk::ParamInfo>&, clang::SourceLocation&) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/ParseDecl.cpp:6732:5
    #10 0x4ece524 in clang::Parser::ParseFunctionDeclarator(clang::Declarator&, clang::ParsedAttributes&, clang::BalancedDelimiterTracker&, bool, bool) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/ParseDecl.cpp:6444:7
    #11 0x4ecc563 in clang::Parser::ParseDirectDeclarator(clang::Declarator&) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/ParseDecl.cpp:6126:7
    #12 0x4ecaf80 in clang::Parser::ParseDeclaratorInternal(clang::Declarator&, void (clang::Parser::*)(clang::Declarator&)) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/ParseDecl.cpp:5679:7
    #13 0x4ecb076 in clang::Parser::ParseDeclaratorInternal(clang::Declarator&, void (clang::Parser::*)(clang::Declarator&)) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/ParseDecl.cpp:5702:5
    #14 0x4ec0b24 in ParseDeclarator /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/ParseDecl.cpp:5547:3
    #15 0x4ec0b24 in clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::SourceLocation*, clang::Parser::ForRangeInit*) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/ParseDecl.cpp:2009:3
    #16 0x4ea1f23 in clang::Parser::ParseDeclOrFunctionDefInternal(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec&, clang::AccessSpecifier) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/Parser.cpp:1109:10
    #17 0x4ea1677 in clang::Parser::ParseDeclarationOrFunctionDefinition(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec*, clang::AccessSpecifier) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/Parser.cpp:1125:12
    #18 0x4ea0a0b in clang::Parser::ParseExternalDeclaration(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec*) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/Parser.cpp:945:12
    #19 0x4e9f2eb in clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, bool) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/Parser.cpp:696:12
    #20 0x4e99c3c in clang::ParseAST(clang::Sema&, bool, bool) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Parse/ParseAST.cpp:158:20
    #21 0x39058b1 in clang::FrontendAction::Execute() /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Frontend/FrontendAction.cpp:940:8
    #22 0x38b631c in clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Frontend/CompilerInstance.cpp:969:33
    #23 0x39f75a3 in clang::ExecuteCompilerInvocation(clang::CompilerInstance*) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:292:25
    #24 0x9df38e in cc1_main(llvm::ArrayRef<char const*>, char const*, void*) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/tools/driver/cc1_main.cpp:240:15
    #25 0x9da28a in ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/tools/driver/driver.cpp:328:12
    #26 0x9d7b61 in main /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/tools/driver/driver.cpp:402:12
    #27 0x7f385c8be2e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
    #28 0x9bbd29 in _start (/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/clang-11+0x9bbd29)

SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/AST/NestedNameSpecifier.cpp:485:23 in 

```

Users:
  rsmith (Author)

https://reviews.llvm.org/rG0e3a48778408