Clang crashes on "(!R.empty() && "empty lookup results when building templateid")"


Bugzilla Link	PR12187
Status	CONFIRMED
Importance	P enhancement
Reported by	Alexander Potapenko (glider@google.com)
Reported on	2012-03-05 06:24:56 -0800
Last modified on	2019-01-24 17:49:39 -0800
Version	trunk
Hardware	PC Linux
CC	dgregor@apple.com, llvm-bugs@lists.llvm.org, mail.sandbox.de@gmail.com, richard-llvm@metafoo.co.uk, rnk@google.com
Fixed by commit(s)
Attachments	`min.c` (5872 bytes, text/x-csrc)
Blocks
Blocked by
See also

$ cat b_u_c_l_u.ii
    namespace std {
            pair<typename      ;
              __base.setf(ios_base::boolalpha);
               __base.setf(ios_base::unitbuf);
            template<typename     class basic_iostream     : public basic_istream<_CharT>   { };
          template<typename To>  To ImplicitCast_() {  }
          typedef bool_constant< ;
              };
               using namespace ::testing::internal2;
             template <> void DefaultPrintTo(IsContainer) {
         }
                        void PrintTo();
              PrintTo(ImplicitCast_<>());
=================================================
$ clang++ -c b_u_c_l_u.ii

b_u_c_l_u.ii:2:13: error: unknown type name 'pair'
            pair<typename      ;
            ^
b_u_c_l_u.ii:2:17: error: expected unqualified-id
            pair<typename      ;
                ^
b_u_c_l_u.ii:3:15: error: unknown type name '__base'
              __base.setf(ios_base::boolalpha);
              ^
b_u_c_l_u.ii:3:21: error: expected unqualified-id
              __base.setf(ios_base::boolalpha);
                    ^
b_u_c_l_u.ii:4:16: error: unknown type name '__base'
               __base.setf(ios_base::unitbuf);
               ^
b_u_c_l_u.ii:4:22: error: expected unqualified-id
               __base.setf(ios_base::unitbuf);
                     ^
b_u_c_l_u.ii:5:35: error: expected a qualified name after 'typename'
            template<typename     class basic_iostream     : public basic_istream<_CharT>   { };
                                  ^
b_u_c_l_u.ii:5:35: error: expected ',' or '>' in template-parameter-list
b_u_c_l_u.ii:5:89: error: expected unqualified-id
            template<typename     class basic_iostream     : public basic_istream<_CharT>   { };
                                                                                        ^
b_u_c_l_u.ii:7:19: error: unknown type name 'bool_constant'
          typedef bool_constant< ;
                  ^
b_u_c_l_u.ii:7:32: error: expected unqualified-id
          typedef bool_constant< ;
                               ^
b_u_c_l_u.ii:9:34: error: no member named 'testing' in the global namespace
               using namespace ::testing::internal2;
                               ~~^
b_u_c_l_u.ii:9:43: error: expected namespace name
               using namespace ::testing::internal2;
                                          ^
b_u_c_l_u.ii:10:14: error: extraneous 'template<>' in declaration of variable
'DefaultPrintTo'
             template <> void DefaultPrintTo(IsContainer) {
             ^~~~~~~~~~~
b_u_c_l_u.ii:10:31: error: variable has incomplete type 'void'
             template <> void DefaultPrintTo(IsContainer) {
                              ^
b_u_c_l_u.ii:10:46: error: use of undeclared identifier 'IsContainer'
             template <> void DefaultPrintTo(IsContainer) {
                                             ^
b_u_c_l_u.ii:10:58: error: expected ';' at end of declaration
             template <> void DefaultPrintTo(IsContainer) {
                                                         ^
                                                         ;
b_u_c_l_u.ii:10:59: error: expected unqualified-id
             template <> void DefaultPrintTo(IsContainer) {
                                                          ^
b_u_c_l_u.ii:13:23: error: no template named 'ImplicitCast_'; did you mean
'std::ImplicitCast_'?
              PrintTo(ImplicitCast_<>());
                      ^~~~~~~~~~~~~
                      std::ImplicitCast_
b_u_c_l_u.ii:6:37: note: 'std::ImplicitCast_' declared here
          template<typename To>  To ImplicitCast_() {  }
                                    ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
Assertion failed: (!R.empty() && "empty lookup results when building
templateid"), function BuildTemplateIdExpr, file /Users/glider/src/asan/asan-
llvm-trunk/llvm/tools/clang/lib/Sema/SemaTemplate.cpp, line 2228.
0  clang             0x0000000101617242 PrintStackTrace(void*) + 34
1  clang             0x00000001016177c9 SignalHandler(int) + 745
2  libSystem.B.dylib 0x00007fff848261ba _sigtramp + 26
3  clang             0x00000001004d6931 (anonymous
namespace)::UnqualUsingDirectiveSet::addUsingDirectives(clang::DeclContext*,
clang::DeclContext*) + 77
4  clang             0x000000010004a586 abort + 22
5  clang             0x000000010004a5d8 __assert_rtn + 56
6  clang             0x000000010053c0b2
clang::Sema::BuildTemplateIdExpr(clang::CXXScopeSpec const&,
clang::SourceLocation, clang::LookupResult&, bool,
clang::TemplateArgumentListInfo const*) + 222
7  clang             0x000000010046f818
clang::Sema::ActOnIdExpression(clang::Scope*, clang::CXXScopeSpec&,
clang::SourceLocation, clang::UnqualifiedId&, bool, bool,
clang::CorrectionCandidateCallback*) + 2132
8  clang             0x00000001002ef827
clang::Parser::ParseCXXIdExpression(bool) + 241
9  clang             0x00000001002e32eb
clang::Parser::ParseCastExpression(bool, bool, bool&,
clang::Parser::TypeCastState) + 7077
10 clang             0x00000001002de895
clang::Parser::ParseAssignmentExpression(clang::Parser::TypeCastState) + 133
11 clang             0x00000001002df4c8
clang::Parser::ParseExpressionList(llvm::SmallVectorImpl<clang::Expr*>&,
llvm::SmallVectorImpl<clang::SourceLocation>&, void
(clang::Sema::*)(clang::Scope*, clang::Expr*, clang::Expr**, unsigned int),
clang::Expr*) + 140
12 clang             0x00000001002c3682
clang::Parser::ParseDeclarationAfterDeclaratorAndAttributes(clang::Declarator&,
clang::Parser::ParsedTemplateInfo const&) + 1518
13 clang             0x00000001002c9b09
clang::Parser::ParseDeclGroup(clang::Parser::ParsingDeclSpec&, unsigned int,
bool, clang::SourceLocation*, clang::Parser::ForRangeInit*) + 1279
14 clang             0x0000000100311096
clang::Parser::ParseDeclarationOrFunctionDefinition(clang::Parser::ParsingDeclSpec&,
clang::AccessSpecifier) + 278
15 clang             0x0000000100311572
clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&,
clang::AccessSpecifier) + 396
16 clang             0x00000001003124dc
clang::Parser::ParseExternalDeclaration(clang::Parser::ParsedAttributesWithRange&,
clang::Parser::ParsingDeclSpec*) + 3706
17 clang             0x0000000100312aee
clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&) + 262
18 clang             0x00000001002bd9b5 clang::ParseAST(clang::Sema&, bool) +
325
19 clang             0x0000000100289833 clang::CodeGenAction::ExecuteAction() +
983
20 clang             0x000000010006c2a8
clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) + 862
21 clang             0x00000001000543cf
clang::ExecuteCompilerInvocation(clang::CompilerInstance*) + 2351
22 clang             0x000000010004e021 cc1_main(char const**, char const**,
char const*, void*) + 3185
23 clang             0x000000010005141d main + 621
24 clang             0x000000010004d39c start + 52
Stack dump:
0.  Program arguments: /Users/glider/src/asan/asan-llvm-
trunk/llvm/build/Release+Asserts/bin/clang -cc1 -triple x86_64-apple-
macosx10.6.0 -emit-obj -mrelax-all -disable-free -main-file-name b_u_c_l_u.ii -
pic-level 1 -mdisable-fp-elim -masm-verbose -munwind-tables -target-cpu core2 -
coverage-file b_u_c_l_u.o -resource-dir /Users/glider/src/asan/asan-llvm-
trunk/llvm/build/Release+Asserts/bin/../lib/clang/3.1 -fdeprecated-macro -
fdebug-compilation-dir /Users/glider/src/chrome-make-asan/src -ferror-limit 19 -
fmessage-length 179 -stack-protector 1 -mstackrealign -fblocks -fobjc-dispatch-
method=mixed -fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor-
diagnostics -o b_u_c_l_u.o -x c++-cpp-output b_u_c_l_u.ii
1.  b_u_c_l_u.ii:13:38: current parser token '('
clang: error: unable to execute command: Illegal instruction
clang: error: clang frontend command failed due to signal (use -v to see
invocation)
clang: note: diagnostic msg: Please submit a bug report to
http://llvm.org/bugs/ and include command line arguments and all diagnostic
information.
clang: note: diagnostic msg: Error generating preprocessed source(s) - no
preprocessable inputs.

This is true for ToT Clang and down to r151100 (I haven't tried further yet)

A minimal testcase: ===================== namespace s{ r<; b.; b.; t<; template<r>Ici(){} b} u; template<>D(w)} P(Ici<>( ===================== $ clang++ -c b_u_c_l_u.ii b_u_c_l_u.ii:2:1: error: unknown type name 'r' r<; ^ b_u_c_l_u.ii:2:2: error: expected unqualified-id r<; ^ b_u_c_l_u.ii:3:1: error: unknown type name 'b' b.; b.; ^ b_u_c_l_u.ii:3:2: error: expected unqualified-id b.; b.; ^ b_u_c_l_u.ii:3:5: error: unknown type name 'b' b.; b.; ^ b_u_c_l_u.ii:3:6: error: expected unqualified-id b.; b.; ^ b_u_c_l_u.ii:4:1: error: unknown type name 't' t<; ^ b_u_c_l_u.ii:4:2: error: expected unqualified-id t<; ^ b_u_c_l_u.ii:5:10: error: unknown type name 'r' template<r>Ici(){} ^ b_u_c_l_u.ii:5:12: error: C++ requires a type specifier for all declarations template<r>Ici(){} ^~~ b_u_c_l_u.ii:6:1: error: unknown type name 'b' b} ^ b_u_c_l_u.ii:6:2: error: expected unqualified-id b} ^ b_u_c_l_u.ii:7:1: error: C++ requires a type specifier for all declarations u; ^ b_u_c_l_u.ii:8:11: error: C++ requires a type specifier for all declarations template<>D(w)} ^ b_u_c_l_u.ii:8:1: error: extraneous 'template<>' in declaration of variable 'D' template<>D(w)} ^~~~~~~~~~ b_u_c_l_u.ii:8:13: error: use of undeclared identifier 'w' template<>D(w)} ^ b_u_c_l_u.ii:8:15: error: expected ';' at end of declaration template<>D(w)} ^ ; b_u_c_l_u.ii:8:15: error: extraneous closing brace ('}') b_u_c_l_u.ii:9:3: error: no template named 'Ici'; did you mean 's::Ici'? P(Ici<>( ^~~ s::Ici b_u_c_l_u.ii:5:12: note: 's::Ici' declared here template<r>Ici(){} ^ fatal error: too many errors emitted, stopping now [-ferror-limit=] Assertion failed: (!R.empty() && "empty lookup results when building templateid"), function BuildTemplateIdExpr, file /Users/glider/src/asan/asan- llvm-trunk/llvm/tools/clang/lib/Sema/SemaTemplate.cpp, line 2228. 0 clang 0x000000010160c372 PrintStackTrace(void*) + 34 1 clang 0x000000010160c8f9 SignalHandler(int) + 745 2 libSystem.B.dylib 0x00007fff848261ba _sigtramp + 26 3 clang 0x00000001004d8f01 (anonymous namespace)::UnqualUsingDirectiveSet::addUsingDirectives(clang::DeclContext*, clang::DeclContext*) + 77 4 clang 0x00000001000486e6 abort + 22 5 clang 0x0000000100048738 __assert_rtn + 56 6 clang 0x000000010053f2d2 clang::Sema::BuildTemplateIdExpr(clang::CXXScopeSpec const&, clang::SourceLocation, clang::LookupResult&, bool, clang::TemplateArgumentListInfo const*) + 222 7 clang 0x000000010046e62a clang::Sema::ActOnIdExpression(clang::Scope*, clang::CXXScopeSpec&, clang::SourceLocation, clang::UnqualifiedId&, bool, bool, clang::CorrectionCandidateCallback*) + 2164 8 clang 0x00000001002e9637 clang::Parser::ParseCXXIdExpression(bool) + 241 9 clang 0x00000001002dcc3b clang::Parser::ParseCastExpression(bool, bool, bool&, clang::Parser::TypeCastState) + 7077 10 clang 0x00000001002d7cb5 clang::Parser::ParseAssignmentExpression(clang::Parser::TypeCastState) + 133 11 clang 0x00000001002d8e18 clang::Parser::ParseExpressionList(llvm::SmallVectorImpl<clang::Expr*>&, llvm::SmallVectorImpl<clang::SourceLocation>&, void (clang::Sema::*)(clang::Scope*, clang::Expr*, llvm::ArrayRef<clang::Expr*>), clang::Expr*) + 140 12 clang 0x00000001002bb1a2 clang::Parser::ParseDeclarationAfterDeclaratorAndAttributes(clang::Declarator&, clang::Parser::ParsedTemplateInfo const&) + 1518 13 clang 0x00000001002c28e9 clang::Parser::ParseDeclGroup(clang::Parser::ParsingDeclSpec&, unsigned int, bool, clang::SourceLocation*, clang::Parser::ForRangeInit*) + 1279 14 clang 0x000000010030b569 clang::Parser::ParseDeclarationOrFunctionDefinition(clang::Parser::ParsingDeclSpec&, clang::AccessSpecifier) + 281 15 clang 0x000000010030ba42 clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::AccessSpecifier) + 396 16 clang 0x000000010030c9bc clang::Parser::ParseExternalDeclaration(clang::Parser::ParsedAttributesWithRange&, clang::Parser::ParsingDeclSpec*) + 3722 17 clang 0x000000010030cfce clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&) + 262 18 clang 0x00000001002b5e95 clang::ParseAST(clang::Sema&, bool) + 325 19 clang 0x0000000100280ad3 clang::CodeGenAction::ExecuteAction() + 983 20 clang 0x000000010006a018 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) + 862 21 clang 0x000000010005279f clang::ExecuteCompilerInvocation(clang::CompilerInstance*) + 2351 22 clang 0x000000010004c181 cc1_main(char const**, char const**, char const*, void*) + 3185 23 clang 0x000000010004f7ed main + 621 24 clang 0x000000010004b4fc start + 52 Stack dump: 0. Program arguments: /Users/glider/src/asan/asan-llvm- trunk/llvm/build/Release+Asserts/bin/clang -cc1 -triple x86_64-apple- macosx10.6.0 -emit-obj -mrelax-all -disable-free -main-file-name b_u_c_l_u.ii - pic-level 1 -mdisable-fp-elim -masm-verbose -munwind-tables -target-cpu core2 - coverage-file b_u_c_l_u.o -resource-dir /Users/glider/src/asan/asan-llvm- trunk/llvm/build/Release+Asserts/bin/../lib/clang/3.1 -fdeprecated-macro - fdebug-compilation-dir /Users/glider/src/chrome-make-asan/src -ferror-limit 19 - fmessage-length 179 -stack-protector 1 -mstackrealign -fblocks -fobjc-dispatch- method=mixed -fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor- diagnostics -o b_u_c_l_u.o -x c++-cpp-output b_u_c_l_u.ii 1. b_u_c_l_u.ii:9:8: current parser token '(' clang: error: unable to execute command: Illegal instruction clang: error: clang frontend command failed due to signal (use -v to see invocation) clang: note: diagnostic msg: Please submit a bug report to http://llvm.org/bugs/ and include command line arguments and all diagnostic information. clang: note: diagnostic msg: Error generating preprocessed source(s) - no preprocessable inputs.

The same error occurred to me today for this little test case: ----------- #include <algorithm> // <- needs to be included for this error //#include <myalgo.hpp> // <- equal<T,U> lives here but accidentally not included int main() { int x, y; equal(x, y); // error: use of undeclared identifier 'equal' equal<int, int>(x, y); // error: no template named 'equal'; did you mean 'std::equal'? return 0; } ----------- clang version 3.2 (trunk 167383) Target: x86_64-unknown-linux-gnu Thread model: posix ----------- /usr/local/bin/clang-3.2 -cc1 -triple x86_64-unknown-linux-gnu -emit-obj - disable-free -main-file-name bugNew.cpp -mrelocation-model static -fmath-errno - masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -momit- leaf-frame-pointer -O3 -std=c++0x -fdeprecated-macro -ferror-limit 1 -fmessage- length 230 -mstackrealign -fobjc-runtime=gcc -fcxx-exceptions -fexceptions - fdiagnostics-show-option -fcolor-diagnostics -x c++ bugNew-DiIzad.cpp --------- Both calls to "equal" are necessary for this crash to happen. If one of the statements is commented out, the compiler properly complains about not finding an appropriate function called equal. ---- clang-3.2: /home/xxx/Lib/llvm/tools/clang/lib/Sema/SemaTemplate.cpp:2291: ExprResult clang::Sema::BuildTemplateIdExpr(const clang::CXXScopeSpec &, clang::SourceLocation, clang::LookupResult &, bool, const clang::TemplateArgumentListInfo *): Assertion `!R.empty() && "empty lookup results when building templateid"' failed. 0 clang-3.2 0x000000000183fdae 1 clang-3.2 0x00000000018402aa 2 libpthread.so.0 0x00007f1696dc0cb0 3 libc.so.6 0x00007f1696216425 gsignal + 53 4 libc.so.6 0x00007f1696219b8b abort + 379 5 libc.so.6 0x00007f169620f0ee 6 libc.so.6 0x00007f169620f192 7 clang-3.2 0x000000000249bd4b clang::Sema::BuildTemplateIdExpr(clang::CXXScopeSpec const&, clang::SourceLocation, clang::LookupResult&, bool, clang::TemplateArgumentListInfo const*) + 107 8 clang-3.2 0x00000000022e267a clang::Sema::ActOnIdExpression(clang::Scope*, clang::CXXScopeSpec&, clang::SourceLocation, clang::UnqualifiedId&, bool, bool, clang::CorrectionCandidateCallback*) + 3066 9 clang-3.2 0x0000000001ca93ec clang::Parser::ParseCXXIdExpression(bool) + 460 10 clang-3.2 0x0000000001c9e6a4 clang::Parser::ParseCastExpression(bool, bool, bool&, clang::Parser::TypeCastState) + 9940 11 clang-3.2 0x0000000001c9a5c3 clang::Parser::ParseCastExpression(bool, bool, clang::Parser::TypeCastState) + 83 12 clang-3.2 0x0000000001c99428 clang::Parser::ParseAssignmentExpression(clang::Parser::TypeCastState) + 200 13 clang-3.2 0x0000000001c9932f clang::Parser::ParseExpression(clang::Parser::TypeCastState) + 31 14 clang-3.2 0x0000000001cca07c clang::Parser::ParseExprStatement() + 60 15 clang-3.2 0x0000000001cc9786 clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, bool, clang::SourceLocation*, clang::Parser::ParsedAttributesWithRange&) + 2070 16 clang-3.2 0x0000000001cc8e55 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, bool, clang::SourceLocation*) + 133 17 clang-3.2 0x0000000001ccfb35 clang::Parser::ParseCompoundStatementBody(bool) + 1477 18 clang-3.2 0x0000000001cd173a clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) + 282 19 clang-3.2 0x0000000001c5f2b7 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) + 3751 20 clang-3.2 0x0000000001c749e3 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, unsigned int, bool, clang::SourceLocation*, clang::Parser::ForRangeInit*) + 467 21 clang-3.2 0x0000000001c5e3fd clang::Parser::ParseDeclOrFunctionDefInternal(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec&, clang::AccessSpecifier) + 1133 22 clang-3.2 0x0000000001c5dbd3 clang::Parser::ParseDeclarationOrFunctionDefinition(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec*, clang::AccessSpecifier) + 147 23 clang-3.2 0x0000000001c5d378 clang::Parser::ParseExternalDeclaration(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec*) + 3384 24 clang-3.2 0x0000000001c5c602 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&) + 466 25 clang-3.2 0x0000000001c58996 clang::ParseAST(clang::Sema&, bool, bool) + 550 26 clang-3.2 0x0000000001b49728 clang::ASTFrontendAction::ExecuteAction() + 312 27 clang-3.2 0x000000000187aa62 clang::CodeGenAction::ExecuteAction() + 1266 28 clang-3.2 0x0000000001b4933d clang::FrontendAction::Execute() + 237 29 clang-3.2 0x0000000001b22dcb clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) + 779 30 clang-3.2 0x0000000001844bf7 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) + 999 31 clang-3.2 0x00000000007b40a8 cc1_main(char const**, char const**, char const*, void*) + 760 32 clang-3.2 0x00000000007abf19 main + 473 33 libc.so.6 0x00007f169620176d __libc_start_main + 237 34 clang-3.2 0x00000000007abc01 Stack dump: 0. Program arguments: /usr/local/bin/clang-3.2 -cc1 -triple x86_64-unknown- linux-gnu -emit-obj -disable-free -main-file-name bugNew.cpp -mrelocation-model static -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -target- cpu x86-64 -momit-leaf-frame-pointer -resource-dir /usr/local/bin/../lib/clang/3.2 -I ../../include -fmodule-cache-path /var/tmp/clang-module-cache -internal-isystem /usr/lib/gcc/x86_64-linux- gnu/4.6/../../../../include/c++/4.6 -internal-isystem /usr/lib/gcc/x86_64-linux- gnu/4.6/../../../../include/c++/4.6/x86_64-linux-gnu -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/backward - internal-isystem /usr/local/include -internal-isystem /usr/local/bin/../lib/clang/3.2/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal- externc-isystem /usr/include -O3 -std=c++0x -fdeprecated-macro -fdebug- compilation-dir /home/xxx/Lib/aura/test/bugNew -ferror-limit 1 -fmessage-length 230 -mstackrealign -fobjc-runtime=gcc -fcxx-exceptions -fexceptions - fdiagnostics-show-option -fcolor-diagnostics -o /tmp/bugNew-hKMSzq.o -x c++ bugNew.cpp 1. bugNew.cpp:9:17: current parser token '(' 2. bugNew.cpp:6:1: parsing function body 'main' 3. bugNew.cpp:6:1: in compound statement ('{}')

Alexander's test cases no longer trigger the assertion for me, but this code does, reduced from clang: ==== namespace a { template < class > b(class TypedefNameDeclType; c( const , ; } g } struct : d::e<const> { g f; i(, ) { h *b< TypedefNameDecl >( ==== Compile with: $ clang -cc1 t.cpp -triple x86_64-linux-gnu -ferror-limit 19 It seems to be related to overrunning the error limit.

Quuxplusone / LLVMBugzillaTest

Clang crashes on "(!R.empty() && "empty lookup results when building templateid")" #12303