<html>
    <head>
      <base href="https://bugs.llvm.org/">
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Crash on invalid: ResolveSingleFunctionTemplateSpecialization"
   href="https://bugs.llvm.org/show_bug.cgi?id=49329">49329</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Crash on invalid: ResolveSingleFunctionTemplateSpecialization
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>clang
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>trunk
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>enhancement
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>C++
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedclangbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>hokein@google.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Testcase:

template <typename T>
class C {
public:
  template<int TT>
  class Type {
  };
};

template <typename T1>
class A {
public:
  void foo() {
    C<T1>::template Type<2>;
  }
};

void test() {
    A<float> a;
    a.foo();
}


Crash stack trace:


clang: llvm-project/llvm/include/llvm/Support/Casting.h:269: typename
cast_retty<X, Y *>::ret_type llvm::cast(Y *) [X = clang::FunctionTemplateDecl,
Y = clang::NamedDecl]: Assertion `isa<X>(Val) && "cast<Ty>() argument of
incompatible type!"' failed.
PLEASE submit a bug report to <a href="https://bugs.llvm.org/">https://bugs.llvm.org/</a> and include the crash
backtrace, preprocessed source, and associated run script.
Stack dump:
0.      Program arguments: ./bin/clang -cc1 -ast-dump /tmp/t1.cpp
1.      <eof> parser at end of file
2.      /tmp/t1.cpp:13:8: instantiating function definition 'A<float>::foo'
 #0 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int)
llvm-project/llvm/lib/Support/Unix/Signals.inc:565:11
 #1 PrintStackTraceSignalHandler(void*)
llvm-project/llvm/lib/Support/Unix/Signals.inc:632:1
 #2 llvm::sys::RunSignalHandlers()
llvm-project/llvm/lib/Support/Signals.cpp:70:5
 #3 SignalHandler(int) llvm-project/llvm/lib/Support/Unix/Signals.inc:407:1
 #4 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14140)
 #5 raise ./signal/../sysdeps/unix/sysv/linux/raise.c:51:1
 #6 abort ./stdlib/abort.c:81:7
 #7 get_sysdep_segment_value ./intl/loadmsgcat.c:509:8
 #8 _nl_load_domain ./intl/loadmsgcat.c:970:34
 #9 (/lib/x86_64-linux-gnu/libc.so.6+0x34662)
#10 llvm::cast_retty<clang::FunctionTemplateDecl, clang::NamedDecl*>::ret_type
llvm::cast<clang::FunctionTemplateDecl, clang::NamedDecl>(clang::NamedDecl*)
llvm-project/llvm/include/llvm/Support/Casting.h:270:10
#11
clang::Sema::ResolveSingleFunctionTemplateSpecialization(clang::OverloadExpr*,
bool, clang::DeclAccessPair*)
llvm-project/clang/lib/Sema/SemaOverload.cpp:12460:27
#12
clang::Sema::ResolveAndFixSingleFunctionTemplateSpecialization(clang::ActionResult<clang::Expr*,
true>&, bool, bool, clang::SourceRange, clang::QualType, unsigned int)
llvm-project/clang/lib/Sema/SemaOverload.cpp:12525:21
#13 clang::Sema::CheckPlaceholderExpr(clang::Expr*)
llvm-project/clang/lib/Sema/SemaExpr.cpp:19272:9
#14 clang::Sema::ActOnFinishFullExpr(clang::Expr*, clang::SourceLocation, bool,
bool) llvm-project/clang/lib/Sema/SemaExprCXX.cpp:8388:16
#15 clang::Sema::ActOnExprStmt(clang::ActionResult<clang::Expr*, true>, bool)
llvm-project/clang/lib/Sema/SemaStmt.cpp:49:8
#16 clang::TreeTransform<(anonymous
namespace)::TemplateInstantiator>::TransformStmt(clang::Stmt*,
clang::TreeTransform<(anonymous
namespace)::TemplateInstantiator>::StmtDiscardKind)
llvm-project/clang/lib/Sema/TreeTransform.h:3687:24
#17 clang::TreeTransform<(anonymous
namespace)::TemplateInstantiator>::TransformCompoundStmt(clang::CompoundStmt*,
bool) llvm-project/clang/lib/Sema/TreeTransform.h:7109:38
#18 clang::TreeTransform<(anonymous
namespace)::TemplateInstantiator>::TransformCompoundStmt(clang::CompoundStmt*)
llvm-project/clang/lib/Sema/TreeTransform.h:7095:23
#19 clang::TreeTransform<(anonymous
namespace)::TemplateInstantiator>::TransformStmt(clang::Stmt*,
clang::TreeTransform<(anonymous
namespace)::TemplateInstantiator>::StmtDiscardKind)
llvm-project/build-debug/tools/clang/include/clang/AST/StmtNodes.inc:73:1
#20 clang::Sema::SubstStmt(clang::Stmt*, clang::MultiLevelTemplateArgumentList
const&) llvm-project/clang/lib/Sema/SemaTemplateInstantiate.cpp:3460:23
#21 clang::Sema::InstantiateFunctionDefinition(clang::SourceLocation,
clang::FunctionDecl*, bool, bool, bool)
llvm-project/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp:4892:14
#22 clang::Sema::PerformPendingInstantiations(bool)
llvm-project/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp:6139:13
#23 clang::Sema::ActOnEndOfTranslationUnitFragment(clang::Sema::TUFragmentKind)
llvm-project/clang/lib/Sema/Sema.cpp:995:3
#24 clang::Sema::ActOnEndOfTranslationUnit()
llvm-project/clang/lib/Sema/Sema.cpp:1030:5

Looks like this is a regression, it is in trunk, but not reproducible in
clang-11.0.1.</pre>
        </div>
      </p>


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