[clang-tidy] Fix crash in modernize-use-noexcept on uninstantiated throw class

[zinovy.nis]

Summary

Bug: https://bugs.llvm.org/show_bug.cgi?id=47446

[njames93]

Please fix the clang-format fail too.

clang-tools-extra/test/clang-tidy/checkers/modernize-use-noexcept-opt.cpp

24

This line is causing tests to fail

[aaron.ballman]

clang-tools-extra/clang-tidy/modernize/UseNoexceptCheck.cpp

81

No need for the clang:: bit.

clang-tools-extra/test/clang-tidy/checkers/modernize-use-noexcept-opt.cpp

24

Another suggestion is to do: using size_t = decltype(sizeof(0)); at the top of the file.

[zinovy.nis]

• Fixed the test.
• Fixed clang-format issues.

[zinovy.nis]

Done.

[aaron.ballman]

LGTM!

clang-tools-extra/clang-tidy/modernize/UseNoexceptCheck.cpp

if (const auto *FuncDecl = Result.Nodes.getNodeAs<FunctionDecl>("funcDecl")) {
     if (const auto *TSI = ParmDecl->getTypeSourceInfo())
       Range = TSI->getTypeLoc()
                   .getNextTypeLoc()
                   .IgnoreParens()
                   .castAs<FunctionProtoTypeLoc>()
                   .getExceptionSpecRange();
   }
 
+  assert(FnTy && "FunctionProtoType is null.");
+  if (isUnresolvedExceptionSpec(FnTy->getExceptionSpecType()))
+    return;
+
   assert(Range.isValid() && "Exception Source Range is invalid.");
 
   CharSourceRange CRange = Lexer::makeFileCharRange(
       CharSourceRange::getTokenRange(Range), *Result.SourceManager,
       Result.Context->getLangOpts());
 
-  assert(FnTy && "FunctionProtoType is null.");
   bool IsNoThrow = FnTy->isNothrow();
   StringRef ReplacementStr =
       IsNoThrow
           ? NoexceptMacro.empty() ? "noexcept" : NoexceptMacro.c_str()
           : NoexceptMacro.empty()
                 ? (DtorOrOperatorDel || UseNoexceptFalse) ? "noexcept(false)"
                                                           : ""
                 : "";

clang-tools-extra/test/clang-tidy/checkers/modernize-use-noexcept-opt.cpp

 // RUN: %check_clang_tidy -std=c++11,c++14 %s modernize-use-noexcept %t -- \
 // RUN:   -config="{CheckOptions: [{key: modernize-use-noexcept.UseNoexceptFalse, value: 0}]}" \
 // RUN:   -- -fexceptions
 // This test is not run in C++17 or later because dynamic exception
 // specifications were removed in C++17.
 
+using size_t = __SIZE_TYPE__;
 class A {};
 class B {};
 
 void foo() throw();
 // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: dynamic exception specification 'throw()' is deprecated; consider using 'noexcept' instead [modernize-use-noexcept]
 // CHECK-FIXES: void foo() noexcept;
 
 void bar() throw(...);
 // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: dynamic exception specification 'throw(...)' is deprecated; consider removing it instead [modernize-use-noexcept]
 // CHECK-FIXES: void bar() ;
 
 void k() throw(int(int));
 // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: dynamic exception specification 'throw(int(int))' is deprecated; consider removing it instead [modernize-use-noexcept]
 // CHECK-FIXES: void k() ;
 
+// Shouldn't crash due to llvm_unreachable in canThrow() on EST_Uninstantiated
+template <int> class c { void *operator new(size_t) throw (int);};
+void s() { c<1> doesnt_crash; }
+// CHECK-MESSAGES: :[[@LINE-2]]:53: warning: dynamic exception specification 'throw (int)' is deprecated; consider removing it instead [modernize-use-noexcept]
+
 void foobar() throw(A, B)
 {}
 // CHECK-MESSAGES: :[[@LINE-2]]:15: warning: dynamic exception specification 'throw(A, B)' is deprecated; consider removing it instead [modernize-use-noexcept]
 // CHECK-FIXES: void foobar()
 
 void baz(int = (throw A(), 0)) throw(A, B) {}
 // CHECK-MESSAGES: :[[@LINE-1]]:32: warning: dynamic exception specification 'throw(A, B)' is deprecated; consider removing it instead [modernize-use-noexcept]
 // CHECK-FIXES: void baz(int = (throw A(), 0)) {}