[clang-tidy] Fix crash on end location inside macro

[Nathan-Huckleberry]

Summary

Lexer::getLocForEndOfToken is defined to return an
invalid location if the given location is inside a macro.
Other checks conditionally warn based off location
validity. Updating this check to do the same.

[Nathan-Huckleberry]

• Ran git-clang-format

[lebedev.ri]

Test?

[Nathan-Huckleberry]

• Add test

[nickdesaulniers]

Thanks for the fix.

clang-tools-extra/clang-tidy/bugprone/BranchCloneCheck.cpp

for (size_t i = 0; i + 1 < N; i++) {
 
         NumCopies++;
         KnownAsClone[j] = true;
 
         if (NumCopies == 2) {
           // We report the first occurence only when we find the second one.
           diag(Branches[i]->getBeginLoc(),
                "repeated branch in conditional chain");
-          diag(Lexer::getLocForEndOfToken(Branches[i]->getEndLoc(), 0,
-                                          *Result.SourceManager, getLangOpts()),
-               "end of the original", DiagnosticIDs::Note);
+          SourceLocation End =
+              Lexer::getLocForEndOfToken(Branches[i]->getEndLoc(), 0,
+                                         *Result.SourceManager, getLangOpts());
+          if (End.isValid()) {
+            diag(End, "end of the original", DiagnosticIDs::Note);
+          }
         }
 
         diag(Branches[j]->getBeginLoc(), "clone %0 starts here",
              DiagnosticIDs::Note)
             << (NumCopies - 1);
       }
     }
     return;
while (BeginCurrent < End) {
         // may be invalid, resuling in an assertation failure down the line.
         // While not optimal, try the begin location in this case, it's still
         // better then nothing.
         if (EndLoc.isInvalid())
           EndLoc = (EndCurrent - 1)->back()->getBeginLoc();
 
         if (EndLoc.isMacroID())
           EndLoc = Context.getSourceManager().getExpansionLoc(EndLoc);
+        EndLoc = Lexer::getLocForEndOfToken(EndLoc, 0, *Result.SourceManager,
+                                            getLangOpts());
 
-        diag(Lexer::getLocForEndOfToken(EndLoc, 0, *Result.SourceManager,
-                                        getLangOpts()),
-             "last of these clones ends here", DiagnosticIDs::Note);
+        if (EndLoc.isValid()) {
+          diag(EndLoc, "last of these clones ends here", DiagnosticIDs::Note);
+        }
       }
       BeginCurrent = EndCurrent;
     }
     return;
   }
 
   llvm_unreachable("No if statement and no switch statement.");
 }
 
 } // namespace bugprone
 } // namespace tidy
 } // namespace clang

clang-tools-extra/test/clang-tidy/bugprone-branch-clone-macro-crash.c

+// RUN: %check_clang_tidy %s bugprone-branch-clone %t
+int x = 0;
+int y = 1;
+#define a(b, c) \
+  typeof(b) d;  \
+  if (b)        \
+    d = b;      \
+  else if (c)   \
+    d = b;
+
+f() {
+  // CHECK-MESSAGES: warning: repeated branch in conditional chain [bugprone-branch-clone]
+  a(x, y)
+}