[clang-tidy] Clarify bugprone-branch-clone diagnostic message

[donat.nagy]

Summary

This simple commit inserts "body" into the message "repeated branch body in conditional chain". This is motivated by feedback from a confused user who (at first glance) thought that clang-tidy complained about a repeated branch condition.

[carlosgalvezp]

LGTM, thanks for the fix! Personally I don't think such a small change is worth mentioning in the Release Notes, but maybe other reviewers think differently, let's give them a couple of days.

[carlosgalvezp]

@donat.nagy Are you available to push the commit yourself? Otherwise I can help you with that, please let me know your name and email (must match those on your Github account) for attribution.

[donat.nagy]

Thanks for the feedback! I can push the commit and I'll do so after a few days (if no changes are suggested).

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

for (size_t I = 0; I + 1 < N; I++) {
           continue;
 
         NumCopies++;
         KnownAsClone[J] = true;
 
         if (NumCopies == 2) {
           // We report the first occurrence only when we find the second one.
           diag(Branches[I]->getBeginLoc(),
-               "repeated branch in conditional chain");
+               "repeated branch body in conditional chain");
           SourceLocation End =
               Lexer::getLocForEndOfToken(Branches[I]->getEndLoc(), 0,
                                          *Result.SourceManager, getLangOpts());
           if (End.isValid()) {
             diag(End, "end of the original", DiagnosticIDs::Note);
           }
         }
 

clang-tools-extra/test/clang-tidy/checkers/bugprone/branch-clone-if-constexpr-template.cpp

 // RUN: %check_clang_tidy %s bugprone-branch-clone %t -- -- -std=c++17
 
 void handle(int);
 
 template <unsigned Index>
 void shouldFail() {
   if constexpr (Index == 0) {
-    // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: repeated branch in conditional chain [bugprone-branch-clone]
+    // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: repeated branch body in conditional chain [bugprone-branch-clone]
     handle(0);
   } else if constexpr (Index == 1) {
     handle(1);
   } else {
     handle(0);
   }
 }
 
 template <unsigned Index>
 void shouldPass() {
   if constexpr (Index == 0) {
     handle(0);
   } else if constexpr (Index == 1) {
     handle(1);
   } else {
     handle(2);
   }
 }
 
 void shouldFailNonTemplate() {
   constexpr unsigned Index = 1;
   if constexpr (Index == 0) {
-    // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: repeated branch in conditional chain [bugprone-branch-clone]
+    // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: repeated branch body in conditional chain [bugprone-branch-clone]
     handle(0);
   } else if constexpr (Index == 1) {
     handle(1);
   } else {
     handle(0);
   }
 }
 

clang-tools-extra/test/clang-tidy/checkers/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;
 
 void f(void) {
-  // CHECK-MESSAGES: warning: repeated branch in conditional chain [bugprone-branch-clone]
+  // CHECK-MESSAGES: warning: repeated branch body in conditional chain [bugprone-branch-clone]
   a(x, y)
 }

clang-tools-extra/test/clang-tidy/checkers/bugprone/branch-clone.cpp

CASE(13)
       out++;
   END
 }
 
 //=========--------------------==========//
 
 void test_chain1(int in, int &out) {
   if (in > 77)
-// CHECK-MESSAGES: :[[@LINE+1]]:5: warning: repeated branch in conditional chain [bugprone-branch-clone]
+// CHECK-MESSAGES: :[[@LINE+1]]:5: warning: repeated branch body in conditional chain [bugprone-branch-clone]
     out++;
 // CHECK-MESSAGES: :[[@LINE-1]]:10: note: end of the original
   else if (in > 55)
 // CHECK-MESSAGES: :[[@LINE+1]]:5: note: clone 1 starts here
     out++;
 
   out++;
 }
 
 void test_chain2(int in, int &out) {
   if (in > 77)
-// CHECK-MESSAGES: :[[@LINE+1]]:5: warning: repeated branch in conditional chain [bugprone-branch-clone]
+// CHECK-MESSAGES: :[[@LINE+1]]:5: warning: repeated branch body in conditional chain [bugprone-branch-clone]
     out++;
 // CHECK-MESSAGES: :[[@LINE-1]]:10: note: end of the original
   else if (in > 55)
 // CHECK-MESSAGES: :[[@LINE+1]]:5: note: clone 1 starts here
     out++;
   else if (in > 42)
     out--;
   else if (in > 28)
 // CHECK-MESSAGES: :[[@LINE+1]]:5: note: clone 2 starts here
     out++;
   else if (in > 12) {
     out++;
     out *= 7;
   } else if (in > 7) {
 // CHECK-MESSAGES: :[[@LINE-1]]:22: note: clone 3 starts here
     out++;
   }
 }
 
 void test_chain3(int in, int &out) {
   if (in > 77) {
-// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: repeated branch in conditional chain [bugprone-branch-clone]
+// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: repeated branch body in conditional chain [bugprone-branch-clone]
     out++;
     out++;
 // CHECK-MESSAGES: :[[@LINE+1]]:4: note: end of the original
   } else if (in > 55) {
 // CHECK-MESSAGES: :[[@LINE-1]]:23: note: clone 1 starts here
     out++;
     out++;
   } else if (in > 42)
// CHECK-MESSAGES: :[[@LINE-1]]:22: note: clone 3 starts here
     out++;
   }
 }
 
 // In this chain there are two clone families; notice that the checker
 // describes all branches of the first one before mentioning the second one.
 void test_chain4(int in, int &out) {
   if (in > 77) {
-// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: repeated branch in conditional chain [bugprone-branch-clone]
+// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: repeated branch body in conditional chain [bugprone-branch-clone]
     out++;
     out++;
 // CHECK-MESSAGES: :[[@LINE+1]]:4: note: end of the original
   } else if (in > 55) {
 // CHECK-MESSAGES: :[[@LINE-1]]:23: note: clone 1 starts here
 // CHECK-MESSAGES: :[[@LINE+8]]:21: note: clone 2 starts here
 // CHECK-MESSAGES: :[[@LINE+15]]:22: note: clone 3 starts here
     out++;
     out++;
   } else if (in > 42)
-// CHECK-MESSAGES: :[[@LINE+1]]:5: warning: repeated branch in conditional chain [bugprone-branch-clone]
+// CHECK-MESSAGES: :[[@LINE+1]]:5: warning: repeated branch body in conditional chain [bugprone-branch-clone]
     out--;
 // CHECK-MESSAGES: :[[@LINE-1]]:10: note: end of the original
   else if (in > 28) {
     out++;
     out++;
   } else if (in > 12) {
     out++;
     out++;
     out++;
     out *= 7;
   } else if (in > 7) {
     out++;
     out++;
   } else if (in > -3) {
 // CHECK-MESSAGES: :[[@LINE-1]]:23: note: clone 1 starts here
     out--;
   }
 }
 
 void test_chain5(int in, int &out) {
   if (in > 77)
-// CHECK-MESSAGES: :[[@LINE+1]]:5: warning: repeated branch in conditional chain [bugprone-branch-clone]
+// CHECK-MESSAGES: :[[@LINE+1]]:5: warning: repeated branch body in conditional chain [bugprone-branch-clone]
     out++;
 // CHECK-MESSAGES: :[[@LINE-1]]:10: note: end of the original
   else if (in > 55)
 // CHECK-MESSAGES: :[[@LINE+1]]:5: note: clone 1 starts here
     out++;
   else if (in > 42)
     out--;
   else if (in > 28)
 // CHECK-MESSAGES: :[[@LINE+1]]:5: note: clone 2 starts here
     out++;
   else if (in > 12) {
     out++;
     out *= 7;
   } else {
 // CHECK-MESSAGES: :[[@LINE-1]]:10: note: clone 3 starts here
     out++;
   }
 }
 
 void test_chain6(int in, int &out) {
   if (in > 77) {
-// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: repeated branch in conditional chain [bugprone-branch-clone]
+// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: repeated branch body in conditional chain [bugprone-branch-clone]
     out++;
     out++;
 // CHECK-MESSAGES: :[[@LINE+1]]:4: note: end of the original
   } else if (in > 55) {
 // CHECK-MESSAGES: :[[@LINE-1]]:23: note: clone 1 starts here
     out++;
     out++;
   } else if (in > 42)
// CHECK-MESSAGES: :[[@LINE-1]]:10: note: clone 3 starts here
   }
 }
 
 void test_nested(int a, int b, int c, int &out) {
   if (a > 5) {
 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: if with identical then and else branches [bugprone-branch-clone]
 // CHECK-MESSAGES: :[[@LINE+27]]:5: note: else branch starts here
     if (b > 5) {
-// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: repeated branch in conditional chain [bugprone-branch-clone]
+// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: repeated branch body in conditional chain [bugprone-branch-clone]
 // CHECK-MESSAGES: :[[@LINE+9]]:6: note: end of the original
 // CHECK-MESSAGES: :[[@LINE+8]]:24: note: clone 1 starts here
 // CHECK-MESSAGES: :[[@LINE+14]]:12: note: clone 2 starts here
       if (c > 5)
 // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: if with identical then and else branches [bugprone-branch-clone]
         out++;
       else
 // CHECK-MESSAGES: :[[@LINE-1]]:7: note: else branch starts here

 // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: if with identical then and else branches [bugprone-branch-clone]
         out++;
       else
 // CHECK-MESSAGES: :[[@LINE-1]]:7: note: else branch starts here
         out++;
     }
   } else {
     if (b > 5) {
-// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: repeated branch in conditional chain [bugprone-branch-clone]
+// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: repeated branch body in conditional chain [bugprone-branch-clone]
 // CHECK-MESSAGES: :[[@LINE+9]]:6: note: end of the original
 // CHECK-MESSAGES: :[[@LINE+8]]:24: note: clone 1 starts here
 // CHECK-MESSAGES: :[[@LINE+14]]:12: note: clone 2 starts here
       if (c > 5)
 // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: if with identical then and else branches [bugprone-branch-clone]
         out++;
       else
 // CHECK-MESSAGES: :[[@LINE-1]]:7: note: else branch starts here

 // The child of the switch statement is not necessarily a compound statement,
 // do not crash in this unusual case.
 char no_real_body(int in, int &out) {
   switch (in)
   case 42:
     return 'A';
 
   if (in > 77)
-// CHECK-MESSAGES: :[[@LINE+1]]:5: warning: repeated branch in conditional chain [bugprone-branch-clone]
+// CHECK-MESSAGES: :[[@LINE+1]]:5: warning: repeated branch body in conditional chain [bugprone-branch-clone]
     out++;
 // CHECK-MESSAGES: :[[@LINE-1]]:10: note: end of the original
   else if (in > 55)
 // CHECK-MESSAGES: :[[@LINE+1]]:5: note: clone 1 starts here
     out++;
   else if (in > 34)
 // CHECK-MESSAGES: :[[@LINE+1]]:5: note: clone 2 starts here
     out++;