[clang-tools-extra] 9a930aa - [clang-tidy] Avoid bugprone-macro-parentheses warnings after goto argument

[Georgy Komarov via cfe-commits]

Author: Georgy Komarov
Date: 2021-04-22T10:14:10+03:00
New Revision: 9a930aa5bd2fc4686002d02411141a19f0ad8f36

URL: https://github.com/llvm/llvm-project/commit/9a930aa5bd2fc4686002d02411141a19f0ad8f36
DIFF: https://github.com/llvm/llvm-project/commit/9a930aa5bd2fc4686002d02411141a19f0ad8f36.diff

LOG: [clang-tidy] Avoid bugprone-macro-parentheses warnings after goto argument

clang-tidy should not generate warnings for the goto argument without
parentheses, because it would be a syntax error.

The only valid case where an argument can be enclosed in parentheses is
"Labels as Values" gcc extension: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html.
This commit adds support for the label-as-values extension as implemented in clang.

Fixes bugzilla issue 49634.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D99924

Added: 
    

Modified: 
    clang-tools-extra/clang-tidy/bugprone/MacroParenthesesCheck.cpp
    clang-tools-extra/test/clang-tidy/checkers/bugprone-macro-parentheses.cpp

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/clang-tidy/bugprone/MacroParenthesesCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/MacroParenthesesCheck.cpp
index 8d4366b51a3ec..303119d8ec812 100644
--- a/clang-tools-extra/clang-tidy/bugprone/MacroParenthesesCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/MacroParenthesesCheck.cpp
@@ -158,6 +158,9 @@ void MacroParenthesesPPCallbacks::argument(const Token &MacroNameTok,
   // Skip variable declaration.
   bool VarDecl = possibleVarDecl(MI, MI->tokens_begin());
 
+  // Skip the goto argument with an arbitrary number of subsequent stars.
+  bool FoundGoto = false;
+
   for (auto TI = MI->tokens_begin(), TE = MI->tokens_end(); TI != TE; ++TI) {
     // First token.
     if (TI == MI->tokens_begin())
@@ -179,9 +182,17 @@ void MacroParenthesesPPCallbacks::argument(const Token &MacroNameTok,
       continue;
     }
 
+    // There should not be extra parentheses for the goto argument.
+    if (Tok.is(tok::kw_goto)) {
+      FoundGoto = true;
+      continue;
+    }
+
     // Only interested in identifiers.
-    if (!Tok.isOneOf(tok::identifier, tok::raw_identifier))
+    if (!Tok.isOneOf(tok::identifier, tok::raw_identifier)) {
+      FoundGoto = false;
       continue;
+    }
 
     // Only interested in macro arguments.
     if (MI->getParameterNum(Tok.getIdentifierInfo()) < 0)
@@ -239,12 +250,16 @@ void MacroParenthesesPPCallbacks::argument(const Token &MacroNameTok,
     if (MI->isVariadic())
       continue;
 
-    Check->diag(Tok.getLocation(), "macro argument should be enclosed in "
-                                   "parentheses")
-        << FixItHint::CreateInsertion(Tok.getLocation(), "(")
-        << FixItHint::CreateInsertion(Tok.getLocation().getLocWithOffset(
-                                          PP->getSpelling(Tok).length()),
-                                      ")");
+    if (!FoundGoto) {
+      Check->diag(Tok.getLocation(), "macro argument should be enclosed in "
+                                     "parentheses")
+          << FixItHint::CreateInsertion(Tok.getLocation(), "(")
+          << FixItHint::CreateInsertion(Tok.getLocation().getLocWithOffset(
+                                            PP->getSpelling(Tok).length()),
+                                        ")");
+    }
+
+    FoundGoto = false;
   }
 }
 

diff  --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone-macro-parentheses.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone-macro-parentheses.cpp
index 8d128352e7894..6c2f42dd2dcd6 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone-macro-parentheses.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone-macro-parentheses.cpp
@@ -10,6 +10,10 @@
 // CHECK-MESSAGES: :[[@LINE-1]]:44: warning: macro argument should be enclosed in parentheses [bugprone-macro-parentheses]
 #define BAD5(X)           A*B=(C*)X+2
 // CHECK-MESSAGES: :[[@LINE-1]]:35: warning: macro argument should be enclosed in parentheses [bugprone-macro-parentheses]
+#define BAD6(x)           goto *x;
+// CHECK-MESSAGES: :[[@LINE-1]]:33: warning: macro argument should be enclosed in parentheses [bugprone-macro-parentheses]
+#define BAD7(x, y)        if (x) goto y; else x;
+// CHECK-MESSAGES: :[[@LINE-1]]:47: warning: macro argument should be enclosed in parentheses [bugprone-macro-parentheses]
 
 #define GOOD1             1
 #define GOOD2             (1+2)
@@ -44,6 +48,8 @@
 #define GOOD31(X)         A*X=2
 #define GOOD32(X)         std::vector<X>
 #define GOOD33(x)         if (!a__##x) a_##x = &f(#x)
+#define GOOD34(x, y)      if (x) goto y;
+#define GOOD35(x, y)      if (x) goto *(y);
 
 // These are allowed for now..
 #define MAYBE1            *12.34