[Diagnostics] Handle string concat pattern and avoid false positives

llvm · Aug 9, 2020 · 975467e · 975467e
1 parent 43bdac2
commit 975467e
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Showing 2 changed files with 13 additions and 4 deletions.
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
@@ -6908,10 +6908,13 @@ Sema::ActOnInitList(SourceLocation LBraceLoc, MultiExprArg InitArgList,
         << InitArgList[I]->getSourceRange();
     } else if (const auto *SL = dyn_cast<StringLiteral>(InitArgList[I])) {
       unsigned NumConcat = SL->getNumConcatenated();
+      const auto *SLNext =
+          dyn_cast<StringLiteral>(InitArgList[I + 1 < E ? I + 1 : 0]);
       // Diagnose missing comma in string array initialization.
-      // Do not warn when all the elements in the initializer are concatenated together.
-      // Do not warn for macros too.
-      if (NumConcat > 1 && E > 2 && !SL->getBeginLoc().isMacroID()) {
+      // Do not warn when all the elements in the initializer are concatenated
+      // together. Do not warn for macros too.
+      if (NumConcat > 1 && E > 2 && !SL->getBeginLoc().isMacroID() && SLNext &&
+          NumConcat != SLNext->getNumConcatenated()) {
         SmallVector<FixItHint, 1> Hints;
         for (unsigned i = 0; i < NumConcat - 1; ++i)
           Hints.push_back(FixItHint::CreateInsertion(

diff --git a/clang/test/Sema/string-concat.c b/clang/test/Sema/string-concat.c
@@ -61,7 +61,7 @@ char missing_comma_inner[][5] = {
 #define TWO "foo"
 const char *macro_test[] = { ONE("foo") "bar", 
                              TWO "bar", 
-                             "foo" TWO // expected-note{{place parentheses around the string literal to silence warning}}
+                             "foo" "bar" TWO // expected-note{{place parentheses around the string literal to silence warning}}
                            };          // expected-warning@-1{{suspicious concatenation of string literals in an array initialization; did you mean to separate the elements with a comma?}}
 
 // Do not warn for macros.
@@ -104,6 +104,12 @@ const char *not_warn[] = {
     "world", "test"
 };
 
+const char *not_warn2[] = {
+    "// Aaa\\\n"   " Bbb\\ \n"   " Ccc?" "?/\n",
+    "// Aaa\\\r\n" " Bbb\\ \r\n" " Ccc?" "?/\r\n",
+    "// Aaa\\\r"   " Bbb\\ \r"   " Ccc?" "?/\r"
+  };
+
 // Do not warn when all the elements in the initializer are concatenated together.
 const char *all_elems_in_init_concatenated[] = {"a" "b" "c"};