[clang-format] Refine structured binding detection

krasimirgg · krasimirgg · commit fc67176eec7e · 2019-03-25T17:29:16.000Z
Summary: Revision r356575 had the unfortunate consequence that now clang-format never detects an ObjC call expression after `&&`. This patch tries harder to distinguish between C++17 structured bindings and ObjC call expressions and adds a few regression tests. Reviewers: klimek Reviewed By: klimek Subscribers: cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D59774 llvm-svn: 356928
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "TokenAnnotator.h"
+#include "FormatToken.h"
 #include "clang/Basic/SourceManager.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/Support/Debug.h"
@@ -440,25 +441,24 @@ class AnnotatingParser {
         Contexts.back().InCSharpAttributeSpecifier;
 
     bool InsideInlineASM = Line.startsWith(tok::kw_asm);
+    bool IsCppStructuredBinding = Left->isCppStructuredBinding(Style);
     bool StartsObjCMethodExpr =
-        !InsideInlineASM && !CppArrayTemplates && Style.isCpp() &&
-        !IsCpp11AttributeSpecifier && Contexts.back().CanBeExpression &&
-        Left->isNot(TT_LambdaLSquare) &&
+        !IsCppStructuredBinding && !InsideInlineASM && !CppArrayTemplates &&
+        Style.isCpp() && !IsCpp11AttributeSpecifier &&
+        Contexts.back().CanBeExpression && Left->isNot(TT_LambdaLSquare) &&
         !CurrentToken->isOneOf(tok::l_brace, tok::r_square) &&
         (!Parent ||
          Parent->isOneOf(tok::colon, tok::l_square, tok::l_paren,
                          tok::kw_return, tok::kw_throw) ||
          Parent->isUnaryOperator() ||
          // FIXME(bug 36976): ObjC return types shouldn't use TT_CastRParen.
          Parent->isOneOf(TT_ObjCForIn, TT_CastRParen) ||
-         // for (auto && [A,B] : C)  && structure binding seen as ObjCMethodExpr
-         (Parent->isNot(tok::ampamp) &&
-          getBinOpPrecedence(Parent->Tok.getKind(), true, true) >
-              prec::Unknown));
+         (getBinOpPrecedence(Parent->Tok.getKind(), true, true) >
+          prec::Unknown));
     bool ColonFound = false;
 
     unsigned BindingIncrease = 1;
-    if (Left->isCppStructuredBinding(Style)) {
+    if (IsCppStructuredBinding) {
       Left->Type = TT_StructuredBindingLSquare;
     } else if (Left->is(TT_Unknown)) {
       if (StartsObjCMethodExpr) {
diff --git a/clang/unittests/Format/FormatTestObjC.cpp b/clang/unittests/Format/FormatTestObjC.cpp
@@ -1357,6 +1357,30 @@ TEST_F(FormatTestObjC, DisambiguatesCallsFromCppLambdas) {
   // verifyFormat("x = ([a foo:bar] >> b->c == 'd');");
 }
 
+TEST_F(FormatTestObjC,  DisambiguatesCallsFromStructuredBindings) {
+  verifyFormat("int f() {\n"
+               "  if (a && [f arg])\n"
+               "    return 0;\n"
+               "}");
+  verifyFormat("int f() {\n"
+               "  if (a & [f arg])\n"
+               "    return 0;\n"
+               "}");
+  verifyFormat("int f() {\n"
+               "  for (auto &[elem] : list)\n"
+               "    return 0;\n"
+               "}");
+  verifyFormat("int f() {\n"
+               "  for (auto &&[elem] : list)\n"
+               "    return 0;\n"
+               "}");
+  verifyFormat(
+      "int f() {\n"
+      "  for (auto /**/ const /**/ volatile /**/ && /**/ [elem] : list)\n"
+      "    return 0;\n"
+      "}");
+}
+
 } // end namespace
 } // end namespace format
 } // end namespace clang
