[clang] c81dd3d - [clang-format] Handle shifts within conditions

[via cfe-commits]

Author: mydeveloperday
Date: 2020-09-08T16:40:04+01:00
New Revision: c81dd3d159ab03d46e4280c458d3c29e56648218

URL: https://github.com/llvm/llvm-project/commit/c81dd3d159ab03d46e4280c458d3c29e56648218
DIFF: https://github.com/llvm/llvm-project/commit/c81dd3d159ab03d46e4280c458d3c29e56648218.diff

LOG: [clang-format] Handle shifts within conditions

In some situation shifts can be treated as a template, and is thus formatted as one. So, by doing a couple extra checks to assure that the condition doesn't contain a template, and is in fact a bit shift should solve this problem.

This is a fix for [[ https://bugs.llvm.org/show_bug.cgi?id=46969 | bug 46969 ]]

Reviewed By: MyDeveloperDay

Patch By: Saldivarcher

Differential Revision: https://reviews.llvm.org/D86581

Added: 
    

Modified: 
    clang/lib/Format/TokenAnnotator.cpp
    clang/unittests/Format/FormatTest.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 5dd6a7a9da40..841f0b41e9a7 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -56,6 +56,13 @@ static bool isLambdaParameterList(const FormatToken *Left) {
          Left->Previous->MatchingParen->is(TT_LambdaLSquare);
 }
 
+/// Returns \c true if the token is followed by a boolean condition, \c false
+/// otherwise.
+static bool isKeywordWithCondition(const FormatToken &Tok) {
+  return Tok.isOneOf(tok::kw_if, tok::kw_for, tok::kw_while, tok::kw_switch,
+                     tok::kw_constexpr, tok::kw_catch);
+}
+
 /// A parser that gathers additional information about tokens.
 ///
 /// The \c TokenAnnotator tries to match parenthesis and square brakets and
@@ -108,6 +115,12 @@ class AnnotatingParser {
 
     while (CurrentToken) {
       if (CurrentToken->is(tok::greater)) {
+        // Try to do a better job at looking for ">>" within the condition of
+        // a statement.
+        if (CurrentToken->Next && CurrentToken->Next->is(tok::greater) &&
+            Left->ParentBracket != tok::less &&
+            isKeywordWithCondition(*Line.First))
+          return false;
         Left->MatchingParen = CurrentToken;
         CurrentToken->MatchingParen = Left;
         // In TT_Proto, we must distignuish between:
@@ -2768,13 +2781,6 @@ bool TokenAnnotator::spaceRequiredBeforeParens(const FormatToken &Right) const {
           Right.ParameterCount > 0);
 }
 
-/// Returns \c true if the token is followed by a boolean condition, \c false
-/// otherwise.
-static bool isKeywordWithCondition(const FormatToken &Tok) {
-  return Tok.isOneOf(tok::kw_if, tok::kw_for, tok::kw_while, tok::kw_switch,
-                     tok::kw_constexpr, tok::kw_catch);
-}
-
 bool TokenAnnotator::spaceRequiredBetween(const AnnotatedLine &Line,
                                           const FormatToken &Left,
                                           const FormatToken &Right) {

diff  --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index b198efa4af9e..98e002003159 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -7565,6 +7565,21 @@ TEST_F(FormatTest, UnderstandsTemplateParameters) {
   verifyFormat("static_assert(is_convertible<A &&, B>::value, \"AAA\");");
   verifyFormat("Constructor(A... a) : a_(X<A>{std::forward<A>(a)}...) {}");
   verifyFormat("< < < < < < < < < < < < < < < < < < < < < < < < < < < < < <");
+  verifyFormat("some_templated_type<decltype([](int i) { return i; })>");
+}
+
+TEST_F(FormatTest, UnderstandsShiftOperators) {
+  verifyFormat("if (i < x >> 1)");
+  verifyFormat("while (i < x >> 1)");
+  verifyFormat("for (unsigned i = 0; i < i; ++i, v = v >> 1)");
+  verifyFormat("for (unsigned i = 0; i < x >> 1; ++i, v = v >> 1)");
+  verifyFormat(
+      "for (std::vector<int>::iterator i = 0; i < x >> 1; ++i, v = v >> 1)");
+  verifyFormat("Foo.call<Bar<Function>>()");
+  verifyFormat("if (Foo.call<Bar<Function>>() == 0)");
+  verifyFormat("for (std::vector<std::pair<int>>::iterator i = 0; i < x >> 1; "
+               "++i, v = v >> 1)");
+  verifyFormat("if (w<u<v<x>>, 1>::t)");
 }
 
 TEST_F(FormatTest, BitshiftOperatorWidth) {