Typz created this revision.
Herald added a subscriber: klimek.

The current code would return an incorrect value when a preprocessor
directive is present immediately after the opening brace: this causes
the nanespace end comment fixer to break in some places, for exemple it
would not add the comment in this case:

  namespace a {
  #define FOO
  }

Fixing the computation is simple enough, but it was breaking a feature,
as it would cause comments to be added also when the namespace
declaration was dependant on conditional compilation.

To fix this, a hash of the current preprocessor stack/branches is
computed at the beginning of parseBlock(), so that we explicitely do not
store the OpeningLineIndex when the beginning and end of the block are
not in the same preprocessor conditions.

Tthe hash is computed based on the line, but this could propbably be
improved by using the actual condition, so that clang-format would be
able to match multiple identical #ifdef blocks.


https://reviews.llvm.org/D35483

Files:
  lib/Format/UnwrappedLineParser.cpp
  lib/Format/UnwrappedLineParser.h
  unittests/Format/NamespaceEndCommentsFixerTest.cpp

Index: unittests/Format/NamespaceEndCommentsFixerTest.cpp
===================================================================
--- unittests/Format/NamespaceEndCommentsFixerTest.cpp
+++ unittests/Format/NamespaceEndCommentsFixerTest.cpp
@@ -509,6 +509,51 @@
                                     "}\n"));
 }
 
+TEST_F(NamespaceEndCommentsFixerTest, AddEndCommentForNamespacesAroundMacros) {
+  EXPECT_EQ("namespace A {\n"
+            "#if 0\n"
+            "int i;\n"
+            "#endif\n"
+            "}// namespace A",
+            fixNamespaceEndComments("namespace A {\n"
+                                    "#if 0\n"
+                                    "int i;\n"
+                                    "#endif\n"
+                                    "}"));
+  EXPECT_EQ("#if 0\n"
+            "#endif\n"
+            "namespace A {\n"
+            "int i;\n"
+            "int j;\n"
+            "}// namespace A",
+            fixNamespaceEndComments("#if 0\n"
+                                    "#endif\n"
+                                    "namespace A {\n"
+                                    "int i;\n"
+                                    "int j;\n"
+                                    "}"));
+  EXPECT_EQ("namespace A {\n"
+            "int i;\n"
+            "int j;\n"
+            "}// namespace A\n"
+            "#if 0\n"
+            "#endif",
+            fixNamespaceEndComments("namespace A {\n"
+                                    "int i;\n"
+                                    "int j;\n"
+                                    "}\n"
+                                    "#if 0\n"
+                                    "#endif"));
+  EXPECT_EQ("namespace A {\n"
+            "#define FOO\n"
+            "int i;\n"
+            "}// namespace A",
+            fixNamespaceEndComments("namespace A {\n"
+                                    "#define FOO\n"
+                                    "int i;\n"
+                                    "}"));
+}
+
 TEST_F(NamespaceEndCommentsFixerTest,
        DoesNotAddEndCommentForNamespacesInMacroDeclarations) {
   EXPECT_EQ("#ifdef 1\n"
Index: lib/Format/UnwrappedLineParser.h
===================================================================
--- lib/Format/UnwrappedLineParser.h
+++ lib/Format/UnwrappedLineParser.h
@@ -155,6 +155,7 @@
   void conditionalCompilationEnd();
 
   bool isOnNewLine(const FormatToken &FormatTok);
+  size_t computePPHash() const;
 
   // FIXME: We are constantly running into bugs where Line.Level is incorrectly
   // subtracted from beyond 0. Introduce a method to subtract from Line.Level
@@ -174,7 +175,7 @@
 
   // Preprocessor directives are parsed out-of-order from other unwrapped lines.
   // Thus, we need to keep a list of preprocessor directives to be reported
-  // after an unwarpped line that has been started was finished.
+  // after an unwrapped line that has been started was finished.
   SmallVector<UnwrappedLine, 4> PreprocessorDirectives;
 
   // New unwrapped lines are added via CurrentLines.
@@ -207,8 +208,15 @@
     PP_Unreachable  // #if 0 or a conditional preprocessor block inside #if 0
   };
 
+  struct PPBranch {
+    PPBranch(PPBranchKind Kind, size_t Line) : Kind(Kind), Line(Line) {}
+    bool operator==(PPBranchKind Kind) const { return Kind == this->Kind; }
+    PPBranchKind Kind;
+    size_t Line;
+  };
+
   // Keeps a stack of currently active preprocessor branching directives.
-  SmallVector<PPBranchKind, 16> PPStack;
+  SmallVector<PPBranch, 16> PPStack;
 
   // The \c UnwrappedLineParser re-parses the code for each combination
   // of preprocessor branches that can be taken.
Index: lib/Format/UnwrappedLineParser.cpp
===================================================================
--- lib/Format/UnwrappedLineParser.cpp
+++ lib/Format/UnwrappedLineParser.cpp
@@ -452,23 +452,43 @@
   FormatTok = Tokens->setPosition(StoredPosition);
 }
 
+template <class T>
+static inline void hash_combine(std::size_t &seed, const T &v) {
+  std::hash<T> hasher;
+  seed ^= hasher(v) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+}
+
+size_t UnwrappedLineParser::computePPHash() const {
+  size_t h = 0;
+  for (const auto &i : PPStack) {
+    hash_combine(h, i.Kind);
+    hash_combine(h, i.Line);
+  }
+  return h;
+}
+
 void UnwrappedLineParser::parseBlock(bool MustBeDeclaration, bool AddLevel,
                                      bool MunchSemi) {
   assert(FormatTok->isOneOf(tok::l_brace, TT_MacroBlockBegin) &&
          "'{' or macro block token expected");
   const bool MacroBlock = FormatTok->is(TT_MacroBlockBegin);
   FormatTok->BlockKind = BK_Block;
 
+  size_t PPStartHash = computePPHash();
+
   unsigned InitialLevel = Line->Level;
   nextToken();
 
   if (MacroBlock && FormatTok->is(tok::l_paren))
     parseParens();
 
+  size_t NbPreprocessorDirectives =
+      CurrentLines == &Lines ? PreprocessorDirectives.size() : 0;
   addUnwrappedLine();
-  size_t OpeningLineIndex = CurrentLines->empty()
-                                ? (UnwrappedLine::kInvalidIndex)
-                                : (CurrentLines->size() - 1);
+  size_t OpeningLineIndex =
+      CurrentLines->empty()
+          ? (UnwrappedLine::kInvalidIndex)
+          : (CurrentLines->size() - 1 - NbPreprocessorDirectives);
 
   ScopedDeclarationState DeclarationState(*Line, DeclarationScopeStack,
                                           MustBeDeclaration);
@@ -486,19 +506,23 @@
     return;
   }
 
+  size_t PPEndHash = computePPHash();
   nextToken(); // Munch the closing brace.
 
   if (MacroBlock && FormatTok->is(tok::l_paren))
     parseParens();
 
   if (MunchSemi && FormatTok->Tok.is(tok::semi))
     nextToken();
   Line->Level = InitialLevel;
-  Line->MatchingOpeningBlockLineIndex = OpeningLineIndex;
-  if (OpeningLineIndex != UnwrappedLine::kInvalidIndex) {
-    // Update the opening line to add the forward reference as well
-    (*CurrentLines)[OpeningLineIndex].MatchingOpeningBlockLineIndex =
-            CurrentLines->size() - 1;
+
+  if (PPStartHash == PPEndHash) {
+    Line->MatchingOpeningBlockLineIndex = OpeningLineIndex;
+    if (OpeningLineIndex != UnwrappedLine::kInvalidIndex) {
+      // Update the opening line to add the forward reference as well
+      (*CurrentLines)[OpeningLineIndex].MatchingOpeningBlockLineIndex =
+          CurrentLines->size() - 1;
+    }
   }
 }
 
@@ -606,10 +630,14 @@
 }
 
 void UnwrappedLineParser::conditionalCompilationCondition(bool Unreachable) {
+  size_t Line = CurrentLines->size();
+  if (CurrentLines == &PreprocessorDirectives)
+    Line += Lines.size();
+
   if (Unreachable || (!PPStack.empty() && PPStack.back() == PP_Unreachable))
-    PPStack.push_back(PP_Unreachable);
+    PPStack.push_back({PP_Unreachable, Line});
   else
-    PPStack.push_back(PP_Conditional);
+    PPStack.push_back({PP_Conditional, Line});
 }
 
 void UnwrappedLineParser::conditionalCompilationStart(bool Unreachable) {
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

Reply via email to