[clang] 8ce15f7 - [SyntaxTree] Fix crash on pointer to member function

[Eduardo Caldas via cfe-commits]

Author: Eduardo Caldas
Date: 2020-08-04T14:31:12Z
New Revision: 8ce15f7eeb122c0bba4b676d797217359dd57c30

URL: https://github.com/llvm/llvm-project/commit/8ce15f7eeb122c0bba4b676d797217359dd57c30
DIFF: https://github.com/llvm/llvm-project/commit/8ce15f7eeb122c0bba4b676d797217359dd57c30.diff

LOG: [SyntaxTree] Fix crash on pointer to member function

Differential Revision: https://reviews.llvm.org/D85146

Added: 
    

Modified: 
    clang/lib/Tooling/Syntax/BuildTree.cpp
    clang/unittests/Tooling/Syntax/TreeTest.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Tooling/Syntax/BuildTree.cpp b/clang/lib/Tooling/Syntax/BuildTree.cpp
index 1f192180ec45..15b7c8fab198 100644
--- a/clang/lib/Tooling/Syntax/BuildTree.cpp
+++ b/clang/lib/Tooling/Syntax/BuildTree.cpp
@@ -939,6 +939,8 @@ class BuildTreeVisitor : public RecursiveASTVisitor<BuildTreeVisitor> {
     return true;
   }
 
+  // FIXME: Deleting the `TraverseParenTypeLoc` override doesn't change test
+  // results. Find test coverage or remove it.
   bool TraverseParenTypeLoc(ParenTypeLoc L) {
     // We reverse order of traversal to get the proper syntax structure.
     if (!WalkUpFromParenTypeLoc(L))
@@ -987,6 +989,16 @@ class BuildTreeVisitor : public RecursiveASTVisitor<BuildTreeVisitor> {
     return WalkUpFromFunctionTypeLoc(L);
   }
 
+  bool TraverseMemberPointerTypeLoc(MemberPointerTypeLoc L) {
+    // In the source code "void (Y::*mp)()" `MemberPointerTypeLoc` corresponds
+    // to "Y::*" but it points to a `ParenTypeLoc` that corresponds to
+    // "(Y::*mp)" We thus reverse the order of traversal to get the proper
+    // syntax structure.
+    if (!WalkUpFromMemberPointerTypeLoc(L))
+      return false;
+    return TraverseTypeLoc(L.getPointeeLoc());
+  }
+
   bool WalkUpFromMemberPointerTypeLoc(MemberPointerTypeLoc L) {
     auto SR = L.getLocalSourceRange();
     Builder.foldNode(Builder.getRange(SR),

diff  --git a/clang/unittests/Tooling/Syntax/TreeTest.cpp b/clang/unittests/Tooling/Syntax/TreeTest.cpp
index a722ca2b1a45..3ccfabb95da9 100644
--- a/clang/unittests/Tooling/Syntax/TreeTest.cpp
+++ b/clang/unittests/Tooling/Syntax/TreeTest.cpp
@@ -4074,6 +4074,99 @@ const int X::* b;
 )txt"));
 }
 
+TEST_P(SyntaxTreeTest, MemberFunctionPointer) {
+  if (!GetParam().isCXX()) {
+    return;
+  }
+  EXPECT_TRUE(treeDumpEqual(
+      R"cpp(
+struct X {
+  struct Y {};
+};
+void (X::*xp)();
+void (X::**xpp)(const int*);
+// FIXME: Generate the right syntax tree for this type,
+// i.e. create a syntax node for the outer member pointer
+void (X::Y::*xyp)(const int*, char);
+)cpp",
+      R"txt(
+*: TranslationUnit
+|-SimpleDeclaration
+| |-struct
+| |-X
+| |-{
+| |-SimpleDeclaration
+| | |-struct
+| | |-Y
+| | |-{
+| | |-}
+| | `-;
+| |-}
+| `-;
+|-SimpleDeclaration
+| |-void
+| |-SimpleDeclarator
+| | |-ParenDeclarator
+| | | |-(
+| | | |-MemberPointer
+| | | | |-X
+| | | | |-::
+| | | | `-*
+| | | |-xp
+| | | `-)
+| | `-ParametersAndQualifiers
+| |   |-(
+| |   `-)
+| `-;
+|-SimpleDeclaration
+| |-void
+| |-SimpleDeclarator
+| | |-ParenDeclarator
+| | | |-(
+| | | |-MemberPointer
+| | | | |-X
+| | | | |-::
+| | | | `-*
+| | | |-*
+| | | |-xpp
+| | | `-)
+| | `-ParametersAndQualifiers
+| |   |-(
+| |   |-SimpleDeclaration
+| |   | |-const
+| |   | |-int
+| |   | `-SimpleDeclarator
+| |   |   `-*
+| |   `-)
+| `-;
+`-SimpleDeclaration
+  |-void
+  |-SimpleDeclarator
+  | |-ParenDeclarator
+  | | |-(
+  | | |-X
+  | | |-::
+  | | |-MemberPointer
+  | | | |-Y
+  | | | |-::
+  | | | `-*
+  | | |-xyp
+  | | `-)
+  | `-ParametersAndQualifiers
+  |   |-(
+  |   |-SimpleDeclaration
+  |   | |-const
+  |   | |-int
+  |   | `-SimpleDeclarator
+  |   |   `-*
+  |   |-,
+  |   |-SimpleDeclaration
+  |   | `-char
+  |   `-)
+  `-;
+)txt"));
+}
+
 TEST_P(SyntaxTreeTest, ComplexDeclarator) {
   EXPECT_TRUE(treeDumpEqual(
       R"cpp(