[Parser] Update CachedTokens while parsing ObjectiveC template argument list

Consider the following ObjC++ snippet:

--
@protocol PA;
@protocol PB;

@class NSArray<ObjectType>;
typedef int some_t;

id<PA> FA(NSArray<id<PB>> *h, some_t group);
--

This would hit an assertion in the parser after generating an annotation token
while trying to update the token cache:

Assertion failed: (CachedTokens[CachedLexPos-1].getLastLoc() == Tok.getAnnotationEndLoc() && "The annotation should be until the most recent cached token")
...
7 clang::Preprocessor::AnnotatePreviousCachedTokens(clang::Token const&) + 494
8 clang::Parser::TryAnnotateTypeOrScopeTokenAfterScopeSpec(bool, bool, clang::CXXScopeSpec&, bool) + 1163
9 clang::Parser::TryAnnotateTypeOrScopeToken(bool, bool) + 361
10 clang::Parser::isCXXDeclarationSpecifier(clang::Parser::TPResult, bool*) + 598
...

The cached preprocessor token in this case is:

greatergreater '>>' Loc=<testcase.mm:7:24>

while the annotation ("NSArray<id<PB>>") ends at "testcase.mm:7:25", hence the
assertion.

Properly update the CachedTokens during template parsing to contain
two greater tokens instead of a greatergreater.

Differential Revision: http://reviews.llvm.org/D15173

rdar://problem/23494277

llvm-svn: 259311

1 files changed, 26 insertions, 0 deletions

diff --git a/clang/lib/Lex/PPCaching.cpp b/clang/lib/Lex/PPCaching.cpp
index bd48ae64ab4..4742aae5c12 100644
--- a/clang/lib/Lex/PPCaching.cpp
+++ b/clang/lib/Lex/PPCaching.cpp
@@ -116,3 +116,29 @@ void Preprocessor::AnnotatePreviousCachedTokens(const Token &Tok) {
     }
   }
 }
+
+bool Preprocessor::IsPreviousCachedToken(const Token &Tok) const {
+  // There's currently no cached token...
+  if (!CachedLexPos)
+    return false;
+
+  const Token LastCachedTok = CachedTokens[CachedLexPos - 1];
+  if (LastCachedTok.getKind() != Tok.getKind())
+    return false;
+
+  int RelOffset = 0;
+  if ((!getSourceManager().isInSameSLocAddrSpace(
+          Tok.getLocation(), getLastCachedTokenLocation(), &RelOffset)) ||
+      RelOffset)
+    return false;
+
+  return true;
+}
+
+void Preprocessor::ReplacePreviousCachedToken(ArrayRef<Token> NewToks) {
+  assert(CachedLexPos != 0 && "Expected to have some cached tokens");
+  CachedTokens.insert(CachedTokens.begin() + CachedLexPos - 1, NewToks.begin(),
+                      NewToks.end());
+  CachedTokens.erase(CachedTokens.begin() + CachedLexPos - 1 + NewToks.size());
+  CachedLexPos += NewToks.size() - 1;
+}