PR41111, PR5925, PR13210: Teach tentative parsing to annotate identifiers and

nested names as id-expressions, using the annot_primary_expr annotation, where
possible. This removes some redundant lookups, and also allows us to
typo-correct within tentative parsing, and to carry on disambiguating past an
identifier which we can determine will fail lookup as both a type and as a
non-type, allowing us to disambiguate more declarations (and thus offer
improved error recovery for such cases).

This also introduces to the parser the notion of a tentatively-declared name,
which is an identifier which we *might* have seen a declaration for in a
tentative parse (but only if we end up disambiguating the tokens as a
declaration). This is necessary to correctly disambiguate cases where a
variable is used within its own initializer.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162159 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 24 insertions, 81 deletions

diff --git a/lib/Parse/ParseStmt.cpp b/lib/Parse/ParseStmt.cpp
index df9b996aa3..0716f6f901 100644
--- a/lib/Parse/ParseStmt.cpp
+++ b/lib/Parse/ParseStmt.cpp
@@ -17,6 +17,7 @@
 #include "clang/Sema/DeclSpec.h"
 #include "clang/Sema/PrettyDeclStackTrace.h"
 #include "clang/Sema/Scope.h"
+#include "clang/Sema/TypoCorrection.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/PrettyStackTrace.h"
 #include "clang/Basic/SourceManager.h"
@@ -130,96 +131,38 @@ Retry:
       return ParseLabeledStatement(Attrs);
     }
 
+    // Look up the identifier, and typo-correct it to a keyword if it's not
+    // found.
     if (Next.isNot(tok::coloncolon)) {
-      CXXScopeSpec SS;
-      IdentifierInfo *Name = Tok.getIdentifierInfo();
-      SourceLocation NameLoc = Tok.getLocation();
-
-      if (getLangOpts().CPlusPlus)
-        CheckForTemplateAndDigraph(Next, ParsedType(),
-                                   /*EnteringContext=*/false, *Name, SS);
-
-      Sema::NameClassification Classification
-        = Actions.ClassifyName(getCurScope(), SS, Name, NameLoc, Next);
-      switch (Classification.getKind()) {
-      case Sema::NC_Keyword:
-        // The identifier was corrected to a keyword. Update the token
-        // to this keyword, and try again.
-        if (Name->getTokenID() != tok::identifier) {
-          Tok.setIdentifierInfo(Name);
-          Tok.setKind(Name->getTokenID());
-          goto Retry;
-        }
-
-        // Fall through via the normal error path.
-        // FIXME: This seems like it could only happen for context-sensitive
-        // keywords.
-
-      case Sema::NC_Error:
+      // Try to limit which sets of keywords should be included in typo
+      // correction based on what the next token is.
+      // FIXME: Pass the next token into the CorrectionCandidateCallback and
+      //        do this filtering in a more fine-grained manner.
+      CorrectionCandidateCallback DefaultValidator;
+      DefaultValidator.WantTypeSpecifiers =
+          Next.is(tok::l_paren) || Next.is(tok::less) ||
+          Next.is(tok::identifier) || Next.is(tok::star) ||
+          Next.is(tok::amp) || Next.is(tok::l_square);
+      DefaultValidator.WantExpressionKeywords =
+          Next.is(tok::l_paren) || Next.is(tok::identifier) ||
+          Next.is(tok::arrow) || Next.is(tok::period);
+      DefaultValidator.WantRemainingKeywords =
+          Next.is(tok::l_paren) || Next.is(tok::semi) ||
+          Next.is(tok::identifier) || Next.is(tok::l_brace);
+      DefaultValidator.WantCXXNamedCasts = false;
+      if (TryAnnotateName(/*IsAddressOfOperand*/false, &DefaultValidator)
+            == ANK_Error) {
         // Handle errors here by skipping up to the next semicolon or '}', and
         // eat the semicolon if that's what stopped us.
         SkipUntil(tok::r_brace, /*StopAtSemi=*/true, /*DontConsume=*/true);
         if (Tok.is(tok::semi))
           ConsumeToken();
         return StmtError();
-
-      case Sema::NC_Unknown:
-        // Either we don't know anything about this identifier, or we know that
-        // we're in a syntactic context we haven't handled yet.
-        break;
-
-      case Sema::NC_Type:
-        Tok.setKind(tok::annot_typename);
-        setTypeAnnotation(Tok, Classification.getType());
-        Tok.setAnnotationEndLoc(NameLoc);
-        PP.AnnotateCachedTokens(Tok);
-        break;
-
-      case Sema::NC_Expression:
-        Tok.setKind(tok::annot_primary_expr);
-        setExprAnnotation(Tok, Classification.getExpression());
-        Tok.setAnnotationEndLoc(NameLoc);
-        PP.AnnotateCachedTokens(Tok);
-        break;
-
-      case Sema::NC_TypeTemplate:
-      case Sema::NC_FunctionTemplate: {
-        ConsumeToken(); // the identifier
-        UnqualifiedId Id;
-        Id.setIdentifier(Name, NameLoc);
-        if (AnnotateTemplateIdToken(
-                            TemplateTy::make(Classification.getTemplateName()),
-                                    Classification.getTemplateNameKind(),
-                                    SS, SourceLocation(), Id,
-                                    /*AllowTypeAnnotation=*/false)) {
-          // Handle errors here by skipping up to the next semicolon or '}', and
-          // eat the semicolon if that's what stopped us.
-          SkipUntil(tok::r_brace, /*StopAtSemi=*/true, /*DontConsume=*/true);
-          if (Tok.is(tok::semi))
-            ConsumeToken();
-          return StmtError();
-        }
-
-        // If the next token is '::', jump right into parsing a
-        // nested-name-specifier. We don't want to leave the template-id
-        // hanging.
-        if (NextToken().is(tok::coloncolon) && TryAnnotateCXXScopeToken(false)){
-          // Handle errors here by skipping up to the next semicolon or '}', and
-          // eat the semicolon if that's what stopped us.
-          SkipUntil(tok::r_brace, /*StopAtSemi=*/true, /*DontConsume=*/true);
-          if (Tok.is(tok::semi))
-            ConsumeToken();
-          return StmtError();
-        }
-
-        // We've annotated a template-id, so try again now.
-        goto Retry;
       }
 
-      case Sema::NC_NestedNameSpecifier:
-        // FIXME: Implement this!
-        break;
-      }
+      // If the identifier was typo-corrected, try again.
+      if (Tok.isNot(tok::identifier))
+        goto Retry;
     }
 
     // Fall through