Recover from errors in enum definition

Previously any error in enum definition body stopped parsing it. With this
change parser tries to recover from errors.
The patch fixes PR10982.

Differential Revision: http://llvm-reviews.chandlerc.com/D2018

llvm-svn: 198259

1 files changed, 29 insertions, 5 deletions

diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index 27d8531c1fd..f664cf20409 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -3888,7 +3888,16 @@ void Parser::ParseEnumBody(SourceLocation StartLoc, Decl *EnumDecl) {
   Decl *LastEnumConstDecl = 0;
 
   // Parse the enumerator-list.
-  while (Tok.is(tok::identifier)) {
+  while (Tok.isNot(tok::r_brace)) {
+    // Parse enumerator. If failed, try skipping till the start of the next
+    // enumerator definition.
+    if (Tok.isNot(tok::identifier)) {
+      Diag(Tok.getLocation(), diag::err_expected) << tok::identifier;
+      if (SkipUntil(tok::comma, tok::r_brace, StopBeforeMatch) &&
+          TryConsumeToken(tok::comma))
+        continue;
+      break;
+    }
     IdentifierInfo *Ident = Tok.getIdentifierInfo();
     SourceLocation IdentLoc = ConsumeToken();
 
@@ -3905,7 +3914,7 @@ void Parser::ParseEnumBody(SourceLocation StartLoc, Decl *EnumDecl) {
     if (TryConsumeToken(tok::equal, EqualLoc)) {
       AssignedVal = ParseConstantExpression();
       if (AssignedVal.isInvalid())
-        SkipUntil(tok::comma, tok::r_brace, StopAtSemi | StopBeforeMatch);
+        SkipUntil(tok::comma, tok::r_brace, StopBeforeMatch);
     }
 
     // Install the enumerator constant into EnumDecl.
@@ -3927,11 +3936,25 @@ void Parser::ParseEnumBody(SourceLocation StartLoc, Decl *EnumDecl) {
       continue;
     }
 
+    // Emumerator definition must be finished, only comma or r_brace are
+    // allowed here.
     SourceLocation CommaLoc;
-    if (!TryConsumeToken(tok::comma, CommaLoc))
-      break;
+    if (Tok.isNot(tok::r_brace) && !TryConsumeToken(tok::comma, CommaLoc)) {
+      if (EqualLoc.isValid())
+        Diag(Tok.getLocation(), diag::err_expected_either) << tok::r_brace
+                                                           << tok::comma;
+      else
+        Diag(Tok.getLocation(), diag::err_expected_end_of_enumerator);
+      if (SkipUntil(tok::comma, tok::r_brace, StopBeforeMatch)) {
+        if (TryConsumeToken(tok::comma, CommaLoc))
+          continue;
+      } else {
+        break;
+      }
+    }
 
-    if (Tok.isNot(tok::identifier)) {
+    // If comma is followed by r_brace, emit appropriate warning.
+    if (Tok.is(tok::r_brace) && CommaLoc.isValid()) {
       if (!getLangOpts().C99 && !getLangOpts().CPlusPlus11)
         Diag(CommaLoc, getLangOpts().CPlusPlus ?
                diag::ext_enumerator_list_comma_cxx :
@@ -3940,6 +3963,7 @@ void Parser::ParseEnumBody(SourceLocation StartLoc, Decl *EnumDecl) {
       else if (getLangOpts().CPlusPlus11)
         Diag(CommaLoc, diag::warn_cxx98_compat_enumerator_list_comma)
           << FixItHint::CreateRemoval(CommaLoc);
+      break;
     }
   }