Refactor and micro-optimize ConsumeToken()

1) Introduce TryConsumeToken() to handle the common test-and-consume pattern.
   This brings about readability improvements in the parser and optimizes to avoid
   redundant checks in the common case.

2) Eliminate the ConsumeCodeCompletionTok special case from ConsumeToken(). This
   was used by only one caller which has been switched over to the more
   appropriate ConsumeCodeCompletionToken() function.

llvm-svn: 197497

1 files changed, 10 insertions, 18 deletions

diff --git a/clang/lib/Parse/ParseCXXInlineMethods.cpp b/clang/lib/Parse/ParseCXXInlineMethods.cpp
index 9a69bec1679..594baa1edaa 100644
--- a/clang/lib/Parse/ParseCXXInlineMethods.cpp
+++ b/clang/lib/Parse/ParseCXXInlineMethods.cpp
@@ -69,9 +69,7 @@ NamedDecl *Parser::ParseCXXInlineMethodDef(AccessSpecifier AS,
 
   D.complete(FnD);
 
-  if (Tok.is(tok::equal)) {
-    ConsumeToken();
-
+  if (TryConsumeToken(tok::equal)) {
     if (!FnD) {
       SkipUntil(tok::semi);
       return 0;
@@ -79,20 +77,16 @@ NamedDecl *Parser::ParseCXXInlineMethodDef(AccessSpecifier AS,
 
     bool Delete = false;
     SourceLocation KWLoc;
-    if (Tok.is(tok::kw_delete)) {
-      Diag(Tok, getLangOpts().CPlusPlus11 ?
-           diag::warn_cxx98_compat_deleted_function :
-           diag::ext_deleted_function);
-
-      KWLoc = ConsumeToken();
+    if (TryConsumeToken(tok::kw_delete, KWLoc)) {
+      Diag(KWLoc, getLangOpts().CPlusPlus11
+                      ? diag::warn_cxx98_compat_deleted_function
+                      : diag::ext_deleted_function);
       Actions.SetDeclDeleted(FnD, KWLoc);
       Delete = true;
-    } else if (Tok.is(tok::kw_default)) {
-      Diag(Tok, getLangOpts().CPlusPlus11 ?
-           diag::warn_cxx98_compat_defaulted_function :
-           diag::ext_defaulted_function);
-
-      KWLoc = ConsumeToken();
+    } else if (TryConsumeToken(tok::kw_default, KWLoc)) {
+      Diag(KWLoc, getLangOpts().CPlusPlus11
+                      ? diag::warn_cxx98_compat_defaulted_function
+                      : diag::ext_defaulted_function);
       Actions.SetDeclDefaulted(FnD, KWLoc);
     } else {
       llvm_unreachable("function definition after = not 'delete' or 'default'");
@@ -348,9 +342,7 @@ void Parser::ParseLexedMethodDeclaration(LateParsedMethodDeclaration &LM) {
       if (DefArgResult.isInvalid())
         Actions.ActOnParamDefaultArgumentError(LM.DefaultArgs[I].Param);
       else {
-        if (Tok.is(tok::cxx_defaultarg_end))
-          ConsumeToken();
-        else {
+        if (!TryConsumeToken(tok::cxx_defaultarg_end)) {
           // The last two tokens are the terminator and the saved value of
           // Tok; the last token in the default argument is the one before
           // those.