Added PTH optimization to not process entire blocks of tokens that appear in skipped preprocessor blocks. This improves PTH speed by 6%. The code for this optimization itself is not very optimized, and will get cleaned up.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60956 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index 2a33531..300ec0b 100644
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -122,6 +122,11 @@
CurPPLexer->pushConditionalLevel(IfTokenLoc, /*isSkipping*/false,
FoundNonSkipPortion, FoundElse);
+ if (CurPTHLexer) {
+ PTHSkipExcludedConditionalBlock();
+ return;
+ }
+
// Enter raw mode to disable identifier lookup (and thus macro expansion),
// disabling warnings, etc.
CurPPLexer->LexingRawMode = true;
@@ -291,6 +296,79 @@
CurPPLexer->LexingRawMode = false;
}
+void Preprocessor::PTHSkipExcludedConditionalBlock() {
+
+ while(1) {
+ assert(CurPTHLexer);
+ assert(CurPTHLexer->LexingRawMode == false);
+
+ // Skip to the next '#else', '#elif', or #endif.
+ if (CurPTHLexer->SkipBlock()) {
+ // We have reached an #endif. Both the '#' and 'endif' tokens
+ // have been consumed by the PTHLexer. Just pop off the condition level.
+ PPConditionalInfo CondInfo;
+ bool InCond = CurPTHLexer->popConditionalLevel(CondInfo);
+ InCond = InCond; // Silence warning in no-asserts mode.
+ assert(!InCond && "Can't be skipping if not in a conditional!");
+ break;
+ }
+
+ // We have reached a '#else' or '#elif'. Lex the next token to get
+ // the directive flavor.
+ Token Tok;
+ LexUnexpandedToken(Tok);
+
+ // We can actually look up the IdentifierInfo here since we aren't in
+ // raw mode.
+ tok::PPKeywordKind K = Tok.getIdentifierInfo()->getPPKeywordID();
+
+ if (K == tok::pp_else) {
+ // #else: Enter the else condition. We aren't in a nested condition
+ // since we skip those. We're always in the one matching the last
+ // blocked we skipped.
+ PPConditionalInfo &CondInfo = CurPTHLexer->peekConditionalLevel();
+ // Note that we've seen a #else in this conditional.
+ CondInfo.FoundElse = true;
+
+ // If the #if block wasn't entered then enter the #else block now.
+ if (!CondInfo.FoundNonSkip) {
+ CondInfo.FoundNonSkip = true;
+ break;
+ }
+
+ // Otherwise skip this block.
+ continue;
+ }
+
+ assert(K == tok::pp_elif);
+ PPConditionalInfo &CondInfo = CurPTHLexer->peekConditionalLevel();
+
+ // If this is a #elif with a #else before it, report the error.
+ if (CondInfo.FoundElse)
+ Diag(Tok, diag::pp_err_elif_after_else);
+
+ // If this is in a skipping block or if we're already handled this #if
+ // block, don't bother parsing the condition. We just skip this block.
+ if (CondInfo.FoundNonSkip)
+ continue;
+
+ // Evaluate the condition of the #elif.
+ IdentifierInfo *IfNDefMacro = 0;
+ CurPTHLexer->ParsingPreprocessorDirective = true;
+ bool ShouldEnter = EvaluateDirectiveExpression(IfNDefMacro);
+ CurPTHLexer->ParsingPreprocessorDirective = false;
+
+ // If this condition is true, enter it!
+ if (ShouldEnter) {
+ CondInfo.FoundNonSkip = true;
+ break;
+ }
+
+ // Otherwise, skip this block and go to the next one.
+ continue;
+ }
+}
+
/// LookupFile - Given a "foo" or <foo> reference, look up the indicated file,
/// return null on failure. isAngled indicates whether the file reference is
/// for system #include's or not (i.e. using <> instead of "").