Allow for unfinished #if blocks in preambles
Previously, a preamble only included #if blocks (and friends like
ifdef) if there was a corresponding #endif before any declaration or
definition. The problem is that any header file that uses include guards
will not have a preamble generated, which can make code-completion very
slow.
To prevent errors about unbalanced preprocessor conditionals in the
preamble, and unbalanced preprocessor conditionals after a preamble
containing unfinished conditionals, the conditional stack is stored
in the pch file.
This fixes PR26045.
Differential Revision: http://reviews.llvm.org/D15994
llvm-svn: 304207
diff --git a/clang/lib/Lex/Lexer.cpp b/clang/lib/Lex/Lexer.cpp
index 92942fd..f5a35e9 100644
--- a/clang/lib/Lex/Lexer.cpp
+++ b/clang/lib/Lex/Lexer.cpp
@@ -550,8 +550,6 @@
enum PreambleDirectiveKind {
PDK_Skipped,
- PDK_StartIf,
- PDK_EndIf,
PDK_Unknown
};
@@ -574,8 +572,6 @@
bool InPreprocessorDirective = false;
Token TheTok;
- Token IfStartTok;
- unsigned IfCount = 0;
SourceLocation ActiveCommentLoc;
unsigned MaxLineOffset = 0;
@@ -658,33 +654,18 @@
.Case("sccs", PDK_Skipped)
.Case("assert", PDK_Skipped)
.Case("unassert", PDK_Skipped)
- .Case("if", PDK_StartIf)
- .Case("ifdef", PDK_StartIf)
- .Case("ifndef", PDK_StartIf)
+ .Case("if", PDK_Skipped)
+ .Case("ifdef", PDK_Skipped)
+ .Case("ifndef", PDK_Skipped)
.Case("elif", PDK_Skipped)
.Case("else", PDK_Skipped)
- .Case("endif", PDK_EndIf)
+ .Case("endif", PDK_Skipped)
.Default(PDK_Unknown);
switch (PDK) {
case PDK_Skipped:
continue;
- case PDK_StartIf:
- if (IfCount == 0)
- IfStartTok = HashTok;
-
- ++IfCount;
- continue;
-
- case PDK_EndIf:
- // Mismatched #endif. The preamble ends here.
- if (IfCount == 0)
- break;
-
- --IfCount;
- continue;
-
case PDK_Unknown:
// We don't know what this directive is; stop at the '#'.
break;
@@ -705,16 +686,13 @@
} while (true);
SourceLocation End;
- if (IfCount)
- End = IfStartTok.getLocation();
- else if (ActiveCommentLoc.isValid())
+ if (ActiveCommentLoc.isValid())
End = ActiveCommentLoc; // don't truncate a decl comment.
else
End = TheTok.getLocation();
return std::make_pair(End.getRawEncoding() - StartLoc.getRawEncoding(),
- IfCount? IfStartTok.isAtStartOfLine()
- : TheTok.isAtStartOfLine());
+ TheTok.isAtStartOfLine());
}
/// AdvanceToTokenCharacter - Given a location that specifies the start of a
@@ -2570,6 +2548,11 @@
return true;
}
+ if (PP->isRecordingPreamble() && !PP->isInMainFile()) {
+ PP->setRecordedPreambleConditionalStack(ConditionalStack);
+ ConditionalStack.clear();
+ }
+
// Issue diagnostics for unterminated #if and missing newline.
// If we are in a #if directive, emit an error.
diff --git a/clang/lib/Lex/PPLexerChange.cpp b/clang/lib/Lex/PPLexerChange.cpp
index 5a589d6..1c0cd56 100644
--- a/clang/lib/Lex/PPLexerChange.cpp
+++ b/clang/lib/Lex/PPLexerChange.cpp
@@ -46,6 +46,12 @@
});
}
+bool Preprocessor::isInMainFile() const {
+ if (IsFileLexer())
+ return IncludeMacroStack.size() == 0;
+ return true;
+}
+
/// getCurrentLexer - Return the current file lexer being lexed from. Note
/// that this ignores any potentially active macro expansions and _Pragma
/// expansions going on at the time.
diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index dce8c1e..3596337 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -150,6 +150,9 @@
Ident_GetExceptionInfo = Ident_GetExceptionCode = nullptr;
Ident_AbnormalTermination = nullptr;
}
+
+ if (this->PPOpts->GeneratePreamble)
+ PreambleConditionalStack.startRecording();
}
Preprocessor::~Preprocessor() {
@@ -532,6 +535,12 @@
// Start parsing the predefines.
EnterSourceFile(FID, nullptr, SourceLocation());
+
+ // Restore the conditional stack from the preamble, if there is one.
+ if (PreambleConditionalStack.isReplaying()) {
+ CurPPLexer->setConditionalLevels(PreambleConditionalStack.getStack());
+ PreambleConditionalStack.doneReplaying();
+ }
}
void Preprocessor::EndSourceFile() {