#line is allowed to have macros that expand to nothing after them.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69401 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index 9e42785..2184acf 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -580,8 +580,9 @@
void HandleDirective(Token &Result);
/// CheckEndOfDirective - Ensure that the next token is a tok::eom token. If
- /// not, emit a diagnostic and consume up until the eom.
- void CheckEndOfDirective(const char *Directive);
+ /// not, emit a diagnostic and consume up until the eom. If EnableMacros is
+ /// true, then we consider macros that expand to zero tokens as being ok.
+ void CheckEndOfDirective(const char *Directive, bool EnableMacros = false);
/// DiscardUntilEndOfDirective - Read and discard all tokens remaining on the
/// current line until the tok::eom token is found.
diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index 7420769..ce86d0e 100644
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -101,12 +101,17 @@
}
/// CheckEndOfDirective - Ensure that the next token is a tok::eom token. If
-/// not, emit a diagnostic and consume up until the eom.
-void Preprocessor::CheckEndOfDirective(const char *DirType) {
+/// not, emit a diagnostic and consume up until the eom. If EnableMacros is
+/// true, then we consider macros that expand to zero tokens as being ok.
+void Preprocessor::CheckEndOfDirective(const char *DirType, bool EnableMacros) {
Token Tmp;
- // Lex unexpanded tokens: macros might expand to zero tokens, causing us to
- // miss diagnosing invalid lines.
- LexUnexpandedToken(Tmp);
+ // Lex unexpanded tokens for most directives: macros might expand to zero
+ // tokens, causing us to miss diagnosing invalid lines. Some directives (like
+ // #line) allow empty macros.
+ if (EnableMacros)
+ Lex(Tmp);
+ else
+ LexUnexpandedToken(Tmp);
// There should be no tokens after the directive, but we allow them as an
// extension.
@@ -694,8 +699,9 @@
FilenameID = SourceMgr.getLineTableFilenameID(Literal.GetString(),
Literal.GetStringLength());
- // Verify that there is nothing after the string, other than EOM.
- CheckEndOfDirective("line");
+ // Verify that there is nothing after the string, other than EOM. Because
+ // of C99 6.10.4p5, macros that expand to empty tokens are ok.
+ CheckEndOfDirective("line", true);
}
SourceMgr.AddLineNote(DigitTok.getLocation(), LineNo, FilenameID);
diff --git a/test/Preprocessor/line-directive.c b/test/Preprocessor/line-directive.c
index 66efae9..1dd8b29 100644
--- a/test/Preprocessor/line-directive.c
+++ b/test/Preprocessor/line-directive.c
@@ -60,3 +60,11 @@
typedef int w; // expected-note {{previous definition is here}}
typedef int w; // expected-error {{redefinition of typedef 'w' is invalid in C}}
+
+
+// This should not produce an "extra tokens at end of #line directive" warning,
+// because #line is allowed to contain expanded tokens.
+#define EMPTY()
+#line 2 "foo.c" EMPTY( )
+#line 2 "foo.c" NONEMPTY( ) // expected-warning{{extra tokens at end of #line directive}}
+