From: Chris Lattner <sabre@nondot.org>
Date: Mon, 24 Sep 2007 05:14:57 +0000 (+0000)
Subject: If we see an invalid #ifdef  directive, enter a conditional compilation region
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f37bb25120f2b9532443aaee03b7a909eb27af9a;p=clang

If we see an invalid #ifdef  directive, enter a conditional compilation region
so that we don't emit an error on the #endif.  Suggestion by Neil.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@42258 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/Lex/Preprocessor.cpp b/Lex/Preprocessor.cpp
index b51222cefd..f43eae1c98 100644
--- a/Lex/Preprocessor.cpp
+++ b/Lex/Preprocessor.cpp
@@ -2121,8 +2121,13 @@ void Preprocessor::HandleIfdefDirective(Token &Result, bool isIfndef,
   ReadMacroName(MacroNameTok);
   
   // Error reading macro name?  If so, diagnostic already issued.
-  if (MacroNameTok.getKind() == tok::eom)
+  if (MacroNameTok.getKind() == tok::eom) {
+    // Skip code until we get to #endif.  This helps with recovery by not
+    // emitting an error when the #endif is reached.
+    SkipExcludedConditionalBlock(DirectiveTok.getLocation(),
+                                 /*Foundnonskip*/false, /*FoundElse*/false);
     return;
+  }
   
   // Check to see if this is the last token on the #if[n]def line.
   CheckEndOfDirective(isIfndef ? "#ifndef" : "#ifdef");
diff --git a/test/Preprocessor/ifdef-recover.c b/test/Preprocessor/ifdef-recover.c
new file mode 100644
index 0000000000..2009514f5e
--- /dev/null
+++ b/test/Preprocessor/ifdef-recover.c
@@ -0,0 +1,7 @@
+/* RUN: clang %s 2>&1 | grep error: | count 1
+ */
+
+#ifdef
+
+#endif
+