From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Sun, 29 Mar 2015 19:05:27 +0000 (+0000)
Subject: [lex] Provide a valid token when __has_include is found outside of a pp directive
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=5d9ea6db7d20ccd7c178fbc3eb86e37a43f09b3a;p=clang

[lex] Provide a valid token when __has_include is found outside of a pp directive

ExpandBuiltinMacro would strip the identifier and downstream users crash
when they encounter an identifier token with nullptr identifier info.

Found by afl-fuzz.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@233497 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index f2baddd0b8..3ceba05401 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -1073,6 +1073,9 @@ static bool EvaluateHasIncludeCommon(Token &Tok,
   // These expressions are only allowed within a preprocessor directive.
   if (!PP.isParsingIfOrElifDirective()) {
     PP.Diag(LParenLoc, diag::err_pp_directive_required) << II->getName();
+    // Return a valid identifier token.
+    assert(Tok.is(tok::identifier));
+    Tok.setIdentifierInfo(II);
     return false;
   }
 
diff --git a/test/SemaCXX/typo-correction.cpp b/test/SemaCXX/typo-correction.cpp
index 324900150c..174b1403e2 100644
--- a/test/SemaCXX/typo-correction.cpp
+++ b/test/SemaCXX/typo-correction.cpp
@@ -634,3 +634,9 @@ namespace testArraySubscriptIndex {
     }
   };
 }
+
+namespace crash_has_include {
+int has_include(int); // expected-note {{'has_include' declared here}}
+// expected-error@+1 {{__has_include must be used within a preprocessing directive}}
+int foo = __has_include(42); // expected-error {{use of undeclared identifier '__has_include'; did you mean 'has_include'?}}
+}