[cfe-commits] r113469 - in /cfe/trunk: lib/Sema/SemaChecking.cpp test/Sema/format-strings.c

[Ted Kremenek]

Author: kremenek
Date: Wed Sep  8 22:51:42 2010
New Revision: 113469

URL: http://llvm.org/viewvc/llvm-project?rev=113469&view=rev
Log:
It appears that technically a null format string is not warned under -Wformat-nonliteral, as
the function processing the format string can decided whether or not to accept a null format string (e.g., asl_log).  Fixes <rdar://problem/8269537>.

Modified:
    cfe/trunk/lib/Sema/SemaChecking.cpp
    cfe/trunk/test/Sema/format-strings.c

Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=113469&r1=113468&r2=113469&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
+++ cfe/trunk/lib/Sema/SemaChecking.cpp Wed Sep  8 22:51:42 2010
@@ -955,6 +955,13 @@
                                   format_idx, firstDataArg, isPrintf);
   }
 
+  case Stmt::IntegerLiteralClass:
+    // Technically -Wformat-nonliteral does not warn about this case.
+    // The behavior of printf and friends in this case is implementation
+    // dependent.  Ideally if the format string cannot be null then
+    // it should have a 'nonnull' attribute in the function prototype.
+    return true;
+
   case Stmt::ImplicitCastExprClass: {
     E = cast<ImplicitCastExpr>(E)->getSubExpr();
     goto tryAgain;

Modified: cfe/trunk/test/Sema/format-strings.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/format-strings.c?rev=113469&r1=113468&r2=113469&view=diff
==============================================================================
--- cfe/trunk/test/Sema/format-strings.c (original)
+++ cfe/trunk/test/Sema/format-strings.c Wed Sep  8 22:51:42 2010
@@ -301,3 +301,10 @@
   printf("%lc", c2); // no-warning
 }
 
+// <rdar://problem/8269537> -Wformat-security says NULL is not a string literal
+void r8269537() {
+  // This is likely to crash in most cases, but -Wformat-nonliteral technically
+  // doesn't warn in this case.
+  printf(0); // no-warning
+}
+