Introduce preliminary support for NSString format-string checking.
Patch by Nikita Zhuk!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@52336 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 63c1635..7c0ff47 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -17,6 +17,7 @@
#include "clang/AST/Decl.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
+#include "clang/AST/ExprObjC.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/LiteralSupport.h"
#include "clang/Basic/SourceManager.h"
@@ -86,6 +87,7 @@
case id_sprintf: format_idx = 1; break;
case id_snprintf: format_idx = 2; break;
case id_asprintf: format_idx = 1; break;
+ case id_NSLog: format_idx = 0; break;
case id_vsnprintf: format_idx = 2; HasVAListArg = true; break;
case id_vasprintf: format_idx = 1; HasVAListArg = true; break;
case id_vfprintf: format_idx = 1; HasVAListArg = true; break;
@@ -361,7 +363,19 @@
// are string literals: (1) permits the checking of format strings by
// the compiler and thereby (2) can practically remove the source of
// many format string exploits.
- StringLiteral *FExpr = dyn_cast<StringLiteral>(OrigFormatExpr);
+
+ // Format string can be either ObjC string (e.g. @"%d") or
+ // C string (e.g. "%d")
+ // ObjC string uses the same format specifiers as C string, so we can use
+ // the same format string checking logic for both ObjC and C strings.
+ ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(OrigFormatExpr);
+ StringLiteral *FExpr = NULL;
+
+ if(ObjCFExpr != NULL)
+ FExpr = ObjCFExpr->getString();
+ else
+ FExpr = dyn_cast<StringLiteral>(OrigFormatExpr);
+
if (FExpr == NULL) {
// For vprintf* functions (i.e., HasVAListArg==true), we add a
// special check to see if the format string is a function parameter
@@ -540,7 +554,25 @@
Diag(Loc, diag::warn_printf_write_back, Fn->getSourceRange());
break;
}
-
+
+ // Handle "%@"
+ case '@':
+ // %@ is allowed in ObjC format strings only.
+ if(ObjCFExpr != NULL)
+ CurrentState = state_OrdChr;
+ else {
+ // Issue a warning: invalid format conversion.
+ SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(),
+ LastConversionIdx+1);
+
+ Diag(Loc, diag::warn_printf_invalid_conversion,
+ std::string(Str+LastConversionIdx,
+ Str+std::min(LastConversionIdx+2, StrLen)),
+ Fn->getSourceRange());
+ }
+ ++numConversions;
+ break;
+
// Handle "%%"
case '%':
// Sanity check: Was the first "%" character the previous one?