[cfe-commits] r149236 - in /cfe/trunk: include/clang/Sema/Sema.h lib/Sema/SemaChecking.cpp test/Sema/format-strings.c test/SemaObjC/format-strings-objc.m
Jean-Daniel Dupas
devlists at shadowlab.org
Mon Jan 30 00:46:47 PST 2012
Author: jddupas
Date: Mon Jan 30 02:46:47 2012
New Revision: 149236
URL: http://llvm.org/viewvc/llvm-project?rev=149236&view=rev
Log:
Update on format attribute handling.
- Remove the printf0 special handling as we treat it as printf anyway.
- Perform basic checks (non-literal, empty) for all formats and not only printf/scanf.
Modified:
cfe/trunk/include/clang/Sema/Sema.h
cfe/trunk/lib/Sema/SemaChecking.cpp
cfe/trunk/test/Sema/format-strings.c
cfe/trunk/test/SemaObjC/format-strings-objc.m
Modified: cfe/trunk/include/clang/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=149236&r1=149235&r2=149236&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/Sema.h (original)
+++ cfe/trunk/include/clang/Sema/Sema.h Mon Jan 30 02:46:47 2012
@@ -6278,8 +6278,6 @@
Expr **Args, unsigned NumArgs);
bool CheckBlockCall(NamedDecl *NDecl, CallExpr *TheCall);
- bool CheckablePrintfAttr(const FormatAttr *Format, Expr **Args,
- unsigned NumArgs, bool IsCXXMemberCall);
bool CheckObjCString(Expr *Arg);
ExprResult CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
@@ -6303,28 +6301,38 @@
bool SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum,
llvm::APSInt &Result);
+ enum FormatStringType {
+ FST_Scanf,
+ FST_Printf,
+ FST_NSString,
+ FST_Strftime,
+ FST_Strfmon,
+ FST_Kprintf,
+ FST_Unknown
+ };
+ static FormatStringType GetFormatStringType(const FormatAttr *Format);
bool SemaCheckStringLiteral(const Expr *E, Expr **Args, unsigned NumArgs,
bool HasVAListArg, unsigned format_idx,
- unsigned firstDataArg, bool isPrintf,
+ unsigned firstDataArg, FormatStringType Type,
bool inFunctionCall = true);
void CheckFormatString(const StringLiteral *FExpr, const Expr *OrigFormatExpr,
Expr **Args, unsigned NumArgs, bool HasVAListArg,
unsigned format_idx, unsigned firstDataArg,
- bool isPrintf, bool inFunctionCall);
-
- void CheckNonNullArguments(const NonNullAttr *NonNull,
- const Expr * const *ExprArgs,
- SourceLocation CallSiteLoc);
+ FormatStringType Type, bool inFunctionCall);
void CheckFormatArguments(const FormatAttr *Format, CallExpr *TheCall);
void CheckFormatArguments(const FormatAttr *Format, Expr **Args,
unsigned NumArgs, bool IsCXXMember,
SourceLocation Loc, SourceRange Range);
- void CheckPrintfScanfArguments(Expr **Args, unsigned NumArgs,
- bool HasVAListArg, unsigned format_idx,
- unsigned firstDataArg, bool isPrintf,
- SourceLocation Loc, SourceRange range);
+ void CheckFormatArguments(Expr **Args, unsigned NumArgs,
+ bool HasVAListArg, unsigned format_idx,
+ unsigned firstDataArg, FormatStringType Type,
+ SourceLocation Loc, SourceRange range);
+
+ void CheckNonNullArguments(const NonNullAttr *NonNull,
+ const Expr * const *ExprArgs,
+ SourceLocation CallSiteLoc);
void CheckMemaccessArguments(const CallExpr *Call,
unsigned BId,
Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=149236&r1=149235&r2=149236&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
+++ cfe/trunk/lib/Sema/SemaChecking.cpp Mon Jan 30 02:46:47 2012
@@ -45,31 +45,6 @@
PP.getLangOptions(), PP.getTargetInfo());
}
-bool Sema::CheckablePrintfAttr(const FormatAttr *Format, Expr **Args,
- unsigned NumArgs, bool IsCXXMemberCall) {
- StringRef Type = Format->getType();
- // FIXME: add support for "CFString" Type. They are not string literal though,
- // so they need special handling.
- if (Type == "printf" || Type == "NSString") return true;
- if (Type == "printf0") {
- // printf0 allows null "format" string; if so don't check format/args
- unsigned format_idx = Format->getFormatIdx() - 1;
- // Does the index refer to the implicit object argument?
- if (IsCXXMemberCall) {
- if (format_idx == 0)
- return false;
- --format_idx;
- }
- if (format_idx < NumArgs) {
- Expr *Format = Args[format_idx]->IgnoreParenCasts();
- if (!Format->isNullPointerConstant(Context,
- Expr::NPC_ValueDependentIsNull))
- return true;
- }
- }
- return false;
-}
-
/// Checks that a call expression's argument count is the desired number.
/// This is useful when doing custom type-checking. Returns true on error.
static bool checkArgCount(Sema &S, CallExpr *call, unsigned desiredArgCount) {
@@ -1384,23 +1359,23 @@
bool Sema::SemaCheckStringLiteral(const Expr *E, Expr **Args,
unsigned NumArgs, bool HasVAListArg,
unsigned format_idx, unsigned firstDataArg,
- bool isPrintf, bool inFunctionCall) {
+ FormatStringType Type, bool inFunctionCall) {
tryAgain:
if (E->isTypeDependent() || E->isValueDependent())
return false;
- E = E->IgnoreParens();
+ E = E->IgnoreParenCasts();
switch (E->getStmtClass()) {
case Stmt::BinaryConditionalOperatorClass:
case Stmt::ConditionalOperatorClass: {
const AbstractConditionalOperator *C = cast<AbstractConditionalOperator>(E);
return SemaCheckStringLiteral(C->getTrueExpr(), Args, NumArgs, HasVAListArg,
- format_idx, firstDataArg, isPrintf,
+ format_idx, firstDataArg, Type,
inFunctionCall)
- && SemaCheckStringLiteral(C->getFalseExpr(), Args, NumArgs, HasVAListArg,
- format_idx, firstDataArg, isPrintf,
- inFunctionCall);
+ && SemaCheckStringLiteral(C->getFalseExpr(), Args, NumArgs, HasVAListArg,
+ format_idx, firstDataArg, Type,
+ inFunctionCall);
}
case Stmt::IntegerLiteralClass:
@@ -1452,7 +1427,7 @@
if (const Expr *Init = VD->getAnyInitializer())
return SemaCheckStringLiteral(Init, Args, NumArgs,
HasVAListArg, format_idx, firstDataArg,
- isPrintf, /*inFunctionCall*/false);
+ Type, /*inFunctionCall*/false);
}
// For vprintf* functions (i.e., HasVAListArg==true), we add a
@@ -1492,7 +1467,7 @@
const Expr *Arg = CE->getArg(ArgIndex - 1);
return SemaCheckStringLiteral(Arg, Args, NumArgs, HasVAListArg,
- format_idx, firstDataArg, isPrintf,
+ format_idx, firstDataArg, Type,
inFunctionCall);
}
}
@@ -1512,7 +1487,7 @@
if (StrE) {
CheckFormatString(StrE, E, Args, NumArgs, HasVAListArg, format_idx,
- firstDataArg, isPrintf, inFunctionCall);
+ firstDataArg, Type, inFunctionCall);
return true;
}
@@ -1538,6 +1513,17 @@
}
}
+Sema::FormatStringType Sema::GetFormatStringType(const FormatAttr *Format) {
+ return llvm::StringSwitch<FormatStringType>(Format->getType())
+ .Case("scanf", FST_Scanf)
+ .Cases("printf", "printf0", FST_Printf)
+ .Cases("NSString", "CFString", FST_NSString)
+ .Case("strftime", FST_Strftime)
+ .Case("strfmon", FST_Strfmon)
+ .Cases("kprintf", "cmn_err", "vcmn_err", "zcmn_err", FST_Kprintf)
+ .Default(FST_Unknown);
+}
+
/// CheckPrintfScanfArguments - Check calls to printf and scanf (and similar
/// functions) for correct use of format strings.
void Sema::CheckFormatArguments(const FormatAttr *Format, CallExpr *TheCall) {
@@ -1558,27 +1544,24 @@
void Sema::CheckFormatArguments(const FormatAttr *Format, Expr **Args,
unsigned NumArgs, bool IsCXXMember,
SourceLocation Loc, SourceRange Range) {
- const bool b = Format->getType() == "scanf";
- if (b || CheckablePrintfAttr(Format, Args, NumArgs, IsCXXMember)) {
- bool HasVAListArg = Format->getFirstArg() == 0;
- unsigned format_idx = Format->getFormatIdx() - 1;
- unsigned firstDataArg = HasVAListArg ? 0 : Format->getFirstArg() - 1;
- if (IsCXXMember) {
- if (format_idx == 0)
- return;
- --format_idx;
- if(firstDataArg != 0)
- --firstDataArg;
- }
- CheckPrintfScanfArguments(Args, NumArgs, HasVAListArg, format_idx,
- firstDataArg, !b, Loc, Range);
+ bool HasVAListArg = Format->getFirstArg() == 0;
+ unsigned format_idx = Format->getFormatIdx() - 1;
+ unsigned firstDataArg = HasVAListArg ? 0 : Format->getFirstArg() - 1;
+ if (IsCXXMember) {
+ if (format_idx == 0)
+ return;
+ --format_idx;
+ if(firstDataArg != 0)
+ --firstDataArg;
}
+ CheckFormatArguments(Args, NumArgs, HasVAListArg, format_idx,
+ firstDataArg, GetFormatStringType(Format), Loc, Range);
}
-void Sema::CheckPrintfScanfArguments(Expr **Args, unsigned NumArgs,
- bool HasVAListArg, unsigned format_idx,
- unsigned firstDataArg, bool isPrintf,
- SourceLocation Loc, SourceRange Range) {
+void Sema::CheckFormatArguments(Expr **Args, unsigned NumArgs,
+ bool HasVAListArg, unsigned format_idx,
+ unsigned firstDataArg, FormatStringType Type,
+ SourceLocation Loc, SourceRange Range) {
// CHECK: printf/scanf-like function is called with no format string.
if (format_idx >= NumArgs) {
Diag(Loc, diag::warn_missing_format_string) << Range;
@@ -1600,7 +1583,7 @@
// 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.
if (SemaCheckStringLiteral(OrigFormatExpr, Args, NumArgs, HasVAListArg,
- format_idx, firstDataArg, isPrintf))
+ format_idx, firstDataArg, Type))
return; // Literal format string found, check done!
// If there are no arguments specified, warn with -Wformat-security, otherwise
@@ -2376,7 +2359,7 @@
const Expr *OrigFormatExpr,
Expr **Args, unsigned NumArgs,
bool HasVAListArg, unsigned format_idx,
- unsigned firstDataArg, bool isPrintf,
+ unsigned firstDataArg, FormatStringType Type,
bool inFunctionCall) {
// CHECK: is the format string a wide literal?
@@ -2403,7 +2386,7 @@
return;
}
- if (isPrintf) {
+ if (Type == FST_Printf || Type == FST_NSString) {
CheckPrintfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg,
numDataArgs, isa<ObjCStringLiteral>(OrigFormatExpr),
Str, HasVAListArg, Args, NumArgs, format_idx,
@@ -2412,8 +2395,7 @@
if (!analyze_format_string::ParsePrintfString(H, Str, Str + StrLen,
getLangOptions()))
H.DoneProcessing();
- }
- else {
+ } else if (Type == FST_Scanf) {
CheckScanfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg,
numDataArgs, isa<ObjCStringLiteral>(OrigFormatExpr),
Str, HasVAListArg, Args, NumArgs, format_idx,
@@ -2422,7 +2404,7 @@
if (!analyze_format_string::ParseScanfString(H, Str, Str + StrLen,
getLangOptions()))
H.DoneProcessing();
- }
+ } // TODO: handle other formats
}
//===--- CHECK: Standard memory functions ---------------------------------===//
Modified: cfe/trunk/test/Sema/format-strings.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/format-strings.c?rev=149236&r1=149235&r2=149236&view=diff
==============================================================================
--- cfe/trunk/test/Sema/format-strings.c (original)
+++ cfe/trunk/test/Sema/format-strings.c Mon Jan 30 02:46:47 2012
@@ -480,3 +480,14 @@
printf("%Lx", x); // no-warning
printf("%Ls", "hello"); // expected-warning {{length modifier 'L' results in undefined behavior or no effect with 's' conversion specifier}}
}
+
+void __attribute__((format(strfmon,1,2))) monformat(const char *fmt, ...);
+void __attribute__((format(strftime,1,0))) dateformat(const char *fmt);
+
+// Other formats
+void test_other_formats() {
+ char *str = "";
+ monformat("", 1); // expected-warning{{format string is empty}}
+ dateformat(""); // expected-warning{{format string is empty}}
+ dateformat(str); // expected-warning{{format string is not a string literal (potentially insecure)}}
+}
Modified: cfe/trunk/test/SemaObjC/format-strings-objc.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjC/format-strings-objc.m?rev=149236&r1=149235&r2=149236&view=diff
==============================================================================
--- cfe/trunk/test/SemaObjC/format-strings-objc.m (original)
+++ cfe/trunk/test/SemaObjC/format-strings-objc.m Mon Jan 30 02:46:47 2012
@@ -97,7 +97,7 @@
printf(s2); // expected-warning {{more '%' conversions than data arguments}}
const char * const s3 = (const char *)0;
- printf(s3); // expected-warning {{format string is not a string literal}}
+ printf(s3); // no-warning (NULL is a valid format string)
NSString * const ns1 = @"constant string %s"; // expected-note {{format string is defined here}}
NSLog(ns1); // expected-warning {{more '%' conversions than data arguments}}
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