1 // FormatString.cpp - Common stuff for handling printf/scanf formats -*- C++ -*-
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Shared details for processing format strings of printf and scanf
13 //===----------------------------------------------------------------------===//
15 #include "FormatStringParsing.h"
17 using clang::analyze_format_string::ArgTypeResult;
18 using clang::analyze_format_string::FormatStringHandler;
19 using clang::analyze_format_string::FormatSpecifier;
20 using clang::analyze_format_string::LengthModifier;
21 using clang::analyze_format_string::OptionalAmount;
22 using clang::analyze_format_string::PositionContext;
23 using clang::analyze_format_string::ConversionSpecifier;
24 using namespace clang;
26 // Key function to FormatStringHandler.
27 FormatStringHandler::~FormatStringHandler() {}
29 //===----------------------------------------------------------------------===//
30 // Functions for parsing format strings components in both printf and
31 // scanf format strings.
32 //===----------------------------------------------------------------------===//
35 clang::analyze_format_string::ParseAmount(const char *&Beg, const char *E) {
37 UpdateOnReturn <const char*> UpdateBeg(Beg, I);
39 unsigned accumulator = 0;
40 bool hasDigits = false;
42 for ( ; I != E; ++I) {
44 if (c >= '0' && c <= '9') {
46 accumulator = (accumulator * 10) + (c - '0');
51 return OptionalAmount(OptionalAmount::Constant, accumulator, Beg, I - Beg,
57 return OptionalAmount();
61 clang::analyze_format_string::ParseNonPositionAmount(const char *&Beg,
66 return OptionalAmount(OptionalAmount::Arg, argIndex++, Beg, 0, false);
69 return ParseAmount(Beg, E);
73 clang::analyze_format_string::ParsePositionAmount(FormatStringHandler &H,
79 const char *I = Beg + 1;
80 const OptionalAmount &Amt = ParseAmount(I, E);
82 if (Amt.getHowSpecified() == OptionalAmount::NotSpecified) {
83 H.HandleInvalidPosition(Beg, I - Beg, p);
84 return OptionalAmount(false);
88 // No more characters left?
89 H.HandleIncompleteSpecifier(Start, E - Start);
90 return OptionalAmount(false);
93 assert(Amt.getHowSpecified() == OptionalAmount::Constant);
96 // Handle positional arguments
98 // Special case: '*0$', since this is an easy mistake.
99 if (Amt.getConstantAmount() == 0) {
100 H.HandleZeroPosition(Beg, I - Beg + 1);
101 return OptionalAmount(false);
104 const char *Tmp = Beg;
107 return OptionalAmount(OptionalAmount::Arg, Amt.getConstantAmount() - 1,
111 H.HandleInvalidPosition(Beg, I - Beg, p);
112 return OptionalAmount(false);
115 return ParseAmount(Beg, E);
120 clang::analyze_format_string::ParseFieldWidth(FormatStringHandler &H,
123 const char *&Beg, const char *E,
124 unsigned *argIndex) {
125 // FIXME: Support negative field widths.
127 CS.setFieldWidth(ParseNonPositionAmount(Beg, E, *argIndex));
130 const OptionalAmount Amt =
131 ParsePositionAmount(H, Start, Beg, E,
132 analyze_format_string::FieldWidthPos);
136 CS.setFieldWidth(Amt);
142 clang::analyze_format_string::ParseArgPosition(FormatStringHandler &H,
149 const OptionalAmount &Amt = ParseAmount(I, E);
152 // No more characters left?
153 H.HandleIncompleteSpecifier(Start, E - Start);
157 if (Amt.getHowSpecified() == OptionalAmount::Constant && *(I++) == '$') {
158 // Special case: '%0$', since this is an easy mistake.
159 if (Amt.getConstantAmount() == 0) {
160 H.HandleZeroPosition(Start, I - Start);
164 FS.setArgIndex(Amt.getConstantAmount() - 1);
165 FS.setUsesPositionalArg();
166 // Update the caller's pointer if we decided to consume
176 clang::analyze_format_string::ParseLengthModifier(FormatSpecifier &FS,
179 LengthModifier::Kind lmKind = LengthModifier::None;
180 const char *lmPosition = I;
186 lmKind = (I != E && *I == 'h') ?
187 ++I, LengthModifier::AsChar : LengthModifier::AsShort;
191 lmKind = (I != E && *I == 'l') ?
192 ++I, LengthModifier::AsLongLong : LengthModifier::AsLong;
194 case 'j': lmKind = LengthModifier::AsIntMax; ++I; break;
195 case 'z': lmKind = LengthModifier::AsSizeT; ++I; break;
196 case 't': lmKind = LengthModifier::AsPtrDiff; ++I; break;
197 case 'L': lmKind = LengthModifier::AsLongDouble; ++I; break;
198 case 'q': lmKind = LengthModifier::AsLongLong; ++I; break;
200 LengthModifier lm(lmPosition, lmKind);
201 FS.setLengthModifier(lm);
205 //===----------------------------------------------------------------------===//
206 // Methods on ArgTypeResult.
207 //===----------------------------------------------------------------------===//
209 bool ArgTypeResult::matchesType(ASTContext &C, QualType argTy) const {
212 assert(false && "ArgTypeResult must be valid");
219 argTy = C.getCanonicalType(argTy).getUnqualifiedType();
222 // Check for "compatible types".
223 if (const BuiltinType *BT = argTy->getAs<BuiltinType>())
224 switch (BT->getKind()) {
227 case BuiltinType::Char_S:
228 case BuiltinType::SChar:
229 return T == C.UnsignedCharTy;
230 case BuiltinType::Char_U:
231 case BuiltinType::UChar:
232 return T == C.SignedCharTy;
233 case BuiltinType::Short:
234 return T == C.UnsignedShortTy;
235 case BuiltinType::UShort:
236 return T == C.ShortTy;
237 case BuiltinType::Int:
238 return T == C.UnsignedIntTy;
239 case BuiltinType::UInt:
241 case BuiltinType::Long:
242 return T == C.UnsignedLongTy;
243 case BuiltinType::ULong:
244 return T == C.LongTy;
245 case BuiltinType::LongLong:
246 return T == C.UnsignedLongLongTy;
247 case BuiltinType::ULongLong:
248 return T == C.LongLongTy;
254 const PointerType *PT = argTy->getAs<PointerType>();
257 QualType pointeeTy = PT->getPointeeType();
258 if (const BuiltinType *BT = pointeeTy->getAs<BuiltinType>())
259 switch (BT->getKind()) {
260 case BuiltinType::Void:
261 case BuiltinType::Char_U:
262 case BuiltinType::UChar:
263 case BuiltinType::Char_S:
264 case BuiltinType::SChar:
274 const PointerType *PT = argTy->getAs<PointerType>();
278 C.getCanonicalType(PT->getPointeeType()).getUnqualifiedType();
279 return pointeeTy == C.getWCharType();
283 // Instead of doing a lookup for the definition of 'wint_t' (which
284 // is defined by the system headers) instead see if wchar_t and
285 // the argument type promote to the same type.
286 QualType PromoWChar =
287 C.getWCharType()->isPromotableIntegerType()
288 ? C.getPromotedIntegerType(C.getWCharType()) : C.getWCharType();
290 argTy->isPromotableIntegerType()
291 ? C.getPromotedIntegerType(argTy) : argTy;
293 PromoWChar = C.getCanonicalType(PromoWChar).getUnqualifiedType();
294 PromoArg = C.getCanonicalType(PromoArg).getUnqualifiedType();
296 return PromoWChar == PromoArg;
300 return argTy->isPointerType() || argTy->isObjCObjectPointerType() ||
301 argTy->isNullPtrType();
304 return argTy->getAs<ObjCObjectPointerType>() != NULL;
307 // FIXME: Should be unreachable, but Clang is currently emitting
312 QualType ArgTypeResult::getRepresentativeType(ASTContext &C) const {
315 assert(false && "No representative type for Invalid ArgTypeResult");
322 return C.getPointerType(C.CharTy);
324 return C.getPointerType(C.getWCharType());
326 return C.ObjCBuiltinIdTy;
330 QualType WC = C.getWCharType();
331 return WC->isPromotableIntegerType() ? C.getPromotedIntegerType(WC) : WC;
335 // FIXME: Should be unreachable, but Clang is currently emitting
340 //===----------------------------------------------------------------------===//
341 // Methods on OptionalAmount.
342 //===----------------------------------------------------------------------===//
345 analyze_format_string::OptionalAmount::getArgType(ASTContext &Ctx) const {
349 //===----------------------------------------------------------------------===//
350 // Methods on LengthModifier.
351 //===----------------------------------------------------------------------===//
354 analyze_format_string::LengthModifier::toString() const {
360 case AsLong: // or AsWideChar
378 //===----------------------------------------------------------------------===//
379 // Methods on OptionalAmount.
380 //===----------------------------------------------------------------------===//
382 void OptionalAmount::toString(llvm::raw_ostream &os) const {
390 if (usesPositionalArg())
391 os << "*" << getPositionalArgIndex() << "$";
403 //===----------------------------------------------------------------------===//
404 // Methods on ConversionSpecifier.
405 //===----------------------------------------------------------------------===//
407 bool FormatSpecifier::hasValidLengthModifier() const {
408 switch (LM.getKind()) {
409 case LengthModifier::None:
412 // Handle most integer flags
413 case LengthModifier::AsChar:
414 case LengthModifier::AsShort:
415 case LengthModifier::AsLongLong:
416 case LengthModifier::AsIntMax:
417 case LengthModifier::AsSizeT:
418 case LengthModifier::AsPtrDiff:
419 switch (CS.getKind()) {
420 case ConversionSpecifier::dArg:
421 case ConversionSpecifier::iArg:
422 case ConversionSpecifier::oArg:
423 case ConversionSpecifier::uArg:
424 case ConversionSpecifier::xArg:
425 case ConversionSpecifier::XArg:
426 case ConversionSpecifier::nArg:
427 case ConversionSpecifier::rArg:
434 case LengthModifier::AsLong:
435 switch (CS.getKind()) {
436 case ConversionSpecifier::dArg:
437 case ConversionSpecifier::iArg:
438 case ConversionSpecifier::oArg:
439 case ConversionSpecifier::uArg:
440 case ConversionSpecifier::xArg:
441 case ConversionSpecifier::XArg:
442 case ConversionSpecifier::aArg:
443 case ConversionSpecifier::AArg:
444 case ConversionSpecifier::fArg:
445 case ConversionSpecifier::FArg:
446 case ConversionSpecifier::eArg:
447 case ConversionSpecifier::EArg:
448 case ConversionSpecifier::gArg:
449 case ConversionSpecifier::GArg:
450 case ConversionSpecifier::nArg:
451 case ConversionSpecifier::cArg:
452 case ConversionSpecifier::sArg:
453 case ConversionSpecifier::rArg:
459 case LengthModifier::AsLongDouble:
460 switch (CS.getKind()) {
461 case ConversionSpecifier::aArg:
462 case ConversionSpecifier::AArg:
463 case ConversionSpecifier::fArg:
464 case ConversionSpecifier::FArg:
465 case ConversionSpecifier::eArg:
466 case ConversionSpecifier::EArg:
467 case ConversionSpecifier::gArg:
468 case ConversionSpecifier::GArg: