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 llvm_unreachable("ArgTypeResult must be valid");
218 argTy = C.getCanonicalType(argTy).getUnqualifiedType();
221 // Check for "compatible types".
222 if (const BuiltinType *BT = argTy->getAs<BuiltinType>())
223 switch (BT->getKind()) {
226 case BuiltinType::Char_S:
227 case BuiltinType::SChar:
228 return T == C.UnsignedCharTy;
229 case BuiltinType::Char_U:
230 case BuiltinType::UChar:
231 return T == C.SignedCharTy;
232 case BuiltinType::Short:
233 return T == C.UnsignedShortTy;
234 case BuiltinType::UShort:
235 return T == C.ShortTy;
236 case BuiltinType::Int:
237 return T == C.UnsignedIntTy;
238 case BuiltinType::UInt:
240 case BuiltinType::Long:
241 return T == C.UnsignedLongTy;
242 case BuiltinType::ULong:
243 return T == C.LongTy;
244 case BuiltinType::LongLong:
245 return T == C.UnsignedLongLongTy;
246 case BuiltinType::ULongLong:
247 return T == C.LongLongTy;
253 const PointerType *PT = argTy->getAs<PointerType>();
256 QualType pointeeTy = PT->getPointeeType();
257 if (const BuiltinType *BT = pointeeTy->getAs<BuiltinType>())
258 switch (BT->getKind()) {
259 case BuiltinType::Void:
260 case BuiltinType::Char_U:
261 case BuiltinType::UChar:
262 case BuiltinType::Char_S:
263 case BuiltinType::SChar:
273 const PointerType *PT = argTy->getAs<PointerType>();
277 C.getCanonicalType(PT->getPointeeType()).getUnqualifiedType();
278 return pointeeTy == C.getWCharType();
282 // Instead of doing a lookup for the definition of 'wint_t' (which
283 // is defined by the system headers) instead see if wchar_t and
284 // the argument type promote to the same type.
285 QualType PromoWChar =
286 C.getWCharType()->isPromotableIntegerType()
287 ? C.getPromotedIntegerType(C.getWCharType()) : C.getWCharType();
289 argTy->isPromotableIntegerType()
290 ? C.getPromotedIntegerType(argTy) : argTy;
292 PromoWChar = C.getCanonicalType(PromoWChar).getUnqualifiedType();
293 PromoArg = C.getCanonicalType(PromoArg).getUnqualifiedType();
295 return PromoWChar == PromoArg;
299 return argTy->isPointerType() || argTy->isObjCObjectPointerType() ||
300 argTy->isNullPtrType();
303 return argTy->getAs<ObjCObjectPointerType>() != NULL;
306 // FIXME: Should be unreachable, but Clang is currently emitting
311 QualType ArgTypeResult::getRepresentativeType(ASTContext &C) const {
314 llvm_unreachable("No representative type for Invalid ArgTypeResult");
320 return C.getPointerType(C.CharTy);
322 return C.getPointerType(C.getWCharType());
324 return C.ObjCBuiltinIdTy;
328 QualType WC = C.getWCharType();
329 return WC->isPromotableIntegerType() ? C.getPromotedIntegerType(WC) : WC;
333 // FIXME: Should be unreachable, but Clang is currently emitting
338 //===----------------------------------------------------------------------===//
339 // Methods on OptionalAmount.
340 //===----------------------------------------------------------------------===//
343 analyze_format_string::OptionalAmount::getArgType(ASTContext &Ctx) const {
347 //===----------------------------------------------------------------------===//
348 // Methods on LengthModifier.
349 //===----------------------------------------------------------------------===//
352 analyze_format_string::LengthModifier::toString() const {
358 case AsLong: // or AsWideChar
376 //===----------------------------------------------------------------------===//
377 // Methods on OptionalAmount.
378 //===----------------------------------------------------------------------===//
380 void OptionalAmount::toString(raw_ostream &os) const {
388 if (usesPositionalArg())
389 os << "*" << getPositionalArgIndex() << "$";
401 //===----------------------------------------------------------------------===//
402 // Methods on ConversionSpecifier.
403 //===----------------------------------------------------------------------===//
405 bool FormatSpecifier::hasValidLengthModifier() const {
406 switch (LM.getKind()) {
407 case LengthModifier::None:
410 // Handle most integer flags
411 case LengthModifier::AsChar:
412 case LengthModifier::AsShort:
413 case LengthModifier::AsLongLong:
414 case LengthModifier::AsIntMax:
415 case LengthModifier::AsSizeT:
416 case LengthModifier::AsPtrDiff:
417 switch (CS.getKind()) {
418 case ConversionSpecifier::dArg:
419 case ConversionSpecifier::iArg:
420 case ConversionSpecifier::oArg:
421 case ConversionSpecifier::uArg:
422 case ConversionSpecifier::xArg:
423 case ConversionSpecifier::XArg:
424 case ConversionSpecifier::nArg:
425 case ConversionSpecifier::rArg:
432 case LengthModifier::AsLong:
433 switch (CS.getKind()) {
434 case ConversionSpecifier::dArg:
435 case ConversionSpecifier::iArg:
436 case ConversionSpecifier::oArg:
437 case ConversionSpecifier::uArg:
438 case ConversionSpecifier::xArg:
439 case ConversionSpecifier::XArg:
440 case ConversionSpecifier::aArg:
441 case ConversionSpecifier::AArg:
442 case ConversionSpecifier::fArg:
443 case ConversionSpecifier::FArg:
444 case ConversionSpecifier::eArg:
445 case ConversionSpecifier::EArg:
446 case ConversionSpecifier::gArg:
447 case ConversionSpecifier::GArg:
448 case ConversionSpecifier::nArg:
449 case ConversionSpecifier::cArg:
450 case ConversionSpecifier::sArg:
451 case ConversionSpecifier::rArg:
457 case LengthModifier::AsLongDouble:
458 switch (CS.getKind()) {
459 case ConversionSpecifier::aArg:
460 case ConversionSpecifier::AArg:
461 case ConversionSpecifier::fArg:
462 case ConversionSpecifier::FArg:
463 case ConversionSpecifier::eArg:
464 case ConversionSpecifier::EArg:
465 case ConversionSpecifier::gArg:
466 case ConversionSpecifier::GArg: