forked from OSchip/llvm-project
613 lines
18 KiB
C++
613 lines
18 KiB
C++
//== PrintfFormatString.cpp - Analysis of printf format strings --*- C++ -*-==//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// Handling of format string in printf and friends. The structure of format
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// strings for fprintf() are described in C99 7.19.6.1.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Analysis/Analyses/FormatString.h"
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#include "FormatStringParsing.h"
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using clang::analyze_format_string::ArgTypeResult;
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using clang::analyze_format_string::FormatStringHandler;
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using clang::analyze_format_string::LengthModifier;
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using clang::analyze_format_string::OptionalAmount;
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using clang::analyze_format_string::ConversionSpecifier;
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using clang::analyze_printf::PrintfSpecifier;
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using namespace clang;
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typedef clang::analyze_format_string::SpecifierResult<PrintfSpecifier>
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PrintfSpecifierResult;
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//===----------------------------------------------------------------------===//
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// Methods for parsing format strings.
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//===----------------------------------------------------------------------===//
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using analyze_format_string::ParseNonPositionAmount;
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static bool ParsePrecision(FormatStringHandler &H, PrintfSpecifier &FS,
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const char *Start, const char *&Beg, const char *E,
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unsigned *argIndex) {
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if (argIndex) {
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FS.setPrecision(ParseNonPositionAmount(Beg, E, *argIndex));
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}
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else {
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const OptionalAmount Amt = ParsePositionAmount(H, Start, Beg, E,
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analyze_format_string::PrecisionPos);
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if (Amt.isInvalid())
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return true;
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FS.setPrecision(Amt);
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}
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return false;
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}
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static PrintfSpecifierResult ParsePrintfSpecifier(FormatStringHandler &H,
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const char *&Beg,
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const char *E,
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unsigned &argIndex) {
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using namespace clang::analyze_format_string;
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using namespace clang::analyze_printf;
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const char *I = Beg;
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const char *Start = 0;
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UpdateOnReturn <const char*> UpdateBeg(Beg, I);
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// Look for a '%' character that indicates the start of a format specifier.
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for ( ; I != E ; ++I) {
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char c = *I;
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if (c == '\0') {
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// Detect spurious null characters, which are likely errors.
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H.HandleNullChar(I);
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return true;
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}
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if (c == '%') {
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Start = I++; // Record the start of the format specifier.
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break;
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}
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}
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// No format specifier found?
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if (!Start)
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return false;
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if (I == E) {
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// No more characters left?
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H.HandleIncompleteSpecifier(Start, E - Start);
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return true;
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}
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PrintfSpecifier FS;
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if (ParseArgPosition(H, FS, Start, I, E))
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return true;
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if (I == E) {
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// No more characters left?
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H.HandleIncompleteSpecifier(Start, E - Start);
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return true;
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}
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// Look for flags (if any).
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bool hasMore = true;
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for ( ; I != E; ++I) {
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switch (*I) {
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default: hasMore = false; break;
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case '-': FS.setIsLeftJustified(I); break;
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case '+': FS.setHasPlusPrefix(I); break;
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case ' ': FS.setHasSpacePrefix(I); break;
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case '#': FS.setHasAlternativeForm(I); break;
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case '0': FS.setHasLeadingZeros(I); break;
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}
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if (!hasMore)
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break;
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}
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if (I == E) {
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// No more characters left?
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H.HandleIncompleteSpecifier(Start, E - Start);
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return true;
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}
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// Look for the field width (if any).
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if (ParseFieldWidth(H, FS, Start, I, E,
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FS.usesPositionalArg() ? 0 : &argIndex))
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return true;
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if (I == E) {
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// No more characters left?
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H.HandleIncompleteSpecifier(Start, E - Start);
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return true;
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}
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// Look for the precision (if any).
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if (*I == '.') {
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++I;
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if (I == E) {
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H.HandleIncompleteSpecifier(Start, E - Start);
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return true;
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}
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if (ParsePrecision(H, FS, Start, I, E,
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FS.usesPositionalArg() ? 0 : &argIndex))
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return true;
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if (I == E) {
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// No more characters left?
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H.HandleIncompleteSpecifier(Start, E - Start);
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return true;
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}
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}
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// Look for the length modifier.
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if (ParseLengthModifier(FS, I, E) && I == E) {
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// No more characters left?
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H.HandleIncompleteSpecifier(Start, E - Start);
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return true;
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}
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if (*I == '\0') {
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// Detect spurious null characters, which are likely errors.
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H.HandleNullChar(I);
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return true;
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}
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// Finally, look for the conversion specifier.
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const char *conversionPosition = I++;
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ConversionSpecifier::Kind k = ConversionSpecifier::InvalidSpecifier;
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switch (*conversionPosition) {
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default:
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break;
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// C99: 7.19.6.1 (section 8).
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case '%': k = ConversionSpecifier::PercentArg; break;
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case 'A': k = ConversionSpecifier::AArg; break;
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case 'E': k = ConversionSpecifier::EArg; break;
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case 'F': k = ConversionSpecifier::FArg; break;
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case 'G': k = ConversionSpecifier::GArg; break;
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case 'X': k = ConversionSpecifier::XArg; break;
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case 'a': k = ConversionSpecifier::aArg; break;
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case 'c': k = ConversionSpecifier::cArg; break;
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case 'd': k = ConversionSpecifier::dArg; break;
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case 'e': k = ConversionSpecifier::eArg; break;
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case 'f': k = ConversionSpecifier::fArg; break;
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case 'g': k = ConversionSpecifier::gArg; break;
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case 'i': k = ConversionSpecifier::iArg; break;
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case 'n': k = ConversionSpecifier::nArg; break;
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case 'o': k = ConversionSpecifier::oArg; break;
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case 'p': k = ConversionSpecifier::pArg; break;
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case 's': k = ConversionSpecifier::sArg; break;
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case 'u': k = ConversionSpecifier::uArg; break;
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case 'x': k = ConversionSpecifier::xArg; break;
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// Mac OS X (unicode) specific
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case 'C': k = ConversionSpecifier::CArg; break;
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case 'S': k = ConversionSpecifier::SArg; break;
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// Objective-C.
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case '@': k = ConversionSpecifier::ObjCObjArg; break;
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// Glibc specific.
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case 'm': k = ConversionSpecifier::PrintErrno; break;
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}
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PrintfConversionSpecifier CS(conversionPosition, k);
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FS.setConversionSpecifier(CS);
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if (CS.consumesDataArgument() && !FS.usesPositionalArg())
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FS.setArgIndex(argIndex++);
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if (k == ConversionSpecifier::InvalidSpecifier) {
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// Assume the conversion takes one argument.
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return !H.HandleInvalidPrintfConversionSpecifier(FS, Beg, I - Beg);
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}
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return PrintfSpecifierResult(Start, FS);
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}
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bool clang::analyze_format_string::ParsePrintfString(FormatStringHandler &H,
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const char *I,
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const char *E) {
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unsigned argIndex = 0;
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// Keep looking for a format specifier until we have exhausted the string.
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while (I != E) {
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const PrintfSpecifierResult &FSR = ParsePrintfSpecifier(H, I, E, argIndex);
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// Did a fail-stop error of any kind occur when parsing the specifier?
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// If so, don't do any more processing.
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if (FSR.shouldStop())
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return true;;
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// Did we exhaust the string or encounter an error that
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// we can recover from?
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if (!FSR.hasValue())
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continue;
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// We have a format specifier. Pass it to the callback.
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if (!H.HandlePrintfSpecifier(FSR.getValue(), FSR.getStart(),
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I - FSR.getStart()))
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return true;
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}
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assert(I == E && "Format string not exhausted");
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return false;
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}
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//===----------------------------------------------------------------------===//
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// Methods on ConversionSpecifier.
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//===----------------------------------------------------------------------===//
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const char *ConversionSpecifier::toString() const {
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switch (kind) {
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case dArg: return "d";
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case iArg: return "i";
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case oArg: return "o";
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case uArg: return "u";
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case xArg: return "x";
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case XArg: return "X";
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case fArg: return "f";
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case FArg: return "F";
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case eArg: return "e";
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case EArg: return "E";
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case gArg: return "g";
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case GArg: return "G";
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case aArg: return "a";
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case AArg: return "A";
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case cArg: return "c";
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case sArg: return "s";
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case pArg: return "p";
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case nArg: return "n";
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case PercentArg: return "%";
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case ScanListArg: return "[";
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case InvalidSpecifier: return NULL;
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// MacOS X unicode extensions.
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case CArg: return "C";
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case SArg: return "S";
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// Objective-C specific specifiers.
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case ObjCObjArg: return "@";
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// GlibC specific specifiers.
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case PrintErrno: return "m";
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}
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return NULL;
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}
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//===----------------------------------------------------------------------===//
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// Methods on PrintfSpecifier.
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//===----------------------------------------------------------------------===//
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ArgTypeResult PrintfSpecifier::getArgType(ASTContext &Ctx) const {
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const PrintfConversionSpecifier &CS = getConversionSpecifier();
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if (!CS.consumesDataArgument())
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return ArgTypeResult::Invalid();
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if (CS.getKind() == ConversionSpecifier::cArg)
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switch (LM.getKind()) {
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case LengthModifier::None: return Ctx.IntTy;
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case LengthModifier::AsLong: return ArgTypeResult::WIntTy;
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default:
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return ArgTypeResult::Invalid();
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}
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if (CS.isIntArg())
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switch (LM.getKind()) {
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case LengthModifier::AsLongDouble:
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return ArgTypeResult::Invalid();
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case LengthModifier::None: return Ctx.IntTy;
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case LengthModifier::AsChar: return Ctx.SignedCharTy;
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case LengthModifier::AsShort: return Ctx.ShortTy;
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case LengthModifier::AsLong: return Ctx.LongTy;
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case LengthModifier::AsLongLong: return Ctx.LongLongTy;
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case LengthModifier::AsIntMax:
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// FIXME: Return unknown for now.
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return ArgTypeResult();
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case LengthModifier::AsSizeT: return Ctx.getSizeType();
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case LengthModifier::AsPtrDiff: return Ctx.getPointerDiffType();
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}
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if (CS.isUIntArg())
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switch (LM.getKind()) {
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case LengthModifier::AsLongDouble:
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return ArgTypeResult::Invalid();
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case LengthModifier::None: return Ctx.UnsignedIntTy;
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case LengthModifier::AsChar: return Ctx.UnsignedCharTy;
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case LengthModifier::AsShort: return Ctx.UnsignedShortTy;
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case LengthModifier::AsLong: return Ctx.UnsignedLongTy;
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case LengthModifier::AsLongLong: return Ctx.UnsignedLongLongTy;
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case LengthModifier::AsIntMax:
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// FIXME: Return unknown for now.
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return ArgTypeResult();
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case LengthModifier::AsSizeT:
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// FIXME: How to get the corresponding unsigned
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// version of size_t?
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return ArgTypeResult();
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case LengthModifier::AsPtrDiff:
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// FIXME: How to get the corresponding unsigned
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// version of ptrdiff_t?
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return ArgTypeResult();
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}
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if (CS.isDoubleArg()) {
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if (LM.getKind() == LengthModifier::AsLongDouble)
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return Ctx.LongDoubleTy;
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return Ctx.DoubleTy;
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}
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switch (CS.getKind()) {
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case ConversionSpecifier::sArg:
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return ArgTypeResult(LM.getKind() == LengthModifier::AsWideChar ?
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ArgTypeResult::WCStrTy : ArgTypeResult::CStrTy);
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case ConversionSpecifier::SArg:
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// FIXME: This appears to be Mac OS X specific.
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return ArgTypeResult::WCStrTy;
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case ConversionSpecifier::CArg:
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return Ctx.WCharTy;
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case ConversionSpecifier::pArg:
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return ArgTypeResult::CPointerTy;
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default:
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break;
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}
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// FIXME: Handle other cases.
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return ArgTypeResult();
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}
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bool PrintfSpecifier::fixType(QualType QT) {
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// Handle strings first (char *, wchar_t *)
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if (QT->isPointerType() && (QT->getPointeeType()->isAnyCharacterType())) {
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CS.setKind(ConversionSpecifier::sArg);
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// Disable irrelevant flags
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HasAlternativeForm = 0;
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HasLeadingZeroes = 0;
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// Set the long length modifier for wide characters
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if (QT->getPointeeType()->isWideCharType())
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LM.setKind(LengthModifier::AsWideChar);
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return true;
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}
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// We can only work with builtin types.
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if (!QT->isBuiltinType())
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return false;
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// Everything else should be a base type
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const BuiltinType *BT = QT->getAs<BuiltinType>();
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// Set length modifier
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switch (BT->getKind()) {
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default:
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// The rest of the conversions are either optional or for non-builtin types
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LM.setKind(LengthModifier::None);
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break;
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case BuiltinType::WChar:
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case BuiltinType::Long:
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case BuiltinType::ULong:
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LM.setKind(LengthModifier::AsLong);
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break;
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case BuiltinType::LongLong:
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case BuiltinType::ULongLong:
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LM.setKind(LengthModifier::AsLongLong);
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break;
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case BuiltinType::LongDouble:
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LM.setKind(LengthModifier::AsLongDouble);
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break;
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}
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// Set conversion specifier and disable any flags which do not apply to it.
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if (QT->isAnyCharacterType()) {
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CS.setKind(ConversionSpecifier::cArg);
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Precision.setHowSpecified(OptionalAmount::NotSpecified);
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HasAlternativeForm = 0;
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HasLeadingZeroes = 0;
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HasPlusPrefix = 0;
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}
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// Test for Floating type first as LongDouble can pass isUnsignedIntegerType
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else if (QT->isRealFloatingType()) {
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CS.setKind(ConversionSpecifier::fArg);
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}
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else if (QT->isPointerType()) {
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CS.setKind(ConversionSpecifier::pArg);
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Precision.setHowSpecified(OptionalAmount::NotSpecified);
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HasAlternativeForm = 0;
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HasLeadingZeroes = 0;
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HasPlusPrefix = 0;
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}
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else if (QT->isSignedIntegerType()) {
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CS.setKind(ConversionSpecifier::dArg);
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HasAlternativeForm = 0;
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}
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else if (QT->isUnsignedIntegerType()) {
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CS.setKind(ConversionSpecifier::uArg);
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HasAlternativeForm = 0;
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HasPlusPrefix = 0;
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}
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else {
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return false;
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}
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return true;
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}
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void PrintfSpecifier::toString(llvm::raw_ostream &os) const {
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// Whilst some features have no defined order, we are using the order
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// appearing in the C99 standard (ISO/IEC 9899:1999 (E) ¤7.19.6.1)
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os << "%";
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// Positional args
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if (usesPositionalArg()) {
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os << getPositionalArgIndex() << "$";
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}
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// Conversion flags
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if (IsLeftJustified) os << "-";
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if (HasPlusPrefix) os << "+";
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if (HasSpacePrefix) os << " ";
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if (HasAlternativeForm) os << "#";
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if (HasLeadingZeroes) os << "0";
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// Minimum field width
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FieldWidth.toString(os);
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// Precision
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Precision.toString(os);
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// Length modifier
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os << LM.toString();
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// Conversion specifier
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os << CS.toString();
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}
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bool PrintfSpecifier::hasValidPlusPrefix() const {
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if (!HasPlusPrefix)
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return true;
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// The plus prefix only makes sense for signed conversions
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switch (CS.getKind()) {
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case ConversionSpecifier::dArg:
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case ConversionSpecifier::iArg:
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case ConversionSpecifier::fArg:
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case ConversionSpecifier::FArg:
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case ConversionSpecifier::eArg:
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case ConversionSpecifier::EArg:
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case ConversionSpecifier::gArg:
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case ConversionSpecifier::GArg:
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case ConversionSpecifier::aArg:
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case ConversionSpecifier::AArg:
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return true;
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default:
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return false;
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}
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}
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bool PrintfSpecifier::hasValidAlternativeForm() const {
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if (!HasAlternativeForm)
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return true;
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// Alternate form flag only valid with the oxaAeEfFgG conversions
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switch (CS.getKind()) {
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case ConversionSpecifier::oArg:
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case ConversionSpecifier::xArg:
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case ConversionSpecifier::aArg:
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case ConversionSpecifier::AArg:
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case ConversionSpecifier::eArg:
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case ConversionSpecifier::EArg:
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case ConversionSpecifier::fArg:
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case ConversionSpecifier::FArg:
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case ConversionSpecifier::gArg:
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case ConversionSpecifier::GArg:
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return true;
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default:
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return false;
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}
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}
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bool PrintfSpecifier::hasValidLeadingZeros() const {
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if (!HasLeadingZeroes)
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return true;
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// Leading zeroes flag only valid with the diouxXaAeEfFgG conversions
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switch (CS.getKind()) {
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case ConversionSpecifier::dArg:
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case ConversionSpecifier::iArg:
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case ConversionSpecifier::oArg:
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case ConversionSpecifier::uArg:
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case ConversionSpecifier::xArg:
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case ConversionSpecifier::XArg:
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case ConversionSpecifier::aArg:
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case ConversionSpecifier::AArg:
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case ConversionSpecifier::eArg:
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case ConversionSpecifier::EArg:
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case ConversionSpecifier::fArg:
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case ConversionSpecifier::FArg:
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case ConversionSpecifier::gArg:
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case ConversionSpecifier::GArg:
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return true;
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|
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool PrintfSpecifier::hasValidSpacePrefix() const {
|
|
if (!HasSpacePrefix)
|
|
return true;
|
|
|
|
// The space prefix only makes sense for signed conversions
|
|
switch (CS.getKind()) {
|
|
case ConversionSpecifier::dArg:
|
|
case ConversionSpecifier::iArg:
|
|
case ConversionSpecifier::fArg:
|
|
case ConversionSpecifier::FArg:
|
|
case ConversionSpecifier::eArg:
|
|
case ConversionSpecifier::EArg:
|
|
case ConversionSpecifier::gArg:
|
|
case ConversionSpecifier::GArg:
|
|
case ConversionSpecifier::aArg:
|
|
case ConversionSpecifier::AArg:
|
|
return true;
|
|
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool PrintfSpecifier::hasValidLeftJustified() const {
|
|
if (!IsLeftJustified)
|
|
return true;
|
|
|
|
// The left justified flag is valid for all conversions except n
|
|
switch (CS.getKind()) {
|
|
case ConversionSpecifier::nArg:
|
|
return false;
|
|
|
|
default:
|
|
return true;
|
|
}
|
|
}
|
|
|
|
bool PrintfSpecifier::hasValidPrecision() const {
|
|
if (Precision.getHowSpecified() == OptionalAmount::NotSpecified)
|
|
return true;
|
|
|
|
// Precision is only valid with the diouxXaAeEfFgGs conversions
|
|
switch (CS.getKind()) {
|
|
case ConversionSpecifier::dArg:
|
|
case ConversionSpecifier::iArg:
|
|
case ConversionSpecifier::oArg:
|
|
case ConversionSpecifier::uArg:
|
|
case ConversionSpecifier::xArg:
|
|
case ConversionSpecifier::XArg:
|
|
case ConversionSpecifier::aArg:
|
|
case ConversionSpecifier::AArg:
|
|
case ConversionSpecifier::eArg:
|
|
case ConversionSpecifier::EArg:
|
|
case ConversionSpecifier::fArg:
|
|
case ConversionSpecifier::FArg:
|
|
case ConversionSpecifier::gArg:
|
|
case ConversionSpecifier::GArg:
|
|
case ConversionSpecifier::sArg:
|
|
return true;
|
|
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
bool PrintfSpecifier::hasValidFieldWidth() const {
|
|
if (FieldWidth.getHowSpecified() == OptionalAmount::NotSpecified)
|
|
return true;
|
|
|
|
// The field width is valid for all conversions except n
|
|
switch (CS.getKind()) {
|
|
case ConversionSpecifier::nArg:
|
|
return false;
|
|
|
|
default:
|
|
return true;
|
|
}
|
|
}
|