179 lines · cpp
1//===-- flags_parser.cpp ----------------------------------------*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "flags_parser.h"10#include "common.h"11#include "report.h"12 13#include <errno.h>14#include <limits.h>15#include <stdlib.h>16#include <string.h>17 18namespace scudo {19 20class UnknownFlagsRegistry {21 static const u32 MaxUnknownFlags = 16;22 const char *UnknownFlagsNames[MaxUnknownFlags];23 u32 NumberOfUnknownFlags;24 25public:26 void add(const char *Name) {27 CHECK_LT(NumberOfUnknownFlags, MaxUnknownFlags);28 UnknownFlagsNames[NumberOfUnknownFlags++] = Name;29 }30 31 void report() {32 if (!NumberOfUnknownFlags)33 return;34 Printf("Scudo WARNING: found %d unrecognized flag(s):\n",35 NumberOfUnknownFlags);36 for (u32 I = 0; I < NumberOfUnknownFlags; ++I)37 Printf(" %s\n", UnknownFlagsNames[I]);38 NumberOfUnknownFlags = 0;39 }40};41static UnknownFlagsRegistry UnknownFlags;42 43void reportUnrecognizedFlags() { UnknownFlags.report(); }44 45void FlagParser::printFlagDescriptions() {46 Printf("Available flags for Scudo:\n");47 for (u32 I = 0; I < NumberOfFlags; ++I)48 Printf("\t%s\n\t\t- %s\n", Flags[I].Name, Flags[I].Desc);49}50 51static bool isSeparator(char C) {52 return C == ' ' || C == ',' || C == ':' || C == '\n' || C == '\t' ||53 C == '\r';54}55 56static bool isSeparatorOrNull(char C) { return !C || isSeparator(C); }57 58void FlagParser::skipWhitespace() {59 while (isSeparator(Buffer[Pos]))60 ++Pos;61}62 63void FlagParser::parseFlag() {64 const uptr NameStart = Pos;65 while (Buffer[Pos] != '=' && !isSeparatorOrNull(Buffer[Pos]))66 ++Pos;67 if (Buffer[Pos] != '=')68 reportError("expected '='");69 const char *Name = Buffer + NameStart;70 const uptr ValueStart = ++Pos;71 const char *Value;72 if (Buffer[Pos] == '\'' || Buffer[Pos] == '"') {73 const char Quote = Buffer[Pos++];74 while (Buffer[Pos] != 0 && Buffer[Pos] != Quote)75 ++Pos;76 if (Buffer[Pos] == 0)77 reportError("unterminated string");78 Value = Buffer + ValueStart + 1;79 ++Pos; // consume the closing quote80 } else {81 while (!isSeparatorOrNull(Buffer[Pos]))82 ++Pos;83 Value = Buffer + ValueStart;84 }85 if (!runHandler(Name, Value, '='))86 reportError("flag parsing failed.");87}88 89void FlagParser::parseFlags() {90 while (true) {91 skipWhitespace();92 if (Buffer[Pos] == 0)93 break;94 parseFlag();95 }96}97 98void FlagParser::parseString(const char *S) {99 if (!S)100 return;101 // Backup current parser state to allow nested parseString() calls.102 const char *OldBuffer = Buffer;103 const uptr OldPos = Pos;104 Buffer = S;105 Pos = 0;106 107 parseFlags();108 109 Buffer = OldBuffer;110 Pos = OldPos;111}112 113inline bool parseBool(const char *Value, bool *b) {114 if (strncmp(Value, "0", 1) == 0 || strncmp(Value, "no", 2) == 0 ||115 strncmp(Value, "false", 5) == 0) {116 *b = false;117 return true;118 }119 if (strncmp(Value, "1", 1) == 0 || strncmp(Value, "yes", 3) == 0 ||120 strncmp(Value, "true", 4) == 0) {121 *b = true;122 return true;123 }124 return false;125}126 127void FlagParser::parseStringPair(const char *Name, const char *Value) {128 if (!runHandler(Name, Value, '\0'))129 reportError("flag parsing failed.");130}131 132bool FlagParser::runHandler(const char *Name, const char *Value,133 const char Sep) {134 for (u32 I = 0; I < NumberOfFlags; ++I) {135 const uptr Len = strlen(Flags[I].Name);136 if (strncmp(Name, Flags[I].Name, Len) != 0 || Name[Len] != Sep)137 continue;138 bool Ok = false;139 switch (Flags[I].Type) {140 case FlagType::FT_bool:141 Ok = parseBool(Value, reinterpret_cast<bool *>(Flags[I].Var));142 if (!Ok)143 reportInvalidFlag("bool", Value);144 break;145 case FlagType::FT_int:146 char *ValueEnd;147 errno = 0;148 long V = strtol(Value, &ValueEnd, 10);149 if (errno != 0 || // strtol failed (over or underflow)150 V > INT_MAX || V < INT_MIN || // overflows integer151 // contains unexpected characters152 (*ValueEnd != '"' && *ValueEnd != '\'' &&153 !isSeparatorOrNull(*ValueEnd))) {154 reportInvalidFlag("int", Value);155 break;156 }157 *reinterpret_cast<int *>(Flags[I].Var) = static_cast<int>(V);158 Ok = true;159 break;160 }161 return Ok;162 }163 // Unrecognized flag. This is not a fatal error, we may print a warning later.164 UnknownFlags.add(Name);165 return true;166}167 168void FlagParser::registerFlag(const char *Name, const char *Desc, FlagType Type,169 void *Var) {170 CHECK_LT(NumberOfFlags, MaxFlags);171 Flags[NumberOfFlags].Name = Name;172 Flags[NumberOfFlags].Desc = Desc;173 Flags[NumberOfFlags].Type = Type;174 Flags[NumberOfFlags].Var = Var;175 ++NumberOfFlags;176}177 178} // namespace scudo179