libsanitizer/sanitizer_common/sanitizer_flag_parser.cpp

   1 //===-- sanitizer_flag_parser.cpp -----------------------------------------===//
   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-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file is a part of ThreadSanitizer/AddressSanitizer runtime.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "sanitizer_flag_parser.h"
  14
  15 #include "sanitizer_common.h"
  16 #include "sanitizer_flag_parser.h"
  17 #include "sanitizer_flags.h"
  18 #include "sanitizer_libc.h"
  19
  20 namespace __sanitizer {
  21
  22 class UnknownFlags {
  23   static const int kMaxUnknownFlags = 20;
  24   const char *unknown_flags_[kMaxUnknownFlags];
  25   int n_unknown_flags_;
  26
  27  public:
  28   void Add(const char *name) {
  29     CHECK_LT(n_unknown_flags_, kMaxUnknownFlags);
  30     unknown_flags_[n_unknown_flags_++] = name;
  31   }
  32
  33   void Report() {
  34     if (!n_unknown_flags_) return;
  35     Printf("WARNING: found %d unrecognized flag(s):\n", n_unknown_flags_);
  36     for (int i = 0; i < n_unknown_flags_; ++i)
  37       Printf("    %s\n", unknown_flags_[i]);
  38     n_unknown_flags_ = 0;
  39   }
  40 };
  41
  42 UnknownFlags unknown_flags;
  43
  44 void ReportUnrecognizedFlags() {
  45   unknown_flags.Report();
  46 }
  47
  48 char *FlagParser::ll_strndup(const char *s, uptr n) {
  49   uptr len = internal_strnlen(s, n);
  50   char *s2 = (char *)GetGlobalLowLevelAllocator().Allocate(len + 1);
  51   internal_memcpy(s2, s, len);
  52   s2[len] = 0;
  53   return s2;
  54 }
  55
  56 void FlagParser::PrintFlagDescriptions() {
  57   char buffer[128];
  58   buffer[sizeof(buffer) - 1] = '\0';
  59   Printf("Available flags for %s:\n", SanitizerToolName);
  60   for (int i = 0; i < n_flags_; ++i) {
  61     bool truncated = !(flags_[i].handler->Format(buffer, sizeof(buffer)));
  62     CHECK_EQ(buffer[sizeof(buffer) - 1], '\0');
  63     const char *truncation_str = truncated ? " Truncated" : "";
  64     Printf("\t%s\n\t\t- %s (Current Value%s: %s)\n", flags_[i].name,
  65            flags_[i].desc, truncation_str, buffer);
  66   }
  67 }
  68
  69 void FlagParser::fatal_error(const char *err) {
  70   Printf("%s: ERROR: %s\n", SanitizerToolName, err);
  71   Die();
  72 }
  73
  74 bool FlagParser::is_space(char c) {
  75   return c == ' ' || c == ',' || c == ':' || c == '\n' || c == '\t' ||
  76          c == '\r';
  77 }
  78
  79 void FlagParser::skip_whitespace() {
  80   while (is_space(buf_[pos_])) ++pos_;
  81 }
  82
  83 void FlagParser::parse_flag(const char *env_option_name) {
  84   uptr name_start = pos_;
  85   while (buf_[pos_] != 0 && buf_[pos_] != '=' && !is_space(buf_[pos_])) ++pos_;
  86   if (buf_[pos_] != '=') {
  87     if (env_option_name) {
  88       Printf("%s: ERROR: expected '=' in %s\n", SanitizerToolName,
  89              env_option_name);
  90       Die();
  91     } else {
  92       fatal_error("expected '='");
  93     }
  94   }
  95   char *name = ll_strndup(buf_ + name_start, pos_ - name_start);
  96
  97   uptr value_start = ++pos_;
  98   char *value;
  99   if (buf_[pos_] == '\'' || buf_[pos_] == '"') {
 100     char quote = buf_[pos_++];
 101     while (buf_[pos_] != 0 && buf_[pos_] != quote) ++pos_;
 102     if (buf_[pos_] == 0) fatal_error("unterminated string");
 103     value = ll_strndup(buf_ + value_start + 1, pos_ - value_start - 1);
 104     ++pos_; // consume the closing quote
 105   } else {
 106     while (buf_[pos_] != 0 && !is_space(buf_[pos_])) ++pos_;
 107     if (buf_[pos_] != 0 && !is_space(buf_[pos_]))
 108       fatal_error("expected separator or eol");
 109     value = ll_strndup(buf_ + value_start, pos_ - value_start);
 110   }
 111
 112   bool res = run_handler(name, value);
 113   if (!res) fatal_error("Flag parsing failed.");
 114 }
 115
 116 void FlagParser::parse_flags(const char *env_option_name) {
 117   while (true) {
 118     skip_whitespace();
 119     if (buf_[pos_] == 0) break;
 120     parse_flag(env_option_name);
 121   }
 122
 123   // Do a sanity check for certain flags.
 124   if (common_flags_dont_use.malloc_context_size < 1)
 125     common_flags_dont_use.malloc_context_size = 1;
 126 }
 127
 128 void FlagParser::ParseStringFromEnv(const char *env_name) {
 129   const char *env = GetEnv(env_name);
 130   VPrintf(1, "%s: %s\n", env_name, env ? env : "<empty>");
 131   ParseString(env, env_name);
 132 }
 133
 134 void FlagParser::ParseString(const char *s, const char *env_option_name) {
 135   if (!s) return;
 136   // Backup current parser state to allow nested ParseString() calls.
 137   const char *old_buf_ = buf_;
 138   uptr old_pos_ = pos_;
 139   buf_ = s;
 140   pos_ = 0;
 141
 142   parse_flags(env_option_name);
 143
 144   buf_ = old_buf_;
 145   pos_ = old_pos_;
 146 }
 147
 148 bool FlagParser::ParseFile(const char *path, bool ignore_missing) {
 149   static const uptr kMaxIncludeSize = 1 << 15;
 150   char *data;
 151   uptr data_mapped_size;
 152   error_t err;
 153   uptr len;
 154   if (!ReadFileToBuffer(path, &data, &data_mapped_size, &len,
 155                         Max(kMaxIncludeSize, GetPageSizeCached()), &err)) {
 156     if (ignore_missing)
 157       return true;
 158     Printf("Failed to read options from '%s': error %d\n", path, err);
 159     return false;
 160   }
 161   ParseString(data, path);
 162   UnmapOrDie(data, data_mapped_size);
 163   return true;
 164 }
 165
 166 bool FlagParser::run_handler(const char *name, const char *value) {
 167   for (int i = 0; i < n_flags_; ++i) {
 168     if (internal_strcmp(name, flags_[i].name) == 0)
 169       return flags_[i].handler->Parse(value);
 170   }
 171   // Unrecognized flag. This is not a fatal error, we may print a warning later.
 172   unknown_flags.Add(name);
 173   return true;
 174 }
 175
 176 void FlagParser::RegisterHandler(const char *name, FlagHandlerBase *handler,
 177                                  const char *desc) {
 178   CHECK_LT(n_flags_, kMaxFlags);
 179   flags_[n_flags_].name = name;
 180   flags_[n_flags_].desc = desc;
 181   flags_[n_flags_].handler = handler;
 182   ++n_flags_;
 183 }
 184
 185 FlagParser::FlagParser() : n_flags_(0), buf_(nullptr), pos_(0) {
 186   flags_ =
 187       (Flag *)GetGlobalLowLevelAllocator().Allocate(sizeof(Flag) * kMaxFlags);
 188 }
 189
 190 }  // namespace __sanitizer