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Diffstat (limited to 'sdch/open-vcdiff/src/gflags.cc')
| -rw-r--r-- | sdch/open-vcdiff/src/gflags.cc | 1916 |
1 files changed, 1916 insertions, 0 deletions
diff --git a/sdch/open-vcdiff/src/gflags.cc b/sdch/open-vcdiff/src/gflags.cc new file mode 100644 index 0000000..2607997 --- /dev/null +++ b/sdch/open-vcdiff/src/gflags.cc @@ -0,0 +1,1916 @@ +// Copyright (c) 2006, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +// --- +// Author: Ray Sidney +// Revamped and reorganized by Craig Silverstein +// +// This file contains the implementation of all our command line flags +// stuff. Here's how everything fits together +// +// * FlagRegistry owns CommandLineFlags owns FlagValue. +// * FlagSaver holds a FlagRegistry (saves it at construct time, +// restores it at destroy time). +// * CommandLineFlagParser lives outside that hierarchy, but works on +// CommandLineFlags (modifying the FlagValues). +// * Free functions like SetCommandLineOption() work via one of the +// above (such as CommandLineFlagParser). +// +// In more detail: +// +// -- The main classes that hold flag data: +// +// FlagValue holds the current value of a flag. It's +// pseudo-templatized: every operation on a FlagValue is typed. It +// also deals with storage-lifetime issues (so flag values don't go +// away in a destructor), which is why we need a whole class to hold a +// variable's value. +// +// CommandLineFlag is all the information about a single command-line +// flag. It has a FlagValue for the flag's current value, but also +// the flag's name, type, etc. +// +// FlagRegistry is a collection of CommandLineFlags. There's the +// global registry, which is where flags defined via DEFINE_foo() +// live. But it's possible to define your own flag, manually, in a +// different registry you create. (In practice, multiple registries +// are used only by FlagSaver). +// +// A given FlagValue is owned by exactly one CommandLineFlag. A given +// CommandLineFlag is owned by exactly one FlagRegistry. FlagRegistry +// has a lock; any operation that writes to a FlagValue or +// CommandLineFlag owned by that registry must acquire the +// FlagRegistry lock before doing so. +// +// --- Some other classes and free functions: +// +// CommandLineFlagInfo is a client-exposed version of CommandLineFlag. +// Once it's instantiated, it has no dependencies or relationships +// with any other part of this file. +// +// FlagRegisterer is the helper class used by the DEFINE_* macros to +// allow work to be done at global initialization time. +// +// CommandLineFlagParser is the class that reads from the commandline +// and instantiates flag values based on that. It needs to poke into +// the innards of the FlagValue->CommandLineFlag->FlagRegistry class +// hierarchy to do that. It's careful to acquire the FlagRegistry +// lock before doing any writing or other non-const actions. +// +// GetCommandLineOption is just a hook into registry routines to +// retrieve a flag based on its name. SetCommandLineOption, on the +// other hand, hooks into CommandLineFlagParser. Other API functions +// are, similarly, mostly hooks into the functionality described above. + +#include "config.h" +// This comes first to ensure we define __STDC_FORMAT_MACROS in time. +#ifdef HAVE_INTTYPES_H +#ifndef __STDC_FORMAT_MACROS +# define __STDC_FORMAT_MACROS 1 // gcc requires this to get PRId64, etc. +#endif +#include <inttypes.h> +#endif // HAVE_INTTYPES_H +#include <ctype.h> +#include <errno.h> +#include <stdio.h> +#include <stdarg.h> // For va_list and related operations +#include <string.h> +#include <assert.h> +#ifdef HAVE_FNMATCH_H +#include <fnmatch.h> +#endif // HAVE_FNMATCH_H +#include <iostream> // for cerr +#include <string> +#include <map> +#include <vector> +#include <utility> // for pair<> +#include <algorithm> +#include "gflags/gflags.h" +#include "mutex.h" + +#ifndef PATH_SEPARATOR +#define PATH_SEPARATOR '/' +#endif + +// Work properly if either strtoll or strtoq is on this system +#ifdef HAVE_STRTOLL +# define strtoint64 strtoll +# define strtouint64 strtoull +#elif HAVE_STRTOQ +# define strtoint64 strtoq +# define strtouint64 strtouq +#else +// Neither strtoll nor strtoq are defined. I hope strtol works! +# define strtoint64 strtol +# define strtouint64 strtoul +#endif + +// If we have inttypes.h, it will have defined PRId32/etc for us. If +// not, take our best guess. +#ifndef PRId32 +# define PRId32 "d" +#endif +#ifndef PRId64 +# define PRId64 "lld" +#endif +#ifndef PRIu64 +# define PRIu64 "llu" +#endif + +using std::map; +using std::vector; +using std::pair; +using std::cerr; +using std::sort; + +// Special flags, type 1: the 'recursive' flags. They set another flag's val. +DEFINE_string(flagfile, "", + "load flags from file"); +DEFINE_string(fromenv, "", + "set flags from the environment" + " [use 'export FLAGS_flag1=value']"); +DEFINE_string(tryfromenv, "", + "set flags from the environment if present"); + +// Special flags, type 2: the 'parsing' flags. They modify how we parse. +DEFINE_string(undefok, "", + "comma-separated list of flag names that it is okay to specify " + "on the command line even if the program does not define a flag " + "with that name. IMPORTANT: flags in this list that have " + "arguments MUST use the flag=value format"); + +namespace google { + +using std::string; + +// The help message indicating that the commandline flag has been +// 'stripped'. It will not show up when doing "-help" and its +// variants. The flag is stripped if STRIP_FLAG_HELP is set to 1 +// before including gflags/gflags.h. + +// This is used by this file, and also in commandlineflags_reporting.cc +const char kStrippedFlagHelp[] = "\001\002\003\004 (unknown) \004\003\002\001"; + +// This is used by the unittest to test error-exit code +void (*commandlineflags_exitfunc)(int) = &exit; // from stdlib.h + +namespace { + +// There are also 'reporting' flags, in commandlineflags_reporting.cc. + +static const char kError[] = "ERROR: "; + +// Indicates that undefined options are to be ignored. +// Enables deferred processing of flags in dynamically loaded libraries. +static bool allow_command_line_reparsing = false; + +static bool logging_is_probably_set_up = false; + +// This is a 'prototype' validate-function. 'Real' validate +// functions, take a flag-value as an argument: ValidateFn(bool) or +// ValidateFn(uint64). However, for easier storage, we strip off this +// argument and then restore it when actually calling the function on +// a flag value. +typedef bool (*ValidateFnProto)(); + +// Whether we should die when reporting an error. +enum DieWhenReporting { DIE, DO_NOT_DIE }; + +// Report Error and exit if requested. +static void ReportError(DieWhenReporting should_die, const char* format, ...) { + va_list ap; + va_start(ap, format); + vfprintf(stderr, format, ap); + va_end(ap); + if (should_die == DIE) + commandlineflags_exitfunc(1); // almost certainly exit() +} + + +// -------------------------------------------------------------------- +// FlagValue +// This represent the value a single flag might have. The major +// functionality is to convert from a string to an object of a +// given type, and back. Thread-compatible. +// -------------------------------------------------------------------- + +class CommandLineFlag; +class FlagValue { + public: + FlagValue(void* valbuf, const char* type); + ~FlagValue(); + + bool ParseFrom(const char* spec); + string ToString() const; + + private: + friend class CommandLineFlag; // for many things, including Validate() + friend class ::google::FlagSaverImpl; // calls New() + friend class FlagRegistry; // checks value_buffer_ for flags_by_ptr_ map + template <typename T> friend T GetFromEnv(const char*, const char*, T); + friend bool TryParseLocked(const CommandLineFlag*, FlagValue*, + const char*, string*); // for New(), CopyFrom() + + enum ValueType {FV_BOOL, FV_INT32, FV_INT64, FV_UINT64, FV_DOUBLE, FV_STRING}; + + const char* TypeName() const; + bool Equal(const FlagValue& x) const; + FlagValue* New() const; // creates a new one with default value + void CopyFrom(const FlagValue& x); + + // Calls the given validate-fn on value_buffer_, and returns + // whatever it returns. But first casts validate_fn_proto to a + // function that takes our value as an argument (eg void + // (*validate_fn)(bool) for a bool flag). + bool Validate(const char* flagname, ValidateFnProto validate_fn_proto) const; + + void* value_buffer_; // points to the buffer holding our data + ValueType type_; // how to interpret value_ + + FlagValue(const FlagValue&); // no copying! + void operator=(const FlagValue&); +}; + + +// This could be a templated method of FlagValue, but doing so adds to the +// size of the .o. Since there's no type-safety here anyway, macro is ok. +#define VALUE_AS(type) *reinterpret_cast<type*>(value_buffer_) +#define OTHER_VALUE_AS(fv, type) *reinterpret_cast<type*>(fv.value_buffer_) +#define SET_VALUE_AS(type, value) VALUE_AS(type) = (value) + +FlagValue::FlagValue(void* valbuf, const char* type) : value_buffer_(valbuf) { + if (strcmp(type, "bool") == 0) type_ = FV_BOOL; + else if (strcmp(type, "int32") == 0) type_ = FV_INT32; + else if (strcmp(type, "int64") == 0) type_ = FV_INT64; + else if (strcmp(type, "uint64") == 0) type_ = FV_UINT64; + else if (strcmp(type, "double") == 0) type_ = FV_DOUBLE; + else if (strcmp(type, "string") == 0) type_ = FV_STRING; + else assert(false); // Unknown typename +} + +FlagValue::~FlagValue() { + switch (type_) { + case FV_BOOL: delete reinterpret_cast<bool*>(value_buffer_); break; + case FV_INT32: delete reinterpret_cast<int32*>(value_buffer_); break; + case FV_INT64: delete reinterpret_cast<int64*>(value_buffer_); break; + case FV_UINT64: delete reinterpret_cast<uint64*>(value_buffer_); break; + case FV_DOUBLE: delete reinterpret_cast<double*>(value_buffer_); break; + case FV_STRING: delete reinterpret_cast<string*>(value_buffer_); break; + } +} + +bool FlagValue::ParseFrom(const char* value) { + if (type_ == FV_BOOL) { + const char* kTrue[] = { "1", "t", "true", "y", "yes" }; + const char* kFalse[] = { "0", "f", "false", "n", "no" }; + for (size_t i = 0; i < sizeof(kTrue)/sizeof(*kTrue); ++i) { + if (strcasecmp(value, kTrue[i]) == 0) { + SET_VALUE_AS(bool, true); + return true; + } else if (strcasecmp(value, kFalse[i]) == 0) { + SET_VALUE_AS(bool, false); + return true; + } + } + return false; // didn't match a legal input + + } else if (type_ == FV_STRING) { + SET_VALUE_AS(string, value); + return true; + } + + // OK, it's likely to be numeric, and we'll be using a strtoXXX method. + if (value[0] == '\0') // empty-string is only allowed for string type. + return false; + char* end; + // Leading 0x puts us in base 16. But leading 0 does not put us in base 8! + // It caused too many bugs when we had that behavior. + int base = 10; // by default + if (value[0] == '0' && (value[1] == 'x' || value[1] == 'X')) + base = 16; + errno = 0; + + switch (type_) { + case FV_INT32: { + const int64 r = strtoint64(value, &end, base); + if (errno || end != value + strlen(value)) return false; // bad parse + if (static_cast<int32>(r) != r) // worked, but number out of range + return false; + SET_VALUE_AS(int32, static_cast<int32>(r)); + return true; + } + case FV_INT64: { + const int64 r = strtoint64(value, &end, base); + if (errno || end != value + strlen(value)) return false; // bad parse + SET_VALUE_AS(int64, r); + return true; + } + case FV_UINT64: { + while (*value == ' ') value++; + if (*value == '-') return false; // negative number + const uint64 r = strtouint64(value, &end, base); + if (errno || end != value + strlen(value)) return false; // bad parse + SET_VALUE_AS(uint64, r); + return true; + } + case FV_DOUBLE: { + const double r = strtod(value, &end); + if (errno || end != value + strlen(value)) return false; // bad parse + SET_VALUE_AS(double, r); + return true; + } + default: { + assert(false); // unknown type + return false; + } + } +} + +string FlagValue::ToString() const { + char intbuf[64]; // enough to hold even the biggest number + switch (type_) { + case FV_BOOL: + return VALUE_AS(bool) ? "true" : "false"; + case FV_INT32: + snprintf(intbuf, sizeof(intbuf), "%"PRId32, VALUE_AS(int32)); + return intbuf; + case FV_INT64: + snprintf(intbuf, sizeof(intbuf), "%"PRId64, VALUE_AS(int64)); + return intbuf; + case FV_UINT64: + snprintf(intbuf, sizeof(intbuf), "%"PRIu64, VALUE_AS(uint64)); + return intbuf; + case FV_DOUBLE: + snprintf(intbuf, sizeof(intbuf), "%.17g", VALUE_AS(double)); + return intbuf; + case FV_STRING: + return VALUE_AS(string); + default: + assert(false); + return ""; // unknown type + } +} + +bool FlagValue::Validate(const char* flagname, + ValidateFnProto validate_fn_proto) const { + switch (type_) { + case FV_BOOL: + return reinterpret_cast<bool (*)(const char*, bool)>( + validate_fn_proto)(flagname, VALUE_AS(bool)); + case FV_INT32: + return reinterpret_cast<bool (*)(const char*, int32)>( + validate_fn_proto)(flagname, VALUE_AS(int32)); + case FV_INT64: + return reinterpret_cast<bool (*)(const char*, int64)>( + validate_fn_proto)(flagname, VALUE_AS(int64)); + case FV_UINT64: + return reinterpret_cast<bool (*)(const char*, uint64)>( + validate_fn_proto)(flagname, VALUE_AS(uint64)); + case FV_DOUBLE: + return reinterpret_cast<bool (*)(const char*, double)>( + validate_fn_proto)(flagname, VALUE_AS(double)); + case FV_STRING: + return reinterpret_cast<bool (*)(const char*, const string&)>( + validate_fn_proto)(flagname, VALUE_AS(string)); + default: + assert(false); // unknown type + return false; + } +} + +const char* FlagValue::TypeName() const { + switch (type_) { + case FV_BOOL: return "bool"; + case FV_INT32: return "int32"; + case FV_INT64: return "int64"; + case FV_UINT64: return "uint64"; + case FV_DOUBLE: return "double"; + case FV_STRING: return "string"; + default: assert(false); return ""; // unknown type + } +} + +bool FlagValue::Equal(const FlagValue& x) const { + if (type_ != x.type_) + return false; + switch (type_) { + case FV_BOOL: return VALUE_AS(bool) == OTHER_VALUE_AS(x, bool); + case FV_INT32: return VALUE_AS(int32) == OTHER_VALUE_AS(x, int32); + case FV_INT64: return VALUE_AS(int64) == OTHER_VALUE_AS(x, int64); + case FV_UINT64: return VALUE_AS(uint64) == OTHER_VALUE_AS(x, uint64); + case FV_DOUBLE: return VALUE_AS(double) == OTHER_VALUE_AS(x, double); + case FV_STRING: return VALUE_AS(string) == OTHER_VALUE_AS(x, string); + default: assert(false); return false; // unknown type + } +} + +FlagValue* FlagValue::New() const { + switch (type_) { + case FV_BOOL: return new FlagValue(new bool(false), "bool"); + case FV_INT32: return new FlagValue(new int32(0), "int32"); + case FV_INT64: return new FlagValue(new int64(0), "int64"); + case FV_UINT64: return new FlagValue(new uint64(0), "uint64"); + case FV_DOUBLE: return new FlagValue(new double(0.0), "double"); + case FV_STRING: return new FlagValue(new string, "string"); + default: assert(false); return NULL; // unknown type + } +} + +void FlagValue::CopyFrom(const FlagValue& x) { + assert(type_ == x.type_); + switch (type_) { + case FV_BOOL: SET_VALUE_AS(bool, OTHER_VALUE_AS(x, bool)); break; + case FV_INT32: SET_VALUE_AS(int32, OTHER_VALUE_AS(x, int32)); break; + case FV_INT64: SET_VALUE_AS(int64, OTHER_VALUE_AS(x, int64)); break; + case FV_UINT64: SET_VALUE_AS(uint64, OTHER_VALUE_AS(x, uint64)); break; + case FV_DOUBLE: SET_VALUE_AS(double, OTHER_VALUE_AS(x, double)); break; + case FV_STRING: SET_VALUE_AS(string, OTHER_VALUE_AS(x, string)); break; + default: assert(false); // unknown type + } +} + +// -------------------------------------------------------------------- +// CommandLineFlag +// This represents a single flag, including its name, description, +// default value, and current value. Mostly this serves as a +// struct, though it also knows how to register itself. +// All CommandLineFlags are owned by a (exactly one) +// FlagRegistry. If you wish to modify fields in this class, you +// should acquire the FlagRegistry lock for the registry that owns +// this flag. +// -------------------------------------------------------------------- + +class CommandLineFlag { + public: + // Note: we take over memory-ownership of current_val and default_val. + CommandLineFlag(const char* name, const char* help, const char* filename, + FlagValue* current_val, FlagValue* default_val); + ~CommandLineFlag(); + + const char* name() const { return name_; } + const char* help() const { return help_; } + const char* filename() const { return file_; } + const char* CleanFileName() const; // nixes irrelevant prefix such as homedir + string current_value() const { return current_->ToString(); } + string default_value() const { return defvalue_->ToString(); } + const char* type_name() const { return defvalue_->TypeName(); } + ValidateFnProto validate_function() const { return validate_fn_proto_; } + + void FillCommandLineFlagInfo(struct CommandLineFlagInfo* result); + + // If validate_fn_proto_ is non-NULL, calls it on value, returns result. + bool Validate(const FlagValue& value) const; + bool ValidateCurrent() const { return Validate(*current_); } + + private: + // for SetFlagLocked() and setting flags_by_ptr_ + friend class FlagRegistry; + friend class ::google::FlagSaverImpl; // for cloning the values + friend bool GetCommandLineOption(const char*, string*, bool*); + // set validate_fn + friend bool AddFlagValidator(const void*, ValidateFnProto); + + // This copies all the non-const members: modified, processed, defvalue, etc. + void CopyFrom(const CommandLineFlag& src); + + void UpdateModifiedBit(); + + const char* const name_; // Flag name + const char* const help_; // Help message + const char* const file_; // Which file did this come from? + bool modified_; // Set after default assignment? + FlagValue* defvalue_; // Default value for flag + FlagValue* current_; // Current value for flag + // This is a casted, 'generic' version of validate_fn, which actually + // takes a flag-value as an arg (void (*validate_fn)(bool), say). + // When we pass this to current_->Validate(), it will cast it back to + // the proper type. This may be NULL to mean we have no validate_fn. + ValidateFnProto validate_fn_proto_; + + CommandLineFlag(const CommandLineFlag&); // no copying! + void operator=(const CommandLineFlag&); +}; + +CommandLineFlag::CommandLineFlag(const char* name, const char* help, + const char* filename, + FlagValue* current_val, FlagValue* default_val) + : name_(name), help_(help), file_(filename), modified_(false), + defvalue_(default_val), current_(current_val), validate_fn_proto_(NULL) { +} + +CommandLineFlag::~CommandLineFlag() { + delete current_; + delete defvalue_; +} + +const char* CommandLineFlag::CleanFileName() const { + // Compute top-level directory & file that this appears in + // search full path backwards. + // Stop going backwards at kRootDir; and skip by the first slash. + static const char kRootDir[] = ""; // can set this to root directory, + // e.g. "myproject" + + if (sizeof(kRootDir)-1 == 0) // no prefix to strip + return filename(); + + const char* clean_name = filename() + strlen(filename()) - 1; + while ( clean_name > filename() ) { + if (*clean_name == PATH_SEPARATOR) { + if (strncmp(clean_name, kRootDir, sizeof(kRootDir)-1) == 0) { + // ".../myproject/base/logging.cc" ==> "base/logging.cc" + clean_name += sizeof(kRootDir)-1; // past "/myproject/" + break; + } + } + --clean_name; + } + while ( *clean_name == PATH_SEPARATOR ) ++clean_name; // Skip any slashes + return clean_name; +} + +void CommandLineFlag::FillCommandLineFlagInfo( + CommandLineFlagInfo* result) { + result->name = name(); + result->type = type_name(); + result->description = help(); + result->current_value = current_value(); + result->default_value = default_value(); + result->filename = CleanFileName(); + UpdateModifiedBit(); + result->is_default = !modified_; + result->has_validator_fn = validate_function() != NULL; +} + +void CommandLineFlag::UpdateModifiedBit() { + // Update the "modified" bit in case somebody bypassed the + // Flags API and wrote directly through the FLAGS_name variable. + if (!modified_ && !current_->Equal(*defvalue_)) { + modified_ = true; + } +} + +void CommandLineFlag::CopyFrom(const CommandLineFlag& src) { + // Note we only copy the non-const members; others are fixed at construct time + if (modified_ != src.modified_) modified_ = src.modified_; + if (!current_->Equal(*src.current_)) current_->CopyFrom(*src.current_); + if (!defvalue_->Equal(*src.defvalue_)) defvalue_->CopyFrom(*src.defvalue_); + if (validate_fn_proto_ != src.validate_fn_proto_) + validate_fn_proto_ = src.validate_fn_proto_; +} + +bool CommandLineFlag::Validate(const FlagValue& value) const { + if (validate_function() == NULL) + return true; + else + return value.Validate(name(), validate_function()); +} + + +// -------------------------------------------------------------------- +// FlagRegistry +// A FlagRegistry singleton object holds all flag objects indexed +// by their names so that if you know a flag's name (as a C +// string), you can access or set it. If the function is named +// FooLocked(), you must own the registry lock before calling +// the function; otherwise, you should *not* hold the lock, and +// the function will acquire it itself if needed. +// -------------------------------------------------------------------- + +struct StringCmp { // Used by the FlagRegistry map class to compare char*'s + bool operator() (const char* s1, const char* s2) const { + return (strcmp(s1, s2) < 0); + } +}; + +class FlagRegistry { + public: + FlagRegistry() { } + + void Lock() { lock_.Lock(); } + void Unlock() { lock_.Unlock(); } + + // Store a flag in this registry. Takes ownership of the given pointer. + void RegisterFlag(CommandLineFlag* flag); + + // Returns the flag object for the specified name, or NULL if not found. + CommandLineFlag* FindFlagLocked(const char* name); + + // Returns the flag object whose current-value is stored at flag_ptr. + // That is, for whom current_->value_buffer_ == flag_ptr + CommandLineFlag* FindFlagViaPtrLocked(const void* flag_ptr); + + // A fancier form of FindFlag that works correctly if name is of the + // form flag=value. In that case, we set key to point to flag, and + // modify v to point to the value (if present), and return the flag + // with the given name. If the flag does not exist, returns NULL + // and sets error_message. + CommandLineFlag* SplitArgumentLocked(const char* argument, + string* key, const char** v, + string* error_message); + + // Set the value of a flag. If the flag was successfully set to + // value, set msg to indicate the new flag-value, and return true. + // Otherwise, set msg to indicate the error, leave flag unchanged, + // and return false. msg can be NULL. + bool SetFlagLocked(CommandLineFlag* flag, const char* value, + FlagSettingMode set_mode, string* msg); + + static FlagRegistry* GlobalRegistry(); // returns a singleton registry + + private: + friend class ::google::FlagSaverImpl; // reads all the flags in order to copy them + friend class CommandLineFlagParser; // for ValidateAllFlags + friend void ::google::GetAllFlags(vector<CommandLineFlagInfo>*); + + // The map from name to flag, for FindFlagLocked(). + typedef map<const char*, CommandLineFlag*, StringCmp> FlagMap; + typedef FlagMap::iterator FlagIterator; + typedef FlagMap::const_iterator FlagConstIterator; + FlagMap flags_; + + // The map from current-value pointer to flag, fo FindFlagViaPtrLocked(). + typedef map<const void*, CommandLineFlag*> FlagPtrMap; + FlagPtrMap flags_by_ptr_; + + Mutex lock_; + + static FlagRegistry* global_registry_; // a singleton registry + static Mutex global_registry_lock_; // guards creation of global_registry_ + + // Disallow + FlagRegistry(const FlagRegistry&); + FlagRegistry& operator=(const FlagRegistry&); +}; + +FlagRegistry* FlagRegistry::global_registry_ = NULL; +Mutex FlagRegistry::global_registry_lock_; + +FlagRegistry* FlagRegistry::GlobalRegistry() { + MutexLock acquire_lock(&global_registry_lock_); + if (!global_registry_) { + global_registry_ = new FlagRegistry; + } + return global_registry_; +} + +void FlagRegistry::RegisterFlag(CommandLineFlag* flag) { + Lock(); + pair<FlagIterator, bool> ins = + flags_.insert(pair<const char*, CommandLineFlag*>(flag->name(), flag)); + if (ins.second == false) { // means the name was already in the map + if (strcmp(ins.first->second->filename(), flag->filename()) != 0) { + ReportError(DIE, "ERROR: flag '%s' was defined more than once " + "(in files '%s' and '%s').\n", + flag->name(), + ins.first->second->filename(), + flag->filename()); + } else { + ReportError(DIE, "ERROR: something wrong with flag '%s' in file '%s'. " + "One possibility: file '%s' is being linked both statically " + "and dynamically into this executable.\n", + flag->name(), + flag->filename(), flag->filename()); + } + } + // Also add to the flags_by_ptr_ map. + flags_by_ptr_[flag->current_->value_buffer_] = flag; + Unlock(); +} + +CommandLineFlag* FlagRegistry::FindFlagLocked(const char* name) { + FlagConstIterator i = flags_.find(name); + if (i == flags_.end()) { + return NULL; + } else { + return i->second; + } +} + +CommandLineFlag* FlagRegistry::FindFlagViaPtrLocked(const void* flag_ptr) { + FlagPtrMap::const_iterator i = flags_by_ptr_.find(flag_ptr); + if (i == flags_by_ptr_.end()) { + return NULL; + } else { + return i->second; + } +} + +CommandLineFlag* FlagRegistry::SplitArgumentLocked(const char* arg, + string* key, + const char** v, + string* error_message) { + // Find the flag object for this option + const char* flag_name; + const char* value = strchr(arg, '='); + if (value == NULL) { + key->assign(arg); + *v = NULL; + } else { + // Strip out the "=value" portion from arg + key->assign(arg, value-arg); + *v = ++value; // advance past the '=' + } + flag_name = key->c_str(); + + CommandLineFlag* flag = FindFlagLocked(flag_name); + + if (flag == NULL) { + // If we can't find the flag-name, then we should return an error. + // The one exception is if 1) the flag-name is 'nox', 2) there + // exists a flag named 'x', and 3) 'x' is a boolean flag. + // In that case, we want to return flag 'x'. + if (!(flag_name[0] == 'n' && flag_name[1] == 'o')) { + // flag-name is not 'nox', so we're not in the exception case. + *error_message = (string(kError) + + "unknown command line flag '" + *key + "'\n"); + return NULL; + } + flag = FindFlagLocked(flag_name+2); + if (flag == NULL) { + // No flag named 'x' exists, so we're not in the exception case. + *error_message = (string(kError) + + "unknown command line flag '" + *key + "'\n"); + return NULL; + } + if (strcmp(flag->type_name(), "bool") != 0) { + // 'x' exists but is not boolean, so we're not in the exception case. + *error_message = (string(kError) + + "boolean value (" + *key + ") specified for " + + flag->type_name() + " command line flag\n"); + return NULL; + } + // We're in the exception case! + // Make up a fake value to replace the "no" we stripped out + key->assign(flag_name+2); // the name without the "no" + *v = "0"; + } + + // Assign a value if this is a boolean flag + if (*v == NULL && strcmp(flag->type_name(), "bool") == 0) { + *v = "1"; // the --nox case was already handled, so this is the --x case + } + + return flag; +} + +bool TryParseLocked(const CommandLineFlag* flag, FlagValue* flag_value, + const char* value, string* msg) { + // Use tenative_value, not flag_value, until we know value is valid. + FlagValue* tentative_value = flag_value->New(); + if (!tentative_value->ParseFrom(value)) { + if (msg) { + *msg += (string(kError) + "illegal value '" + value + + + "' specified for " + flag->type_name() + " flag '" + + flag->name() + "'\n"); + } + delete tentative_value; + return false; + } else if (!flag->Validate(*tentative_value)) { + if (msg) { + *msg += (string(kError) + "failed validation of new value " + + "'" + tentative_value->ToString() + "' for flag '" + + + flag->name() + "'\n"); + } + delete tentative_value; + return false; + } else { + flag_value->CopyFrom(*tentative_value); + if (msg) { + *msg += (string(flag->name()) + " set to " + flag_value->ToString() + + "\n"); + } + delete tentative_value; + return true; + } +} + +bool FlagRegistry::SetFlagLocked(CommandLineFlag* flag, + const char* value, + FlagSettingMode set_mode, + string* msg) { + flag->UpdateModifiedBit(); + switch (set_mode) { + case SET_FLAGS_VALUE: { + // set or modify the flag's value + if (!TryParseLocked(flag, flag->current_, value, msg)) + return false; + flag->modified_ = true; + break; + } + case SET_FLAG_IF_DEFAULT: { + // set the flag's value, but only if it hasn't been set by someone else + if (!flag->modified_) { + if (!TryParseLocked(flag, flag->current_, value, msg)) + return false; + flag->modified_ = true; + } else { + *msg = string(flag->name()) + " set to " + flag->current_value(); + } + break; + } + case SET_FLAGS_DEFAULT: { + // modify the flag's default-value + if (!TryParseLocked(flag, flag->defvalue_, value, msg)) + return false; + if (!flag->modified_) { + // Need to set both defvalue *and* current, in this case + TryParseLocked(flag, flag->current_, value, NULL); + } + break; + } + default: { + // unknown set_mode + assert(false); + return false; + } + } + + return true; +} + +class FlagRegistryLock { + public: + explicit FlagRegistryLock(FlagRegistry* fr) : fr_(fr) { fr_->Lock(); } + ~FlagRegistryLock() { fr_->Unlock(); } + private: + FlagRegistry *const fr_; +}; + +// -------------------------------------------------------------------- +// CommandLineFlagParser +// Parsing is done in two stages. In the first, we go through +// argv. For every flag-like arg we can make sense of, we parse +// it and set the appropriate FLAGS_* variable. For every flag- +// like arg we can't make sense of, we store it in a vector, +// along with an explanation of the trouble. In stage 2, we +// handle the 'reporting' flags like --help and --mpm_version. +// (This is via a call to HandleCommandLineHelpFlags(), in +// gflags_reporting.cc.) +// An optional stage 3 prints out the error messages. +// This is a bit of a simplification. For instance, --flagfile +// is handled as soon as it's seen in stage 1, not in stage 2. +// -------------------------------------------------------------------- + +class CommandLineFlagParser { + public: + // The argument is the flag-registry to register the parsed flags in + explicit CommandLineFlagParser(FlagRegistry* reg) : registry_(reg) {} + ~CommandLineFlagParser() {} + + // Stage 1: Every time this is called, it reads all flags in argv. + // However, it ignores all flags that have been successfully set + // before. Typically this is only called once, so this 'reparsing' + // behavior isn't important. It can be useful when trying to + // reparse after loading a dll, though. + uint32 ParseNewCommandLineFlags(int* argc, char*** argv, bool remove_flags); + + // Stage 2: print reporting info and exit, if requested. + // In gflags_reporting.cc:HandleCommandLineHelpFlags(). + + // Stage 3: validate all the commandline flags that have validators + // registered. + void ValidateAllFlags(); + + // Stage 4: report any errors and return true if any were found. + bool ReportErrors(); + + // Set a particular command line option. "newval" is a string + // describing the new value that the option has been set to. If + // option_name does not specify a valid option name, or value is not + // a valid value for option_name, newval is empty. Does recursive + // processing for --flagfile and --fromenv. Returns the new value + // if everything went ok, or empty-string if not. (Actually, the + // return-string could hold many flag/value pairs due to --flagfile.) + // NB: Must have called registry_->Lock() before calling this function. + string ProcessSingleOptionLocked(CommandLineFlag* flag, + const char* value, + FlagSettingMode set_mode); + + // Set a whole batch of command line options as specified by contentdata, + // which is in flagfile format (and probably has been read from a flagfile). + // Returns the new value if everything went ok, or empty-string if + // not. (Actually, the return-string could hold many flag/value + // pairs due to --flagfile.) + // NB: Must have called registry_->Lock() before calling this function. + string ProcessOptionsFromStringLocked(const string& contentdata, + FlagSettingMode set_mode); + + // These are the 'recursive' flags, defined at the top of this file. + // Whenever we see these flags on the commandline, we must take action. + // These are called by ProcessSingleOptionLocked and, similarly, return + // new values if everything went ok, or the empty-string if not. + string ProcessFlagfileLocked(const string& flagval, FlagSettingMode set_mode); + // diff fromenv/tryfromenv + string ProcessFromenvLocked(const string& flagval, FlagSettingMode set_mode, + bool errors_are_fatal); + + private: + FlagRegistry* const registry_; + map<string, string> error_flags_; // map from name to error message + // This could be a set<string>, but we reuse the map to minimize the .o size + map<string, string> undefined_names_; // --[flag] name was not registered +}; + + +// Parse a list of (comma-separated) flags. +static void ParseFlagList(const char* value, vector<string>* flags) { + for (const char *p = value; p && *p; value = p) { + p = strchr(value, ','); + int len; + if (p) { + len = static_cast<int>(p - value); + p++; + } else { + len = static_cast<int>(strlen(value)); + } + + if (len == 0) + ReportError(DIE, "ERROR: empty flaglist entry\n"); + if (value[0] == '-') + ReportError(DIE, "ERROR: flag \"%*s\" begins with '-'\n", len, value); + + flags->push_back(string(value, len)); + } +} + +// Snarf an entire file into a C++ string. This is just so that we +// can do all the I/O in one place and not worry about it everywhere. +// Plus, it's convenient to have the whole file contents at hand. +// Adds a newline at the end of the file. +#define PFATAL(s) do { perror(s); commandlineflags_exitfunc(1); } while (0) + +static string ReadFileIntoString(const char* filename) { + const int kBufSize = 8092; + char buffer[kBufSize]; + string s; + FILE* fp = fopen(filename, "r"); + if (!fp) PFATAL(filename); + size_t n; + while ( (n=fread(buffer, 1, kBufSize, fp)) > 0 ) { + if (ferror(fp)) PFATAL(filename); + s.append(buffer, n); + } + fclose(fp); + return s; +} + +uint32 CommandLineFlagParser::ParseNewCommandLineFlags(int* argc, char*** argv, + bool remove_flags) { + const char *program_name = strrchr((*argv)[0], PATH_SEPARATOR); // nix path + program_name = (program_name == NULL ? (*argv)[0] : program_name+1); + + int first_nonopt = *argc; // for non-options moved to the end + + registry_->Lock(); + for (int i = 1; i < first_nonopt; i++) { + char* arg = (*argv)[i]; + + // Like getopt(), we permute non-option flags to be at the end. + if (arg[0] != '-' || // must be a program argument + (arg[0] == '-' && arg[1] == '\0')) { // "-" is an argument, not a flag + memmove((*argv) + i, (*argv) + i+1, (*argc - (i+1)) * sizeof((*argv)[i])); + (*argv)[*argc-1] = arg; // we go last + first_nonopt--; // we've been pushed onto the stack + i--; // to undo the i++ in the loop + continue; + } + + if (arg[0] == '-') arg++; // allow leading '-' + if (arg[0] == '-') arg++; // or leading '--' + + // -- alone means what it does for GNU: stop options parsing + if (*arg == '\0') { + first_nonopt = i+1; + break; + } + + // Find the flag object for this option + string key; + const char* value; + string error_message; + CommandLineFlag* flag = registry_->SplitArgumentLocked(arg, &key, &value, + &error_message); + if (flag == NULL) { + undefined_names_[key] = ""; // value isn't actually used + error_flags_[key] = error_message; + continue; + } + + if (value == NULL) { + // Boolean options are always assigned a value by SplitArgumentLocked() + assert(strcmp(flag->type_name(), "bool") != 0); + if (i+1 >= first_nonopt) { + // This flag needs a value, but there is nothing available + error_flags_[key] = (string(kError) + "flag '" + (*argv)[i] + "'" + + " is missing its argument"); + if (flag->help() && flag->help()[0] > '\001') { + // Be useful in case we have a non-stripped description. + error_flags_[key] += string("; flag description: ") + flag->help(); + } + error_flags_[key] += "\n"; + break; // we treat this as an unrecoverable error + } else { + value = (*argv)[++i]; // read next arg for value + + // Heuristic to detect the case where someone treats a string arg + // like a bool: + // --my_string_var --foo=bar + // We look for a flag of string type, whose value begins with a + // dash, and where the flag-name and value are separated by a + // space rather than an '='. + // To avoid false positives, we also require the word "true" + // or "false" in the help string. Without this, a valid usage + // "-lat -30.5" would trigger the warning. The common cases we + // want to solve talk about true and false as values. + if (value[0] == '-' + && strcmp(flag->type_name(), "string") == 0 + && (strstr(flag->help(), "true") + || strstr(flag->help(), "false"))) { + fprintf(stderr, "Did you really mean to set flag '%s'" + " to the value '%s'?\n", + flag->name(), value); + } + } + } + + // TODO(csilvers): only set a flag if we hadn't set it before here + ProcessSingleOptionLocked(flag, value, SET_FLAGS_VALUE); + } + registry_->Unlock(); + + if (remove_flags) { // Fix up argc and argv by removing command line flags + (*argv)[first_nonopt-1] = (*argv)[0]; + (*argv) += (first_nonopt-1); + (*argc) -= (first_nonopt-1); + first_nonopt = 1; // because we still don't count argv[0] + } + + logging_is_probably_set_up = true; // because we've parsed --logdir, etc. + + return first_nonopt; +} + +string CommandLineFlagParser::ProcessFlagfileLocked(const string& flagval, + FlagSettingMode set_mode) { + if (flagval.empty()) + return ""; + + string msg; + vector<string> filename_list; + ParseFlagList(flagval.c_str(), &filename_list); // take a list of filenames + for (size_t i = 0; i < filename_list.size(); ++i) { + const char* file = filename_list[i].c_str(); + msg += ProcessOptionsFromStringLocked(ReadFileIntoString(file), set_mode); + } + return msg; +} + +string CommandLineFlagParser::ProcessFromenvLocked(const string& flagval, + FlagSettingMode set_mode, + bool errors_are_fatal) { + if (flagval.empty()) + return ""; + + string msg; + vector<string> flaglist; + ParseFlagList(flagval.c_str(), &flaglist); + + for (size_t i = 0; i < flaglist.size(); ++i) { + const char* flagname = flaglist[i].c_str(); + CommandLineFlag* flag = registry_->FindFlagLocked(flagname); + if (flag == NULL) { + error_flags_[flagname] = (string(kError) + "unknown command line flag" + + " '" + flagname + "'" + + " (via --fromenv or --tryfromenv)\n"); + undefined_names_[flagname] = ""; + continue; + } + + const string envname = string("FLAGS_") + string(flagname); + const char* envval = getenv(envname.c_str()); + if (!envval) { + if (errors_are_fatal) { + error_flags_[flagname] = (string(kError) + envname + + " not found in environment\n"); + } + continue; + } + + // Avoid infinite recursion. + if ((strcmp(envval, "fromenv") == 0) || + (strcmp(envval, "tryfromenv") == 0)) { + error_flags_[flagname] = (string(kError) + "infinite recursion on " + + "environment flag '" + envval + "'\n"); + continue; + } + + msg += ProcessSingleOptionLocked(flag, envval, set_mode); + } + return msg; +} + +string CommandLineFlagParser::ProcessSingleOptionLocked( + CommandLineFlag* flag, const char* value, FlagSettingMode set_mode) { + string msg; + if (value && !registry_->SetFlagLocked(flag, value, set_mode, &msg)) { + error_flags_[flag->name()] = msg; + return ""; + } + + // The recursive flags, --flagfile and --fromenv and --tryfromenv, + // must be dealt with as soon as they're seen. They will emit + // messages of their own. + if (strcmp(flag->name(), "flagfile") == 0) { + msg += ProcessFlagfileLocked(FLAGS_flagfile, set_mode); + + } else if (strcmp(flag->name(), "fromenv") == 0) { + // last arg indicates envval-not-found is fatal (unlike in --tryfromenv) + msg += ProcessFromenvLocked(FLAGS_fromenv, set_mode, true); + + } else if (strcmp(flag->name(), "tryfromenv") == 0) { + msg += ProcessFromenvLocked(FLAGS_tryfromenv, set_mode, false); + } + + return msg; +} + +void CommandLineFlagParser::ValidateAllFlags() { + FlagRegistryLock frl(registry_); + for (FlagRegistry::FlagConstIterator i = registry_->flags_.begin(); + i != registry_->flags_.end(); ++i) { + if (!i->second->ValidateCurrent()) { + // only set a message if one isn't already there. (If there's + // an error message, our job is done, even if it's not exactly + // the same error.) + if (error_flags_[i->second->name()].empty()) + error_flags_[i->second->name()] = + string(kError) + "--" + i->second->name() + + " must be set on the commandline" + " (default value fails validation)\n"; + } + } +} + +bool CommandLineFlagParser::ReportErrors() { + // error_flags_ indicates errors we saw while parsing. + // But we ignore undefined-names if ok'ed by --undef_ok + if (!FLAGS_undefok.empty()) { + vector<string> flaglist; + ParseFlagList(FLAGS_undefok.c_str(), &flaglist); + for (size_t i = 0; i < flaglist.size(); ++i) { + // We also deal with --no<flag>, in case the flagname was boolean + const string no_version = string("no") + flaglist[i]; + if (undefined_names_.find(flaglist[i]) != undefined_names_.end()) { + error_flags_[flaglist[i]] = ""; // clear the error message + } else if (undefined_names_.find(no_version) != undefined_names_.end()) { + error_flags_[no_version] = ""; + } + } + } + // Likewise, if they decided to allow reparsing, all undefined-names + // are ok; we just silently ignore them now, and hope that a future + // parse will pick them up somehow. + if (allow_command_line_reparsing) { + for (map<string, string>::const_iterator it = undefined_names_.begin(); + it != undefined_names_.end(); ++it) + error_flags_[it->first] = ""; // clear the error message + } + + bool found_error = false; + string error_message; + for (map<string, string>::const_iterator it = error_flags_.begin(); + it != error_flags_.end(); ++it) { + if (!it->second.empty()) { + error_message.append(it->second.data(), it->second.size()); + found_error = true; + } + } + if (found_error) + ReportError(DO_NOT_DIE, "%s", error_message.c_str()); + return found_error; +} + +string CommandLineFlagParser::ProcessOptionsFromStringLocked( + const string& contentdata, FlagSettingMode set_mode) { + string retval; + const char* flagfile_contents = contentdata.c_str(); + bool flags_are_relevant = true; // set to false when filenames don't match + bool in_filename_section = false; + + const char* line_end = flagfile_contents; + // We read this file a line at a time. + for (; line_end; flagfile_contents = line_end + 1) { + while (*flagfile_contents && isspace(*flagfile_contents)) + ++flagfile_contents; + line_end = strchr(flagfile_contents, '\n'); + size_t len = line_end ? static_cast<size_t>(line_end - flagfile_contents) + : strlen(flagfile_contents); + string line(flagfile_contents, len); + + // Each line can be one of four things: + // 1) A comment line -- we skip it + // 2) An empty line -- we skip it + // 3) A list of filenames -- starts a new filenames+flags section + // 4) A --flag=value line -- apply if previous filenames match + if (line.empty() || line[0] == '#') { + // comment or empty line; just ignore + + } else if (line[0] == '-') { // flag + in_filename_section = false; // instead, it was a flag-line + if (!flags_are_relevant) // skip this flag; applies to someone else + continue; + + const char* name_and_val = line.c_str() + 1; // skip the leading - + if (*name_and_val == '-') + name_and_val++; // skip second - too + string key; + const char* value; + string error_message; + CommandLineFlag* flag = registry_->SplitArgumentLocked(name_and_val, + &key, &value, + &error_message); + // By API, errors parsing flagfile lines are silently ignored. + if (flag == NULL) { + // "WARNING: flagname '" + key + "' not found\n" + } else if (value == NULL) { + // "WARNING: flagname '" + key + "' missing a value\n" + } else { + retval += ProcessSingleOptionLocked(flag, value, set_mode); + } + + } else { // a filename! + if (!in_filename_section) { // start over: assume filenames don't match + in_filename_section = true; + flags_are_relevant = false; + } + + // Split the line up at spaces into glob-patterns + const char* space = line.c_str(); // just has to be non-NULL + for (const char* word = line.c_str(); *space; word = space+1) { + if (flags_are_relevant) // we can stop as soon as we match + break; + space = strchr(word, ' '); + if (space == NULL) + space = word + strlen(word); + const string glob(word, space - word); + // We try matching both against the full argv0 and basename(argv0) +#ifdef HAVE_FNMATCH_H + if (fnmatch(glob.c_str(), + ProgramInvocationName(), + FNM_PATHNAME) == 0 || + fnmatch(glob.c_str(), + ProgramInvocationShortName(), + FNM_PATHNAME) == 0) { +#else // !HAVE_FNMATCH_H + if ((glob == ProgramInvocationName()) || + (glob == ProgramInvocationShortName())) { +#endif // HAVE_FNMATCH_H + flags_are_relevant = true; + } + } + } + } + return retval; +} + +// -------------------------------------------------------------------- +// GetFromEnv() +// AddFlagValidator() +// These are helper functions for routines like BoolFromEnv() and +// RegisterFlagValidator, defined below. They're defined here so +// they can live in the unnamed namespace (which makes friendship +// declarations for these classes possible). +// -------------------------------------------------------------------- + +template<typename T> +T GetFromEnv(const char *varname, const char* type, T dflt) { + const char* const valstr = getenv(varname); + if (!valstr) + return dflt; + FlagValue ifv(new T, type); + if (!ifv.ParseFrom(valstr)) + ReportError(DIE, "ERROR: error parsing env variable '%s' with value '%s'\n", + varname, valstr); + return OTHER_VALUE_AS(ifv, T); +} + +bool AddFlagValidator(const void* flag_ptr, ValidateFnProto validate_fn_proto) { + // We want a lock around this routine, in case two threads try to + // add a validator (hopefully the same one!) at once. We could use + // our own thread, but we need to loook at the registry anyway, so + // we just steal that one. + FlagRegistry* const registry = FlagRegistry::GlobalRegistry(); + FlagRegistryLock frl(registry); + // First, find the flag whose current-flag storage is 'flag'. + // This is the CommandLineFlag whose current_->value_buffer_ == flag + CommandLineFlag* flag = registry->FindFlagViaPtrLocked(flag_ptr); + if (!flag) { + // WARNING << "Ignoring RegisterValidateFunction() for flag pointer " + // << flag_ptr << ": no flag found at that address"; + return false; + } else if (validate_fn_proto == flag->validate_function()) { + return true; // ok to register the same function over and over again + } else if (validate_fn_proto != NULL && flag->validate_function() != NULL) { + // WARNING << "Ignoring RegisterValidateFunction() for flag '" + // << flag->name() << "': validate-fn already registered"; + return false; + } else { + flag->validate_fn_proto_ = validate_fn_proto; + return true; + } +} + +} // end unnamed namespaces + + +// Now define the functions that are exported via the .h file + +// -------------------------------------------------------------------- +// FlagRegisterer +// This class exists merely to have a global constructor (the +// kind that runs before main(), that goes an initializes each +// flag that's been declared. Note that it's very important we +// don't have a destructor that deletes flag_, because that would +// cause us to delete current_storage/defvalue_storage as well, +// which can cause a crash if anything tries to access the flag +// values in a global destructor. +// -------------------------------------------------------------------- + +// TODO(csilvers): When we're ready to have this error be a fatal one, +// change this to give a compilation error (via COMPILE_ASSERT(false)). +bool FlagsTypeWarn(const char *name) { + cerr << "Flag " << name << " is of type bool, but its default" + << " value is not a boolean. NOTE: This will soon be a" + << " compilations error!"; + return false; +} + +FlagRegisterer::FlagRegisterer(const char* name, const char* type, + const char* help, const char* filename, + void* current_storage, void* defvalue_storage) { + if (help == NULL) + help = ""; + // FlagValue expects the type-name to not include any namespace + // components, so we get rid of those, if any. + if (strchr(type, ':')) + type = strrchr(type, ':') + 1; + FlagValue* current = new FlagValue(current_storage, type); + FlagValue* defvalue = new FlagValue(defvalue_storage, type); + // Importantly, flag_ will never be deleted, so storage is always good. + CommandLineFlag* flag = new CommandLineFlag(name, help, filename, + current, defvalue); + FlagRegistry::GlobalRegistry()->RegisterFlag(flag); // default registry +} + +// -------------------------------------------------------------------- +// GetAllFlags() +// The main way the FlagRegistry class exposes its data. This +// returns, as strings, all the info about all the flags in +// the main registry, sorted first by filename they are defined +// in, and then by flagname. +// -------------------------------------------------------------------- + +struct FilenameFlagnameCmp { + bool operator()(const CommandLineFlagInfo& a, + const CommandLineFlagInfo& b) const { + int cmp = strcmp(a.filename.c_str(), b.filename.c_str()); + if (cmp == 0) + cmp = strcmp(a.name.c_str(), b.name.c_str()); // secondary sort key + return cmp < 0; + } +}; + +void GetAllFlags(vector<CommandLineFlagInfo>* OUTPUT) { + FlagRegistry* const registry = FlagRegistry::GlobalRegistry(); + registry->Lock(); + for (FlagRegistry::FlagConstIterator i = registry->flags_.begin(); + i != registry->flags_.end(); ++i) { + CommandLineFlagInfo fi; + i->second->FillCommandLineFlagInfo(&fi); + OUTPUT->push_back(fi); + } + registry->Unlock(); + // Now sort the flags, first by filename they occur in, then alphabetically + sort(OUTPUT->begin(), OUTPUT->end(), FilenameFlagnameCmp()); +} + +// -------------------------------------------------------------------- +// SetArgv() +// GetArgvs() +// GetArgv() +// GetArgv0() +// ProgramInvocationName() +// ProgramInvocationShortName() +// SetUsageMessage() +// ProgramUsage() +// Functions to set and get argv. Typically the setter is called +// by ParseCommandLineFlags. Also can get the ProgramUsage string, +// set by SetUsageMessage. +// -------------------------------------------------------------------- + +// These values are not protected by a Mutex because they are normally +// set only once during program startup. +static const char* argv0 = "UNKNOWN"; // just the program name +static const char* cmdline = ""; // the entire command-line +static vector<string> argvs; +static uint32 argv_sum = 0; +static const char* program_usage = NULL; + +void SetArgv(int argc, const char** argv) { + static bool called_set_argv = false; + if (called_set_argv) // we already have an argv for you + return; + + called_set_argv = true; + + assert(argc > 0); // every program has at least a progname + argv0 = strdup(argv[0]); // small memory leak, but fn only called once + assert(argv0); + + string cmdline_string; // easier than doing strcats + for (int i = 0; i < argc; i++) { + if (i != 0) { + cmdline_string += " "; + } + cmdline_string += argv[i]; + argvs.push_back(argv[i]); + } + cmdline = strdup(cmdline_string.c_str()); // another small memory leak + assert(cmdline); + + // Compute a simple sum of all the chars in argv + for (const char* c = cmdline; *c; c++) + argv_sum += *c; +} + +const vector<string>& GetArgvs() { return argvs; } +const char* GetArgv() { return cmdline; } +const char* GetArgv0() { return argv0; } +uint32 GetArgvSum() { return argv_sum; } +const char* ProgramInvocationName() { // like the GNU libc fn + return GetArgv0(); +} +const char* ProgramInvocationShortName() { // like the GNU libc fn + const char* slash = strrchr(argv0, '/'); +#ifdef OS_WINDOWS + if (!slash) slash = strrchr(argv0, '\\'); +#endif + return slash ? slash + 1 : argv0; +} + +void SetUsageMessage(const string& usage) { + if (program_usage != NULL) + ReportError(DIE, "ERROR: SetUsageMessage() called twice\n"); + program_usage = strdup(usage.c_str()); // small memory leak +} + +const char* ProgramUsage() { + if (program_usage) { + return program_usage; + } + return "Warning: SetUsageMessage() never called"; +} + +// -------------------------------------------------------------------- +// GetCommandLineOption() +// GetCommandLineFlagInfo() +// GetCommandLineFlagInfoOrDie() +// SetCommandLineOption() +// SetCommandLineOptionWithMode() +// The programmatic way to set a flag's value, using a string +// for its name rather than the variable itself (that is, +// SetCommandLineOption("foo", x) rather than FLAGS_foo = x). +// There's also a bit more flexibility here due to the various +// set-modes, but typically these are used when you only have +// that flag's name as a string, perhaps at runtime. +// All of these work on the default, global registry. +// For GetCommandLineOption, return false if no such flag +// is known, true otherwise. We clear "value" if a suitable +// flag is found. +// -------------------------------------------------------------------- + + +bool GetCommandLineOption(const char* name, string* value) { + if (NULL == name) + return false; + assert(value); + + FlagRegistry* const registry = FlagRegistry::GlobalRegistry(); + FlagRegistryLock frl(registry); + CommandLineFlag* flag = registry->FindFlagLocked(name); + if (flag == NULL) { + return false; + } else { + *value = flag->current_value(); + return true; + } +} + +bool GetCommandLineFlagInfo(const char* name, CommandLineFlagInfo* OUTPUT) { + if (NULL == name) return false; + FlagRegistry* const registry = FlagRegistry::GlobalRegistry(); + FlagRegistryLock frl(registry); + CommandLineFlag* flag = registry->FindFlagLocked(name); + if (flag == NULL) { + return false; + } else { + assert(OUTPUT); + flag->FillCommandLineFlagInfo(OUTPUT); + return true; + } +} + +CommandLineFlagInfo GetCommandLineFlagInfoOrDie(const char* name) { + CommandLineFlagInfo info; + if (!GetCommandLineFlagInfo(name, &info)) { + fprintf(stderr, "FATAL ERROR: flag name '%s' doesn't exit", name); + commandlineflags_exitfunc(1); // almost certainly exit() + } + return info; +} + +string SetCommandLineOptionWithMode(const char* name, const char* value, + FlagSettingMode set_mode) { + string result; + FlagRegistry* const registry = FlagRegistry::GlobalRegistry(); + FlagRegistryLock frl(registry); + CommandLineFlag* flag = registry->FindFlagLocked(name); + if (flag) { + CommandLineFlagParser parser(registry); + result = parser.ProcessSingleOptionLocked(flag, value, set_mode); + if (!result.empty()) { // in the error case, we've already logged + // You could consider logging this change, if you wanted to know it: + //fprintf(stderr, "%sFLAGS_%s\n", + // (set_mode == SET_FLAGS_DEFAULT ? "default value of " : ""), + // result); + } + } + // The API of this function is that we return empty string on error + return result; +} + +string SetCommandLineOption(const char* name, const char* value) { + return SetCommandLineOptionWithMode(name, value, SET_FLAGS_VALUE); +} + +// -------------------------------------------------------------------- +// FlagSaver +// FlagSaverImpl +// This class stores the states of all flags at construct time, +// and restores all flags to that state at destruct time. +// Its major implementation challenge is that it never modifies +// pointers in the 'main' registry, so global FLAG_* vars always +// point to the right place. +// -------------------------------------------------------------------- + +class FlagSaverImpl { + public: + // Constructs an empty FlagSaverImpl object. + explicit FlagSaverImpl(FlagRegistry* main_registry) + : main_registry_(main_registry) { } + ~FlagSaverImpl() { + // reclaim memory from each of our CommandLineFlags + vector<CommandLineFlag*>::const_iterator it; + for (it = backup_registry_.begin(); it != backup_registry_.end(); ++it) + delete *it; + } + + // Saves the flag states from the flag registry into this object. + // It's an error to call this more than once. + // Must be called when the registry mutex is not held. + void SaveFromRegistry() { + FlagRegistryLock frl(main_registry_); + assert(backup_registry_.empty()); // call only once! + for (FlagRegistry::FlagConstIterator it = main_registry_->flags_.begin(); + it != main_registry_->flags_.end(); + ++it) { + const CommandLineFlag* main = it->second; + // Sets up all the const variables in backup correctly + CommandLineFlag* backup = new CommandLineFlag( + main->name(), main->help(), main->filename(), + main->current_->New(), main->defvalue_->New()); + // Sets up all the non-const variables in backup correctly + backup->CopyFrom(*main); + backup_registry_.push_back(backup); // add it to a convenient list + } + } + + // Restores the saved flag states into the flag registry. We + // assume no flags were added or deleted from the registry since + // the SaveFromRegistry; if they were, that's trouble! Must be + // called when the registry mutex is not held. + void RestoreToRegistry() { + FlagRegistryLock frl(main_registry_); + vector<CommandLineFlag*>::const_iterator it; + for (it = backup_registry_.begin(); it != backup_registry_.end(); ++it) { + CommandLineFlag* main = main_registry_->FindFlagLocked((*it)->name()); + if (main != NULL) { // if NULL, flag got deleted from registry(!) + main->CopyFrom(**it); + } + } + } + + private: + FlagRegistry* const main_registry_; + vector<CommandLineFlag*> backup_registry_; + + FlagSaverImpl(const FlagSaverImpl&); // no copying! + void operator=(const FlagSaverImpl&); +}; + +FlagSaver::FlagSaver() + : impl_(new FlagSaverImpl(FlagRegistry::GlobalRegistry())) { + impl_->SaveFromRegistry(); +} + +FlagSaver::~FlagSaver() { + impl_->RestoreToRegistry(); + delete impl_; +} + + +// -------------------------------------------------------------------- +// CommandlineFlagsIntoString() +// ReadFlagsFromString() +// AppendFlagsIntoFile() +// ReadFromFlagsFile() +// These are mostly-deprecated routines that stick the +// commandline flags into a file/string and read them back +// out again. I can see a use for CommandlineFlagsIntoString, +// for creating a flagfile, but the rest don't seem that useful +// -- some, I think, are a poor-man's attempt at FlagSaver -- +// and are included only until we can delete them from callers. +// Note they don't save --flagfile flags (though they do save +// the result of having called the flagfile, of course). +// -------------------------------------------------------------------- + +static string TheseCommandlineFlagsIntoString( + const vector<CommandLineFlagInfo>& flags) { + vector<CommandLineFlagInfo>::const_iterator i; + + size_t retval_space = 0; + for (i = flags.begin(); i != flags.end(); ++i) { + // An (over)estimate of how much space it will take to print this flag + retval_space += i->name.length() + i->current_value.length() + 5; + } + + string retval; + retval.reserve(retval_space); + for (i = flags.begin(); i != flags.end(); ++i) { + retval += "--"; + retval += i->name; + retval += "="; + retval += i->current_value; + retval += "\n"; + } + return retval; +} + +string CommandlineFlagsIntoString() { + vector<CommandLineFlagInfo> sorted_flags; + GetAllFlags(&sorted_flags); + return TheseCommandlineFlagsIntoString(sorted_flags); +} + +bool ReadFlagsFromString(const string& flagfilecontents, + const char* /*prog_name*/, // TODO(csilvers): nix this + bool errors_are_fatal) { + FlagRegistry* const registry = FlagRegistry::GlobalRegistry(); + FlagSaverImpl saved_states(registry); + saved_states.SaveFromRegistry(); + + CommandLineFlagParser parser(registry); + registry->Lock(); + parser.ProcessOptionsFromStringLocked(flagfilecontents, SET_FLAGS_VALUE); + registry->Unlock(); + // Should we handle --help and such when reading flags from a string? Sure. + HandleCommandLineHelpFlags(); + if (parser.ReportErrors()) { + // Error. Restore all global flags to their previous values. + if (errors_are_fatal) + commandlineflags_exitfunc(1); // almost certainly exit() + saved_states.RestoreToRegistry(); + return false; + } + return true; +} + +// TODO(csilvers): nix prog_name in favor of ProgramInvocationShortName() +bool AppendFlagsIntoFile(const string& filename, const char *prog_name) { + FILE *fp = fopen(filename.c_str(), "a"); + if (!fp) { + return false; + } + + if (prog_name) + fprintf(fp, "%s\n", prog_name); + + vector<CommandLineFlagInfo> flags; + GetAllFlags(&flags); + // But we don't want --flagfile, which leads to weird recursion issues + vector<CommandLineFlagInfo>::iterator i; + for (i = flags.begin(); i != flags.end(); ++i) { + if (strcmp(i->name.c_str(), "flagfile") == 0) { + flags.erase(i); + break; + } + } + fprintf(fp, "%s", TheseCommandlineFlagsIntoString(flags).c_str()); + + fclose(fp); + return true; +} + +bool ReadFromFlagsFile(const string& filename, const char* prog_name, + bool errors_are_fatal) { + return ReadFlagsFromString(ReadFileIntoString(filename.c_str()), + prog_name, errors_are_fatal); +} + + +// -------------------------------------------------------------------- +// BoolFromEnv() +// Int32FromEnv() +// Int64FromEnv() +// Uint64FromEnv() +// DoubleFromEnv() +// StringFromEnv() +// Reads the value from the environment and returns it. +// We use an FlagValue to make the parsing easy. +// Example usage: +// DEFINE_bool(myflag, BoolFromEnv("MYFLAG_DEFAULT", false), "whatever"); +// -------------------------------------------------------------------- + +bool BoolFromEnv(const char *v, bool dflt) { + return GetFromEnv(v, "bool", dflt); +} +int32 Int32FromEnv(const char *v, int32 dflt) { + return GetFromEnv(v, "int32", dflt); +} +int64 Int64FromEnv(const char *v, int64 dflt) { + return GetFromEnv(v, "int64", dflt); +} +uint64 Uint64FromEnv(const char *v, uint64 dflt) { + return GetFromEnv(v, "uint64", dflt); +} +double DoubleFromEnv(const char *v, double dflt) { + return GetFromEnv(v, "double", dflt); +} +const char *StringFromEnv(const char *varname, const char *dflt) { + const char* const val = getenv(varname); + return val ? val : dflt; +} + + +// -------------------------------------------------------------------- +// RegisterFlagValidator() +// RegisterFlagValidator() is the function that clients use to +// 'decorate' a flag with a validation function. Once this is +// done, every time the flag is set (including when the flag +// is parsed from argv), the validator-function is called. +// These functions return true if the validator was added +// successfully, or false if not: the flag already has a validator, +// (only one allowed per flag), the 1st arg isn't a flag, etc. +// This function is not thread-safe. +// -------------------------------------------------------------------- + +bool RegisterFlagValidator(const bool* flag, + bool (*validate_fn)(const char*, bool)) { + return AddFlagValidator(flag, reinterpret_cast<ValidateFnProto>(validate_fn)); +} +bool RegisterFlagValidator(const int32* flag, + bool (*validate_fn)(const char*, int32)) { + return AddFlagValidator(flag, reinterpret_cast<ValidateFnProto>(validate_fn)); +} +bool RegisterFlagValidator(const int64* flag, + bool (*validate_fn)(const char*, int64)) { + return AddFlagValidator(flag, reinterpret_cast<ValidateFnProto>(validate_fn)); +} +bool RegisterFlagValidator(const uint64* flag, + bool (*validate_fn)(const char*, uint64)) { + return AddFlagValidator(flag, reinterpret_cast<ValidateFnProto>(validate_fn)); +} +bool RegisterFlagValidator(const double* flag, + bool (*validate_fn)(const char*, double)) { + return AddFlagValidator(flag, reinterpret_cast<ValidateFnProto>(validate_fn)); +} +bool RegisterFlagValidator(const string* flag, + bool (*validate_fn)(const char*, const string&)) { + return AddFlagValidator(flag, reinterpret_cast<ValidateFnProto>(validate_fn)); +} + + +// -------------------------------------------------------------------- +// ParseCommandLineFlags() +// ParseCommandLineNonHelpFlags() +// HandleCommandLineHelpFlags() +// This is the main function called from main(), to actually +// parse the commandline. It modifies argc and argv as described +// at the top of gflags.h. You can also divide this +// function into two parts, if you want to do work between +// the parsing of the flags and the printing of any help output. +// -------------------------------------------------------------------- + +static uint32 ParseCommandLineFlagsInternal(int* argc, char*** argv, + bool remove_flags, bool do_report) { + SetArgv(*argc, const_cast<const char**>(*argv)); // save it for later + + FlagRegistry* const registry = FlagRegistry::GlobalRegistry(); + CommandLineFlagParser parser(registry); + + // When we parse the commandline flags, we'll handle --flagfile, + // --tryfromenv, etc. as we see them (since flag-evaluation order + // may be important). But sometimes apps set FLAGS_tryfromenv/etc. + // manually before calling ParseCommandLineFlags. We want to evaluate + // those too, as if they were the first flags on the commandline. + registry->Lock(); + parser.ProcessFlagfileLocked(FLAGS_flagfile, SET_FLAGS_VALUE); + // Last arg here indicates whether flag-not-found is a fatal error or not + parser.ProcessFromenvLocked(FLAGS_fromenv, SET_FLAGS_VALUE, true); + parser.ProcessFromenvLocked(FLAGS_tryfromenv, SET_FLAGS_VALUE, false); + registry->Unlock(); + + // Now get the flags specified on the commandline + const int r = parser.ParseNewCommandLineFlags(argc, argv, remove_flags); + + if (do_report) + HandleCommandLineHelpFlags(); // may cause us to exit on --help, etc. + + // See if any of the unset flags fail their validation checks + parser.ValidateAllFlags(); + + if (parser.ReportErrors()) // may cause us to exit on illegal flags + commandlineflags_exitfunc(1); // almost certainly exit() + return r; +} + +uint32 ParseCommandLineFlags(int* argc, char*** argv, bool remove_flags) { + return ParseCommandLineFlagsInternal(argc, argv, remove_flags, true); +} + +uint32 ParseCommandLineNonHelpFlags(int* argc, char*** argv, + bool remove_flags) { + return ParseCommandLineFlagsInternal(argc, argv, remove_flags, false); +} + +// -------------------------------------------------------------------- +// AllowCommandLineReparsing() +// ReparseCommandLineNonHelpFlags() +// This is most useful for shared libraries. The idea is if +// a flag is defined in a shared library that is dlopen'ed +// sometime after main(), you can ParseCommandLineFlags before +// the dlopen, then ReparseCommandLineNonHelpFlags() after the +// dlopen, to get the new flags. But you have to explicitly +// Allow() it; otherwise, you get the normal default behavior +// of unrecognized flags calling a fatal error. +// TODO(csilvers): this isn't used. Just delete it? +// -------------------------------------------------------------------- + +void AllowCommandLineReparsing() { + allow_command_line_reparsing = true; +} + +uint32 ReparseCommandLineNonHelpFlags() { + // We make a copy of argc and argv to pass in + const vector<string>& argvs = GetArgvs(); + int tmp_argc = static_cast<int>(argvs.size()); + char** tmp_argv = new char* [tmp_argc + 1]; + for (int i = 0; i < tmp_argc; ++i) + tmp_argv[i] = strdup(argvs[i].c_str()); // TODO(csilvers): don't dup + + const int retval = ParseCommandLineNonHelpFlags(&tmp_argc, &tmp_argv, false); + + for (int i = 0; i < tmp_argc; ++i) + free(tmp_argv[i]); + delete[] tmp_argv; + + return retval; +} + +} // namespace google |