| // 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. |
| |
| // --- |
| // Revamped and reorganized by Craig Silverstein |
| // |
| // This is the file that should be included by any file which declares |
| // or defines a command line flag or wants to parse command line flags |
| // or print a program usage message (which will include information about |
| // flags). Executive summary, in the form of an example foo.cc file: |
| // |
| // #include "foo.h" // foo.h has a line "DECLARE_int32(start);" |
| // #include "validators.h" // hypothetical file defining ValidateIsFile() |
| // |
| // DEFINE_int32(end, 1000, "The last record to read"); |
| // |
| // DEFINE_string(filename, "my_file.txt", "The file to read"); |
| // // Crash if the specified file does not exist. |
| // static bool dummy = RegisterFlagValidator(&FLAGS_filename, |
| // &ValidateIsFile); |
| // |
| // DECLARE_bool(verbose); // some other file has a DEFINE_bool(verbose, ...) |
| // |
| // void MyFunc() { |
| // if (FLAGS_verbose) printf("Records %d-%d\n", FLAGS_start, FLAGS_end); |
| // } |
| // |
| // Then, at the command-line: |
| // ./foo --noverbose --start=5 --end=100 |
| // |
| // For more details, see |
| // doc/gflags.html |
| // |
| // --- A note about thread-safety: |
| // |
| // We describe many functions in this routine as being thread-hostile, |
| // thread-compatible, or thread-safe. Here are the meanings we use: |
| // |
| // thread-safe: it is safe for multiple threads to call this routine |
| // (or, when referring to a class, methods of this class) |
| // concurrently. |
| // thread-hostile: it is not safe for multiple threads to call this |
| // routine (or methods of this class) concurrently. In gflags, |
| // most thread-hostile routines are intended to be called early in, |
| // or even before, main() -- that is, before threads are spawned. |
| // thread-compatible: it is safe for multiple threads to read from |
| // this variable (when applied to variables), or to call const |
| // methods of this class (when applied to classes), as long as no |
| // other thread is writing to the variable or calling non-const |
| // methods of this class. |
| |
| #ifndef GFLAGS_GFLAGS_H_ |
| #define GFLAGS_GFLAGS_H_ |
| |
| #include <string> |
| #include <vector> |
| |
| #include "gflags_declare.h" // IWYU pragma: export |
| |
| |
| // We always want to export variables defined in user code |
| #ifndef GFLAGS_DLL_DEFINE_FLAG |
| # ifdef _MSC_VER |
| # define GFLAGS_DLL_DEFINE_FLAG __declspec(dllexport) |
| # else |
| # define GFLAGS_DLL_DEFINE_FLAG |
| # endif |
| #endif |
| |
| |
| namespace GFLAGS_NAMESPACE { |
| |
| |
| // -------------------------------------------------------------------- |
| // To actually define a flag in a file, use DEFINE_bool, |
| // DEFINE_string, etc. at the bottom of this file. You may also find |
| // it useful to register a validator with the flag. This ensures that |
| // when the flag is parsed from the commandline, or is later set via |
| // SetCommandLineOption, we call the validation function. It is _not_ |
| // called when you assign the value to the flag directly using the = operator. |
| // |
| // The validation function should return true if the flag value is valid, and |
| // false otherwise. If the function returns false for the new setting of the |
| // flag, the flag will retain its current value. If it returns false for the |
| // default value, ParseCommandLineFlags() will die. |
| // |
| // This function is safe to call at global construct time (as in the |
| // example below). |
| // |
| // Example use: |
| // static bool ValidatePort(const char* flagname, int32 value) { |
| // if (value > 0 && value < 32768) // value is ok |
| // return true; |
| // printf("Invalid value for --%s: %d\n", flagname, (int)value); |
| // return false; |
| // } |
| // DEFINE_int32(port, 0, "What port to listen on"); |
| // static bool dummy = RegisterFlagValidator(&FLAGS_port, &ValidatePort); |
| |
| // Returns true if successfully registered, false if not (because the |
| // first argument doesn't point to a command-line flag, or because a |
| // validator is already registered for this flag). |
| extern GFLAGS_DLL_DECL bool RegisterFlagValidator(const bool* flag, bool (*validate_fn)(const char*, bool)); |
| extern GFLAGS_DLL_DECL bool RegisterFlagValidator(const int32* flag, bool (*validate_fn)(const char*, int32)); |
| extern GFLAGS_DLL_DECL bool RegisterFlagValidator(const int64* flag, bool (*validate_fn)(const char*, int64)); |
| extern GFLAGS_DLL_DECL bool RegisterFlagValidator(const uint64* flag, bool (*validate_fn)(const char*, uint64)); |
| extern GFLAGS_DLL_DECL bool RegisterFlagValidator(const double* flag, bool (*validate_fn)(const char*, double)); |
| extern GFLAGS_DLL_DECL bool RegisterFlagValidator(const std::string* flag, bool (*validate_fn)(const char*, const std::string&)); |
| |
| // Convenience macro for the registration of a flag validator |
| #define DEFINE_validator(name, validator) \ |
| static const bool name##_validator_registered = \ |
| GFLAGS_NAMESPACE::RegisterFlagValidator(&FLAGS_##name, validator) |
| |
| |
| // -------------------------------------------------------------------- |
| // These methods are the best way to get access to info about the |
| // list of commandline flags. Note that these routines are pretty slow. |
| // GetAllFlags: mostly-complete info about the list, sorted by file. |
| // ShowUsageWithFlags: pretty-prints the list to stdout (what --help does) |
| // ShowUsageWithFlagsRestrict: limit to filenames with restrict as a substr |
| // |
| // In addition to accessing flags, you can also access argv[0] (the program |
| // name) and argv (the entire commandline), which we sock away a copy of. |
| // These variables are static, so you should only set them once. |
| // |
| // No need to export this data only structure from DLL, avoiding VS warning 4251. |
| struct CommandLineFlagInfo { |
| std::string name; // the name of the flag |
| std::string type; // the type of the flag: int32, etc |
| std::string description; // the "help text" associated with the flag |
| std::string current_value; // the current value, as a string |
| std::string default_value; // the default value, as a string |
| std::string filename; // 'cleaned' version of filename holding the flag |
| bool has_validator_fn; // true if RegisterFlagValidator called on this flag |
| bool is_default; // true if the flag has the default value and |
| // has not been set explicitly from the cmdline |
| // or via SetCommandLineOption |
| const void* flag_ptr; // pointer to the flag's current value (i.e. FLAGS_foo) |
| }; |
| |
| // Using this inside of a validator is a recipe for a deadlock. |
| // TODO(user) Fix locking when validators are running, to make it safe to |
| // call validators during ParseAllFlags. |
| // Also make sure then to uncomment the corresponding unit test in |
| // gflags_unittest.sh |
| extern GFLAGS_DLL_DECL void GetAllFlags(std::vector<CommandLineFlagInfo>* OUTPUT); |
| // These two are actually defined in gflags_reporting.cc. |
| extern GFLAGS_DLL_DECL void ShowUsageWithFlags(const char *argv0); // what --help does |
| extern GFLAGS_DLL_DECL void ShowUsageWithFlagsRestrict(const char *argv0, const char *restrict); |
| |
| // Create a descriptive string for a flag. |
| // Goes to some trouble to make pretty line breaks. |
| extern GFLAGS_DLL_DECL std::string DescribeOneFlag(const CommandLineFlagInfo& flag); |
| |
| // Thread-hostile; meant to be called before any threads are spawned. |
| extern GFLAGS_DLL_DECL void SetArgv(int argc, const char** argv); |
| |
| // The following functions are thread-safe as long as SetArgv() is |
| // only called before any threads start. |
| extern GFLAGS_DLL_DECL const std::vector<std::string>& GetArgvs(); |
| extern GFLAGS_DLL_DECL const char* GetArgv(); // all of argv as a string |
| extern GFLAGS_DLL_DECL const char* GetArgv0(); // only argv0 |
| extern GFLAGS_DLL_DECL uint32 GetArgvSum(); // simple checksum of argv |
| extern GFLAGS_DLL_DECL const char* ProgramInvocationName(); // argv0, or "UNKNOWN" if not set |
| extern GFLAGS_DLL_DECL const char* ProgramInvocationShortName(); // basename(argv0) |
| |
| // ProgramUsage() is thread-safe as long as SetUsageMessage() is only |
| // called before any threads start. |
| extern GFLAGS_DLL_DECL const char* ProgramUsage(); // string set by SetUsageMessage() |
| |
| // VersionString() is thread-safe as long as SetVersionString() is only |
| // called before any threads start. |
| extern GFLAGS_DLL_DECL const char* VersionString(); // string set by SetVersionString() |
| |
| |
| |
| // -------------------------------------------------------------------- |
| // Normally you access commandline flags by just saying "if (FLAGS_foo)" |
| // or whatever, and set them by calling "FLAGS_foo = bar" (or, more |
| // commonly, via the DEFINE_foo macro). But if you need a bit more |
| // control, we have programmatic ways to get/set the flags as well. |
| // These programmatic ways to access flags are thread-safe, but direct |
| // access is only thread-compatible. |
| |
| // Return true iff the flagname was found. |
| // OUTPUT is set to the flag's value, or unchanged if we return false. |
| extern GFLAGS_DLL_DECL bool GetCommandLineOption(const char* name, std::string* OUTPUT); |
| |
| // Return true iff the flagname was found. OUTPUT is set to the flag's |
| // CommandLineFlagInfo or unchanged if we return false. |
| extern GFLAGS_DLL_DECL bool GetCommandLineFlagInfo(const char* name, CommandLineFlagInfo* OUTPUT); |
| |
| // Return the CommandLineFlagInfo of the flagname. exit() if name not found. |
| // Example usage, to check if a flag's value is currently the default value: |
| // if (GetCommandLineFlagInfoOrDie("foo").is_default) ... |
| extern GFLAGS_DLL_DECL CommandLineFlagInfo GetCommandLineFlagInfoOrDie(const char* name); |
| |
| enum GFLAGS_DLL_DECL FlagSettingMode { |
| // update the flag's value (can call this multiple times). |
| SET_FLAGS_VALUE, |
| // update the flag's value, but *only if* it has not yet been updated |
| // with SET_FLAGS_VALUE, SET_FLAG_IF_DEFAULT, or "FLAGS_xxx = nondef". |
| SET_FLAG_IF_DEFAULT, |
| // set the flag's default value to this. If the flag has not yet updated |
| // yet (via SET_FLAGS_VALUE, SET_FLAG_IF_DEFAULT, or "FLAGS_xxx = nondef") |
| // change the flag's current value to the new default value as well. |
| SET_FLAGS_DEFAULT |
| }; |
| |
| // Set a particular flag ("command line option"). Returns a string |
| // describing the new value that the option has been set to. The |
| // return value API is not well-specified, so basically just depend on |
| // it to be empty if the setting failed for some reason -- the name is |
| // not a valid flag name, or the value is not a valid value -- and |
| // non-empty else. |
| |
| // SetCommandLineOption uses set_mode == SET_FLAGS_VALUE (the common case) |
| extern GFLAGS_DLL_DECL std::string SetCommandLineOption (const char* name, const char* value); |
| extern GFLAGS_DLL_DECL std::string SetCommandLineOptionWithMode(const char* name, const char* value, FlagSettingMode set_mode); |
| |
| |
| // -------------------------------------------------------------------- |
| // Saves the states (value, default value, whether the user has set |
| // the flag, registered validators, etc) of all flags, and restores |
| // them when the FlagSaver is destroyed. This is very useful in |
| // tests, say, when you want to let your tests change the flags, but |
| // make sure that they get reverted to the original states when your |
| // test is complete. |
| // |
| // Example usage: |
| // void TestFoo() { |
| // FlagSaver s1; |
| // FLAG_foo = false; |
| // FLAG_bar = "some value"; |
| // |
| // // test happens here. You can return at any time |
| // // without worrying about restoring the FLAG values. |
| // } |
| // |
| // Note: This class is marked with GFLAGS_ATTRIBUTE_UNUSED because all |
| // the work is done in the constructor and destructor, so in the standard |
| // usage example above, the compiler would complain that it's an |
| // unused variable. |
| // |
| // This class is thread-safe. However, its destructor writes to |
| // exactly the set of flags that have changed value during its |
| // lifetime, so concurrent _direct_ access to those flags |
| // (i.e. FLAGS_foo instead of {Get,Set}CommandLineOption()) is unsafe. |
| |
| class GFLAGS_DLL_DECL FlagSaver { |
| public: |
| FlagSaver(); |
| ~FlagSaver(); |
| |
| private: |
| class FlagSaverImpl* impl_; // we use pimpl here to keep API steady |
| |
| FlagSaver(const FlagSaver&); // no copying! |
| void operator=(const FlagSaver&); |
| }__attribute((unused)); |
| |
| // -------------------------------------------------------------------- |
| // Some deprecated or hopefully-soon-to-be-deprecated functions. |
| |
| // This is often used for logging. TODO(csilvers): figure out a better way |
| extern GFLAGS_DLL_DECL std::string CommandlineFlagsIntoString(); |
| // Usually where this is used, a FlagSaver should be used instead. |
| extern GFLAGS_DLL_DECL |
| bool ReadFlagsFromString(const std::string& flagfilecontents, |
| const char* prog_name, |
| bool errors_are_fatal); // uses SET_FLAGS_VALUE |
| |
| // These let you manually implement --flagfile functionality. |
| // DEPRECATED. |
| extern GFLAGS_DLL_DECL bool AppendFlagsIntoFile(const std::string& filename, const char* prog_name); |
| extern GFLAGS_DLL_DECL bool ReadFromFlagsFile(const std::string& filename, const char* prog_name, bool errors_are_fatal); // uses SET_FLAGS_VALUE |
| |
| |
| // -------------------------------------------------------------------- |
| // Useful routines for initializing flags from the environment. |
| // In each case, if 'varname' does not exist in the environment |
| // return defval. If 'varname' does exist but is not valid |
| // (e.g., not a number for an int32 flag), abort with an error. |
| // Otherwise, return the value. NOTE: for booleans, for true use |
| // 't' or 'T' or 'true' or '1', for false 'f' or 'F' or 'false' or '0'. |
| |
| extern GFLAGS_DLL_DECL bool BoolFromEnv(const char *varname, bool defval); |
| extern GFLAGS_DLL_DECL int32 Int32FromEnv(const char *varname, int32 defval); |
| extern GFLAGS_DLL_DECL int64 Int64FromEnv(const char *varname, int64 defval); |
| extern GFLAGS_DLL_DECL uint64 Uint64FromEnv(const char *varname, uint64 defval); |
| extern GFLAGS_DLL_DECL double DoubleFromEnv(const char *varname, double defval); |
| extern GFLAGS_DLL_DECL const char *StringFromEnv(const char *varname, const char *defval); |
| |
| |
| // -------------------------------------------------------------------- |
| // The next two functions parse gflags from main(): |
| |
| // Set the "usage" message for this program. For example: |
| // string usage("This program does nothing. Sample usage:\n"); |
| // usage += argv[0] + " <uselessarg1> <uselessarg2>"; |
| // SetUsageMessage(usage); |
| // Do not include commandline flags in the usage: we do that for you! |
| // Thread-hostile; meant to be called before any threads are spawned. |
| extern GFLAGS_DLL_DECL void SetUsageMessage(const std::string& usage); |
| |
| // Sets the version string, which is emitted with --version. |
| // For instance: SetVersionString("1.3"); |
| // Thread-hostile; meant to be called before any threads are spawned. |
| extern GFLAGS_DLL_DECL void SetVersionString(const std::string& version); |
| |
| |
| // Looks for flags in argv and parses them. Rearranges argv to put |
| // flags first, or removes them entirely if remove_flags is true. |
| // If a flag is defined more than once in the command line or flag |
| // file, the last definition is used. Returns the index (into argv) |
| // of the first non-flag argument. |
| // See top-of-file for more details on this function. |
| #ifndef SWIG // In swig, use ParseCommandLineFlagsScript() instead. |
| extern GFLAGS_DLL_DECL uint32 ParseCommandLineFlags(int *argc, char*** argv, bool remove_flags); |
| #endif |
| |
| |
| // Calls to ParseCommandLineNonHelpFlags and then to |
| // HandleCommandLineHelpFlags can be used instead of a call to |
| // ParseCommandLineFlags during initialization, in order to allow for |
| // changing default values for some FLAGS (via |
| // e.g. SetCommandLineOptionWithMode calls) between the time of |
| // command line parsing and the time of dumping help information for |
| // the flags as a result of command line parsing. If a flag is |
| // defined more than once in the command line or flag file, the last |
| // definition is used. Returns the index (into argv) of the first |
| // non-flag argument. (If remove_flags is true, will always return 1.) |
| extern GFLAGS_DLL_DECL uint32 ParseCommandLineNonHelpFlags(int *argc, char*** argv, bool remove_flags); |
| |
| // This is actually defined in gflags_reporting.cc. |
| // This function is misnamed (it also handles --version, etc.), but |
| // it's too late to change that now. :-( |
| extern GFLAGS_DLL_DECL void HandleCommandLineHelpFlags(); // in gflags_reporting.cc |
| |
| // Allow command line reparsing. Disables the error normally |
| // generated when an unknown flag is found, since it may be found in a |
| // later parse. Thread-hostile; meant to be called before any threads |
| // are spawned. |
| extern GFLAGS_DLL_DECL void AllowCommandLineReparsing(); |
| |
| // Reparse the flags that have not yet been recognized. Only flags |
| // registered since the last parse will be recognized. Any flag value |
| // must be provided as part of the argument using "=", not as a |
| // separate command line argument that follows the flag argument. |
| // Intended for handling flags from dynamically loaded libraries, |
| // since their flags are not registered until they are loaded. |
| extern GFLAGS_DLL_DECL void ReparseCommandLineNonHelpFlags(); |
| |
| // Clean up memory allocated by flags. This is only needed to reduce |
| // the quantity of "potentially leaked" reports emitted by memory |
| // debugging tools such as valgrind. It is not required for normal |
| // operation, or for the google perftools heap-checker. It must only |
| // be called when the process is about to exit, and all threads that |
| // might access flags are quiescent. Referencing flags after this is |
| // called will have unexpected consequences. This is not safe to run |
| // when multiple threads might be running: the function is |
| // thread-hostile. |
| extern GFLAGS_DLL_DECL void ShutDownCommandLineFlags(); |
| |
| |
| // -------------------------------------------------------------------- |
| // Now come the command line flag declaration/definition macros that |
| // will actually be used. They're kind of hairy. A major reason |
| // for this is initialization: we want people to be able to access |
| // variables in global constructors and have that not crash, even if |
| // their global constructor runs before the global constructor here. |
| // (Obviously, we can't guarantee the flags will have the correct |
| // default value in that case, but at least accessing them is safe.) |
| // The only way to do that is have flags point to a static buffer. |
| // So we make one, using a union to ensure proper alignment, and |
| // then use placement-new to actually set up the flag with the |
| // correct default value. In the same vein, we have to worry about |
| // flag access in global destructors, so FlagRegisterer has to be |
| // careful never to destroy the flag-values it constructs. |
| // |
| // Note that when we define a flag variable FLAGS_<name>, we also |
| // preemptively define a junk variable, FLAGS_no<name>. This is to |
| // cause a link-time error if someone tries to define 2 flags with |
| // names like "logging" and "nologging". We do this because a bool |
| // flag FLAG can be set from the command line to true with a "-FLAG" |
| // argument, and to false with a "-noFLAG" argument, and so this can |
| // potentially avert confusion. |
| // |
| // We also put flags into their own namespace. It is purposefully |
| // named in an opaque way that people should have trouble typing |
| // directly. The idea is that DEFINE puts the flag in the weird |
| // namespace, and DECLARE imports the flag from there into the current |
| // namespace. The net result is to force people to use DECLARE to get |
| // access to a flag, rather than saying "extern GFLAGS_DLL_DECL bool FLAGS_whatever;" |
| // or some such instead. We want this so we can put extra |
| // functionality (like sanity-checking) in DECLARE if we want, and |
| // make sure it is picked up everywhere. |
| // |
| // We also put the type of the variable in the namespace, so that |
| // people can't DECLARE_int32 something that they DEFINE_bool'd |
| // elsewhere. |
| |
| class GFLAGS_DLL_DECL FlagRegisterer { |
| public: |
| FlagRegisterer(const char* name, const char* type, |
| const char* help, const char* filename, |
| void* current_storage, void* defvalue_storage); |
| }; |
| |
| // If your application #defines STRIP_FLAG_HELP to a non-zero value |
| // before #including this file, we remove the help message from the |
| // binary file. This can reduce the size of the resulting binary |
| // somewhat, and may also be useful for security reasons. |
| |
| extern GFLAGS_DLL_DECL const char kStrippedFlagHelp[]; |
| |
| |
| } // namespace GFLAGS_NAMESPACE |
| |
| |
| #ifndef SWIG // In swig, ignore the main flag declarations |
| |
| #if defined(STRIP_FLAG_HELP) && STRIP_FLAG_HELP > 0 |
| // Need this construct to avoid the 'defined but not used' warning. |
| #define MAYBE_STRIPPED_HELP(txt) \ |
| (false ? (txt) : GFLAGS_NAMESPACE::kStrippedFlagHelp) |
| #else |
| #define MAYBE_STRIPPED_HELP(txt) txt |
| #endif |
| |
| // Each command-line flag has two variables associated with it: one |
| // with the current value, and one with the default value. However, |
| // we have a third variable, which is where value is assigned; it's a |
| // constant. This guarantees that FLAG_##value is initialized at |
| // static initialization time (e.g. before program-start) rather than |
| // than global construction time (which is after program-start but |
| // before main), at least when 'value' is a compile-time constant. We |
| // use a small trick for the "default value" variable, and call it |
| // FLAGS_no<name>. This serves the second purpose of assuring a |
| // compile error if someone tries to define a flag named no<name> |
| // which is illegal (--foo and --nofoo both affect the "foo" flag). |
| #define DEFINE_VARIABLE(type, shorttype, name, value, help) \ |
| namespace fL##shorttype { \ |
| static const type FLAGS_nono##name = value; \ |
| /* We always want to export defined variables, dll or no */ \ |
| GFLAGS_DLL_DEFINE_FLAG type FLAGS_##name = FLAGS_nono##name; \ |
| type FLAGS_no##name = FLAGS_nono##name; \ |
| static GFLAGS_NAMESPACE::FlagRegisterer o_##name( \ |
| #name, #type, MAYBE_STRIPPED_HELP(help), __FILE__, \ |
| &FLAGS_##name, &FLAGS_no##name); \ |
| } \ |
| using fL##shorttype::FLAGS_##name |
| |
| // For DEFINE_bool, we want to do the extra check that the passed-in |
| // value is actually a bool, and not a string or something that can be |
| // coerced to a bool. These declarations (no definition needed!) will |
| // help us do that, and never evaluate From, which is important. |
| // We'll use 'sizeof(IsBool(val))' to distinguish. This code requires |
| // that the compiler have different sizes for bool & double. Since |
| // this is not guaranteed by the standard, we check it with a |
| // COMPILE_ASSERT. |
| namespace fLB { |
| struct CompileAssert {}; |
| typedef CompileAssert expected_sizeof_double_neq_sizeof_bool[ |
| (sizeof(double) != sizeof(bool)) ? 1 : -1]; |
| template<typename From> double GFLAGS_DLL_DECL IsBoolFlag(const From& from); |
| GFLAGS_DLL_DECL bool IsBoolFlag(bool from); |
| } // namespace fLB |
| |
| // Here are the actual DEFINE_*-macros. The respective DECLARE_*-macros |
| // are in a separate include, gflags_declare.h, for reducing |
| // the physical transitive size for DECLARE use. |
| #define DEFINE_bool(name, val, txt) \ |
| namespace fLB { \ |
| typedef ::fLB::CompileAssert FLAG_##name##_value_is_not_a_bool[ \ |
| (sizeof(::fLB::IsBoolFlag(val)) != sizeof(double))? 1: -1]; \ |
| } \ |
| DEFINE_VARIABLE(bool, B, name, val, txt) |
| |
| #define DEFINE_int32(name, val, txt) \ |
| DEFINE_VARIABLE(GFLAGS_NAMESPACE::int32, I, \ |
| name, val, txt) |
| |
| #define DEFINE_int64(name, val, txt) \ |
| DEFINE_VARIABLE(GFLAGS_NAMESPACE::int64, I64, \ |
| name, val, txt) |
| |
| #define DEFINE_uint64(name,val, txt) \ |
| DEFINE_VARIABLE(GFLAGS_NAMESPACE::uint64, U64, \ |
| name, val, txt) |
| |
| #define DEFINE_double(name, val, txt) \ |
| DEFINE_VARIABLE(double, D, name, val, txt) |
| |
| // Strings are trickier, because they're not a POD, so we can't |
| // construct them at static-initialization time (instead they get |
| // constructed at global-constructor time, which is much later). To |
| // try to avoid crashes in that case, we use a char buffer to store |
| // the string, which we can static-initialize, and then placement-new |
| // into it later. It's not perfect, but the best we can do. |
| |
| namespace fLS { |
| |
| inline clstring* dont_pass0toDEFINE_string(char *stringspot, |
| const char *value) { |
| return new(stringspot) clstring(value); |
| } |
| inline clstring* dont_pass0toDEFINE_string(char *stringspot, |
| const clstring &value) { |
| return new(stringspot) clstring(value); |
| } |
| inline clstring* dont_pass0toDEFINE_string(char *stringspot, |
| int value); |
| } // namespace fLS |
| |
| // We need to define a var named FLAGS_no##name so people don't define |
| // --string and --nostring. And we need a temporary place to put val |
| // so we don't have to evaluate it twice. Two great needs that go |
| // great together! |
| // The weird 'using' + 'extern' inside the fLS namespace is to work around |
| // an unknown compiler bug/issue with the gcc 4.2.1 on SUSE 10. See |
| // http://code.google.com/p/google-gflags/issues/detail?id=20 |
| #define DEFINE_string(name, val, txt) \ |
| namespace fLS { \ |
| using ::fLS::clstring; \ |
| static union { void* align; char s[sizeof(clstring)]; } s_##name[2]; \ |
| clstring* const FLAGS_no##name = ::fLS:: \ |
| dont_pass0toDEFINE_string(s_##name[0].s, \ |
| val); \ |
| static GFLAGS_NAMESPACE::FlagRegisterer o_##name( \ |
| #name, "string", MAYBE_STRIPPED_HELP(txt), __FILE__, \ |
| s_##name[0].s, new (s_##name[1].s) clstring(*FLAGS_no##name)); \ |
| extern GFLAGS_DLL_DEFINE_FLAG clstring& FLAGS_##name; \ |
| using fLS::FLAGS_##name; \ |
| clstring& FLAGS_##name = *FLAGS_no##name; \ |
| } \ |
| using fLS::FLAGS_##name |
| |
| #endif // SWIG |
| |
| |
| // Import gflags library symbols into alternative/deprecated namespace(s) |
| #include "gflags_gflags.h" |
| |
| |
| #endif // GFLAGS_GFLAGS_H_ |