X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=libiberty%2Fpexecute.txh;h=8baf9a0d01bcc514547c561dbd2fb920096ad376;hb=d9220fc19d19cf10042dc29a0b658b4c8e50ea14;hp=269f031cc727c292055345ecb7547ebd92b6cf97;hpb=8cb0536d25508acaffb368dc075c5038eaa4e068;p=pf3gnuchains%2Fgcc-fork.git diff --git a/libiberty/pexecute.txh b/libiberty/pexecute.txh index 269f031cc72..8baf9a0d01b 100644 --- a/libiberty/pexecute.txh +++ b/libiberty/pexecute.txh @@ -1,63 +1,298 @@ -@deftypefn Extension int pexecute (const char *@var{program}, char * const *@var{argv}, const char *@var{this_pname}, const char *@var{temp_base}, char **@var{errmsg_fmt}, char **@var{errmsg_arg}, int flags) +@c -*- mode: texinfo -*- +@deftypefn Extension {struct pex_obj *} pex_init (int @var{flags}, const char *@var{pname}, const char *@var{tempbase}) -Executes a program. +Prepare to execute one or more programs, with standard output of each +program fed to standard input of the next. This is a system +independent interface to execute a pipeline. -@var{program} and @var{argv} are the arguments to -@code{execv}/@code{execvp}. +@var{flags} is a bitwise combination of the following: -@var{this_pname} is name of the calling program (i.e., @code{argv[0]}). +@table @code -@var{temp_base} is the path name, sans suffix, of a temporary file to -use if needed. This is currently only needed for MS-DOS ports that -don't use @code{go32} (do any still exist?). Ports that don't need it -can pass @code{NULL}. +@vindex PEX_RECORD_TIMES +@item PEX_RECORD_TIMES +Record subprocess times if possible. -(@code{@var{flags} & PEXECUTE_SEARCH}) is non-zero if @env{PATH} -should be searched (??? It's not clear that GCC passes this flag -correctly). (@code{@var{flags} & PEXECUTE_FIRST}) is nonzero for the -first process in chain. (@code{@var{flags} & PEXECUTE_FIRST}) is -nonzero for the last process in chain. The first/last flags could be -simplified to only mark the last of a chain of processes but that -requires the caller to always mark the last one (and not give up -early if some error occurs). It's more robust to require the caller -to mark both ends of the chain. +@vindex PEX_USE_PIPES +@item PEX_USE_PIPES +Use pipes for communication between processes, if possible. -The result is the pid on systems like Unix where we -@code{fork}/@code{exec} and on systems like WIN32 and OS/2 where we -use @code{spawn}. It is up to the caller to wait for the child. +@vindex PEX_SAVE_TEMPS +@item PEX_SAVE_TEMPS +Don't delete temporary files used for communication between +processes. -The result is the @code{WEXITSTATUS} on systems like MS-DOS where we -@code{spawn} and wait for the child here. +@end table -Upon failure, @var{errmsg_fmt} and @var{errmsg_arg} are set to the -text of the error message with an optional argument (if not needed, -@var{errmsg_arg} is set to @code{NULL}), and @minus{}1 is returned. -@code{errno} is available to the caller to use. +@var{pname} is the name of program to be executed, used in error +messages. @var{tempbase} is a base name to use for any required +temporary files; it may be @code{NULL} to use a randomly chosen name. @end deftypefn -@deftypefn Extension int pwait (int @var{pid}, int *@var{status}, int @var{flags}) +@deftypefn Extension {const char *} pex_run (struct pex_obj *@var{obj}, int @var{flags}, const char *@var{executable}, char * const *@var{argv}, const char *@var{outname}, const char *@var{errname}, int *@var{err}) + +Execute one program in a pipeline. On success this returns +@code{NULL}. On failure it returns an error message, a statically +allocated string. + +@var{obj} is returned by a previous call to @code{pex_init}. + +@var{flags} is a bitwise combination of the following: + +@table @code + +@vindex PEX_LAST +@item PEX_LAST +This must be set on the last program in the pipeline. In particular, +it should be set when executing a single program. The standard output +of the program will be sent to @var{outname}, or, if @var{outname} is +@code{NULL}, to the standard output of the calling program. Do @emph{not} +set this bit if you want to call @code{pex_read_output} +(described below). After a call to @code{pex_run} with this bit set, +@var{pex_run} may no longer be called with the same @var{obj}. + +@vindex PEX_SEARCH +@item PEX_SEARCH +Search for the program using the user's executable search path. + +@vindex PEX_SUFFIX +@item PEX_SUFFIX +@var{outname} is a suffix. See the description of @var{outname}, +below. + +@vindex PEX_STDERR_TO_STDOUT +@item PEX_STDERR_TO_STDOUT +Send the program's standard error to standard output, if possible. + +@vindex PEX_BINARY_INPUT +@vindex PEX_BINARY_OUTPUT +@vindex PEX_BINARY_ERROR +@item PEX_BINARY_INPUT +@itemx PEX_BINARY_OUTPUT +@itemx PEX_BINARY_ERROR +The standard input (output or error) of the program should be read (written) in +binary mode rather than text mode. These flags are ignored on systems +which do not distinguish binary mode and text mode, such as Unix. For +proper behavior these flags should match appropriately---a call to +@code{pex_run} using @code{PEX_BINARY_OUTPUT} should be followed by a +call using @code{PEX_BINARY_INPUT}. + +@vindex PEX_STDERR_TO_PIPE +@item PEX_STDERR_TO_PIPE +Send the program's standard error to a pipe, if possible. This flag +cannot be specified together with @code{PEX_STDERR_TO_STDOUT}. This +flag can be specified only on the last program in pipeline. + +@end table + +@var{executable} is the program to execute. @var{argv} is the set of +arguments to pass to the program; normally @code{@var{argv}[0]} will +be a copy of @var{executable}. + +@var{outname} is used to set the name of the file to use for standard +output. There are two cases in which no output file will be used: + +@enumerate +@item +if @code{PEX_LAST} is not set in @var{flags}, and @code{PEX_USE_PIPES} +was set in the call to @code{pex_init}, and the system supports pipes + +@item +if @code{PEX_LAST} is set in @var{flags}, and @var{outname} is +@code{NULL} +@end enumerate + +@noindent +Otherwise the code will use a file to hold standard +output. If @code{PEX_LAST} is not set, this file is considered to be +a temporary file, and it will be removed when no longer needed, unless +@code{PEX_SAVE_TEMPS} was set in the call to @code{pex_init}. + +There are two cases to consider when setting the name of the file to +hold standard output. + +@enumerate +@item +@code{PEX_SUFFIX} is set in @var{flags}. In this case +@var{outname} may not be @code{NULL}. If the @var{tempbase} parameter +to @code{pex_init} was not @code{NULL}, then the output file name is +the concatenation of @var{tempbase} and @var{outname}. If +@var{tempbase} was @code{NULL}, then the output file name is a random +file name ending in @var{outname}. + +@item +@code{PEX_SUFFIX} was not set in @var{flags}. In this +case, if @var{outname} is not @code{NULL}, it is used as the output +file name. If @var{outname} is @code{NULL}, and @var{tempbase} was +not NULL, the output file name is randomly chosen using +@var{tempbase}. Otherwise the output file name is chosen completely +at random. +@end enumerate + +@var{errname} is the file name to use for standard error output. If +it is @code{NULL}, standard error is the same as the caller's. +Otherwise, standard error is written to the named file. + +On an error return, the code sets @code{*@var{err}} to an @code{errno} +value, or to 0 if there is no relevant @code{errno}. + +@end deftypefn + +@deftypefn Extension {const char *} pex_run_in_environment (struct pex_obj *@var{obj}, int @var{flags}, const char *@var{executable}, char * const *@var{argv}, char * const *@var{env}, int @var{env_size}, const char *@var{outname}, const char *@var{errname}, int *@var{err}) + +Execute one program in a pipeline, permitting the environment for the +program to be specified. Behaviour and parameters not listed below are +as for @code{pex_run}. + +@var{env} is the environment for the child process, specified as an array of +character pointers. Each element of the array should point to a string of the +form @code{VAR=VALUE}, with the exception of the last element that must be +@code{NULL}. + +@end deftypefn + +@deftypefn Extension {FILE *} pex_input_file (struct pex_obj *@var{obj}, int @var{flags}, const char *@var{in_name}) + +Return a stream for a temporary file to pass to the first program in +the pipeline as input. + +The name of the input file is chosen according to the same rules +@code{pex_run} uses to choose output file names, based on +@var{in_name}, @var{obj} and the @code{PEX_SUFFIX} bit in @var{flags}. + +Don't call @code{fclose} on the returned stream; the first call to +@code{pex_run} closes it automatically. + +If @var{flags} includes @code{PEX_BINARY_OUTPUT}, open the stream in +binary mode; otherwise, open it in the default mode. Including +@code{PEX_BINARY_OUTPUT} in @var{flags} has no effect on Unix. +@end deftypefn + +@deftypefn Extension {FILE *} pex_input_pipe (struct pex_obj *@var{obj}, int @var{binary}) -Waits for a program started by @code{pexecute} to finish. +Return a stream @var{fp} for a pipe connected to the standard input of +the first program in the pipeline; @var{fp} is opened for writing. +You must have passed @code{PEX_USE_PIPES} to the @code{pex_init} call +that returned @var{obj}. -@var{pid} is the process id of the task to wait for. @var{status} is -the `status' argument to wait. @var{flags} is currently unused -(allows future enhancement without breaking upward compatibility). -Pass 0 for now. +You must close @var{fp} using @code{fclose} yourself when you have +finished writing data to the pipeline. -The result is the pid of the child reaped, or -1 for failure -(@code{errno} says why). +The file descriptor underlying @var{fp} is marked not to be inherited +by child processes. -On systems that don't support waiting for a particular child, -@var{pid} is ignored. On systems like MS-DOS that don't really -multitask @code{pwait} is just a mechanism to provide a consistent -interface for the caller. +On systems that do not support pipes, this function returns +@code{NULL}, and sets @code{errno} to @code{EINVAL}. If you would +like to write code that is portable to all systems the @code{pex} +functions support, consider using @code{pex_input_file} instead. + +There are two opportunities for deadlock using +@code{pex_input_pipe}: + +@itemize @bullet +@item +Most systems' pipes can buffer only a fixed amount of data; a process +that writes to a full pipe blocks. Thus, if you write to @file{fp} +before starting the first process, you run the risk of blocking when +there is no child process yet to read the data and allow you to +continue. @code{pex_input_pipe} makes no promises about the +size of the pipe's buffer, so if you need to write any data at all +before starting the first process in the pipeline, consider using +@code{pex_input_file} instead. + +@item +Using @code{pex_input_pipe} and @code{pex_read_output} together +may also cause deadlock. If the output pipe fills up, so that each +program in the pipeline is waiting for the next to read more data, and +you fill the input pipe by writing more data to @var{fp}, then there +is no way to make progress: the only process that could read data from +the output pipe is you, but you are blocked on the input pipe. + +@end itemize + +@end deftypefn + +@deftypefn Extension {FILE *} pex_read_output (struct pex_obj *@var{obj}, int @var{binary}) + +Returns a @code{FILE} pointer which may be used to read the standard +output of the last program in the pipeline. When this is used, +@code{PEX_LAST} should not be used in a call to @code{pex_run}. After +this is called, @code{pex_run} may no longer be called with the same +@var{obj}. @var{binary} should be non-zero if the file should be +opened in binary mode. Don't call @code{fclose} on the returned file; +it will be closed by @code{pex_free}. + +@end deftypefn + +@deftypefn Extension {FILE *} pex_read_err (struct pex_obj *@var{obj}, int @var{binary}) + +Returns a @code{FILE} pointer which may be used to read the standard +error of the last program in the pipeline. When this is used, +@code{PEX_LAST} should not be used in a call to @code{pex_run}. After +this is called, @code{pex_run} may no longer be called with the same +@var{obj}. @var{binary} should be non-zero if the file should be +opened in binary mode. Don't call @code{fclose} on the returned file; +it will be closed by @code{pex_free}. + +@end deftypefn + + +@deftypefn Extension int pex_get_status (struct pex_obj *@var{obj}, int @var{count}, int *@var{vector}) + +Returns the exit status of all programs run using @var{obj}. +@var{count} is the number of results expected. The results will be +placed into @var{vector}. The results are in the order of the calls +to @code{pex_run}. Returns 0 on error, 1 on success. + +@end deftypefn + +@deftypefn Extension int pex_get_times (struct pex_obj *@var{obj}, int @var{count}, struct pex_time *@var{vector}) + +Returns the process execution times of all programs run using +@var{obj}. @var{count} is the number of results expected. The +results will be placed into @var{vector}. The results are in the +order of the calls to @code{pex_run}. Returns 0 on error, 1 on +success. + +@code{struct pex_time} has the following fields of the type +@code{unsigned long}: @code{user_seconds}, +@code{user_microseconds}, @code{system_seconds}, +@code{system_microseconds}. On systems which do not support reporting +process times, all the fields will be set to @code{0}. + +@end deftypefn + +@deftypefn Extension void pex_free (struct pex_obj @var{obj}) + +Clean up and free all data associated with @var{obj}. If you have not +yet called @code{pex_get_times} or @code{pex_get_status}, this will +try to kill the subprocesses. + +@end deftypefn + +@deftypefn Extension {const char *} pex_one (int @var{flags}, const char *@var{executable}, char * const *@var{argv}, const char *@var{pname}, const char *@var{outname}, const char *@var{errname}, int *@var{status}, int *@var{err}) + +An interface to permit the easy execution of a +single program. The return value and most of the parameters are as +for a call to @code{pex_run}. @var{flags} is restricted to a +combination of @code{PEX_SEARCH}, @code{PEX_STDERR_TO_STDOUT}, and +@code{PEX_BINARY_OUTPUT}. @var{outname} is interpreted as if +@code{PEX_LAST} were set. On a successful return, @code{*@var{status}} will +be set to the exit status of the program. @end deftypefn -@undocumented pfinish +@deftypefn Extension int pexecute (const char *@var{program}, char * const *@var{argv}, const char *@var{this_pname}, const char *@var{temp_base}, char **@var{errmsg_fmt}, char **@var{errmsg_arg}, int @var{flags}) -pfinish: finish generation of script +This is the old interface to execute one or more programs. It is +still supported for compatibility purposes, but is no longer +documented. + +@end deftypefn -pfinish is necessary for systems like MPW where a script is generated -that runs the requested programs. +@deftypefn Extension int pwait (int @var{pid}, int *@var{status}, int @var{flags}) + +Another part of the old execution interface. + +@end deftypefn