In various places we were passing flags and characters to compare, then
using complex conditionals to see where to stop in string searches.
Performance numbers reveal that we were spending as much as 23% of our
processing time in these functions, most of it in the comparison lines.
Instead create a character map and use a single bitwise comparison to
determine if this is any one of the stop characters.
Ensure all simple flags are kept in the initial batch of flags.
Do not allow any flags with options in that batch.
If there are only non-simple flags ensure MAKEFLAGS begins with " ".
Don't let MFLAGS start with "- ".
This pointer is almost never needed, and it increases the size of the filedef
struct for all files (of which there are a huge number for large builds).
Instead keep a bit field marking whether the file is a loaded object and if so
call a new function to unload it. In load.c we keep a simple linked list of
loaded objects (of which there will be very few typically) and their dlopen()
pointers.
load.c (load_object, load_file): Accept an additional argument
DLP and return in it a pointer that can be used to unload the
dynamic object.
read.c (eval): Call load_file with an additional argument, and
record the pointer returned there in the 'struct file' object of
dynamic objects in that object's 'struct file'.
commands.c (execute_file_commands): Unload dynamic objects
before remaking them, to avoid failure to remake if the OS doesn't
allow overwriting objects that are in use.
filedef.h (struct file): New member dlopen_ptr.
gnumake.h (GMK_EXPORT): Define to dllexport/dllimport
decorations for Windows and to nothing on other platforms.
(gmk_eval, gmk_expand, gmk_add_function): Add GMK_EXPORT qualifier
to prototypes.
makeint.h (MAIN): Define before including gnumake.h, to give
correct dllexport decorations to exported functions.
(load_file): Adjust prototype.
loadapi.c: Don't include gnumake.h, since makeint.h already
includes it, and takes care of defining MAIN before doing so.
build_w32.bat (LinkGCC): Produce an import library for functions
exported by Make for loadable dynamic objects.
w32/compat/posixfcn.c (dlclose): New function.
w32/include/dlfcn.h (dlclose): Add prototype.
scripts/features/load: Fix signatures of testload_gmk_setup and
explicit_setup, to bring them in line with the documentation.
read.c (record_files): Pay attention to .ONESHELL in MS-Windows.
job.c (construct_command_argv_internal): Support .ONESHELL on
MS-Windows, when the shell is not a Unixy shell.
w32/compat/posixfcn.c: New file, with emulations of Posix
functions and Posix functionality for MS-Windows.
w32/subproc/sub_proc.c: Include io.h.
(process_noinherit): New function, forces a file descriptor to not
be inherited by child processes.
(process_easy): Accept two additional arguments, and use them to
set up the standard output and standard error handles of the child
process.
w32/include/sub_proc.h (process_easy): Adjust prototype.
(process_noinherit): Add prototype.
read.c [WINDOWS32]: Include windows.h and sub_proc.h.
makeint.h (LOCALEDIR) [WINDOWS32}: Define to NULL if not
defined. This is needed because the MS-Windows build doesn't have
a canonical place for LOCALEDIR.
(WIN32_LEAN_AND_MEAN) [WINDOWS32]: Define, to avoid getting from
windows.h header too much stuff that could conflict with the code.
main.c <sync_mutex>: New static variable.
<switches>: Add support for "--sync-mutex" switch.
(decode_output_sync_flags): Decode the --sync-mutex= switch.
(prepare_mutex_handle_string) [WINDOWS32]: New function.
(main): Add "output-sync" to .FEATURES.
job.h (CLOSE_ON_EXEC) [WINDOWS32]: Define to call
process_noinherit.
(F_GETFD, F_SETLKW, F_WRLCK, F_UNLCK, struct flock) [WINDOWS32]:
New macros.
(RECORD_SYNC_MUTEX): New macro, a no-op for Posix platforms.
(sync_handle_t): New typedef.
job.c <sync_handle>: Change type to sync_handle_t.
(FD_NOT_EMPTY): Seek to the file's end. Suggested by Frank
Heckenbach <f.heckenbach@fh-soft.de>.
(pump_from_tmp_fd) [WINDOWS32]: Switch to_fd to binary mode for
the duration of this function, and then change back before
returning.
(start_job_command) [WINDOWS32]: Support output_sync mode on
MS-Windows. Use a system-wide mutex instead of locking
stdout/stderr. Call process_easy with two additional arguments:
child->outfd and child->errfd.
(exec_command) [WINDOWS32]: Pass two additional arguments, both
-1, to process_easy, to adjust for the changed function signature.
function.c (windows32_openpipe) [WINDOWS32]: This function now
returns an int, which is -1 if it fails and zero otherwise. It
also calls 'error' instead of 'fatal', to avoid exiting
prematurely.
(func_shell_base) [WINDOWS32]: Call perror_with_name if
windows32_openpipe fails, now that it always returns. This avoids
a compiler warning that error_prefix is not used in the MS-Windows
build.
config.h.W32.template (OUTPUT_SYNC): Define.
build_w32.bat: Add w32/compat/posixfcn.c to compilation and
linking commands.
From Frank Heckenbach <f.heckenbach@fh-soft.de>:
job.c (sync_output): Don't discard the output if
acquire_semaphore fails; instead, dump the output unsynchronized.
Provide a simple API for loaded objects to interact with GNU make. I still
won't guarantee that this API won't change but it's much closer to something
that's supported and provides easy-to-use interfaces with a public header
file.
backward-incompatible change in the 2008 POSIX specification.
- Add the .SHELLFLAGS variable so people can choose their own shell flags.
- Add tests for this.
- Add documentation for this.
