POSIX does not guarantee that writes will be atomic if a file is
opened for normal (non-append) output. That means if multiple processes
are writing to the same file, output could be lost. I can't think of
a real use-case where we would NOT want append for stdout/stderr, so
force it if we can.
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.
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.
If -R is set in the makefile and not the command line, then go through all the
default variables and undefine them. If -r is set in the makefile and not in
the command line, then remove all .SUFFIX prefixes (unless the user set it)
and SUFFIX variable setting. In -p mode don't print builtins.
This mode replaces the previous heuristic setting enabled with -O, where we
would log directory enter/leave for each synchronized output. Now we only
do that if --trace=dir is given.
gnumake.h (GMK_EXPORT) [_WIN32]: Move the dllexport declaration
here from makeint.h.
makeint.h (GMK_BUILDING_MAKE) [WINDOWS32]: Define before
including gnumake.h.
GCC was giving us warnings, most OS's now just run fork() when you call
vfork(), and looking at the standard definition of vfork() we are a long way
from using it safely anyway: you're not allowed to even call a function before
you exec().
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.
Enhance the child_error() function so that it will write error output to the
child's sync output buffer, if it exists. If it doesn't the output goes to
stdout/stderr.
We've required support for ANSI C (ISO C 89) or better for quite a while. Get
rid of the old varags.h, doprnt() stuff and simply assume ANSI C variadic
function capability and basic C runtime library support (vfprintf, vsprintf,
etc.)
A new flag to the -O/--output-sync, "job", selects a per-job (that is, per
line of a recipe) output synchronization. To support this move the close of
the temp file out of the sync_output() function and don't do it until we free
the child, since we may call sync_output() multiple times in a given recipe.
When we set up for a new temp file, if we're in per-job mode we truncate the
file and seek to the beginning to re-use it for every job.
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.
