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* Fix up and document $(apply ...) function.

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Paul Smith 1999-07-15 07:36:44 +00:00
parent adb1632033
commit 9d89ad56bf
9 changed files with 181 additions and 121 deletions
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16
ChangeLog
View file

@ -1,3 +1,12 @@
1999-07-15 Paul D. Smith <psmith@gnu.org>
* function.c (func_apply): Various code cleanup and tightening.
(function_table): Add "apply" as a valid builtin function.
* make.texinfo (Apply Function): Document it.
* NEWS: Announce it.
1999-07-09 Paul D. Smith <psmith@gnu.org>
* job.c (start_waiting_job): Don't get a second job token if we
@ -227,7 +236,12 @@
* function.c: Rewrite to use one C function per make function,
instead of a huge switch statement. Also allows some cleanup of
multi-architecture issues.
multi-architecture issues, and a cleaner API which makes things
like func_apply() simple.
* function.c (func_apply): Initial implementation. Expand either
a builtin function or a make variable in the context of some
arguments, provided as $1, $2, ... $N.
1999-03-19 Eli Zaretskii <eliz@is.elta.co.il>
1999-03-19 Rob Tulloh <rob_tulloh@dev.tivoli.com>

7
NEWS
View file

@ -18,6 +18,11 @@ Version 3.78
causes the text provided to be printed as a warning message, but make
proceeds normally.
* A new function, $(apply ...) is provided. This allows users to create
their own parameterized macros and invoke them later. This
implementation of this feature was provided by Han-Wen Nienhuys
<hanwen@cs.uu.nl>.
* Make defines a new variable, .LIBPATTERNS. This variable controls how
library dependency expansion (dependencies like ``-lfoo'') is performed.
@ -29,7 +34,7 @@ Version 3.78
LD, AR, etc.). Specifying this option forces -r (--no-builtin-rules)
as well.
* A "job server" feature, proposed by Howard Chu <hyc@highlandsun.com>.
* A "job server" feature, suggested by Howard Chu <hyc@highlandsun.com>.
On systems that support POSIX pipe(2) semantics, GNU make can now pass
-jN options to submakes rather than forcing them all to use -j1. The

3
dep.h
View file

@ -38,8 +38,7 @@ struct dep
struct dep *next;
char *name;
struct file *file;
unsigned short changed;
unsigned short deferred; /* Only used in update_goal_chain(). */
int changed;
};

3
file.c
View file

@ -348,6 +348,8 @@ in favor of those for `%s'.",
/* %%% Kludge so -W wins on a file that gets vpathized. */
oldfile->last_mtime = file->last_mtime;
oldfile->mtime_before_update = file->mtime_before_update;
#define MERGE(field) oldfile->field |= file->field
MERGE (precious);
MERGE (tried_implicit);
@ -468,6 +470,7 @@ snap_deps ()
/* Mark this file as phony and nonexistent. */
f2->phony = 1;
f2->last_mtime = (FILE_TIMESTAMP) -1;
f2->mtime_before_update = (FILE_TIMESTAMP) -1;
}
for (f = lookup_file (".INTERMEDIATE"); f != 0; f = f->prev)

2
filedef.h
View file

@ -35,6 +35,8 @@ struct file
rule has been used */
struct dep *also_make; /* Targets that are made by making this. */
FILE_TIMESTAMP last_mtime; /* File's modtime, if already known. */
FILE_TIMESTAMP mtime_before_update; /* File's modtime before any updating
has been performed. */
struct file *prev; /* Previous entry for same file name;
used when there are multiple double-colon
entries for the same file. */

147
function.c
View file

@ -1719,130 +1719,83 @@ func_if (char* o, char **argv, char *funcname)
}
#endif
/* This might not be very useful, but the code was simple to
implement, I just had to do it.
/* User-defined functions. Expand the first argument as either a builtin
function or a make variable, in the context of the rest of the arguments
assigned to $1, $2, ... $N. $0 is the name of the function. */
Here goes anyway
Apply & User defined functions.
SYNTAX
$(apply funcname, arg1, arg2, .. )
SEMANTICS
You can specify a builtin function, for funcname, eg
f = addprefix
$(apply addprefix,a, b c d)
This will result in
ab ac ad
You can specify your own functions, eg
funcname=BODY
BODY contains $(1) .. $(N) as argument markers.
upon expansions the strings ARG1 .. ARGN are substituted for $(1) .. $(N)
into BODY
Because the funcname is computed as well you can combine this do some
funky things, eg
map=$(foreach a, $(2), $(apply $(1), $(a)))
LIMITATIONS.
Make has no support for nested lists (or tuples), so you can't do
stuff like (Haskell notation):
f :: (a,b) -> c -- type of F
map :: (a->b) -> [a] -> b -- type of MAP
map f [(1,2), (2,3)] -- map F over list containing (1,2) and (2,3)
to get
[f (1, 2), f (2, 3)]
If only we had nested lists and quotes, we could duplicate LISP in make by
transforming
$(a, b, c) <-> (a b c)
$(quote $(a, b, c)) <-> '(a b c)
(or something alike ;-) (We could have automatic integration of
GUILE and make :-)
[Actually -- why should this be a joke? If we could somehow integrate the
rules and targets into a functional model make could be a lot cleaner in
concept. ]
*/
char *
func_apply (o, argv, funcname)
char *o;
char **argv;
const char *funcname;
{
char *userfunc_name;
int func_len;
char *body = 0;
char *expanded_body = 0;
char *fname;
int flen;
char *body;
int i;
const struct function_table_entry *entry_p;
userfunc_name = argv[0];
while (isspace (*userfunc_name))
++userfunc_name;
/* Applying nothing is a no-op. */
if (*argv[0] == '\0')
return o;
entry_p = lookup_function (function_table, userfunc_name);
/* There is no way to define a variable with a space in the name, so strip
trailing whitespace as a favor to the user. */
flen = strlen (argv[0]);
fname = argv[0] + flen - 1;
while (isspace (*fname))
--fname;
fname[1] = '\0';
flen = fname - argv[0] + 1;
fname = argv[0];
/* Are we invoking a builtin function? */
entry_p = lookup_function (function_table, fname);
/* builtin function? */
if (entry_p)
{
for (i=0; argv[i+1]; i++)
for (i=0; argv[i+1]; ++i)
;
o = expand_builtin_function (o, i, argv + 1, entry_p);
return o;
return expand_builtin_function (o, i, argv + 1, entry_p);
}
func_len = strlen (userfunc_name);
body = xmalloc (func_len + 4);
strcpy (body + 2, userfunc_name);
body [func_len+2]=')';
body [func_len+3]= 0;
body [1]='(';
body [0]='$';
/* No, so the first argument is the name of a variable to be expanded and
interpreted as a function. Create the variable reference. */
body = alloca (flen + 4);
body[0]='$';
body[1]='(';
strcpy (body + 2, fname);
body[flen+2]=')';
body[flen+3]= '\0';
/* Set up arguments $(1) .. $(N). $(0) is the function name. */
push_new_variable_scope ();
/* set up arguments $(1) .. $(N) */
for (i=0; argv[i]; i++)
for (i=0; *argv; ++i, ++argv)
{
char num[10];
struct variable* var;
char num[11];
sprintf (num, "%d", i);
var = define_variable (num, strlen (num), argv[i], o_automatic, 0);
define_variable (num, strlen (num), *argv, o_automatic, 0);
}
expanded_body = allocated_variable_expand (body);
o = variable_buffer_output (o, expanded_body, strlen (expanded_body));
free (expanded_body);
/* Expand the body in the context of the arguments, adding the result to
the variable buffer. */
o = variable_expand_string (o, body, flen+3);
pop_variable_scope ();
free (body);
return o;
return o + strlen(o);
}
#define STRING_SIZE_TUPLE(s) (s), (sizeof(s)-1)
#define STRING_SIZE_TUPLE(_s) (_s), (sizeof(_s)-1)
/* Lookup table for builtin functions.
@ -1851,7 +1804,7 @@ func_apply (o, argv, funcname)
table.
REQUIRED_ARGUMENTS is the minimum number of arguments. A function
can have more, but they will be ignored.
can have more, but if they have less an error will be generated.
EXPAND_ALL_ARGUMENTS means that all arguments should be expanded
before invocation. Functions that do namespace tricks (foreach)
@ -1881,11 +1834,11 @@ static struct function_table_entry function_table[] =
{ STRING_SIZE_TUPLE("wordlist"), 3, 1, func_wordlist},
{ STRING_SIZE_TUPLE("words"), 1, 1, func_words},
{ STRING_SIZE_TUPLE("origin"), 1, 1, func_origin},
{ STRING_SIZE_TUPLE("foreach"), 3, 0, func_foreach},
{ STRING_SIZE_TUPLE("apply"), 1, 1, func_apply},
{ STRING_SIZE_TUPLE("error"), 1, 1, func_error},
{ STRING_SIZE_TUPLE("warning"), 1, 1, func_error},
{ STRING_SIZE_TUPLE("foreach"), 3, 0, func_foreach},
#ifdef EXPERIMENTAL
{ STRING_SIZE_TUPLE("apply"), 1, 1, func_apply},
{ STRING_SIZE_TUPLE("eq"), 2, 1, func_eq},
{ STRING_SIZE_TUPLE("if"), 3, 0, func_if},
{ STRING_SIZE_TUPLE("not"), 1, 1, func_not},

4
main.c
View file

@ -1358,7 +1358,7 @@ int main (int argc, char ** argv)
for (p = old_files->list; *p != 0; ++p)
{
f = enter_command_line_file (*p);
f->last_mtime = (FILE_TIMESTAMP) 1;
f->last_mtime = f->mtime_before_update = (FILE_TIMESTAMP) 1;
f->updated = 1;
f->update_status = 0;
f->command_state = cs_finished;
@ -1369,7 +1369,7 @@ int main (int argc, char ** argv)
for (p = new_files->list; *p != 0; ++p)
{
f = enter_command_line_file (*p);
f->last_mtime = NEW_MTIME;
f->last_mtime = f->mtime_before_update = NEW_MTIME;
}
}

100
make.texinfo
View file

@ -269,6 +269,7 @@ Functions for Transforming Text
* Text Functions:: General-purpose text manipulation functions.
* File Name Functions:: Functions for manipulating file names.
* Foreach Function:: Repeat some text with controlled variation.
* Apply Function:: Expand a user-defined function.
* Origin Function:: Find where a variable got its value.
* Shell Function:: Substitute the output of a shell command.
@ -5199,6 +5200,7 @@ call, just as a variable might be substituted.
* Text Functions:: General-purpose text manipulation functions.
* File Name Functions:: Functions for manipulating file names.
* Foreach Function:: Repeat some text with controlled variation.
* Apply Function:: Expand a user-defined function.
* Origin Function:: Find where a variable got its value.
* Shell Function:: Substitute the output of a shell command.
* Make Control Functions:: Functions that control how make runs.
@ -5224,8 +5226,9 @@ or like this:
$@{@var{function} @var{arguments}@}
@end example
Here @var{function} is a function name; one of a short list of names that
are part of @code{make}. There is no provision for defining new functions.
Here @var{function} is a function name; one of a short list of names
that are part of @code{make}. You can also essentially create your own
functions by using the @code{apply} builtin function.
The @var{arguments} are the arguments of the function. They are
separated from the function name by one or more spaces or tabs, and if
@ -5746,7 +5749,7 @@ that match the pattern.
@xref{Wildcards, ,Using Wildcard Characters in File Names}.
@end table
@node Foreach Function, Origin Function, File Name Functions, Functions
@node Foreach Function, Apply Function, File Name Functions, Functions
@section The @code{foreach} Function
@findex foreach
@cindex words, iterating over
@ -5834,7 +5837,96 @@ might be useful if the value of @code{find_files} references the variable
whose name is @samp{Esta escrito en espanol!} (es un nombre bastante largo,
no?), but it is more likely to be a mistake.
@node Origin Function, Shell Function, Foreach Function, Functions
@node Apply Function, Origin Function, Foreach Function, Functions
@section The @code{apply} Function
@findex apply
@cindex functions, user defined
@cindex user defined functions
The @code{apply} function is unique in that it can be used to create new
parameterized functions. You can write a complex expression as the
value of a variable, then use @code{apply} to expand it with different
values.
The syntax of the @code{apply} function is:
@example
$(apply @var{variable}, @var{param}, @var{param}, @dots{})
@end example
When @code{make} expands this function, it assigns each @var{param} to
temporary variables @var{$(1)}, @var{$(2)}, etc. The variable
@var{$(0)} will contain @var{variable}. There is no maximum number of
parameter arguments. There is no minimum, either, but it doesn't make
sense to use @code{apply} with no parameters.
Then @var{variable} is expanded as a @code{make} variable in the context
of these temporary assignments. Thus, any reference to @var{$(1)} in
the value of @var{variable} will resolve to the first @var{param} in the
invocation of @code{apply}.
Note that @var{variable} is the @emph{name} of a variable, not a
@emph{reference} to that variable. Therefore you would not normally use
a @samp{$} or parentheses when writing it. (You can, however, use a
variable reference in the name if you want the name not to be a
constant.)
If @var{variable} is the name of a builtin function, the builtin function
is always invoked (even if a @code{make} variable by that name also
exists).
Some examples may make this clearer.
This macro simply reverses its arguments:
@smallexample
reverse = $2 $1
foo = a b
bar = $(apply reverse,$(foo))
@end smallexample
@noindent
Here @var{bar} will contain @samp{b a}.
This one is slightly more interesting: it defines a macro to search for
the first instance of a program in @code{PATH}:
@smallexample
pathsearch = $(firstword $(wildcard $(addsufix /$1,$(subst :, ,$(PATH)))))
LS := $(apply pathsearch,ls)
@end smallexample
@noindent
Now the variable LS contains @code{/bin/ls} or similar.
The @code{apply} function can be nested. Each recursive invocation gets
its own local values for @var{$(1)}, etc. that mask the values of
higher-level @code{apply}. For example, here is an implementation of a
@dfn{map} function:
@smallexample
map = $(foreach a,$2,$(apply $1,$a))
@end smallexample
Now you can @var{map} a function that normally takes only one argument,
such as @code{origin}, to multiple values in one step:
@smallexample
o = $(apply map,origin,o map MAKE)
@end smallexample
and end up with @var{o} containing something like @samp{file file default}.
A final caution: be careful when adding whitespace to the arguments to
@code{apply}. As with other functions, any whitespace contained in the
second and subsequent arguments is kept; this can cause strange
effects. It's generally safest to remove all extraneous whitespace when
defining variables for use with @code{apply}.
@node Origin Function, Shell Function, Apply Function, Functions
@section The @code{origin} Function
@findex origin
@cindex variables, origin of

20
remake.c
View file

@ -94,7 +94,7 @@ update_goal_chain (goals, makefiles)
struct dep *g;
for (g = goals; g != 0; g = g->next)
g->changed = g->deferred = 0;
g->changed = 0;
}
#if 0
@ -134,7 +134,6 @@ update_goal_chain (goals, makefiles)
{
unsigned int ocommands_started;
int x;
FILE_TIMESTAMP mtime = MTIME (file);
check_renamed (file);
if (makefiles)
{
@ -161,16 +160,6 @@ update_goal_chain (goals, makefiles)
decide when to give an "up to date" diagnostic. */
g->changed += commands_started - ocommands_started;
/* Set the goal's `deferred' flag if we started a command but
it didn't finish (parallel builds). We need to remember
this, because the next time through the goal chain the call
to reap_children() will set the mtime, not the call to
update_file() above. So, the saved mtime from before
update_file() will be the same as the mtime after it, and
we'll think nothing changed when it did (see below). */
if (file->command_state == cs_running)
g->deferred = 1;
stop = 0;
if (x != 0 || file->updated)
{
@ -191,7 +180,8 @@ update_goal_chain (goals, makefiles)
stop = (!keep_going_flag && !question_flag
&& !makefiles);
}
else if (MTIME (file) != mtime || g->deferred)
else if (file->updated && g->changed &&
file->last_mtime != file->mtime_before_update)
{
/* Updating was done. If this is a makefile and
just_print_flag or question_flag is set
@ -199,7 +189,6 @@ update_goal_chain (goals, makefiles)
specified as a command-line target), don't
change STATUS. If STATUS is changed, we will
get re-exec'd, and fall into an infinite loop. */
g->deferred = 0;
if (!makefiles
|| (!just_print_flag && !question_flag))
status = 0;
@ -736,6 +725,9 @@ notice_finished_file (file)
{
struct file *f;
assert(file->mtime_before_update == 0);
file->mtime_before_update = file->last_mtime;
if (just_print_flag || question_flag
|| (file->is_target && file->cmds == 0))
file->last_mtime = NEW_MTIME;