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New variables, .VARIABLES and .TARGETS.

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This commit is contained in:
Paul Smith 2002-08-01 13:16:57 +00:00
parent a56563badd
commit bccb277dda
9 changed files with 210 additions and 21 deletions

25
ChangeLog
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@ -1,3 +1,28 @@
2002-08-01 Paul D. Smith <psmith@gnu.org>
Add new introspection variables .VARIABLES and .TARGETS.
* variable.c (handle_special_var): New function. If the variable
reference passed in is "special" (.VARIABLES or .TARGETS),
calculate the new value if necessary. .VARIABLES is handled here:
walk through the hash of defined variables and construct a value
which is a list of the names. .TARGETS is handled by
build_target_list().
(lookup_variable): Invoke handle_special_var().
* file.c (build_target_list): Walk through the hask of known files
and construct a list of the names of all the ones marked as
targets.
* main.c (main): Initialize them to empty (and as simple variables).
* doc/make.texi (Special Variables): Document them.
* NEWS: Mention them.
* variable.h (struct variable): Add a new flag "exportable" which
is true if the variable name is valid for export.
* variable.c (define_variable_in_set): Set "exportable" when a new
variable is defined.
(target_environment): Use the "exportable" flag instead of
re-checking the name here... an efficiency improvement.
2002-07-10 Paul D. Smith <psmith@gnu.org>
* variable.c (pop_variable_scope): Remove variable made unused by

7
NEWS
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@ -26,7 +26,7 @@ Version 3.80
This syntax is only valid within explicit and static pattern rules: it
cannot be used in implicit (suffix or pattern) rules. Edouard G. Parmelan
<egp@free.fr> provided a patch implementing this feature; however, I
decided to implemented it myself in a different way.
decided to implemented it in a different way.
* A new function is defined: $(quote ...). The argument to this
function is the _name_ of a variable. The result of the function is
@ -44,6 +44,11 @@ Version 3.80
list when a makefile is just being read (before any includes) is the
name of the current makefile.
* GNU make now supports some simple introspection capability: two new
built-in variables are defined: $(.VARIABLES) and $(.TARGETS). These
expand to a complete list of variables and targets, respectively,
defined by all makefiles at the time the variables are expanded.
* The arguments to $(call ...) functions were being stored in $1, $2,
etc. as recursive variables, even though they are fully expanded
before assignment. This means that escaped dollar signs ($$ etc.)

36
doc/make.texi
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@ -149,6 +149,7 @@ Writing Makefiles
* Include:: How one makefile can use another makefile.
* MAKEFILES Variable:: The environment can specify extra makefiles.
* MAKEFILE_LIST Variable:: Discover which makefiles have been read.
* Special Variables:: Other special variables.
* Remaking Makefiles:: How makefiles get remade.
* Overriding Makefiles:: How to override part of one makefile
with another makefile.
@ -929,6 +930,7 @@ reading a data base called the @dfn{makefile}.
* Include:: How one makefile can use another makefile.
* MAKEFILES Variable:: The environment can specify extra makefiles.
* MAKEFILE_LIST Variable:: Discover which makefiles have been read.
* Special Variables:: Other special variables.
* Remaking Makefiles:: How makefiles get remade.
* Overriding Makefiles:: How to override part of one makefile
with another makefile.
@ -1184,7 +1186,7 @@ This is a very bad idea, because such makefiles will fail to work if run by
anyone else. It is much better to write explicit @code{include} directives
in the makefiles. @xref{Include, , Including Other Makefiles}.
@node MAKEFILE_LIST Variable, Remaking Makefiles, MAKEFILES Variable, Makefiles
@node MAKEFILE_LIST Variable, Special Variables, MAKEFILES Variable, Makefiles
@comment node-name, next, previous, up
@section The Variable @code{MAKEFILE_LIST}
@cindex makefiles, and @code{MAKEFILE_LIST} variable
@ -1232,7 +1234,37 @@ name2 = inc.mk
Variables}, for more information on simply-expanded (@code{:=})
variable definitions.
@node Remaking Makefiles, Overriding Makefiles, MAKEFILE_LIST Variable, Makefiles
@node Special Variables, Remaking Makefiles, MAKEFILE_LIST Variable, Makefiles
@comment node-name, next, previous, up
@section Other Special Variables
@cindex makefiles, and special variables
@cindex special variables
GNU @code{make} also supports two other special variables. Note that
any value you assign to these variables will be ignored; they will
always return their special value.
@vindex $(.VARIABLES)
@vindex .VARIABLES @r{(list of variables)}
The first special variable is @code{.VARIABLES}. When expanded, the
value consists of a list of the @emph{names} of all global variables
defined in all makefiles read up until that point. This includes
variables which have empty values, as well as built-in variables
(@pxref{Implicit Variables, , Variables Used by Implicit Rules}), but
does not include any variables which are only defined in a
target-specific context.
@vindex $(.TARGETS)
@vindex .TARGETS @r{(list of targets)}
The second special variable is @code{.TARGETS}. When expanded, the
value consists of a list of all targets defined in all makefiles read
up until that point. Note it's not enough for a file to be simply
mentioned in the makefile to be listed in this variable, even if it
would match an implicit rule and become an ``implicit target''. The
file must appear as a target, on the left-hand side of a ``:'', to be
considered a target for the purposes of this variable.
@node Remaking Makefiles, Overriding Makefiles, Special Variables, Makefiles
@section How Makefiles Are Remade
@cindex updating makefiles

49
file.c
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@ -765,6 +765,55 @@ print_file_data_base ()
hash_print_stats (&files, stdout);
}
#define EXPANSION_INCREMENT(_l) ((((_l) / 500) + 1) * 500)
char *
build_target_list (value)
char *value;
{
static unsigned long last_targ_count = 0;
if (files.ht_fill != last_targ_count)
{
unsigned long max = EXPANSION_INCREMENT (strlen (value));
unsigned long len;
char *p;
struct file **fp = (struct file **) files.ht_vec;
struct file **end = &fp[files.ht_size];
/* Make sure we have at least MAX bytes in the allocated buffer. */
value = xrealloc (value, max);
p = value;
len = 0;
for (; fp < end; ++fp)
if (!HASH_VACANT (*fp) && (*fp)->is_target)
{
struct file *f = *fp;
int l = strlen (f->name);
len += l + 1;
if (len > max)
{
unsigned long off = p - value;
max += EXPANSION_INCREMENT (l + 1);
value = xrealloc (value, max);
p = &value[off];
}
bcopy (f->name, p, l);
p += l;
*(p++) = ' ';
}
*(p-1) = '\0';
last_targ_count = files.ht_fill;
}
return value;
}
void
init_hash_files ()
{

1
filedef.h
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@ -111,6 +111,7 @@ extern void rehash_file PARAMS ((struct file *file, char *name));
extern void set_command_state PARAMS ((struct file *file, int state));
extern void notice_finished_file PARAMS ((struct file *file));
extern void init_hash_files PARAMS ((void));
extern char *build_target_list PARAMS ((char *old_list));
#if FILE_TIMESTAMP_HI_RES
# define FILE_TIMESTAMP_STAT_MODTIME(fname, st) \

4
main.c
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@ -988,6 +988,10 @@ int main (int argc, char ** argv)
atexit (msdos_return_to_initial_directory);
#endif
/* Initialize the special variables. */
define_variable (".VARIABLES", 10, "", o_default, 0);
define_variable (".TARGETS", 8, "", o_default, 0);
/* Read in variables from the environment. It is important that this be
done before $(MAKE) is figured out so its definitions will not be
from the environment. */

4
make.h
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@ -297,10 +297,10 @@ extern char *strsignal PARAMS ((int signum));
- It's guaranteed to evaluate its argument exactly once.
NOTE! Make relies on this behavior, don't change it!
- It's typically faster.
Posix 1003.2-1992 section 2.5.2.1 page 50 lines 1556-1558 says that
POSIX 1003.2-1992 section 2.5.2.1 page 50 lines 1556-1558 says that
only '0' through '9' are digits. Prefer ISDIGIT to isdigit() unless
it's important to use the locale's definition of `digit' even when the
host does not conform to Posix. */
host does not conform to POSIX. */
#define ISDIGIT(c) ((unsigned) (c) - '0' <= 9)
#ifndef iAPX286

95
variable.c
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@ -157,8 +157,86 @@ define_variable_in_set (name, length, value, origin, recursive, set, flocp)
v->append = 0;
v->export = v_default;
v->exportable = 1;
if (*name != '_' && (*name < 'A' || *name > 'Z')
&& (*name < 'a' || *name > 'z'))
v->exportable = 0;
else
{
for (++name; *name != '\0'; ++name)
if (*name != '_' && (*name < 'a' || *name > 'z')
&& (*name < 'A' || *name > 'Z') && !ISDIGIT(*name))
break;
if (*name != '\0')
v->exportable = 0;
}
return v;
}
/* If the variable passed in is "special", handle its special nature.
Currently there are two such variables, both used for introspection:
.MAKE_VARS expands to a list of all the variables defined in this instance
of make.
.MAKE_TARGETS expands to a list of all the targets defined in this
instance of make.
Returns the variable reference passed in. */
#define EXPANSION_INCREMENT(_l) ((((_l) / 500) + 1) * 500)
static struct variable *
handle_special_var (var)
struct variable *var;
{
static unsigned long last_var_count = 0;
if (streq (var->name, ".MAKE_TARGETS"))
var->value = build_target_list (var->value);
else if (streq (var->name, ".MAKE_VARS")
&& global_variable_set.table.ht_fill != last_var_count)
{
unsigned long max = EXPANSION_INCREMENT (strlen (var->value));
unsigned long len;
char *p;
struct variable **vp = (struct variable **) global_variable_set.table.ht_vec;
struct variable **end = &vp[global_variable_set.table.ht_size];
/* Make sure we have at least MAX bytes in the allocated buffer. */
var->value = xrealloc (var->value, max);
p = var->value;
len = 0;
for (; vp < end; ++vp)
if (!HASH_VACANT (*vp))
{
struct variable *v = *vp;
int l = v->length;
len += l + 1;
if (len > max)
{
unsigned long off = p - var->value;
max += EXPANSION_INCREMENT (l + 1);
var->value = xrealloc (var->value, max);
p = &var->value[off];
}
bcopy (v->name, p, l);
p += l;
*(p++) = ' ';
}
*(p-1) = '\0';
last_var_count = global_variable_set.table.ht_fill;
}
return var;
}
/* Lookup a variable whose name is a string starting at NAME
and with LENGTH chars. NAME need not be null-terminated.
@ -184,7 +262,7 @@ lookup_variable (name, length)
v = (struct variable *) hash_find_item ((struct hash_table *) &set->table, &var_key);
if (v)
return v;
return handle_special_var (v);
}
#ifdef VMS
@ -570,7 +648,6 @@ target_environment (file)
{
struct variable **new_slot;
struct variable *v = *v_slot;
char *p = v->name;
/* If this is a per-target variable and it hasn't been touched
already then look up the global version and take its export
@ -592,20 +669,14 @@ target_environment (file)
/* Only export default variables by explicit request. */
continue;
/* The variable doesn't have a name that can be exported. */
if (! v->exportable)
continue;
if (! export_all_variables
&& v->origin != o_command
&& v->origin != o_env && v->origin != o_env_override)
continue;
if (*p != '_' && (*p < 'A' || *p > 'Z')
&& (*p < 'a' || *p > 'z'))
continue;
for (++p; *p != '\0'; ++p)
if (*p != '_' && (*p < 'a' || *p > 'z')
&& (*p < 'A' || *p > 'Z') && (*p < '0' || *p > '9'))
continue;
if (*p != '\0')
continue;
break;
case v_export:

10
variable.h
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@ -57,17 +57,19 @@ struct variable
char *value; /* Variable value. */
struct floc fileinfo; /* Where the variable was defined. */
unsigned int recursive:1; /* Gets recursively re-evaluated. */
unsigned int expanding:1; /* Nonzero if currently being expanded. */
unsigned int exp_count:EXP_COUNT_BITS;
/* If >1, allow this many self-referential
expansions */
unsigned int per_target:1; /* Nonzero if a target-specific variable. */
unsigned int append:1; /* Nonzero if an appending target-specific
variable. */
unsigned int expanding:1; /* Nonzero if currently being expanded. */
unsigned int exp_count:EXP_COUNT_BITS;
/* If >1, allow this many self-referential
expansions. */
enum variable_origin
origin ENUM_BITFIELD (3); /* Variable origin. */
unsigned int exportable:1; /* Nonzero if the variable _could_ be
exported. */
enum variable_export
{
v_export, /* Export this variable. */