rules.h #5

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/*
 * Copyright 1993, 1995 Christopher Seiwald.
 *
 * This file is part of Jam - see jam.c for Copyright information.
 */

/*
 * rules.h -  targets, rules, and related information
 *
 * This file describes the structures holding the targets, rules, and
 * related information accumulated by interpreting the statements
 * of the jam files.
 *
 * The following are defined:
 *
 *	RULE - a generic jam rule, the product of RULE and ACTIONS 
 *	ACTIONS - a chain of ACTIONs 
 *	ACTION - a RULE instance with targets and sources 
 *	SETTINGS - variables to set when executing a TARGET's ACTIONS 
 *	TARGETS - a chain of TARGETs 
 *	TARGET - a file or "thing" that can be built 
 *
 * 04/11/94 (seiwald) - Combined deps & headers into deps[2] in TARGET.
 * 04/12/94 (seiwald) - actionlist() now just appends a single action.
 * 06/01/94 (seiwald) - new 'actions existing' does existing sources
 * 12/20/94 (seiwald) - NOTIME renamed NOTFILE.
 * 01/19/95 (seiwald) - split DONTKNOW into CANTFIND/CANTMAKE.
 * 02/02/95 (seiwald) - new LEAVES modifier on targets.
 * 02/14/95 (seiwald) - new NOUPDATE modifier on targets.
 */

typedef struct _rule RULE;
typedef struct _target TARGET;
typedef struct _targets TARGETS;
typedef struct _action ACTION;
typedef struct _actions ACTIONS;
typedef struct _settings SETTINGS ;

/* RULE - a generic jam rule, the product of RULE and ACTIONS */

struct _rule {
	char	*name;
	PARSE	*procedure;		/* parse tree from RULE */
	char	*actions;		/* command string from ACTIONS */
	LIST	*bindlist;		/* variable to bind for actions */
	LIST	*params;		/* bind args to local vars */
	int	flags;			/* modifiers on ACTIONS */

# define	RULE_UPDATED	0x01	/* $(>) is updated sources only */
# define	RULE_TOGETHER	0x02	/* combine actions on single target */
# define	RULE_IGNORE	0x04	/* ignore return status of executes */
# define	RULE_QUIETLY	0x08	/* don't mention it unless verbose */
# define	RULE_PIECEMEAL	0x10	/* split exec so each $(>) is small */
# define	RULE_EXISTING	0x20	/* $(>) is pre-exisitng sources only */

} ;

/* ACTIONS - a chain of ACTIONs */

struct _actions {
	ACTIONS	*next;
	ACTIONS	*tail;			/* valid only for head */
	ACTION	*action;
} ;

/* ACTION - a RULE instance with targets and sources */

struct _action {
	RULE	*rule;
	TARGETS	*targets;
	TARGETS	*sources;		/* aka $(>) */
	char	running;		/* has been started */
	char	status;			/* see TARGET status */
} ;

/* SETTINGS - variables to set when executing a TARGET's ACTIONS */

struct _settings {
	SETTINGS *next;
	char	*symbol;		/* symbol name for var_set() */
	LIST	*value;			/* symbol value for var_set() */
} ;

/* TARGETS - a chain of TARGETs */

struct _targets {
	TARGETS	*next;
	TARGETS	*tail;			/* valid only for head */
	TARGET	*target;
} ;

/* TARGET - a file or "thing" that can be built */

struct _target {
	char	*name;
	char	*boundname;		/* if search() relocates target */
	ACTIONS	*actions;		/* rules to execute, if any */
	SETTINGS *settings;		/* variables to define */

	char	flags;			/* status info */

# define 	T_FLAG_TEMP 	0x01	/* TEMPORARY applied */
# define 	T_FLAG_NOCARE 	0x02	/* NOCARE applied */
# define 	T_FLAG_NOTFILE 	0x04	/* NOTFILE applied */
# define	T_FLAG_TOUCHED	0x08	/* ALWAYS applied or -t target */
# define	T_FLAG_LEAVES	0x10	/* LEAVES applied */
# define	T_FLAG_NOUPDATE	0x20	/* NOUPDATE applied */

	char	binding;		/* how target relates to real file */

# define 	T_BIND_UNBOUND	0	/* a disembodied name */
# define 	T_BIND_MISSING	1	/* couldn't find real file */
# define 	T_BIND_PARENTS	2	/* using parent's timestamp */
# define 	T_BIND_EXISTS	3	/* real file, timestamp valid */

	TARGETS	*deps[2];		/* dependencies */

# define	T_DEPS_DEPENDS	0	/* due to DEPENDS */
# define	T_DEPS_INCLUDES	1	/* due to INCLUDES */

	time_t	time;			/* update time */
	time_t	leaf;			/* update time of leaf sources */
	time_t	htime;			/* header's time */
	time_t	hleaf;			/* update time of leaf headers */

	char	fate;			/* make0()'s diagnosis */
	char	hfate;			/* collected fate for headers */

# define 	T_FATE_INIT	0	/* nothing done to target */
# define 	T_FATE_MAKING	1	/* make0(target) on stack */

# define 	T_FATE_STABLE	2	/* target didn't need updating */
# define	T_FATE_NEWER	3	/* target newer than parent */

# define	T_FATE_SPOIL	4	/* >= SPOIL rebuilds parents */
# define 	T_FATE_ISTMP	4	/* unneeded temp target oddly present */

# define	T_FATE_BUILD	5	/* >= BUILD rebuilds target */
# define	T_FATE_TOUCHED	5	/* manually touched with -t */
# define	T_FATE_MISSING	6	/* is missing, needs updating */
# define	T_FATE_NEEDTMP	7	/* missing temp that must be rebuild */
# define 	T_FATE_OUTDATED	8	/* is out of date, needs updating */
# define 	T_FATE_UPDATE	9	/* deps updated, needs updating */

# define 	T_FATE_BROKEN	10	/* >= BROKEN ruins parents */
# define 	T_FATE_CANTFIND	10	/* no rules to make missing target */
# define 	T_FATE_CANTMAKE	11	/* can't find dependents */

	char	progress;		/* tracks make1() progress */

# define	T_MAKE_INIT	0	/* make1(target) not yet called */
# define	T_MAKE_ONSTACK	1	/* make1(target) on stack */
# define	T_MAKE_ACTIVE	2	/* make1(target) in make1b() */
# define	T_MAKE_RUNNING	3	/* make1(target) running commands */
# define	T_MAKE_DONE	4	/* make1(target) done */

	char	status;			/* execcmd() result */

	int	asynccnt;		/* child deps outstanding */
	TARGETS	*parents;		/* used by make1() for completion */
	char	*cmds;			/* type-punned command list */
} ;

RULE 	*bindrule( char *rulename );
TARGET *bindtarget( char *targetname );
void 	touchtarget( char *t );
TARGETS *targetlist( TARGETS *chain, LIST  *targets );
TARGETS *targetentry( TARGETS *chain, TARGET *target );
ACTIONS *actionlist( ACTIONS *chain, ACTION *action );
SETTINGS *addsettings( SETTINGS *head, int append, char *symbol, LIST *value );
void 	pushsettings( SETTINGS *v );
void 	popsettings( SETTINGS *v );
void 	freesettings( SETTINGS *v );
void	donerules();
# Change User Description Committed
#12 3065 Perforce staff Support for 'actions ...
maxline value', to set a command
specific maxline (rather than the OS-specific maximum).

Undocumented.
#11 2614 rmg Fix to includes of includes not being considered, broken by 2499.

Details taken from email to jamming:

       The challenge is to make included includes appear as direct
       includes, so that they get considered.  This used to work by
       recursion, because each TARGET node computed the summary of its
       includes -- the hfate and htime -- along with the summary of
       its dependents -- the fate and time.  Alas, that previous
       arrangement confused make1() into treating headers as direct
       dependencies during the build phase.

               A.o
               |
               A.c -- A.h

               (Read depends down, includes across)
               (Failed build of A.h aborts build of A.c)

       The fix to the confused make1() problem was to consolidate the
       special handling of includes by having make0() tack onto a
       target's list of dependendies any of the target's dependents'
       includes.  Unfortunately, this fix did not recurse: if the
       target's dependents' includes included other files, those files
       were not added to the target's dependencies.

               A.o
               |
               A.c -- A.h -- B.h -- C.h

               is rewritten to:

               A.o
               |  \
               A.c A.h -- B.h -- C.h

               (A.o depends on A.h, but not B.h or C.h.  This is
               the current, broken state of jam 2.5rc1.)

       Matt's bugfix added some recursion at this point, by transitively
       appending includes' includes onto the includes chain.  But, as
       he found out (and I did before), this can slow make0() down
       considerably, as typically header files all include each other
       and you wind up with lots of really long chains.

               A.o
               |
               A.c -- A.h -- B.h -- C.h

               is rewritten to:

               A.o
               |
               A.c -- A.h -- B.h -- C.h
                    - B.h  - C.h
                    - C.h

               (Matt's fix: if the .h files include each other, the
                includes chains get very long.)

       The final(?) fix I have is relatively simple, but is an extra
       step:  to have make0() replace a target's includes chain with
       a single pseudo-target whose dependencies are the original
       target's includes.  That pseudo-target gets passed to make0(),
       which then recursively consolidates its fate and time.  This
       then makes a target's includes fate and time available in a
       single target hanging off the original target.

               A.o
               |
               A.c -- A.h -- B.h -- C.h

               is rewritten to:

               A.o
               |   \
               A.c  A.c-includes
                    |    \
                    A.h  A.h-includes
                         |    \
                         B.h  B.h-includes
                              |
                              C.h

               (New pseudo-target xxx-includes recursively consolidates
               fate and time of all included targets.)

       While this new scheme does add a node for every include file,
       it is linear, rather than exponential, and the time is pretty
       much neglible.

User-visible bugfix not documented, because there is no place
in RELNOTES for release-candidate fixes.

Bumped patchlevel to 2.5rc2.
#10 2559 rmg Fix 'var on target ?= value' so that var is only set if it
did not have a target-specific value.  Previously, it would
just overwrite the var's value.

Bug fix documented in RELNOTES.

=== computer:1666: Change 39566 by seiwald@play-seiwald on 2002/12/27 14:44:01
#9 2529 rmg Fix "on target" variables during header scan, from Matt Armstrong.

Setting target-specific variables while under the influence of
the target's target-specific variables caused the _global_ values
to be modified.  This happened both during header file scanning
and with the "on target statement" syntax.

The manifestation of this was if a file #included itself, HdrRule
would accidentally set HDRRULE/HDRSCAN globally, and then all
files (executables, etc) would get scanned for includes.

While this borrows from Matt's fix, it is a slightly different
implementation.

User visible fix documented in RELNOTES.

=== computer:1666: Change 39095 by seiwald@play-seiwald on 2002/12/17 14:00:58
#8 2499 rmg Fix 'includes' support so that included files aren't treated as
direct dependencies during the command execution phase.  If an
included file failed to build, make1() would bypass the including
file.

Now make0() appends each child's 'includes' onto its own 'depends'
list, eliminating 'includes'-specific code in make0() and make1().
This not only fixes the bug, but removes some complexity as well.

Bug fix documented in RELNOTES.

=== computer:1666: Change 38399 by seiwald@play-seiwald on 2002/12/03 16:00:40
#7 2493 rmg Rewrite the past: update all jam's source with comments to
reflect changes since about 2.3, very early 2001.

Whitespace only change.

=== computer:1666: Change 37660 by seiwald@play-seiwald on 2002/11/06 22:41:35

Note: I regenerated jamgram.c on my linux 7.3 system prior to
the submit, since patch was so unhappy trying to lay down the
changes from Christopher's change. Presumably this is just due to
different yacc/bison/whatever particulars on the system where
Christopher made the changes originally. - rmg
#6 2491 rmg Some consting in jam to make it more compilable by C++ compilers.

No functional change.

=== computer:1666: Change 37433 by perforce@perforce on 2002/10/30 16:08:51

Recreational const-ing of jam, for compilers that don't allow
"string" to be passed as a non-const char *.

This included a few places where we were modifying what could
possibly have been read-only storage, oddly enough.

No functional change.

=== computer:1666: Change 37602 by seiwald@play-seiwald on 2002/11/04 17:25:40
#5 2484 rmg Rework make0() to consider headers when deciding whether to
update a temporary source file.  This makes it possible to
have generated, temporary source files that must be regened
because an included header has been updated.

=== computer:1666: Change 35018 by seiwald@play-seiwald on 2002/07/17 10:41:35

Followon to 35018: actually update a "needtmp" target (duh).

=== computer:1666: Change 35023 by seiwald@play-seiwald on 2002/07/17 11:10:16

Fix to 35018, which handled out-of-date header files built from
temporary sources.  Unfortunately, the change made circular header
dependencies (which are legion) get reported.  Now the circular
dependency reporting is done in the call to make0() rather than at
the beginning of make0(), and step 3b (the header recursion)
simply skips that check.

Change to unreleased behavior.

=== computer:1666: Change 36247 by seiwald@waffle-cyg-seiwald on 2002/09/16 16:15:10
#4 2482 rmg Jam.html partial rewrite and the support for named
parameters to rules.

=== computer:1666: Change 34516 by seiwald@play-seiwald on 2002/06/21 23:59:12
#3 1492 Perforce staff Replace action modifiers EXEC_* from compile.h with RULE_* flags
from rules.h.  They've always been the same quantity defined in
two places.  Note that RULE_NEWSRCS is now RULE_UPDATED, to be
consistent with 'actions updated'.

No functional change.
#2 486 Perforce staff Jam 2.3.
 See RELNOTES for a list of changes from 2.2.x.

Just about every source file was touched when jam got ANSI-fied.
#1 2 laura Add Jam/MR 2.2 source