bullet3/jam-2.5/variable.c
2006-05-25 19:18:29 +00:00

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/*
* Copyright 1993-2002 Christopher Seiwald and Perforce Software, Inc.
*
* This file is part of Jam - see jam.c for Copyright information.
*/
/*
* variable.c - handle jam multi-element variables
*
* External routines:
*
* var_defines() - load a bunch of variable=value settings
* var_string() - expand a string with variables in it
* var_get() - get value of a user defined symbol
* var_set() - set a variable in jam's user defined symbol table
* var_swap() - swap a variable's value with the given one
* var_done() - free variable tables
*
* Internal routines:
*
* var_enter() - make new var symbol table entry, returning var ptr
* var_dump() - dump a variable to stdout
*
* 04/13/94 (seiwald) - added shorthand L0 for null list pointer
* 08/23/94 (seiwald) - Support for '+=' (append to variable)
* 01/22/95 (seiwald) - split environment variables at blanks or :'s
* 05/10/95 (seiwald) - split path variables at SPLITPATH (not :)
* 09/11/00 (seiwald) - defunct var_list() removed
* 10/22/02 (seiwald) - list_new() now does its own newstr()/copystr()
* 11/04/02 (seiwald) - const-ing for string literals
*/
# include "jam.h"
# include "lists.h"
# include "parse.h"
# include "variable.h"
# include "expand.h"
# include "hash.h"
# include "newstr.h"
static struct hash *varhash = 0;
/*
* VARIABLE - a user defined multi-value variable
*/
typedef struct _variable VARIABLE ;
struct _variable {
const char *symbol;
LIST *value;
} ;
static VARIABLE *var_enter( const char *symbol );
static void var_dump( const char *symbol, LIST *value, const char *what );
/*
* var_defines() - load a bunch of variable=value settings
*
* If variable name ends in PATH, split value at :'s.
* Otherwise, split at blanks.
*/
void
var_defines( const char **e )
{
for( ; *e; e++ )
{
const char *val;
/* Just say "no": windows defines this in the env, */
/* but we don't want it to override our notion of OS. */
if( !strcmp( *e, "OS=Windows_NT" ) )
continue;
# ifdef OS_MAC
/* On the mac (MPW), the var=val is actually var\0val */
/* Think different. */
if( ( val = strchr( *e, '=' ) ) || ( val = *e + strlen( *e ) ) )
# else
if( val = strchr( *e, '=' ) )
# endif
{
LIST *l = L0;
const char *pp, *p;
# ifdef OS_MAC
char split = ',';
# else
char split = ' ';
# endif
char buf[ MAXSYM ];
/* Split *PATH at :'s, not spaces */
if( val - 4 >= *e )
{
if( !strncmp( val - 4, "PATH", 4 ) ||
!strncmp( val - 4, "Path", 4 ) ||
!strncmp( val - 4, "path", 4 ) )
split = SPLITPATH;
}
/* Do the split */
for( pp = val + 1; p = strchr( pp, split ); pp = p + 1 )
{
strncpy( buf, pp, p - pp );
buf[ p - pp ] = '\0';
l = list_new( l, buf, 0 );
}
l = list_new( l, pp, 0 );
/* Get name */
strncpy( buf, *e, val - *e );
buf[ val - *e ] = '\0';
var_set( buf, l, VAR_SET );
}
}
}
/*
* var_string() - expand a string with variables in it
*
* Copies in to out; doesn't modify targets & sources.
*/
int
var_string(
const char *in,
char *out,
int outsize,
LOL *lol )
{
char *out0 = out;
char *oute = out + outsize - 1;
while( *in )
{
char *lastword;
int dollar = 0;
/* Copy white space */
while( isspace( *in ) )
{
if( out >= oute )
return -1;
*out++ = *in++;
}
lastword = out;
/* Copy non-white space, watching for variables */
while( *in && !isspace( *in ) )
{
if( out >= oute )
return -1;
if( in[0] == '$' && in[1] == '(' )
dollar++;
*out++ = *in++;
}
/* If a variable encountered, expand it and and embed the */
/* space-separated members of the list in the output. */
if( dollar )
{
LIST *l = var_expand( L0, lastword, out, lol, 0 );
out = lastword;
while( l )
{
int so = strlen( l->string );
if( out + so >= oute )
return -1;
strcpy( out, l->string );
out += so;
/* Separate with space */
if( l = list_next( l ) )
*out++ = ' ';
}
list_free( l );
}
}
if( out >= oute )
return -1;
*out++ = '\0';
return out - out0;
}
/*
* var_get() - get value of a user defined symbol
*
* Returns NULL if symbol unset.
*/
LIST *
var_get( const char *symbol )
{
VARIABLE var, *v = &var;
v->symbol = symbol;
if( varhash && hashcheck( varhash, (HASHDATA **)&v ) )
{
if( DEBUG_VARGET )
var_dump( v->symbol, v->value, "get" );
return v->value;
}
return 0;
}
/*
* var_set() - set a variable in jam's user defined symbol table
*
* 'flag' controls the relationship between new and old values of
* the variable: SET replaces the old with the new; APPEND appends
* the new to the old; DEFAULT only uses the new if the variable
* was previously unset.
*
* Copies symbol. Takes ownership of value.
*/
void
var_set(
const char *symbol,
LIST *value,
int flag )
{
VARIABLE *v = var_enter( symbol );
if( DEBUG_VARSET )
var_dump( symbol, value, "set" );
switch( flag )
{
case VAR_SET:
/* Replace value */
list_free( v->value );
v->value = value;
break;
case VAR_APPEND:
/* Append value */
v->value = list_append( v->value, value );
break;
case VAR_DEFAULT:
/* Set only if unset */
if( !v->value )
v->value = value;
else
list_free( value );
break;
}
}
/*
* var_swap() - swap a variable's value with the given one
*/
LIST *
var_swap(
const char *symbol,
LIST *value )
{
VARIABLE *v = var_enter( symbol );
LIST *oldvalue = v->value;
if( DEBUG_VARSET )
var_dump( symbol, value, "set" );
v->value = value;
return oldvalue;
}
/*
* var_enter() - make new var symbol table entry, returning var ptr
*/
static VARIABLE *
var_enter( const char *symbol )
{
VARIABLE var, *v = &var;
if( !varhash )
varhash = hashinit( sizeof( VARIABLE ), "variables" );
v->symbol = symbol;
v->value = 0;
if( hashenter( varhash, (HASHDATA **)&v ) )
v->symbol = newstr( symbol ); /* never freed */
return v;
}
/*
* var_dump() - dump a variable to stdout
*/
static void
var_dump(
const char *symbol,
LIST *value,
const char *what )
{
printf( "%s %s = ", what, symbol );
list_print( value );
printf( "\n" );
}
/*
* var_done() - free variable tables
*/
void
var_done()
{
hashdone( varhash );
}