Home | History | Annotate | Download | only in make-3.81
      1 /* Definitions for using variables in GNU Make.
      2 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
      3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software
      4 Foundation, Inc.
      5 This file is part of GNU Make.
      6 
      7 GNU Make is free software; you can redistribute it and/or modify it under the
      8 terms of the GNU General Public License as published by the Free Software
      9 Foundation; either version 2, or (at your option) any later version.
     10 
     11 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
     12 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
     13 A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
     14 
     15 You should have received a copy of the GNU General Public License along with
     16 GNU Make; see the file COPYING.  If not, write to the Free Software
     17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.  */
     18 
     19 #include "hash.h"
     20 
     21 /* Codes in a variable definition saying where the definition came from.
     22    Increasing numeric values signify less-overridable definitions.  */
     23 enum variable_origin
     24   {
     25     o_default,		/* Variable from the default set.  */
     26     o_env,		/* Variable from environment.  */
     27     o_file,		/* Variable given in a makefile.  */
     28     o_env_override,	/* Variable from environment, if -e.  */
     29     o_command,		/* Variable given by user.  */
     30     o_override, 	/* Variable from an `override' directive.  */
     31     o_automatic,	/* Automatic variable -- cannot be set.  */
     32     o_invalid		/* Core dump time.  */
     33   };
     34 
     35 enum variable_flavor
     36   {
     37     f_bogus,            /* Bogus (error) */
     38     f_simple,           /* Simple definition (:=) */
     39     f_recursive,        /* Recursive definition (=) */
     40     f_append,           /* Appending definition (+=) */
     41     f_conditional       /* Conditional definition (?=) */
     42   };
     43 
     44 /* Structure that represents one variable definition.
     45    Each bucket of the hash table is a chain of these,
     46    chained through `next'.  */
     47 
     48 #define EXP_COUNT_BITS  15      /* This gets all the bitfields into 32 bits */
     49 #define EXP_COUNT_MAX   ((1<<EXP_COUNT_BITS)-1)
     50 
     51 struct variable
     52   {
     53     char *name;			/* Variable name.  */
     54     int length;			/* strlen (name) */
     55     char *value;		/* Variable value.  */
     56     struct floc fileinfo;       /* Where the variable was defined.  */
     57     unsigned int recursive:1;	/* Gets recursively re-evaluated.  */
     58     unsigned int append:1;	/* Nonzero if an appending target-specific
     59                                    variable.  */
     60     unsigned int conditional:1; /* Nonzero if set with a ?=. */
     61     unsigned int per_target:1;	/* Nonzero if a target-specific variable.  */
     62     unsigned int special:1;     /* Nonzero if this is a special variable. */
     63     unsigned int exportable:1;  /* Nonzero if the variable _could_ be
     64                                    exported.  */
     65     unsigned int expanding:1;	/* Nonzero if currently being expanded.  */
     66     unsigned int exp_count:EXP_COUNT_BITS;
     67                                 /* If >1, allow this many self-referential
     68                                    expansions.  */
     69     enum variable_flavor
     70       flavor ENUM_BITFIELD (3);	/* Variable flavor.  */
     71     enum variable_origin
     72       origin ENUM_BITFIELD (3);	/* Variable origin.  */
     73     enum variable_export
     74       {
     75 	v_export,		/* Export this variable.  */
     76 	v_noexport,		/* Don't export this variable.  */
     77 	v_ifset,		/* Export it if it has a non-default value.  */
     78 	v_default		/* Decide in target_environment.  */
     79       } export ENUM_BITFIELD (2);
     80   };
     81 
     82 /* Structure that represents a variable set.  */
     83 
     84 struct variable_set
     85   {
     86     struct hash_table table;	/* Hash table of variables.  */
     87   };
     88 
     89 /* Structure that represents a list of variable sets.  */
     90 
     91 struct variable_set_list
     92   {
     93     struct variable_set_list *next;	/* Link in the chain.  */
     94     struct variable_set *set;		/* Variable set.  */
     95   };
     96 
     97 /* Structure used for pattern-specific variables.  */
     98 
     99 struct pattern_var
    100   {
    101     struct pattern_var *next;
    102     char *target;
    103     unsigned int len;
    104     char *suffix;
    105     struct variable variable;
    106   };
    107 
    108 extern char *variable_buffer;
    109 extern struct variable_set_list *current_variable_set_list;
    110 
    111 /* expand.c */
    112 extern char *variable_buffer_output PARAMS ((char *ptr, char *string, unsigned int length));
    113 extern char *variable_expand PARAMS ((char *line));
    114 extern char *variable_expand_for_file PARAMS ((char *line, struct file *file));
    115 extern char *allocated_variable_expand_for_file PARAMS ((char *line, struct file *file));
    116 #define	allocated_variable_expand(line) \
    117   allocated_variable_expand_for_file (line, (struct file *) 0)
    118 extern char *expand_argument PARAMS ((const char *str, const char *end));
    119 extern char *variable_expand_string PARAMS ((char *line, char *string,
    120                                              long length));
    121 extern void install_variable_buffer PARAMS ((char **bufp, unsigned int *lenp));
    122 extern void restore_variable_buffer PARAMS ((char *buf, unsigned int len));
    123 
    124 /* function.c */
    125 extern int handle_function PARAMS ((char **op, char **stringp));
    126 extern int pattern_matches PARAMS ((char *pattern, char *percent, char *str));
    127 extern char *subst_expand PARAMS ((char *o, char *text, char *subst, char *replace,
    128 		unsigned int slen, unsigned int rlen, int by_word));
    129 extern char *patsubst_expand PARAMS ((char *o, char *text, char *pattern, char *replace,
    130 		char *pattern_percent, char *replace_percent));
    131 
    132 /* expand.c */
    133 extern char *recursively_expand_for_file PARAMS ((struct variable *v,
    134                                                   struct file *file));
    135 #define recursively_expand(v)   recursively_expand_for_file (v, NULL)
    136 
    137 /* variable.c */
    138 extern struct variable_set_list *create_new_variable_set PARAMS ((void));
    139 extern void free_variable_set PARAMS ((struct variable_set_list *));
    140 extern struct variable_set_list *push_new_variable_scope PARAMS ((void));
    141 extern void pop_variable_scope PARAMS ((void));
    142 extern void define_automatic_variables PARAMS ((void));
    143 extern void initialize_file_variables PARAMS ((struct file *file, int read));
    144 extern void print_file_variables PARAMS ((struct file *file));
    145 extern void print_variable_set PARAMS ((struct variable_set *set, char *prefix));
    146 extern void merge_variable_set_lists PARAMS ((struct variable_set_list **to_list, struct variable_set_list *from_list));
    147 extern struct variable *do_variable_definition PARAMS ((const struct floc *flocp, const char *name, char *value, enum variable_origin origin, enum variable_flavor flavor, int target_var));
    148 extern struct variable *parse_variable_definition PARAMS ((struct variable *v, char *line));
    149 extern struct variable *try_variable_definition PARAMS ((const struct floc *flocp, char *line, enum variable_origin origin, int target_var));
    150 extern void init_hash_global_variable_set PARAMS ((void));
    151 extern void hash_init_function_table PARAMS ((void));
    152 extern struct variable *lookup_variable PARAMS ((const char *name, unsigned int length));
    153 extern struct variable *lookup_variable_in_set PARAMS ((const char *name,
    154                                                         unsigned int length,
    155                                                         const struct variable_set *set));
    156 
    157 extern struct variable *define_variable_in_set
    158     PARAMS ((const char *name, unsigned int length, char *value,
    159              enum variable_origin origin, int recursive,
    160              struct variable_set *set, const struct floc *flocp));
    161 
    162 /* Define a variable in the current variable set.  */
    163 
    164 #define define_variable(n,l,v,o,r) \
    165           define_variable_in_set((n),(l),(v),(o),(r),\
    166                                  current_variable_set_list->set,NILF)
    167 
    168 /* Define a variable with a location in the current variable set.  */
    169 
    170 #define define_variable_loc(n,l,v,o,r,f) \
    171           define_variable_in_set((n),(l),(v),(o),(r),\
    172                                  current_variable_set_list->set,(f))
    173 
    174 /* Define a variable with a location in the global variable set.  */
    175 
    176 #define define_variable_global(n,l,v,o,r,f) \
    177           define_variable_in_set((n),(l),(v),(o),(r),NULL,(f))
    178 
    179 /* Define a variable in FILE's variable set.  */
    180 
    181 #define define_variable_for_file(n,l,v,o,r,f) \
    182           define_variable_in_set((n),(l),(v),(o),(r),(f)->variables->set,NILF)
    183 
    184 /* Warn that NAME is an undefined variable.  */
    185 
    186 #define warn_undefined(n,l) do{\
    187                               if (warn_undefined_variables_flag) \
    188                                 error (reading_file, \
    189                                        _("warning: undefined variable `%.*s'"), \
    190                                 (int)(l), (n)); \
    191                               }while(0)
    192 
    193 extern char **target_environment PARAMS ((struct file *file));
    194 
    195 extern struct pattern_var *create_pattern_var PARAMS ((char *target, char *suffix));
    196 
    197 extern int export_all_variables;
    198 
    199 #define MAKELEVEL_NAME "MAKELEVEL"
    200 #define MAKELEVEL_LENGTH (sizeof (MAKELEVEL_NAME) - 1)
    201