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author | Roland McGrath <roland@redhat.com> | 1991-10-07 22:04:20 +0000 |
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committer | Roland McGrath <roland@redhat.com> | 1991-10-07 22:04:20 +0000 |
commit | 97d38d08176611af5e10ab84e4c812962bf98600 (patch) | |
tree | 67d966aad231da27fcfb620aa4e4573c1d231c48 /variable.c | |
parent | bd3a693fd4cd0f91bc0a6e598dac260438d2acbd (diff) | |
download | make-97d38d08176611af5e10ab84e4c812962bf98600.tar.gz |
Initial revision
Diffstat (limited to 'variable.c')
-rw-r--r-- | variable.c | 768 |
1 files changed, 768 insertions, 0 deletions
diff --git a/variable.c b/variable.c new file mode 100644 index 0000000..019d802 --- /dev/null +++ b/variable.c @@ -0,0 +1,768 @@ +/* Internals of variables for GNU Make. +Copyright (C) 1988, 1989, 1990, 1991 Free Software Foundation, Inc. +This file is part of GNU Make. + +GNU Make is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Make is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Make; see the file COPYING. If not, write to +the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include "make.h" +#include "commands.h" +#include "variable.h" +#include "dep.h" +#include "file.h" + +#ifdef __GNUC__ +#define max(a, b) \ + ({ register int __a = (a), __b = (b); __a > __b ? __a : __b; }) +#else +#define max(a, b) ((a) > (b) ? (a) : (b)) +#endif + + +/* Hash table of all global variable definitions. */ + +#ifndef VARIABLE_BUCKETS +#define VARIABLE_BUCKETS 523 +#endif +#ifndef PERFILE_VARIABLE_BUCKETS +#define PERFILE_VARIABLE_BUCKETS 23 +#endif +#ifndef SMALL_SCOPE_VARIABLE_BUCKETS +#define SMALL_SCOPE_VARIABLE_BUCKETS 13 +#endif +static struct variable *variable_table[VARIABLE_BUCKETS]; +static struct variable_set global_variable_set + = { variable_table, VARIABLE_BUCKETS }; +static struct variable_set_list global_setlist + = { 0, &global_variable_set }; +struct variable_set_list *current_variable_set_list = &global_setlist; + +/* The next two describe the variable output buffer. + This buffer is used to hold the variable-expansion of a line of the + makefile. It is made bigger with realloc whenever it is too small. + variable_buffer_length is the size currently allocated. + variable_buffer is the address of the buffer. */ + +static unsigned int variable_buffer_length; +static char *variable_buffer; + +/* Implement variables. */ + +/* Define variable named NAME with value VALUE in SET. VALUE is copied. + LENGTH is the length of NAME, which does not need to be null-terminated. + ORIGIN specifies the origin of the variable (makefile, command line + or environment). + If RECURSIVE is nonzero a flag is set in the variable saying + that it should be recursively re-expanded. */ + +static struct variable * +define_variable_in_set (name, length, value, origin, recursive, set) + char *name; + unsigned int length; + char *value; + enum variable_origin origin; + int recursive; + struct variable_set *set; +{ + register unsigned int i; + register unsigned int hashval; + register struct variable *v; + + hashval = 0; + for (i = 0; i < length; ++i) + HASH (hashval, name[i]); + hashval %= set->buckets; + + for (v = set->table[hashval]; v != 0; v = v->next) + if (*v->name == *name + && !strncmp (v->name + 1, name + 1, length - 1) + && v->name[length] == '\0') + break; + + if (env_overrides && origin == o_env) + origin = o_env_override; + + if (v != 0) + { + if (env_overrides && v->origin == o_env) + /* V came from in the environment. Since it was defined + before the switches were parsed, it wasn't affected by -e. */ + v->origin = o_env_override; + + /* A variable of this name is already defined. + If the old definition is from a stronger source + than this one, don't redefine it. */ + if ((int) origin >= (int) v->origin) + { + v->value = savestring (value, strlen (value)); + v->origin = origin; + v->recursive = recursive; + } + return v; + } + + /* Create a new variable definition and add it to the hash table. */ + + v = (struct variable *) xmalloc (sizeof (struct variable)); + v->name = savestring (name, length); + v->value = savestring (value, strlen (value)); + v->origin = origin; + v->recursive = recursive; + v->expanding = 0; + v->next = set->table[hashval]; + set->table[hashval] = v; + return v; +} + +/* Define a variable in the current variable set. */ + +struct variable * +define_variable (name, length, value, origin, recursive) + char *name; + unsigned int length; + char *value; + enum variable_origin origin; + int recursive; +{ + return define_variable_in_set (name, length, value, origin, recursive, + current_variable_set_list->set); +} + +/* Define a variable in FILE's variable set. */ + +struct variable * +define_variable_for_file (name, length, value, origin, recursive, file) + char *name; + unsigned int length; + char *value; + enum variable_origin origin; + int recursive; + struct file *file; +{ + return define_variable_in_set (name, length, value, origin, recursive, + file->variables->set); +} + +/* Lookup a variable whose name is a string starting at NAME + and with LENGTH chars. NAME need not be null-terminated. + Returns address of the `struct variable' containing all info + on the variable, or nil if no such variable is defined. */ + +struct variable * +lookup_variable (name, length) + char *name; + unsigned int length; +{ + register struct variable_set_list *setlist; + + register unsigned int i; + register unsigned int rawhash = 0; + + for (i = 0; i < length; ++i) + HASH (rawhash, name[i]); + + for (setlist = current_variable_set_list; + setlist != 0; setlist = setlist->next) + { + register struct variable_set *set = setlist->set; + register unsigned int hashval = rawhash % set->buckets; + register struct variable *v; + + for (v = set->table[hashval]; v != 0; v = v->next) + if (*v->name == *name + && !strncmp (v->name + 1, name + 1, length - 1) + && v->name[length] == 0) + return v; + } + + return 0; +} + +/* Initialize FILE's variable set list. If FILE already has a variable set + list, the topmost variable set is left intact, but the the rest of the + chain is replaced with FILE->parent's setlist. */ + +void +initialize_file_variables (file) + struct file *file; +{ + register struct variable_set_list *l = file->variables; + if (l == 0) + { + l = (struct variable_set_list *) + xmalloc (sizeof (struct variable_set_list)); + l->set = (struct variable_set *) xmalloc (sizeof (struct variable_set)); + l->set->buckets = PERFILE_VARIABLE_BUCKETS; + l->set->table = (struct variable **) + xmalloc (l->set->buckets * sizeof (struct variable *)); + bzero ((char *) l->set->table, + l->set->buckets * sizeof (struct variable *)); + file->variables = l; + } + + if (file->parent == 0) + l->next = &global_setlist; + else + { + if (file->parent->variables == 0) + initialize_file_variables (file->parent); + l->next = file->parent->variables; + } +} + +/* Pop the top set off the current variable set list, + and free all its storage. */ + +void +pop_variable_scope () +{ + register struct variable_set_list *setlist = current_variable_set_list; + register struct variable_set *set = setlist->set; + register unsigned int i; + + current_variable_set_list = setlist->next; + free ((char *) setlist); + + for (i = 0; i < set->buckets; ++i) + { + register struct variable *next = set->table[i]; + while (next != 0) + { + register struct variable *v = next; + next = v->next; + + free (v->name); + free ((char *) v); + } + } + free ((char *) set->table); + free ((char *) set); +} + +/* Create a new variable set and push it on the current setlist. */ + +void +push_new_variable_scope () +{ + register struct variable_set_list *setlist; + register struct variable_set *set; + + set = (struct variable_set *) xmalloc (sizeof (struct variable_set)); + set->buckets = SMALL_SCOPE_VARIABLE_BUCKETS; + set->table = (struct variable **) + xmalloc (set->buckets * sizeof (struct variable *)); + bzero ((char *) set->table, set->buckets * sizeof (struct variable *)); + + setlist = (struct variable_set_list *) + xmalloc (sizeof (struct variable_set_list)); + setlist->set = set; + setlist->next = current_variable_set_list; + current_variable_set_list = setlist; +} + +/* Merge SET1 into SET0, freeing unused storage in SET1. */ + +static void +merge_variable_sets (set0, set1) + struct variable_set *set0, *set1; +{ + register unsigned int bucket1; + + for (bucket1 = 0; bucket1 < set1->buckets; ++bucket1) + { + register struct variable *v1 = set1->table[bucket1]; + while (v1 != 0) + { + struct variable *next = v1->next; + unsigned int bucket0; + register struct variable *v0; + + if (set1->buckets >= set0->buckets) + bucket0 = bucket1; + else + { + register char *n; + bucket0 = 0; + for (n = v1->name; *n != '\0'; ++n) + HASH (bucket0, *n); + } + bucket0 %= set0->buckets; + + for (v0 = set0->table[bucket0]; v0 != 0; v0 = v0->next) + if (streq (v0->name, v1->name)) + break; + + if (v0 == 0) + { + /* There is no variable in SET0 with the same name. */ + v1->next = set0->table[bucket0]; + set0->table[bucket0] = v1; + } + else + { + /* The same variable exists in both sets. + SET0 takes precedence. */ + free (v1->value); + free ((char *) v1); + } + + v1 = next; + } + } +} + +/* Merge SETLIST1 into SETLIST0, freeing unused storage in SETLIST1. */ + +void +merge_variable_set_lists (setlist0, setlist1) + struct variable_set_list **setlist0, *setlist1; +{ + register struct variable_set_list *list0 = *setlist0; + struct variable_set_list *last0 = 0; + + while (setlist1 != 0 && list0 != 0) + { + struct variable_set_list *next = setlist1; + setlist1 = setlist1->next; + + merge_variable_sets (list0->set, next->set); + + free ((char *) next); + + last0 = list0; + list0 = list0->next; + } + + if (setlist1 != 0) + { + if (last0 == 0) + *setlist0 = setlist1; + else + last0->next = setlist1; + } +} + +/* Define the automatic variables, and record the addresses + of their structures so we can change their values quickly. */ + +void +define_automatic_variables () +{ + extern char default_shell[]; + register struct variable *v; + char buf[100]; + + sprintf (buf, "%u", makelevel); + (void) define_variable ("MAKELEVEL", 9, buf, o_env, 0); + + /* This won't override any definition, but it + will provide one if there isn't one there. */ + v = define_variable ("SHELL", 5, default_shell, o_default, 0); + + /* Don't let SHELL come from the environment + if MAKELEVEL is 0. Also, SHELL must not be empty. */ + if (*v->value == '\0' || (v->origin == o_env && makelevel == 0)) + { + v->origin = o_file; + v->value = savestring ("/bin/sh", 7); + } +} + +/* Subroutine of variable_expand and friends: + The text to add is LENGTH chars starting at STRING to the variable_buffer. + The text is added to the buffer at PTR, and the updated pointer into + the buffer is returned as the value. Thus, the value returned by + each call to variable_buffer_output should be the first argument to + the following call. */ + +char * +variable_buffer_output (ptr, string, length) + char *ptr, *string; + unsigned int length; +{ + register unsigned int newlen = length + (ptr - variable_buffer); + + if (newlen > variable_buffer_length) + { + unsigned int offset = ptr - variable_buffer; + variable_buffer_length = max (2 * variable_buffer_length, newlen + 100); + variable_buffer = (char *) xrealloc (variable_buffer, + variable_buffer_length); + ptr = variable_buffer + offset; + } + + bcopy (string, ptr, length); + return ptr + length; +} + +/* Return a pointer to the beginning of the variable buffer. */ + +char * +initialize_variable_output () +{ + /* If we don't have a variable output buffer yet, get one. */ + + if (variable_buffer == 0) + { + variable_buffer_length = 200; + variable_buffer = (char *) xmalloc (variable_buffer_length); + } + + return variable_buffer; +} + +/* Create a new environment for FILE's commands. + The child's MAKELEVEL variable is incremented. */ + +char ** +target_environment (file) + struct file *file; +{ + register struct variable_set_list *s; + struct variable_bucket + { + struct variable_bucket *next; + struct variable *variable; + }; + struct variable_bucket **table; + unsigned int buckets; + register unsigned int i; + register unsigned nvariables; + char **result; + + int noexport = enter_file (".NOEXPORT")->is_target; + + /* Find the lowest number of buckets in any set in the list. */ + s = file->variables; + buckets = s->set->buckets; + for (s = s->next; s != 0; s = s->next) + if (s->set->buckets < buckets) + buckets = s->set->buckets; + + /* Temporarily allocate a table with that many buckets. */ + table = (struct variable_bucket **) + alloca (buckets * sizeof (struct variable_bucket *)); + bzero ((char *) table, buckets * sizeof (struct variable_bucket *)); + + /* Run through all the variable sets in the list, + accumulating variables in TABLE. */ + nvariables = 0; + for (s = file->variables; s != 0; s = s->next) + { + register struct variable_set *set = s->set; + for (i = 0; i < set->buckets; ++i) + { + register struct variable *v; + for (v = set->table[i]; v != 0; v = v->next) + { + extern char *getenv (); + unsigned int j = i % buckets; + register struct variable_bucket *ov; + register char *p = v->name; + + /* If `.NOEXPORT' was specified, only export command-line and + environment variables. This is a temporary (very ugly) hack + until I fix this problem the right way in version 4. Ick. */ + if (noexport + && (v->origin != o_command + && v->origin != o_env && v->origin != o_env_override + && !(v->origin == o_file && getenv (p) != 0))) + continue; + + if (v->origin == o_default + || streq (p, "MAKELEVEL")) + 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')) + break; + if (*p != '\0') + continue; + + for (ov = table[j]; ov != 0; ov = ov->next) + if (streq (v->name, ov->variable->name)) + break; + if (ov == 0) + { + register struct variable_bucket *entry; + entry = (struct variable_bucket *) + alloca (sizeof (struct variable_bucket)); + entry->next = table[j]; + entry->variable = v; + table[j] = entry; + ++nvariables; + } + } + } + } + + result = (char **) xmalloc ((nvariables + 2) * sizeof (char *)); + nvariables = 0; + for (i = 0; i < buckets; ++i) + { + register struct variable_bucket *b; + for (b = table[i]; b != 0; b = b->next) + { + register struct variable *v = b->variable; + result[nvariables++] = concat (v->name, "=", v->value); + } + } + result[nvariables] = (char *) xmalloc (100); + (void) sprintf (result[nvariables], "MAKELEVEL=%u", makelevel + 1); + result[++nvariables] = 0; + + return result; +} + +/* Try to interpret LINE (a null-terminated string) + as a variable definition. If it is one, define the + variable and return 1. Otherwise return 0. + + ORIGIN may be o_file, o_override, o_env, o_env_override, + or o_command specifying that the variable definition comes + from a makefile, an override directive, the environment with + or without the -e switch, or the command line. + + A variable definition has the form "name = value" or "name := value". + Any whitespace around the "=" or ":=" is removed. The first form + defines a variable that is recursively re-evaluated. The second form + defines a variable whose value is variable-expanded at the time of + definition and then is evaluated only once at the time of expansion. */ + +int +try_variable_definition (line, origin) + char *line; + enum variable_origin origin; +{ + register int c; + register char *p = line; + register char *beg; + register char *end; + register int recursive; + + if (*p == '\t') + return 0; + while (1) + { + c = *p++; + if (c == '\0' || c == '#') + return 0; + if (c == '=') + { + recursive = 1; + break; + } + else if (c == ':') + if (*p == '=') + { + ++p; + recursive = 0; + break; + } + else + return 0; + } + + beg = next_token (line); + end = p - 1; + if (!recursive) + --end; + while (isblank (end[-1])) + --end; + p = next_token (p); + + (void) define_variable (beg, end - beg, recursive ? p : variable_expand (p), + origin, recursive); + + return 1; +} + +/* Print information for variable V, prefixing it with PREFIX. */ + +static void +print_variable (v, prefix) + register struct variable *v; + char *prefix; +{ + char *origin; + + switch (v->origin) + { + case o_default: + origin = "default"; + break; + case o_env: + origin = "environment"; + break; + case o_file: + origin = "makefile"; + break; + case o_env_override: + origin = "environment under -e"; + break; + case o_command: + origin = "command line"; + break; + case o_override: + origin = "`override' directive"; + break; + case o_automatic: + origin = "automatic"; + break; + case o_invalid: + default: + abort (); + break; + } + printf ("# %s\n", origin); + + fputs (prefix, stdout); + + /* Is this a `define'? */ + if (v->recursive && index (v->value, '\n') != 0) + printf ("define %s\n%s\nendef\n", v->name, v->value); + else + { + register char *p; + + printf ("%s %s= ", v->name, v->recursive ? "" : ":"); + + /* Check if the value is just whitespace. */ + p = next_token (v->value); + if (p != v->value && *p == '\0') + /* All whitespace. */ + printf ("$(subst ,,%s)", v->value); + else if (v->recursive) + fputs (v->value, stdout); + else + /* Double up dollar signs. */ + for (p = v->value; *p != '\0'; ++p) + { + if (*p == '$') + putchar ('$'); + putchar (*p); + } + putchar ('\n'); + } +} + + +/* Print all the variables in SET. PREFIX is printed before + the actual variable definitions (everything else is comments). */ + +static void +print_variable_set (set, prefix) + register struct variable_set *set; + char *prefix; +{ + register unsigned int i, nvariables, per_bucket; + register struct variable *v; + + per_bucket = nvariables = 0; + for (i = 0; i < set->buckets; ++i) + { + register unsigned int this_bucket = 0; + + for (v = set->table[i]; v != 0; v = v->next) + { + ++this_bucket; + print_variable (v, prefix); + } + + nvariables += this_bucket; + if (this_bucket > per_bucket) + per_bucket = this_bucket; + } + + if (nvariables == 0) + puts ("# No variables."); + else + { + printf ("# %u variables in %u hash buckets.\n", + nvariables, set->buckets); +#ifndef NO_FLOAT + printf ("# average of %.1f variables per bucket, \ +max %u in one bucket.\n", + ((double) nvariables) * 100.0 / (double) set->buckets, + per_bucket); +#endif + } +} + + +/* Print the data base of variables. */ + +void +print_variable_data_base () +{ + puts ("\n# Variables\n"); + + print_variable_set (&global_variable_set, ""); +} + + +/* Print all the local variables of FILE. */ + +void +print_file_variables (file) + struct file *file; +{ + if (file->variables != 0) + print_variable_set (file->variables->set, "# "); +} + +struct output_state + { + char *buffer; + unsigned int length; + }; + +/* Save the current variable output state and return a pointer + to storage describing it. Then reset the output state. */ + +char * +save_variable_output () +{ + struct output_state *state; + + state = (struct output_state *) xmalloc (sizeof (struct output_state)); + state->buffer = variable_buffer; + state->length = variable_buffer_length; + + variable_buffer = 0; + variable_buffer_length = 0; + + return (char *) state; +} + +/* Restore the variable output state saved in SAVE. */ + +void +restore_variable_output (save) + char *save; +{ + register struct output_state *state = (struct output_state *) save; + + if (variable_buffer != 0) + free (variable_buffer); + + variable_buffer = state->buffer; + variable_buffer_length = state->length; + + free ((char *) state); +} |