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diff --git a/implicit.c b/implicit.c
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+/* Implicit rule searching 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 "rule.h"
+#include "dep.h"
+#include "file.h"
+
+static int pattern_search ();
+
+/* For a FILE which has no commands specified, try to figure out some
+ from the implicit pattern rules.
+ Returns 1 if a suitable implicit rule was found,
+ after modifying FILE to contain the appropriate commands and deps,
+ or returns 0 if no implicit rule was found. */
+
+int
+try_implicit_rule (file, depth)
+ struct file *file;
+ unsigned int depth;
+{
+ DEBUGPR ("Looking for an implicit rule for `%s'.\n");
+
+#ifndef NO_ARCHIVES
+ /* If this is an archive member reference, use just the
+ archive member name to search for implicit rules. */
+ if (ar_name (file->name))
+ {
+ DEBUGPR ("Looking for archive-member implicit rule for `%s'.\n");
+ if (pattern_search (file, 1, depth, 0))
+ return 1;
+ }
+#endif
+
+ return pattern_search (file, 0, depth, 0);
+}
+
+#define DEBUGP2(msg, a1, a2) \
+ if (debug_flag) \
+ { print_spaces (depth); printf (msg, a1, a2); fflush (stdout); } else
+
+/* Search the pattern rules for a rule with an existing dependency to make
+ FILE. If a rule is found, the appropriate commands and deps are put in FILE
+ and 1 is returned. If not, 0 is returned.
+
+ If ARCHIVE is nonzero, FILE->name is of the form "LIB(MEMBER)". A rule for
+ "(MEMBER)" will be searched for, and "(MEMBER)" will not be chopped up into
+ directory and filename parts.
+
+ If an intermediate file is found by pattern search, the intermediate file
+ is set up as a target by the recursive call and is also made a dependency
+ of FILE.
+
+ DEPTH is used for debugging messages. */
+
+static int
+pattern_search (file, archive, depth, recursions)
+ struct file *file;
+ int archive;
+ unsigned int depth;
+ unsigned int recursions;
+{
+ /* Filename we are searching for a rule for. */
+ char *filename = archive ? index (file->name, '(') : file->name;
+
+ /* Length of FILENAME. */
+ unsigned int namelen = strlen (filename);
+
+ /* The last slash in FILENAME (or nil if there is none). */
+ char *lastslash;
+
+ /* This is a file-object used as an argument in
+ recursive calls. It never contains any data
+ except during a recursive call. */
+ struct file *intermediate_file = 0;
+
+ /* List of dependencies found recursively. */
+ struct file **intermediate_files
+ = (struct file **) alloca (max_pattern_deps * sizeof (struct file *));
+
+ /* List of the patterns used to find intermediate files. */
+ char **intermediate_patterns
+ = (char **) alloca (max_pattern_deps * sizeof (char *));
+
+ /* This buffer records all the dependencies actually found for a rule. */
+ char **found_files = (char **) alloca (max_pattern_deps * sizeof (char *));
+ /* Number of dep names now in FOUND_FILES. */
+ unsigned int deps_found;
+
+ /* Names of possible dependencies are constructed in this buffer. */
+ register char *depname = (char *) alloca (namelen + max_pattern_dep_length);
+
+ /* The start and length of the stem of FILENAME for the current rule. */
+ register char *stem;
+ register unsigned int stemlen;
+
+ /* Buffer in which we store all the rules that are possibly applicable. */
+ struct rule **tryrules
+ = (struct rule **) alloca (num_pattern_rules * sizeof (struct rule *));
+
+ /* Number of valid elements in TRYRULES. */
+ unsigned int nrules;
+
+ /* The numbers of the rule targets of each rule
+ in TRYRULES that matched the target file. */
+ unsigned int *matches
+ = (unsigned int *) alloca (num_pattern_rules * sizeof (unsigned int));
+
+ /* Each element is nonzero if LASTSLASH was used in
+ matching the corresponding element of TRYRULES. */
+ char *checked_lastslash
+ = (char *) alloca (num_pattern_rules * sizeof (char));
+
+ /* The index in TRYRULES of the rule we found. */
+ unsigned int foundrule;
+
+ /* Nonzero if should consider intermediate files as dependencies. */
+ int intermed_ok;
+
+ /* Nonzero if we have matched a pattern-rule target
+ that is not just `%'. */
+ int specific_rule_matched = 0;
+
+ register unsigned int i;
+ register struct rule *rule;
+ register struct dep *dep;
+
+ char *p;
+
+#ifndef NO_ARCHIVES
+ if (archive || ar_name (filename))
+ lastslash = 0;
+ else
+#endif
+ {
+ /* Set LASTSLASH to point at the last slash in FILENAME
+ but not counting any slash at the end. (foo/bar/ counts as
+ bar/ in directory foo/, not empty in directory foo/bar/.) */
+ lastslash = rindex (filename, '/');
+ if (lastslash != 0 && lastslash[1] == '\0')
+ lastslash = 0;
+ }
+
+ /* First see which pattern rules match this target
+ and may be considered. Put them in TRYRULES. */
+
+ nrules = 0;
+ for (rule = pattern_rules; rule != 0; rule = rule->next)
+ {
+ int specific_rule_may_have_matched = 0;
+ int check_lastslash;
+
+ /* If the pattern rule has deps but no commands, ignore it.
+ Users cancel built-in rules by redefining them without commands. */
+ if (rule->deps != 0 && rule->cmds == 0)
+ continue;
+
+ /* If this rule is in use by a parent pattern_search,
+ don't use it here. */
+ if (rule->in_use)
+ {
+ DEBUGP2 ("Avoiding implicit rule recursion.\n", 0, 0);
+ continue;
+ }
+
+ for (i = 0; rule->targets[i] != 0; ++i)
+ {
+ char *target = rule->targets[i];
+ char *suffix = rule->suffixes[i];
+
+ /* Rules that can match any filename and are not terminal
+ are ignored if we're recursing, so that they cannot be
+ intermediate files. */
+ if (recursions > 0 && target[1] == '\0' && !rule->terminal)
+ continue;
+
+ if (rule->lens[i] > namelen)
+ /* It can't possibly match. */
+ continue;
+
+ /* From the lengths of the filename and the pattern parts,
+ find the stem: the part of the filename that matches the %. */
+ stem = filename + (suffix - target - 1);
+ stemlen = namelen - rule->lens[i] + 1;
+
+ /* Set CHECK_LASTSLASH if FILENAME contains a directory
+ prefix and the target pattern does not contain a slash. */
+
+ check_lastslash = lastslash != 0 && index (target, '/') == 0;
+ if (check_lastslash)
+ {
+ /* In that case, don't include the
+ directory prefix in STEM here. */
+ unsigned int difference = lastslash - filename + 1;
+ if (difference > stemlen)
+ continue;
+ stemlen -= difference;
+ stem += difference;
+ }
+
+ /* Check that the rule pattern matches the text before the stem. */
+ if (check_lastslash)
+ {
+ if (stem > (lastslash + 1)
+ && strncmp (target, lastslash + 1, stem - lastslash - 1))
+ continue;
+ }
+ else if (stem > filename
+ && strncmp (target, filename, stem - filename))
+ continue;
+
+ /* Check that the rule pattern matches the text after the stem.
+ We could test simply use streq, but this way we compare the
+ first two characters immediately. This saves time in the very
+ common case where the first character matches because it is a
+ period. */
+ if (*suffix != stem[stemlen]
+ || (*suffix != '\0' && !streq (&suffix[1], &stem[stemlen + 1])))
+ continue;
+
+ /* Record if we match a rule that not all filenames will match. */
+ if (target[1] != '\0')
+ specific_rule_may_have_matched = 1;
+
+ /* We have a matching target. Don't search for any more. */
+ break;
+ }
+
+ /* None of the targets matched. */
+ if (rule->targets[i] == 0)
+ continue;
+
+ specific_rule_matched |= specific_rule_may_have_matched;
+
+ /* A rule with no dependencies and no commands exists solely to set
+ specific_rule_matched when it matches. Don't try to use it. */
+ if (rule->deps == 0 && rule->cmds == 0)
+ continue;
+
+ /* Record this rule in TRYRULES and the index
+ of the (first) matching target in MATCHES. */
+ tryrules[nrules] = rule;
+ matches[nrules] = i;
+ checked_lastslash[nrules] = check_lastslash;
+ ++nrules;
+ }
+
+ /* If we have found a matching rule that won't match all filenames,
+ retroactively reject any "terminal" rules that do always match. */
+ if (specific_rule_matched)
+ for (i = 0; i < nrules; ++i)
+ if (!tryrules[i]->terminal)
+ {
+ register unsigned int j;
+ for (j = 0; tryrules[i]->targets[j] != 0; ++j)
+ if (tryrules[i]->targets[j][1] == '\0')
+ break;
+ if (tryrules[i]->targets[j] != 0)
+ tryrules[i] = 0;
+ }
+
+ /* Try each rule once without intermediate files, then once with them. */
+ for (intermed_ok = 0; intermed_ok == !!intermed_ok; ++intermed_ok)
+ {
+ /* Try each pattern rule till we find one that applies.
+ If it does, copy the names of its dependencies (as substituted)
+ and store them in FOUND_FILES. DEPS_FOUND is the number of them. */
+
+ for (i = 0; i < nrules; i++)
+ {
+ int check_lastslash;
+
+ rule = tryrules[i];
+
+ /* RULE is nil when we discover that a rule,
+ already placed in TRYRULES, should not be applied. */
+ if (rule == 0)
+ continue;
+
+ /* Reject any terminal rules if we're
+ looking to make intermediate files. */
+ if (intermed_ok && rule->terminal)
+ continue;
+
+ /* Mark this rule as in use so a recursive
+ pattern_search won't try to use it. */
+ rule->in_use = 1;
+
+ /* From the lengths of the filename and the matching pattern parts,
+ find the stem: the part of the filename that matches the %. */
+ stem = filename
+ + (rule->suffixes[matches[i]] - rule->targets[matches[i]]) - 1;
+ stemlen = namelen - rule->lens[matches[i]] + 1;
+ check_lastslash = (lastslash != 0
+ && index (rule->targets[matches[i]], '/') == 0);
+ if (check_lastslash)
+ {
+ stem += lastslash - filename + 1;
+ stemlen -= (lastslash - filename) + 1;
+ }
+
+ DEBUGP2 ("Trying pattern rule with stem `%.*s'.\n",
+ stemlen, stem);
+
+ /* Try each dependency; see if it "exists". */
+
+ deps_found = 0;
+ for (dep = rule->deps; dep != 0; dep = dep->next)
+ {
+ /* If the dependency name has a %, substitute the stem. */
+ p = index (dep_name (dep), '%');
+ if (p != 0)
+ {
+ register unsigned int i;
+ if (check_lastslash)
+ {
+ i = lastslash - filename + 1;
+ bcopy (filename, depname, i);
+ }
+ else
+ i = 0;
+ bcopy (dep_name (dep), depname + i, p - dep_name (dep));
+ i += p - dep_name (dep);
+ bcopy (stem, depname + i, stemlen);
+ i += stemlen;
+ strcpy (depname + i, p + 1);
+ p = depname;
+ }
+ else
+ p = dep_name (dep);
+
+ /* P is now the actual dependency name as substituted. */
+
+ if (file_impossible_p (p))
+ {
+ /* If this dependency has already been ruled
+ "impossible", then the rule fails and don't
+ bother trying it on the second pass either
+ since we know that will fail too. */
+ DEBUGP2 ("Rejecting impossible %s dependent `%s'.\n",
+ p == depname ? "implicit" : "rule", p);
+ tryrules[i] = 0;
+ break;
+ }
+
+ intermediate_files[deps_found] = 0;
+
+ DEBUGP2 ("Trying %s dependency `%s'.\n",
+ p == depname ? "implicit" : "rule", p);
+ if (!rule->subdir && lookup_file (p) != 0 || file_exists_p (p))
+ {
+ found_files[deps_found++] = savestring (p, strlen (p));
+ continue;
+ }
+ /* This code, given FILENAME = "lib/foo.o", dependency name
+ "lib/foo.c", and VPATH=src, searches for "src/lib/foo.c". */
+ if (vpath_search (&p))
+ {
+ DEBUGP2 ("Found dependent as `%s'.\n", p, 0);
+ found_files[deps_found++] = p;
+ continue;
+ }
+
+ /* We could not find the file in any place we should look.
+ Try to make this dependency as an intermediate file,
+ but only on the second pass. */
+
+ if (intermed_ok)
+ {
+ if (intermediate_file == 0)
+ intermediate_file
+ = (struct file *) alloca (sizeof (struct file));
+
+ DEBUGP2 ("Looking for a rule with intermediate file `%s'.\n",
+ p, 0);
+
+ bzero ((char *) intermediate_file, sizeof (struct file));
+ intermediate_file->name = p;
+ if (pattern_search (intermediate_file, 0, depth + 1,
+ recursions + 1))
+ {
+ p = savestring (p, strlen (p));
+ intermediate_patterns[deps_found]
+ = intermediate_file->name;
+ found_files[deps_found] = p;
+ intermediate_file->name = p;
+ intermediate_files[deps_found] = intermediate_file;
+ intermediate_file = 0;
+ ++deps_found;
+ continue;
+ }
+
+ /* If we have tried to find P as an intermediate
+ file and failed, mark that name as impossible
+ so we won't go through the search again later. */
+ file_impossible (p);
+ }
+
+ /* A dependency of this rule does not exist.
+ Therefore, this rule fails. */
+ break;
+ }
+
+ /* This rule is no longer `in use' for recursive searches. */
+ rule->in_use = 0;
+
+ if (dep != 0)
+ {
+ /* This pattern rule does not apply.
+ If some of its dependencies succeeded,
+ free the data structure describing them. */
+ while (deps_found-- > 0)
+ {
+ register struct file *f = intermediate_files[deps_found];
+ free (found_files[deps_found]);
+ if (f != 0
+ && (f->stem < f->name
+ || f->stem > f->name + strlen (f->name)))
+ free (f->stem);
+ }
+ }
+ else
+ /* This pattern rule does apply. Stop looking for one. */
+ break;
+ }
+
+ /* If we found an applicable rule without
+ intermediate files, don't try with them. */
+ if (i < nrules)
+ break;
+
+ rule = 0;
+ }
+
+ /* RULE is nil if the loop went all the way
+ through the list and everything failed. */
+ if (rule == 0)
+ return 0;
+
+ foundrule = i;
+
+ /* If we are recursing, store the pattern that matched
+ FILENAME in FILE->name for use in upper levels. */
+
+ if (recursions > 0)
+ /* Kludge-o-matic */
+ file->name = rule->targets[matches[foundrule]];
+
+ /* FOUND_FILES lists the dependencies for the rule we found.
+ This includes the intermediate files, if any.
+ Convert them into entries on the deps-chain of FILE. */
+
+ while (deps_found-- > 0)
+ {
+ register char *s;
+
+ if (intermediate_files[deps_found] != 0)
+ {
+ /* If we need to use an intermediate file,
+ make sure it is entered as a target, with the info that was
+ found for it in the recursive pattern_search call.
+ We know that the intermediate file did not already exist as
+ a target; therefore we can assume that the deps and cmds
+ of F below are null before we change them. */
+
+ struct file *imf = intermediate_files[deps_found];
+ register struct file *f = enter_file (imf->name);
+ f->deps = imf->deps;
+ f->cmds = imf->cmds;
+ f->stem = imf->stem;
+ imf = lookup_file (intermediate_patterns[deps_found]);
+ if (imf != 0 && imf->precious)
+ f->precious = 1;
+ f->intermediate = 1;
+ f->tried_implicit = 1;
+ for (dep = f->deps; dep != 0; dep = dep->next)
+ {
+ dep->file = enter_file (dep->name);
+ dep->name = 0;
+ dep->file->tried_implicit |= dep->changed;
+ }
+ num_intermediates++;
+ }
+
+ dep = (struct dep *) xmalloc (sizeof (struct dep));
+ s = found_files[deps_found];
+ if (recursions == 0)
+ {
+ dep->name = 0;
+ dep->file = enter_file (s);
+ }
+ else
+ {
+ dep->name = s;
+ dep->file = 0;
+ dep->changed = 0;
+ }
+ if (intermediate_files[deps_found] == 0 && tryrules[foundrule]->terminal)
+ {
+ /* If the file actually existed (was not an intermediate file),
+ and the rule that found it was a terminal one, then we want
+ to mark the found file so that it will not have implicit rule
+ search done for it. If we are not entering a `struct file' for
+ it now, we indicate this with the `changed' flag. */
+ if (dep->file == 0)
+ dep->changed = 1;
+ else
+ dep->file->tried_implicit = 1;
+ }
+ dep->next = file->deps;
+ file->deps = dep;
+ }
+
+ uniquize_deps (file->deps);
+
+ if (!checked_lastslash[foundrule])
+ file->stem = stem[stemlen] == '\0' ? stem : savestring (stem, stemlen);
+ else
+ {
+ file->stem = (char *) xmalloc (((lastslash + 1) - filename)
+ + stemlen + 1);
+ bcopy (filename, file->stem, (lastslash + 1) - filename);
+ bcopy (stem, file->stem + ((lastslash + 1) - filename), stemlen);
+ file->stem[((lastslash + 1) - filename) + stemlen] = '\0';
+ }
+
+ file->cmds = rule->cmds;
+
+ /* Put the targets other than the one that
+ matched into FILE's `also_make' member. */
+
+ /* If there was only one target, there is nothing to do. */
+ if (rule->targets[1] != 0)
+ {
+ unsigned int max_targets = 2;
+ register unsigned int idx;
+
+ file->also_make = (char **) xmalloc (2 * sizeof (char *));
+
+ idx = 0;
+ for (i = 0; rule->targets[i] != 0; ++i)
+ if (i != matches[foundrule])
+ {
+ if (idx == max_targets - 1)
+ {
+ max_targets += 5;
+ file->also_make
+ = (char **) xrealloc ((char *) file->also_make,
+ max_targets * sizeof (char *));
+ }
+
+ p = file->also_make[idx++] = (char *) xmalloc (rule->lens[i] +
+ stemlen + 1);
+ bcopy (rule->targets[i], p,
+ rule->suffixes[i] - rule->targets[i] - 1);
+ p += rule->suffixes[i] - rule->targets[i] - 1;
+ bcopy (stem, p, stemlen);
+ p += stemlen;
+ bcopy (rule->suffixes[i], p,
+ rule->lens[i]
+ - (rule->suffixes[i] - rule->targets[i] - 1) + 1);
+ }
+
+ file->also_make[idx] = 0;
+ if (idx < max_targets - 1)
+ file->also_make = (char **) xrealloc ((char *) file->also_make,
+ (idx + 1) * sizeof (char *));
+ }
+
+ return 1;
+}