Merge branch 'jc/gitlink' into next
[gitweb.git] / builtin-grep.c
index fead35662944070f8502ed0484fe6b6085d7ac86..36512d8a17abccb67654b5bcfcd74a441b3e4586 100644 (file)
@@ -12,6 +12,7 @@
 #include "builtin.h"
 #include <regex.h>
 #include <fnmatch.h>
+#include <sys/wait.h>
 
 /*
  * git grep pathspecs are somewhat different from diff-tree pathspecs;
@@ -409,12 +410,155 @@ static int grep_file(struct grep_opt *opt, const char *filename)
        return i;
 }
 
+static int exec_grep(int argc, const char **argv)
+{
+       pid_t pid;
+       int status;
+
+       argv[argc] = NULL;
+       pid = fork();
+       if (pid < 0)
+               return pid;
+       if (!pid) {
+               execvp("grep", (char **) argv);
+               exit(255);
+       }
+       while (waitpid(pid, &status, 0) < 0) {
+               if (errno == EINTR)
+                       continue;
+               return -1;
+       }
+       if (WIFEXITED(status)) {
+               if (!WEXITSTATUS(status))
+                       return 1;
+               return 0;
+       }
+       return -1;
+}
+
+#define MAXARGS 1000
+#define ARGBUF 4096
+#define push_arg(a) do { \
+       if (nr < MAXARGS) argv[nr++] = (a); \
+       else die("maximum number of args exceeded"); \
+       } while (0)
+
+static int external_grep(struct grep_opt *opt, const char **paths, int cached)
+{
+       int i, nr, argc, hit, len;
+       const char *argv[MAXARGS+1];
+       char randarg[ARGBUF];
+       char *argptr = randarg;
+       struct grep_pat *p;
+
+       len = nr = 0;
+       push_arg("grep");
+       if (opt->fixed)
+               push_arg("-F");
+       if (opt->linenum)
+               push_arg("-n");
+       if (opt->regflags & REG_EXTENDED)
+               push_arg("-E");
+       if (opt->word_regexp)
+               push_arg("-w");
+       if (opt->name_only)
+               push_arg("-l");
+       if (opt->unmatch_name_only)
+               push_arg("-L");
+       if (opt->count)
+               push_arg("-c");
+       if (opt->post_context || opt->pre_context) {
+               if (opt->post_context != opt->pre_context) {
+                       if (opt->pre_context) {
+                               push_arg("-B");
+                               len += snprintf(argptr, sizeof(randarg)-len,
+                                               "%u", opt->pre_context);
+                               if (sizeof(randarg) <= len)
+                                       die("maximum length of args exceeded");
+                               push_arg(argptr);
+                               argptr += len;
+                       }
+                       if (opt->post_context) {
+                               push_arg("-A");
+                               len += snprintf(argptr, sizeof(randarg)-len,
+                                               "%u", opt->post_context);
+                               if (sizeof(randarg) <= len)
+                                       die("maximum length of args exceeded");
+                               push_arg(argptr);
+                               argptr += len;
+                       }
+               }
+               else {
+                       push_arg("-C");
+                       len += snprintf(argptr, sizeof(randarg)-len,
+                                       "%u", opt->post_context);
+                       if (sizeof(randarg) <= len)
+                               die("maximum length of args exceeded");
+                       push_arg(argptr);
+                       argptr += len;
+               }
+       }
+       for (p = opt->pattern_list; p; p = p->next) {
+               push_arg("-e");
+               push_arg(p->pattern);
+       }
+
+       if (NO_H_OPTION_IN_GREP)
+               push_arg("/dev/null");
+       else {
+               push_arg("-H");
+               push_arg("--");
+       }
+
+       hit = 0;
+       argc = nr;
+       for (i = 0; i < active_nr; i++) {
+               struct cache_entry *ce = active_cache[i];
+               if (ce_stage(ce) || !S_ISREG(ntohl(ce->ce_mode)))
+                       continue;
+               if (!pathspec_matches(paths, ce->name))
+                       continue;
+               argv[argc++] = ce->name;
+               if (argc < MAXARGS)
+                       continue;
+               hit += exec_grep(argc, argv);
+               argc = nr;
+       }
+       if (argc > nr)
+               hit += exec_grep(argc, argv);
+       return 0;
+}
+
 static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
 {
        int hit = 0;
        int nr;
        read_cache();
 
+#ifdef __unix__
+       /*
+        * Use the external "grep" command for the case where
+        * we grep through the checked-out files. It tends to
+        * be a lot more optimized
+        *
+        * Some grep implementations do not understand -H nor --
+        * but /dev/null can be used as a substitution in most
+        * cases.
+        *
+        * However -L and -c would slightly misbehave (-L would
+        * list /dev/null as a hit, and -c would report 0 hits
+        * from /dev/null); so do not use the external one on
+        * such platforms.
+        */
+       if (!cached &&
+           (!NO_H_OPTION_IN_GREP ||
+            (!opt->count && !opt->unmatch_name_only))) {
+               hit = external_grep(opt, paths, cached);
+               if (hit >= 0)
+                       return hit;
+       }
+#endif
+
        for (nr = 0; nr < active_nr; nr++) {
                struct cache_entry *ce = active_cache[nr];
                if (ce_stage(ce) || !S_ISREG(ntohl(ce->ce_mode)))