bisect: use new "struct argv_array" to prepare argv for "setup_revisions"
[gitweb.git] / bisect.c
index 27def7dacf3b81b216b9ae574061e199f1aedcc2..8e34186f9599ea265e0d779fb0b9bbdae85ec7fa 100644 (file)
--- a/bisect.c
+++ b/bisect.c
@@ -2,8 +2,36 @@
 #include "commit.h"
 #include "diff.h"
 #include "revision.h"
+#include "refs.h"
+#include "list-objects.h"
+#include "quote.h"
+#include "sha1-lookup.h"
+#include "run-command.h"
 #include "bisect.h"
 
+struct sha1_array {
+       unsigned char (*sha1)[20];
+       int sha1_nr;
+       int sha1_alloc;
+};
+
+static struct sha1_array good_revs;
+static struct sha1_array skipped_revs;
+
+static const unsigned char *current_bad_sha1;
+
+struct argv_array {
+       const char **argv;
+       int argv_nr;
+       int argv_alloc;
+};
+
+struct argv_array rev_argv;
+
+static const char *argv_diff_tree[] = {"diff-tree", "--pretty", NULL, NULL};
+static const char *argv_checkout[] = {"checkout", "-q", NULL, "--", NULL};
+static const char *argv_show_branch[] = {"show-branch", NULL, NULL};
+
 /* bits #0-15 in revision.h */
 
 #define COUNTED                (1u<<16)
@@ -386,3 +414,260 @@ struct commit_list *find_bisection(struct commit_list *list,
        return best;
 }
 
+static void argv_array_push(struct argv_array *array, const char *string)
+{
+       ALLOC_GROW(array->argv, array->argv_nr + 1, array->argv_alloc);
+       array->argv[array->argv_nr++] = string;
+}
+
+static void argv_array_push_sha1(struct argv_array *array,
+                                const unsigned char *sha1,
+                                const char *format)
+{
+       struct strbuf buf = STRBUF_INIT;
+       strbuf_addf(&buf, format, sha1_to_hex(sha1));
+       argv_array_push(array, strbuf_detach(&buf, NULL));
+}
+
+static void sha1_array_push(struct sha1_array *array,
+                           const unsigned char *sha1)
+{
+       ALLOC_GROW(array->sha1, array->sha1_nr + 1, array->sha1_alloc);
+       hashcpy(array->sha1[array->sha1_nr++], sha1);
+}
+
+static int register_ref(const char *refname, const unsigned char *sha1,
+                       int flags, void *cb_data)
+{
+       if (!strcmp(refname, "bad")) {
+               current_bad_sha1 = sha1;
+       } else if (!prefixcmp(refname, "good-")) {
+               sha1_array_push(&good_revs, sha1);
+       } else if (!prefixcmp(refname, "skip-")) {
+               sha1_array_push(&skipped_revs, sha1);
+       }
+
+       return 0;
+}
+
+static int read_bisect_refs(void)
+{
+       return for_each_ref_in("refs/bisect/", register_ref, NULL);
+}
+
+void read_bisect_paths(struct argv_array *array)
+{
+       struct strbuf str = STRBUF_INIT;
+       const char *filename = git_path("BISECT_NAMES");
+       FILE *fp = fopen(filename, "r");
+
+       if (!fp)
+               die("Could not open file '%s': %s", filename, strerror(errno));
+
+       while (strbuf_getline(&str, fp, '\n') != EOF) {
+               char *quoted;
+               int res;
+
+               strbuf_trim(&str);
+               quoted = strbuf_detach(&str, NULL);
+               res = sq_dequote_to_argv(quoted, &array->argv,
+                                        &array->argv_nr, &array->argv_alloc);
+               if (res)
+                       die("Badly quoted content in file '%s': %s",
+                           filename, quoted);
+       }
+
+       strbuf_release(&str);
+       fclose(fp);
+}
+
+static int skipcmp(const void *a, const void *b)
+{
+       return hashcmp(a, b);
+}
+
+static void prepare_skipped(void)
+{
+       qsort(skipped_revs.sha1, skipped_revs.sha1_nr,
+             sizeof(*skipped_revs.sha1), skipcmp);
+}
+
+static const unsigned char *skipped_sha1_access(size_t index, void *table)
+{
+       unsigned char (*skipped)[20] = table;
+       return skipped[index];
+}
+
+static int lookup_skipped(unsigned char *sha1)
+{
+       return sha1_pos(sha1, skipped_revs.sha1, skipped_revs.sha1_nr,
+                       skipped_sha1_access);
+}
+
+struct commit_list *filter_skipped(struct commit_list *list,
+                                  struct commit_list **tried,
+                                  int show_all)
+{
+       struct commit_list *filtered = NULL, **f = &filtered;
+
+       *tried = NULL;
+
+       if (!skipped_revs.sha1_nr)
+               return list;
+
+       prepare_skipped();
+
+       while (list) {
+               struct commit_list *next = list->next;
+               list->next = NULL;
+               if (0 <= lookup_skipped(list->item->object.sha1)) {
+                       /* Move current to tried list */
+                       *tried = list;
+                       tried = &list->next;
+               } else {
+                       if (!show_all)
+                               return list;
+                       /* Move current to filtered list */
+                       *f = list;
+                       f = &list->next;
+               }
+               list = next;
+       }
+
+       return filtered;
+}
+
+static void bisect_rev_setup(struct rev_info *revs, const char *prefix)
+{
+       int i;
+
+       init_revisions(revs, prefix);
+       revs->abbrev = 0;
+       revs->commit_format = CMIT_FMT_UNSPECIFIED;
+
+       if (read_bisect_refs())
+               die("reading bisect refs failed");
+
+       /* rev_argv.argv[0] will be ignored by setup_revisions */
+       argv_array_push(&rev_argv, xstrdup("bisect_rev_setup"));
+       argv_array_push_sha1(&rev_argv, current_bad_sha1, "%s");
+       for (i = 0; i < good_revs.sha1_nr; i++)
+               argv_array_push_sha1(&rev_argv, good_revs.sha1[i], "^%s");
+       argv_array_push(&rev_argv, xstrdup("--"));
+       read_bisect_paths(&rev_argv);
+       argv_array_push(&rev_argv, NULL);
+
+       setup_revisions(rev_argv.argv_nr, rev_argv.argv, revs, NULL);
+       revs->limited = 1;
+}
+
+static void bisect_common(struct rev_info *revs, const char *prefix,
+                         int *reaches, int *all)
+{
+       bisect_rev_setup(revs, prefix);
+
+       if (prepare_revision_walk(revs))
+               die("revision walk setup failed");
+       if (revs->tree_objects)
+               mark_edges_uninteresting(revs->commits, revs, NULL);
+
+       revs->commits = find_bisection(revs->commits, reaches, all,
+                                      !!skipped_revs.sha1_nr);
+}
+
+static void exit_if_skipped_commits(struct commit_list *tried,
+                                   const unsigned char *bad)
+{
+       if (!tried)
+               return;
+
+       printf("There are only 'skip'ped commits left to test.\n"
+              "The first bad commit could be any of:\n");
+       print_commit_list(tried, "%s\n", "%s\n");
+       if (bad)
+               printf("%s\n", sha1_to_hex(bad));
+       printf("We cannot bisect more!\n");
+       exit(2);
+}
+
+static void mark_expected_rev(char *bisect_rev_hex)
+{
+       int len = strlen(bisect_rev_hex);
+       const char *filename = git_path("BISECT_EXPECTED_REV");
+       int fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, 0600);
+
+       if (fd < 0)
+               die("could not create file '%s': %s",
+                   filename, strerror(errno));
+
+       bisect_rev_hex[len] = '\n';
+       write_or_die(fd, bisect_rev_hex, len + 1);
+       bisect_rev_hex[len] = '\0';
+
+       if (close(fd) < 0)
+               die("closing file %s: %s", filename, strerror(errno));
+}
+
+static int bisect_checkout(char *bisect_rev_hex)
+{
+       int res;
+
+       mark_expected_rev(bisect_rev_hex);
+
+       argv_checkout[2] = bisect_rev_hex;
+       res = run_command_v_opt(argv_checkout, RUN_GIT_CMD);
+       if (res)
+               exit(res);
+
+       argv_show_branch[1] = bisect_rev_hex;
+       return run_command_v_opt(argv_show_branch, RUN_GIT_CMD);
+}
+
+/*
+ * We use the convention that exiting with an exit code 10 means that
+ * the bisection process finished successfully.
+ * In this case the calling shell script should exit 0.
+ */
+int bisect_next_exit(const char *prefix)
+{
+       struct rev_info revs;
+       struct commit_list *tried;
+       int reaches = 0, all = 0, nr;
+       const unsigned char *bisect_rev;
+       char bisect_rev_hex[41];
+
+       bisect_common(&revs, prefix, &reaches, &all);
+
+       revs.commits = filter_skipped(revs.commits, &tried, 0);
+
+       if (!revs.commits) {
+               /*
+                * We should exit here only if the "bad"
+                * commit is also a "skip" commit.
+                */
+               exit_if_skipped_commits(tried, NULL);
+
+               printf("%s was both good and bad\n",
+                      sha1_to_hex(current_bad_sha1));
+               exit(1);
+       }
+
+       bisect_rev = revs.commits->item->object.sha1;
+       memcpy(bisect_rev_hex, sha1_to_hex(bisect_rev), 41);
+
+       if (!hashcmp(bisect_rev, current_bad_sha1)) {
+               exit_if_skipped_commits(tried, current_bad_sha1);
+               printf("%s is first bad commit\n", bisect_rev_hex);
+               argv_diff_tree[2] = bisect_rev_hex;
+               run_command_v_opt(argv_diff_tree, RUN_GIT_CMD);
+               /* This means the bisection process succeeded. */
+               exit(10);
+       }
+
+       nr = all - reaches - 1;
+       printf("Bisecting: %d revisions left to test after this "
+              "(roughly %d steps)\n", nr, estimate_bisect_steps(all));
+
+       return bisect_checkout(bisect_rev_hex);
+}
+