bisect: use new "struct argv_array" to prepare argv for "setup_revisions"
[gitweb.git] / bisect.c
index 3279fb12b2abcdd90fd58d30d1694f9d7a0d36a6..8e34186f9599ea265e0d779fb0b9bbdae85ec7fa 100644 (file)
--- a/bisect.c
+++ b/bisect.c
@@ -6,15 +6,31 @@
 #include "list-objects.h"
 #include "quote.h"
 #include "sha1-lookup.h"
+#include "run-command.h"
 #include "bisect.h"
 
-static unsigned char (*skipped_sha1)[20];
-static int skipped_sha1_nr;
-static int skipped_sha1_alloc;
+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 **rev_argv;
-static int rev_argv_nr;
-static int rev_argv_alloc;
+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 */
 
@@ -398,23 +414,37 @@ 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")) {
-               ALLOC_GROW(rev_argv, rev_argv_nr + 1, rev_argv_alloc);
-               rev_argv[rev_argv_nr++] = xstrdup(sha1_to_hex(sha1));
+               current_bad_sha1 = sha1;
        } else if (!prefixcmp(refname, "good-")) {
-               const char *hex = sha1_to_hex(sha1);
-               char *good = xmalloc(strlen(hex) + 2);
-               *good = '^';
-               memcpy(good + 1, hex, strlen(hex) + 1);
-               ALLOC_GROW(rev_argv, rev_argv_nr + 1, rev_argv_alloc);
-               rev_argv[rev_argv_nr++] = good;
+               sha1_array_push(&good_revs, sha1);
        } else if (!prefixcmp(refname, "skip-")) {
-               ALLOC_GROW(skipped_sha1, skipped_sha1_nr + 1,
-                          skipped_sha1_alloc);
-               hashcpy(skipped_sha1[skipped_sha1_nr++], sha1);
+               sha1_array_push(&skipped_revs, sha1);
        }
 
        return 0;
@@ -425,7 +455,7 @@ static int read_bisect_refs(void)
        return for_each_ref_in("refs/bisect/", register_ref, NULL);
 }
 
-void read_bisect_paths(void)
+void read_bisect_paths(struct argv_array *array)
 {
        struct strbuf str = STRBUF_INIT;
        const char *filename = git_path("BISECT_NAMES");
@@ -440,8 +470,8 @@ void read_bisect_paths(void)
 
                strbuf_trim(&str);
                quoted = strbuf_detach(&str, NULL);
-               res = sq_dequote_to_argv(quoted, &rev_argv,
-                                        &rev_argv_nr, &rev_argv_alloc);
+               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);
@@ -458,7 +488,8 @@ static int skipcmp(const void *a, const void *b)
 
 static void prepare_skipped(void)
 {
-       qsort(skipped_sha1, skipped_sha1_nr, sizeof(*skipped_sha1), skipcmp);
+       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)
@@ -469,7 +500,7 @@ static const unsigned char *skipped_sha1_access(size_t index, void *table)
 
 static int lookup_skipped(unsigned char *sha1)
 {
-       return sha1_pos(sha1, skipped_sha1, skipped_sha1_nr,
+       return sha1_pos(sha1, skipped_revs.sha1, skipped_revs.sha1_nr,
                        skipped_sha1_access);
 }
 
@@ -481,7 +512,7 @@ struct commit_list *filter_skipped(struct commit_list *list,
 
        *tried = NULL;
 
-       if (!skipped_sha1_nr)
+       if (!skipped_revs.sha1_nr)
                return list;
 
        prepare_skipped();
@@ -508,44 +539,135 @@ struct commit_list *filter_skipped(struct commit_list *list,
 
 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;
 
-       /* argv[0] will be ignored by setup_revisions */
-       ALLOC_GROW(rev_argv, rev_argv_nr + 1, rev_argv_alloc);
-       rev_argv[rev_argv_nr++] = xstrdup("bisect_rev_setup");
-
        if (read_bisect_refs())
                die("reading bisect refs failed");
 
-       ALLOC_GROW(rev_argv, rev_argv_nr + 1, rev_argv_alloc);
-       rev_argv[rev_argv_nr++] = xstrdup("--");
+       /* 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);
 
-       read_bisect_paths();
+       setup_revisions(rev_argv.argv_nr, rev_argv.argv, revs, NULL);
+       revs->limited = 1;
+}
 
-       ALLOC_GROW(rev_argv, rev_argv_nr + 1, rev_argv_alloc);
-       rev_argv[rev_argv_nr++] = NULL;
+static void bisect_common(struct rev_info *revs, const char *prefix,
+                         int *reaches, int *all)
+{
+       bisect_rev_setup(revs, prefix);
 
-       setup_revisions(rev_argv_nr, rev_argv, revs, NULL);
+       if (prepare_revision_walk(revs))
+               die("revision walk setup failed");
+       if (revs->tree_objects)
+               mark_edges_uninteresting(revs->commits, revs, NULL);
 
-       revs->limited = 1;
+       revs->commits = find_bisection(revs->commits, reaches, all,
+                                      !!skipped_revs.sha1_nr);
 }
 
-int bisect_next_vars(const char *prefix)
+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;
-       int reaches = 0, all = 0;
+       struct commit_list *tried;
+       int reaches = 0, all = 0, nr;
+       const unsigned char *bisect_rev;
+       char bisect_rev_hex[41];
 
-       bisect_rev_setup(&revs, prefix);
+       bisect_common(&revs, prefix, &reaches, &all);
 
-       if (prepare_revision_walk(&revs))
-               die("revision walk setup failed");
-       if (revs.tree_objects)
-               mark_edges_uninteresting(revs.commits, &revs, NULL);
+       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);
 
-       revs.commits = find_bisection(revs.commits, &reaches, &all,
-                                     !!skipped_sha1_nr);
+               printf("%s was both good and bad\n",
+                      sha1_to_hex(current_bad_sha1));
+               exit(1);
+       }
 
-       return show_bisect_vars(&revs, reaches, all, 0, 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);
 }
+