[PATCH] Fixes compile warning with -Wimplicit-fallthrough CFLAGS
- From
Elia Pinto <gitter.spiros@gmail.com>
- Date
- Jan 22, 2018, 23:51 UTC
- Message-ID
- <1516665078-107974-1-git-send-email-gitter.spiros@gmail.com>
This patch add explicit fallthrough compiler attribute when needed on switch case statement eliminating the compile warning [-Werror=implicit-fallthrough=]. It does this by means of a macro that takes into account the versions of the compilers that include that attribute.
The fallthrough (or clang::fallthrough) attribute is used to annotate intentional fall-through between switch labels. Traditionally these are marked with a specific comment, but this attribute is meant to replace comments with a more strict annotation, which can be checked by the compiler (gcc-7 or clang). The flags in question were introduced in gcc 7 and are also enabled with -Wextra.
It would also have been possible to introduce a specific comment accepted by gcc 7 instead of the fallthrough attribute for this warning, but clang does not have a similar implementation. The macro replaces the previous, not uniform, comments and can acts as a comment itself.
Signed-off-by: Elia Pinto <gitter.spiros@gmail.com> --- apply.c | 6 +++--- builtin/blame.c | 2 +- builtin/cat-file.c | 2 +- builtin/checkout.c | 2 +- builtin/fast-export.c | 4 ++-- builtin/fetch.c | 2 +- builtin/init-db.c | 2 +- builtin/log.c | 4 ++-- builtin/ls-files.c | 2 +- builtin/remote-ext.c | 2 +- builtin/reset.c | 2 +- builtin/submodule--helper.c | 2 +- config.c | 4 ++-- connect.c | 6 +++--- convert.c | 4 ++-- diff.c | 2 +- dir.c | 2 +- fsck.c | 2 +- git-compat-util.h | 17 +++++++++++++++++ ll-merge.c | 2 +- mailinfo.c | 2 +- notes.c | 4 ++-- pretty.c | 2 +- quote.c | 4 ++-- read-cache.c | 4 ++-- refs/files-backend.c | 2 +- revision.c | 2 +- send-pack.c | 2 +- strbuf.c | 2 +- streaming.c | 2 +- upload-pack.c | 3 +-- wildmatch.c | 2 +- wt-status.c | 4 ++-- 33 files changed, 61 insertions(+), 45 deletions(-)
diff --git a/apply.c b/apply.c index 321a9fa68..a22fb2881 100644 --- a/apply.c +++ b/apply.c @@ -1450,7 +1450,7 @@ static void recount_diff(const char *line, int size, struct fragment *fragment) switch (*line) { case ' ': case '\n': newlines++; - /* fall through */ + GIT_FALLTHROUGH; case '-': oldlines++; continue; @@ -2896,7 +2896,7 @@ static int apply_one_fragment(struct apply_state *state, if (plen && (ws_rule & WS_BLANK_AT_EOF) && ws_blank_line(patch + 1, plen, ws_rule)) is_blank_context = 1; - /* fallthrough */ + GIT_FALLTHROUGH; case '-': memcpy(old, patch + 1, plen); add_line_info(&preimage, old, plen, @@ -2904,7 +2904,7 @@ static int apply_one_fragment(struct apply_state *state, old += plen; if (first == '-') break; - /* fallthrough */ + GIT_FALLTHROUGH; case '+': /* --no-add does not add new lines */ if (first == '+' && state->no_add) diff --git a/builtin/blame.c b/builtin/blame.c index 005f55aaa..acc2c1e93 100644 --- a/builtin/blame.c +++ b/builtin/blame.c @@ -834,7 +834,7 @@ int cmd_blame(int argc, const char **argv, const char *prefix) argv[1] = argv[3]; argv[3] = argv[2]; argv[2] = "--"; - /* FALLTHROUGH */ + GIT_FALLTHROUGH; case 1: /* (1a) */ path = add_prefix(prefix, argv[--argc]); argv[argc] = NULL; diff --git a/builtin/cat-file.c b/builtin/cat-file.c index cf9ea5c79..eb4fa9247 100644 --- a/builtin/cat-file.c +++ b/builtin/cat-file.c @@ -113,7 +113,7 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name, if (textconv_object(path, obj_context.mode, &oid, 1, &buf, &size)) break; - /* else fallthrough */ + GIT_FALLTHROUGH; case 'p': type = sha1_object_info(oid.hash, NULL); diff --git a/builtin/checkout.c b/builtin/checkout.c index c54c78df5..2db0e16d1 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -441,7 +441,7 @@ static int reset_tree(struct tree *tree, const struct checkout_opts *o, * update paths in the work tree, and we cannot revert * them. */ - /* fallthrough */ + GIT_FALLTHROUGH; case 0: return 0; default: diff --git a/builtin/fast-export.c b/builtin/fast-export.c index 796d0cd66..972f0a3f0 100644 --- a/builtin/fast-export.c +++ b/builtin/fast-export.c @@ -385,7 +385,7 @@ static void show_filemodify(struct diff_queue_struct *q, ospec->mode == spec->mode) break; } - /* fallthrough */ + GIT_FALLTHROUGH; case DIFF_STATUS_TYPE_CHANGED: case DIFF_STATUS_MODIFIED: @@ -733,7 +733,7 @@ static void handle_tag(const char *name, struct tag *tag) case WARN_STRIP: warning ("Stripping signature from tag %s", oid_to_hex(&tag->object.oid)); - /* fallthru */ + GIT_FALLTHROUGH; case STRIP: message_size = signature + 1 - message; break; diff --git a/builtin/fetch.c b/builtin/fetch.c index 8ee998ea2..320fd54de 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -848,7 +848,7 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, switch (rm->fetch_head_status) { case FETCH_HEAD_NOT_FOR_MERGE: merge_status_marker = "not-for-merge"; - /* fall-through */ + GIT_FALLTHROUGH; case FETCH_HEAD_MERGE: fprintf(fp, "%s\t%s\t%s", oid_to_hex(&rm->old_oid), diff --git a/builtin/init-db.c b/builtin/init-db.c index c9b7946ba..6554172da 100644 --- a/builtin/init-db.c +++ b/builtin/init-db.c @@ -511,7 +511,7 @@ int cmd_init_db(int argc, const char **argv, const char *prefix) break; case SCLD_EXISTS: errno = EEXIST; - /* fallthru */ + GIT_FALLTHROUGH; default: die_errno(_("cannot mkdir %s"), argv[0]); break; diff --git a/builtin/log.c b/builtin/log.c index 46b4ca13e..ae6f2257a 100644 --- a/builtin/log.c +++ b/builtin/log.c @@ -1902,10 +1902,10 @@ int cmd_cherry(int argc, const char **argv, const char *prefix) switch (argc) { case 3: limit = argv[2]; - /* FALLTHROUGH */ + GIT_FALLTHROUGH; case 2: head = argv[1]; - /* FALLTHROUGH */ + GIT_FALLTHROUGH; case 1: upstream = argv[0]; break; diff --git a/builtin/ls-files.c b/builtin/ls-files.c index 2fc836e33..57aac6024 100644 --- a/builtin/ls-files.c +++ b/builtin/ls-files.c @@ -448,7 +448,7 @@ void overlay_tree_on_index(struct index_state *istate, switch (ce_stage(ce)) { case 0: last_stage0 = ce; - /* fallthru */ + GIT_FALLTHROUGH; default: continue; case 1: diff --git a/builtin/remote-ext.c b/builtin/remote-ext.c index 6a9127a33..909f8995e 100644 --- a/builtin/remote-ext.c +++ b/builtin/remote-ext.c @@ -57,7 +57,7 @@ static char *strip_escapes(const char *str, const char *service, special = str[rpos]; if (rpos == 1) break; - /* fallthrough */ + GIT_FALLTHROUGH; default: die("Bad remote-ext placeholder '%%%c'.", str[rpos]); diff --git a/builtin/reset.c b/builtin/reset.c index e15f59579..00e21958f 100644 --- a/builtin/reset.c +++ b/builtin/reset.c @@ -65,7 +65,7 @@ static int reset_index(const struct object_id *oid, int reset_type, int quiet) break; case HARD: opts.update = 1; - /* fallthrough */ + GIT_FALLTHROUGH; default: opts.reset = 1; } diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c index a5c4a8a69..bc2fb2ebd 100644 --- a/builtin/submodule--helper.c +++ b/builtin/submodule--helper.c @@ -1425,7 +1425,7 @@ static int push_check(int argc, const char **argv, const char *prefix) break; die("HEAD does not match the named branch in the superproject"); } - /* fallthrough */ + GIT_FALLTHROUGH; default: die("src refspec '%s' must name a ref", rs->src); diff --git a/config.c b/config.c index 70ce6e704..6f89f3925 100644 --- a/config.c +++ b/config.c @@ -2286,7 +2286,7 @@ static int store_aux(const char *key, const char *value, void *cb) ALLOC_GROW(store.offset, store.seen + 1, store.offset_alloc); store.offset[store.seen] = cf->do_ftell(cf); - /* fallthru */ + GIT_FALLTHROUGH; case SECTION_END_SEEN: case START: if (matches(key, value)) { @@ -2387,7 +2387,7 @@ static ssize_t write_pair(int fd, const char *key, const char *value) case '"': case '\\': strbuf_addch(&sb, '\\'); - /* fallthrough */ + GIT_FALLTHROUGH; default: strbuf_addch(&sb, value[i]); break; diff --git a/connect.c b/connect.c index c3a014c5b..3b4a30520 100644 --- a/connect.c +++ b/connect.c @@ -251,7 +251,7 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len, break; } state = EXPECTING_FIRST_REF; - /* fallthrough */ + GIT_FALLTHROUGH; case EXPECTING_FIRST_REF: process_capabilities(&len); if (process_dummy_ref()) { @@ -259,12 +259,12 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len, break; } state = EXPECTING_REF; - /* fallthrough */ + GIT_FALLTHROUGH; case EXPECTING_REF: if (process_ref(len, &list, flags, extra_have)) break; state = EXPECTING_SHALLOW; - /* fallthrough */ + GIT_FALLTHROUGH; case EXPECTING_SHALLOW: if (process_shallow(len, shallow_points)) break; diff --git a/convert.c b/convert.c index 1a41a48e1..81c2098a4 100644 --- a/convert.c +++ b/convert.c @@ -72,7 +72,7 @@ static void gather_stats(const char *buf, unsigned long size, struct text_stat * break; case 0: stats->nul++; - /* fall through */ + GIT_FALLTHROUGH; default: stats->nonprintable++; } @@ -1554,7 +1554,7 @@ static int ident_filter_fn(struct stream_filter *filter, switch (ident->state) { default: strbuf_add(&ident->left, head, ident->state); - /* fallthrough */ + GIT_FALLTHROUGH; case IDENT_SKIPPING: /* fallthrough */ case IDENT_DRAINING: diff --git a/diff.c b/diff.c index 0a9a0cdf1..b632d6fde 100644 --- a/diff.c +++ b/diff.c @@ -3869,7 +3869,7 @@ static void fill_metainfo(struct strbuf *msg, set, similarity_index(p), reset); break; } - /* fallthru */ + GIT_FALLTHROUGH; default: *must_show_header = 0; } diff --git a/dir.c b/dir.c index a605e0169..146b40c96 100644 --- a/dir.c +++ b/dir.c @@ -700,7 +700,7 @@ static void trim_trailing_spaces(char *buf) p++; if (!*p) return; - /* fallthrough */ + GIT_FALLTHROUGH; default: last_space = NULL; } diff --git a/fsck.c b/fsck.c index 032699e9a..3b2d07cbb 100644 --- a/fsck.c +++ b/fsck.c @@ -588,7 +588,7 @@ static int fsck_tree(struct tree *item, struct fsck_options *options) case S_IFREG | 0664: if (!options->strict) break; - /* fallthrough */ + GIT_FALLTHROUGH; default: has_bad_modes = 1; } diff --git a/git-compat-util.h b/git-compat-util.h index 68b2ad531..158f5fffb 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -1214,4 +1214,21 @@ extern void unleak_memory(const void *ptr, size_t len); #define UNLEAK(var) do {} while (0) #endif +/* + * Define a generic macro for suppress implicit case fall-through + * warning for different versions of C/C++ compiler. + * + */ +#if defined(__cplusplus) && __cplusplus >= 201703L +#define GIT_FALLTHROUGH [[fallthrough]] +#elif defined(__cplusplus) && __cplusplus >= 201103L && defined(__clang__) +#define GIT_FALLTHROUGH [[clang::fallthrough]] +#elif defined(__cplusplus) && __cplusplus >= 201103L && __GNUC__ >= 7 +#define GIT_FALLTHROUGH [[gnu::fallthrough]] +#elif __GNUC__ >= 7 // gcc 7 +#define GIT_FALLTHROUGH __attribute__ ((fallthrough)) +#else // C++11 on gcc 6, and all other cases +#define GIT_FALLTHROUGH +#endif + #endif diff --git a/ll-merge.c b/ll-merge.c index a6ad2ec12..be7a21975 100644 --- a/ll-merge.c +++ b/ll-merge.c @@ -59,7 +59,7 @@ static int ll_binary_merge(const struct ll_merge_driver *drv_unused, default: warning("Cannot merge binary files: %s (%s vs. %s)", path, name1, name2); - /* fallthru */ + GIT_FALLTHROUGH; case XDL_MERGE_FAVOR_OURS: stolen = src1; break; diff --git a/mailinfo.c b/mailinfo.c index a89db22ab..4e4fd31c5 100644 --- a/mailinfo.c +++ b/mailinfo.c @@ -827,7 +827,7 @@ static void handle_filter(struct mailinfo *mi, struct strbuf *line) if (!handle_commit_msg(mi, line)) break; mi->filter_stage++; - /* fallthrough */ + GIT_FALLTHROUGH; case 1: handle_patch(mi, line); break; diff --git a/notes.c b/notes.c index c7f21fae4..7e4b73086 100644 --- a/notes.c +++ b/notes.c @@ -128,7 +128,7 @@ static void **note_tree_search(struct notes_tree *t, struct int_node **tree, free(l); return note_tree_search(t, tree, n, key_sha1); } - /* fall through */ + GIT_FALLTHROUGH; default: return &((*tree)->a[i]); } @@ -326,7 +326,7 @@ static void note_tree_free(struct int_node *tree) switch (GET_PTR_TYPE(p)) { case PTR_TYPE_INTERNAL: note_tree_free(CLR_PTR_TYPE(p)); - /* fall through */ + GIT_FALLTHROUGH; case PTR_TYPE_NOTE: case PTR_TYPE_SUBTREE: free(CLR_PTR_TYPE(p)); diff --git a/pretty.c b/pretty.c index f7ce49023..c942ce8dd 100644 --- a/pretty.c +++ b/pretty.c @@ -274,7 +274,7 @@ static void add_rfc822_quoted(struct strbuf *out, const char *s, int len) case '"': case '\\': strbuf_addch(out, '\\'); - /* fall through */ + GIT_FALLTHROUGH; default: strbuf_addch(out, s[i]); } diff --git a/quote.c b/quote.c index de2922ddd..f1733de19 100644 --- a/quote.c +++ b/quote.c @@ -99,7 +99,7 @@ static char *sq_dequote_step(char *arg, char **next) *dst++ = c; continue; } - /* Fallthrough */ + GIT_FALLTHROUGH; default: if (!next || !isspace(*src)) return NULL; @@ -431,7 +431,7 @@ void tcl_quote_buf(struct strbuf *sb, const char *src) case '{': case '}': case '$': case '\\': case '"': strbuf_addch(sb, '\\'); - /* fallthrough */ + GIT_FALLTHROUGH; default: strbuf_addch(sb, c); break; diff --git a/read-cache.c b/read-cache.c index 2eb81a66b..abe655024 100644 --- a/read-cache.c +++ b/read-cache.c @@ -225,7 +225,7 @@ static int ce_modified_check_fs(const struct cache_entry *ce, struct stat *st) case S_IFDIR: if (S_ISGITLINK(ce->ce_mode)) return ce_compare_gitlink(ce) ? DATA_CHANGED : 0; - /* else fallthrough */ + GIT_FALLTHROUGH; default: return TYPE_CHANGED; } @@ -840,7 +840,7 @@ static int verify_dotfile(const char *rest) if (rest[2] != 't' && rest[2] != 'T') break; rest += 2; - /* fallthrough */ + GIT_FALLTHROUGH; case '.': if (rest[1] == '\0' || is_dir_sep(rest[1])) return 0; diff --git a/refs/files-backend.c b/refs/files-backend.c index f75d960e1..d6a2f8129 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -562,7 +562,7 @@ static int lock_raw_ref(struct files_ref_store *refs, /* Maybe another process was tidying up. Try again. */ if (--attempts_remaining > 0) goto retry; - /* fall through */ + GIT_FALLTHROUGH; default: strbuf_addf(err, "unable to create directory for %s", ref_file.buf); diff --git a/revision.c b/revision.c index 236d0d579..e34c2dfe1 100644 --- a/revision.c +++ b/revision.c @@ -702,7 +702,7 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit) oid_to_hex(&p->object.oid)); p->parents = NULL; } - /* fallthrough */ + GIT_FALLTHROUGH; case REV_TREE_OLD: case REV_TREE_DIFFERENT: if (relevant_commit(p)) diff --git a/send-pack.c b/send-pack.c index 2112d3b27..58f1dcbea 100644 --- a/send-pack.c +++ b/send-pack.c @@ -487,7 +487,7 @@ int send_pack(struct send_pack_args *args, strbuf_release(&cap_buf); return atomic_push_failure(args, remote_refs, ref); } - /* else fallthrough */ + GIT_FALLTHROUGH; default: continue; } diff --git a/strbuf.c b/strbuf.c index 1df674e91..281f6e254 100644 --- a/strbuf.c +++ b/strbuf.c @@ -838,7 +838,7 @@ void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm, fmt++; break; } - /* FALLTHROUGH */ + GIT_FALLTHROUGH; default: strbuf_addch(&munged_fmt, '%'); } diff --git a/streaming.c b/streaming.c index 5892b50bd..ac46c9079 100644 --- a/streaming.c +++ b/streaming.c @@ -124,7 +124,7 @@ static enum input_source istream_source(const unsigned char *sha1, case OI_PACKED: if (!oi->u.packed.is_delta && big_file_threshold < size) return pack_non_delta; - /* fallthru */ + GIT_FALLTHROUGH; default: return incore; } diff --git a/upload-pack.c b/upload-pack.c index f51b6cfca..3ff2a0f06 100644 --- a/upload-pack.c +++ b/upload-pack.c @@ -1105,8 +1105,7 @@ int cmd_main(int argc, const char **argv) */ if (advertise_refs || !stateless_rpc) packet_write_fmt(1, "version 1\n"); - - /* fallthrough */ + GIT_FALLTHROUGH; case protocol_v0: upload_pack(); break; diff --git a/wildmatch.c b/wildmatch.c index d074c1be1..594f7585c 100644 --- a/wildmatch.c +++ b/wildmatch.c @@ -71,7 +71,7 @@ static int dowild(const uchar *p, const uchar *text, unsigned int flags) /* Literal match with following character. Note that the test * in "default" handles the p[1] == '\0' failure case. */ p_ch = *++p; - /* FALLTHROUGH */ + GIT_FALLTHROUGH; default: if (t_ch != p_ch) return WM_NOMATCH; diff --git a/wt-status.c b/wt-status.c index f5debcd2b..f35452119 100644 --- a/wt-status.c +++ b/wt-status.c @@ -473,7 +473,7 @@ static void wt_status_collect_changed_cb(struct diff_queue_struct *q, d->rename_source = xstrdup(p->one->path); d->rename_score = p->score * 100 / MAX_SCORE; d->rename_status = p->status; - /* fallthru */ + GIT_FALLTHROUGH; case DIFF_STATUS_MODIFIED: case DIFF_STATUS_TYPE_CHANGED: case DIFF_STATUS_UNMERGED: @@ -550,7 +550,7 @@ static void wt_status_collect_updated_cb(struct diff_queue_struct *q, d->rename_source = xstrdup(p->one->path); d->rename_score = p->score * 100 / MAX_SCORE; d->rename_status = p->status; - /* fallthru */ + GIT_FALLTHROUGH; case DIFF_STATUS_MODIFIED: case DIFF_STATUS_TYPE_CHANGED: d->mode_head = p->one->mode;
-- 2.16.0.312.g896df04.dirty