Am 09.05.19 um 20:38 schrieb Jeff King: > I do dream of a world where we do not have a bunch of implicit > conversions (both signedness but also truncation) in our code base, and > can compile cleanly with -Wconversion We know that this case is > perfectly fine, but I am sure there are many that are not. However, I'm > not sure if we'll ever get there, and in the meantime I don't think it's > worth worrying too much about individual cases like this. Here's a rough take on how to silence that warning for archive-tar.c using GCC 8.3. Some of the changes are worth polishing and submitting. Some are silly. The one for regexec_buf() is scary; I don't see a clean way of dealing with that size_t to int conversion. --- archive-tar.c | 54 +++++++++++++++++++++++++++++++---------------- cache.h | 10 ++++----- git-compat-util.h | 21 +++++++++++++++--- hash.h | 2 +- strbuf.h | 2 +- 5 files changed, 61 insertions(+), 28 deletions(-) diff --git a/archive-tar.c b/archive-tar.c index 3e53aac1e6..bfd91782ab 100644 --- a/archive-tar.c +++ b/archive-tar.c @@ -15,7 +15,7 @@ static char block[BLOCKSIZE]; static unsigned long offset; -static int tar_umask = 002; +static mode_t tar_umask = 002; static int write_tar_filter_archive(const struct archiver *ar, struct archiver_args *args); @@ -99,7 +99,7 @@ static void write_blocked(const void *data, unsigned long size) */ static void write_trailer(void) { - int tail = BLOCKSIZE - offset; + size_t tail = BLOCKSIZE - offset; memset(block + offset, 0, tail); write_or_die(1, block, BLOCKSIZE); if (tail < 2 * RECORDSIZE) { @@ -127,12 +127,13 @@ static int stream_blocked(const struct object_id *oid) readlen = read_istream(st, buf, sizeof(buf)); if (readlen <= 0) break; - do_write_blocked(buf, readlen); + do_write_blocked(buf, (size_t)readlen); } close_istream(st); - if (!readlen) - finish_record(); - return readlen; + if (readlen < 0) + return -1; + finish_record(); + return 0; } /* @@ -142,9 +143,9 @@ static int stream_blocked(const struct object_id *oid) * string and appends it to a struct strbuf. */ static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword, - const char *value, unsigned int valuelen) + const char *value, size_t valuelen) { - int len, tmp; + size_t len, tmp; /* "%u %s=%s\n" */ len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1; @@ -152,7 +153,7 @@ static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword, len++; strbuf_grow(sb, len); - strbuf_addf(sb, "%u %s=", len, keyword); + strbuf_addf(sb, "%"PRIuMAX" %s=", (uintmax_t)len, keyword); strbuf_add(sb, value, valuelen); strbuf_addch(sb, '\n'); } @@ -168,7 +169,9 @@ static void strbuf_append_ext_header_uint(struct strbuf *sb, int len; len = xsnprintf(buf, sizeof(buf), "%"PRIuMAX, value); - strbuf_append_ext_header(sb, keyword, buf, len); + if (len < 0) + BUG("unable to convert %"PRIuMAX" to decimal", value); + strbuf_append_ext_header(sb, keyword, buf, (size_t)len); } static unsigned int ustar_header_chksum(const struct ustar_header *header) @@ -177,7 +180,7 @@ static unsigned int ustar_header_chksum(const struct ustar_header *header) unsigned int chksum = 0; while (p < (const unsigned char *)header->chksum) chksum += *p++; - chksum += sizeof(header->chksum) * ' '; + chksum += (unsigned int)sizeof(header->chksum) * ' '; p += sizeof(header->chksum); while (p < (const unsigned char *)header + sizeof(struct ustar_header)) chksum += *p++; @@ -355,12 +358,14 @@ static void write_global_extended_header(struct archiver_args *args) } static struct archiver **tar_filters; -static int nr_tar_filters; -static int alloc_tar_filters; +static size_t nr_tar_filters; +static size_t alloc_tar_filters; -static struct archiver *find_tar_filter(const char *name, int len) +static struct archiver *find_tar_filter(const char *name, size_t len) { int i; + if (len < 1) + return NULL; for (i = 0; i < nr_tar_filters; i++) { struct archiver *ar = tar_filters[i]; if (!strncmp(ar->name, name, len) && !ar->name[len]) @@ -369,14 +374,27 @@ static struct archiver *find_tar_filter(const char *name, int len) return NULL; } +static int parse_config_key2(const char *var, const char *section, + const char **subsection, size_t *subsection_len, + const char **key) +{ + int rc, len; + + rc = parse_config_key(var, section, subsection, &len, key); + if (!rc && len < 0) + return -1; + *subsection_len = (size_t)len; + return rc; +} + static int tar_filter_config(const char *var, const char *value, void *data) { struct archiver *ar; const char *name; const char *type; - int namelen; + size_t namelen; - if (parse_config_key(var, "tar", &name, &namelen, &type) < 0 || !name) + if (parse_config_key2(var, "tar", &name, &namelen, &type) < 0 || !name) return 0; ar = find_tar_filter(name, namelen); @@ -400,7 +418,7 @@ static int tar_filter_config(const char *var, const char *value, void *data) if (git_config_bool(var, value)) ar->flags |= ARCHIVER_REMOTE; else - ar->flags &= ~ARCHIVER_REMOTE; + ar->flags &= ~(unsigned int)ARCHIVER_REMOTE; return 0; } @@ -414,7 +432,7 @@ static int git_tar_config(const char *var, const char *value, void *cb) tar_umask = umask(0); umask(tar_umask); } else { - tar_umask = git_config_int(var, value); + tar_umask = (mode_t)git_config_ulong(var, value); } return 0; } diff --git a/cache.h b/cache.h index 67cc2e1806..a791034260 100644 --- a/cache.h +++ b/cache.h @@ -241,7 +241,7 @@ static inline void copy_cache_entry(struct cache_entry *dst, const struct cache_entry *src) { unsigned int state = dst->ce_flags & CE_HASHED; - int mem_pool_allocated = dst->mem_pool_allocated; + unsigned int mem_pool_allocated = dst->mem_pool_allocated; /* Don't copy hash chain and name */ memcpy(&dst->ce_stat_data, &src->ce_stat_data, @@ -249,7 +249,7 @@ static inline void copy_cache_entry(struct cache_entry *dst, offsetof(struct cache_entry, ce_stat_data)); /* Restore the hash state */ - dst->ce_flags = (dst->ce_flags & ~CE_HASHED) | state; + dst->ce_flags = (dst->ce_flags & ~(unsigned int)CE_HASHED) | state; /* Restore the mem_pool_allocated flag */ dst->mem_pool_allocated = mem_pool_allocated; @@ -1314,7 +1314,7 @@ extern int check_and_freshen_file(const char *fn, int freshen); extern const signed char hexval_table[256]; static inline unsigned int hexval(unsigned char c) { - return hexval_table[c]; + return (unsigned int)hexval_table[c]; } /* @@ -1323,8 +1323,8 @@ static inline unsigned int hexval(unsigned char c) */ static inline int hex2chr(const char *s) { - unsigned int val = hexval(s[0]); - return (val & ~0xf) ? val : (val << 4) | hexval(s[1]); + int val = hexval_table[(unsigned char)s[0]]; + return (val < 0) ? val : (val << 4) | hexval_table[(unsigned char)s[1]]; } /* Convert to/from hex/sha1 representation */ diff --git a/git-compat-util.h b/git-compat-util.h index 4386b3e1c8..cf33e84c96 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -1068,7 +1068,7 @@ static inline int strtoul_ui(char const *s, int base, unsigned int *result) ul = strtoul(s, &p, base); if (errno || *p || p == s || (unsigned int) ul != ul) return -1; - *result = ul; + *result = (unsigned int)ul; return 0; } @@ -1081,7 +1081,7 @@ static inline int strtol_i(char const *s, int base, int *result) ul = strtol(s, &p, base); if (errno || *p || p == s || (int) ul != ul) return -1; - *result = ul; + *result = (int)ul; return 0; } @@ -1119,7 +1119,22 @@ static inline int regexec_buf(const regex_t *preg, const char *buf, size_t size, { assert(nmatch > 0 && pmatch); pmatch[0].rm_so = 0; - pmatch[0].rm_eo = size; + pmatch[0].rm_eo = (regoff_t)size; + if (pmatch[0].rm_eo != size) { + if (((regoff_t)-1) < 0) { + if (sizeof(regoff_t) == sizeof(int)) + pmatch[0].rm_eo = (regoff_t)INT_MAX; + else if (sizeof(regoff_t) == sizeof(long)) + pmatch[0].rm_eo = (regoff_t)LONG_MAX; + else + die("unable to determine maximum value of regoff_t"); + } else { + pmatch[0].rm_eo = (regoff_t)-1; + } + warning("buffer too big (%"PRIuMAX"), " + "will search only the first %"PRIuMAX" bytes", + (uintmax_t)size, (uintmax_t)pmatch[0].rm_eo); + } return regexec(preg, buf, nmatch, pmatch, eflags | REG_STARTEND); } diff --git a/hash.h b/hash.h index 661c9f2281..7056f89eb4 100644 --- a/hash.h +++ b/hash.h @@ -134,7 +134,7 @@ int hash_algo_by_id(uint32_t format_id); /* Identical, except based on the length. */ int hash_algo_by_length(int len); /* Identical, except for a pointer to struct git_hash_algo. */ -static inline int hash_algo_by_ptr(const struct git_hash_algo *p) +static inline ptrdiff_t hash_algo_by_ptr(const struct git_hash_algo *p) { return p - hash_algos; } diff --git a/strbuf.h b/strbuf.h index c8d98dfb95..30659f2d5d 100644 --- a/strbuf.h +++ b/strbuf.h @@ -225,7 +225,7 @@ int strbuf_cmp(const struct strbuf *first, const struct strbuf *second); /** * Add a single character to the buffer. */ -static inline void strbuf_addch(struct strbuf *sb, int c) +static inline void strbuf_addch(struct strbuf *sb, char c) { if (!strbuf_avail(sb)) strbuf_grow(sb, 1); -- 2.21.0