[PATCH v3 1/2] set errno=0 before strtoX calls
- From
Kyle Lippincott via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Aug 5, 2024, 17:10 UTC
- Message-ID
- <4dbd0bec40a0f9fd715e07a56bc6f12c4b29a83c.1722877808.git.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.1756.v3.git.git.1722877808.gitgitgadget@gmail.com>
From: Kyle Lippincott <spectral@google.com>
To detect conversion failure after calls to functions like `strtod`, one can check `errno == ERANGE`. These functions are not guaranteed to set `errno` to `0` on successful conversion, however. Manual manipulation of `errno` can likely be avoided by checking that the output pointer differs from the input pointer, but that's not how other locations, such as parse.c:139, handle this issue; they set errno to 0 prior to executing the function.
For every place I could find a strtoX function with an ERANGE check following it, set `errno = 0;` prior to executing the conversion function.
Signed-off-by: Kyle Lippincott <spectral@google.com> --- builtin/get-tar-commit-id.c | 1 + ref-filter.c | 1 + t/helper/test-json-writer.c | 2 ++ t/helper/test-trace2.c | 1 + 4 files changed, 5 insertions(+)
diff --git a/builtin/get-tar-commit-id.c b/builtin/get-tar-commit-id.c index 66a7389f9f4..7195a072edc 100644 --- a/builtin/get-tar-commit-id.c +++ b/builtin/get-tar-commit-id.c @@ -35,6 +35,7 @@ int cmd_get_tar_commit_id(int argc, const char **argv UNUSED, const char *prefix if (header->typeflag[0] != TYPEFLAG_GLOBAL_HEADER) return 1; + errno = 0; len = strtol(content, &end, 10); if (errno == ERANGE || end == content || len < 0) return 1; diff --git a/ref-filter.c b/ref-filter.c index 8c5e673fc0a..54880a2497a 100644 --- a/ref-filter.c +++ b/ref-filter.c @@ -1628,6 +1628,7 @@ static void grab_date(const char *buf, struct atom_value *v, const char *atomnam timestamp = parse_timestamp(eoemail + 2, &zone, 10); if (timestamp == TIME_MAX) goto bad; + errno = 0; tz = strtol(zone, NULL, 10); if ((tz == LONG_MIN || tz == LONG_MAX) && errno == ERANGE) goto bad; diff --git a/t/helper/test-json-writer.c b/t/helper/test-json-writer.c index ed52eb76bfc..a288069b04c 100644 --- a/t/helper/test-json-writer.c +++ b/t/helper/test-json-writer.c @@ -415,6 +415,7 @@ static void get_i(struct line *line, intmax_t *s_in) get_s(line, &s); + errno = 0; *s_in = strtol(s, &endptr, 10); if (*endptr || errno == ERANGE) die("line[%d]: invalid integer value", line->nr); @@ -427,6 +428,7 @@ static void get_d(struct line *line, double *s_in) get_s(line, &s); + errno = 0; *s_in = strtod(s, &endptr); if (*endptr || errno == ERANGE) die("line[%d]: invalid float value", line->nr); diff --git a/t/helper/test-trace2.c b/t/helper/test-trace2.c index cd955ec63e9..c588c273ce7 100644 --- a/t/helper/test-trace2.c +++ b/t/helper/test-trace2.c @@ -26,6 +26,7 @@ static int get_i(int *p_value, const char *data) if (!data || !*data) return MyError; + errno = 0; *p_value = strtol(data, &endptr, 10); if (*endptr || errno == ERANGE) return MyError;
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