diff --git a/ChangeLog b/ChangeLog index 785fbc44b..902c5262c 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,19 @@ +2021-08-26 Paul Eggert + + regex: use __attr_access and C99-style array arg + This should help with some static checking. + Derived from a suggestion by Martin Sebor in: + https://sourceware.org/pipermail/libc-alpha/2021-August/130336.html + * lib/regex.c: Ignore -Wvla for the whole file. + * lib/regex.h (_REGEX_NELTS, _Attr_access_): New macros. + Ignore -Wvla when declaring regexec. + (re_compile_pattern, re_search, re_search2, re_match, re_match_2) + (regerror): Mark with _Attr_access_, as glibc does. + * lib/regex.h (regexec): + * lib/regexec.c (regexec, __compat_regexec): + Use _REGEX_NELTS for each array parameter whose size is another arg + but with an access pattern that cannot be captured with __attr_access. + 2021-08-25 Bruno Haible execute tests: Fix test failure when libtool is in use. diff --git a/lib/regex.c b/lib/regex.c index 7296be0f0..d32863972 100644 --- a/lib/regex.c +++ b/lib/regex.c @@ -24,6 +24,7 @@ # if __GNUC_PREREQ (4, 6) # pragma GCC diagnostic ignored "-Wsuggest-attribute=pure" +# pragma GCC diagnostic ignored "-Wvla" # endif # if __GNUC_PREREQ (4, 3) # pragma GCC diagnostic ignored "-Wold-style-definition" diff --git a/lib/regex.h b/lib/regex.h index 8e4ef4557..adb69768e 100644 --- a/lib/regex.h +++ b/lib/regex.h @@ -522,6 +522,30 @@ typedef struct /* Declarations for routines. */ +#ifndef _REGEX_NELTS +# if (defined __STDC_VERSION__ && 199901L <= __STDC_VERSION__ \ + && !defined __STDC_NO_VLA__) +# define _REGEX_NELTS(n) n +# else +# define _REGEX_NELTS(n) +# endif +#endif + +#if defined __GNUC__ && 4 < __GNUC__ + (6 <= __GNUC_MINOR__) +# pragma GCC diagnostic push +# pragma GCC diagnostic ignored "-Wvla" +#endif + +#ifndef _Attr_access_ +# ifdef __attr_access +# define _Attr_access_(arg) __attr_access (arg) +# elif defined __GNUC__ && 10 <= __GNUC__ +# define _Attr_access_(x) __attribute__ ((__access__ x)) +# else +# define _Attr_access_(x) +# endif +#endif + #ifdef __USE_GNU /* Sets the current default syntax to SYNTAX, and return the old syntax. You can also simply assign to the 're_syntax_options' variable. */ @@ -536,7 +560,8 @@ extern reg_syntax_t re_set_syntax (reg_syntax_t __syntax); 'regcomp', with a malloc'ed value, or set to NULL before calling 'regfree'. */ extern const char *re_compile_pattern (const char *__pattern, size_t __length, - struct re_pattern_buffer *__buffer); + struct re_pattern_buffer *__buffer) + _Attr_access_ ((__read_only__, 1, 2)); /* Compile a fastmap for the compiled pattern in BUFFER; used to @@ -553,7 +578,8 @@ extern int re_compile_fastmap (struct re_pattern_buffer *__buffer); extern regoff_t re_search (struct re_pattern_buffer *__buffer, const char *__String, regoff_t __length, regoff_t __start, regoff_t __range, - struct re_registers *__regs); + struct re_registers *__regs) + _Attr_access_ ((__read_only__, 2, 3)); /* Like 're_search', but search in the concatenation of STRING1 and @@ -563,14 +589,17 @@ extern regoff_t re_search_2 (struct re_pattern_buffer *__buffer, const char *__string2, regoff_t __length2, regoff_t __start, regoff_t __range, struct re_registers *__regs, - regoff_t __stop); + regoff_t __stop) + _Attr_access_ ((__read_only__, 2, 3)) + _Attr_access_ ((__read_only__, 4, 5)); /* Like 're_search', but return how many characters in STRING the regexp in BUFFER matched, starting at position START. */ extern regoff_t re_match (struct re_pattern_buffer *__buffer, const char *__String, regoff_t __length, - regoff_t __start, struct re_registers *__regs); + regoff_t __start, struct re_registers *__regs) + _Attr_access_ ((__read_only__, 2, 3)); /* Relates to 're_match' as 're_search_2' relates to 're_search'. */ @@ -578,7 +607,9 @@ extern regoff_t re_match_2 (struct re_pattern_buffer *__buffer, const char *__string1, regoff_t __length1, const char *__string2, regoff_t __length2, regoff_t __start, struct re_registers *__regs, - regoff_t __stop); + regoff_t __stop) + _Attr_access_ ((__read_only__, 2, 3)) + _Attr_access_ ((__read_only__, 4, 5)); /* Set REGS to hold NUM_REGS registers, storing them in STARTS and @@ -647,14 +678,19 @@ extern int regcomp (regex_t *_Restrict_ __preg, extern int regexec (const regex_t *_Restrict_ __preg, const char *_Restrict_ __String, size_t __nmatch, - regmatch_t __pmatch[_Restrict_arr_], + regmatch_t __pmatch[_Restrict_arr_ + _REGEX_NELTS (__nmatch)], int __eflags); extern size_t regerror (int __errcode, const regex_t *_Restrict_ __preg, - char *_Restrict_ __errbuf, size_t __errbuf_size); + char *_Restrict_ __errbuf, size_t __errbuf_size) + _Attr_access_ ((__write_only__, 3, 4)); extern void regfree (regex_t *__preg); +#if defined __GNUC__ && 4 < __GNUC__ + (6 <= __GNUC_MINOR__) +# pragma GCC diagnostic pop +#endif #ifdef __cplusplus } diff --git a/lib/regexec.c b/lib/regexec.c index 5e4eb497a..83e9aaf8c 100644 --- a/lib/regexec.c +++ b/lib/regexec.c @@ -191,7 +191,7 @@ static reg_errcode_t extend_buffers (re_match_context_t *mctx, int min_len); int regexec (const regex_t *__restrict preg, const char *__restrict string, - size_t nmatch, regmatch_t pmatch[], int eflags) + size_t nmatch, regmatch_t pmatch[_REGEX_NELTS (nmatch)], int eflags) { reg_errcode_t err; Idx start, length; @@ -235,7 +235,7 @@ int attribute_compat_text_section __compat_regexec (const regex_t *__restrict preg, const char *__restrict string, size_t nmatch, - regmatch_t pmatch[], int eflags) + regmatch_t pmatch[_REGEX_NELTS (nmatch)], int eflags) { return regexec (preg, string, nmatch, pmatch, eflags & (REG_NOTBOL | REG_NOTEOL));