diff options
Diffstat (limited to 'awk.h')
| -rw-r--r-- | awk.h | 76 |
1 files changed, 71 insertions, 5 deletions
@@ -392,8 +392,11 @@ typedef struct exp_node { /* type = Node_val */ /* - * STRING and NUMBER are mutually exclusive. They represent the - * type of a value as assigned. + * STRING and NUMBER are mutually exclusive, except for the special + * case of an uninitialized value, represented internally by + * Nnull_string. They represent the type of a value as assigned. + * Nnull_string has both STRING and NUMBER attributes, but all other + * scalar values should have precisely one of these bits set. * * STRCUR and NUMCUR are not mutually exclusive. They represent that * the particular type of value is up to date. For example, @@ -408,7 +411,8 @@ typedef struct exp_node { * * MAYBE_NUM is the joker. It means "this is string data, but * the user may have really wanted it to be a number. If we have - * to guess, like in a comparison, turn it into a number." + * to guess, like in a comparison, turn it into a number if the string + * is indeed numeric." * For example, gawk -v a=42 .... * Here, `a' gets STRING|STRCUR|MAYBE_NUM and then when used where * a number is needed, it gets turned into a NUMBER and STRING @@ -472,6 +476,13 @@ typedef struct exp_node { #define re_cnt flags /* Node_val */ +/* + * Note that the string in stptr may not be NUL-terminated, but it is + * guaranteed to have at least one extra byte that may be temporarily set + * to '\0'. This is helpful when calling functions such as strtod that require + * a NUL-terminated argument. In particular, field values $n for n > 0 and + * n < NF will not have a NUL terminator, since they point into the $0 buffer. + */ #define stptr sub.val.sp #define stlen sub.val.slen #define valref sub.val.sref @@ -486,6 +497,16 @@ typedef struct exp_node { #define numbr sub.val.fltnum #endif +/* + * If stfmt is set to STFMT_UNUSED, it means that the string representation + * stored in stptr is not a function of the value of CONVFMT or OFMT. That + * indicates that either the string value was explicitly assigned, or it + * was converted from a NUMBER that has an integer value. When stfmt is not + * set to STFMT_UNUSED, it is an offset into the fmt_list array of distinct + * CONVFMT and OFMT node pointers. + */ +#define STFMT_UNUSED -1 + /* Node_arrayfor */ #define for_list sub.nodep.r.av #define for_list_size sub.nodep.reflags @@ -1401,7 +1422,7 @@ extern NODE *do_or(int nargs); extern NODE *do_xor(int nargs); extern NODE *do_compl(int nargs); extern NODE *do_strtonum(int nargs); -extern AWKNUM nondec2awknum(char *str, size_t len); +extern AWKNUM nondec2awknum(char *str, size_t len, char **endptr); extern NODE *do_dcgettext(int nargs); extern NODE *do_dcngettext(int nargs); extern NODE *do_bindtextdomain(int nargs); @@ -1787,7 +1808,7 @@ force_string(NODE *s) return dupnode(s->re_exp); if ((s->flags & STRCUR) != 0 - && (s->stfmt == -1 || s->stfmt == CONVFMTidx) + && (s->stfmt == STFMT_UNUSED || s->stfmt == CONVFMTidx) ) return s; return format_val(CONVFMT, CONVFMTidx, s); @@ -1820,6 +1841,51 @@ force_number(NODE *n) #endif /* GAWKDEBUG */ + +/* fixtype --- make a node decide if it's a number or a string */ + +/* + * In certain contexts, the true type of a scalar value matters, and we + * must ascertain whether it is a NUMBER or a STRING. In such situations, + * please use this function to resolve the type. + * + * It is safe to assume that the return value will be the same NODE, + * since force_number on a MAYBE_NUM should always return the same NODE, + * and force_string on an INTIND should as well. + * + * There is no way to handle a Node_typedregex correctly, so we ignore + * that case. + */ + +static inline NODE * +fixtype(NODE *n) +{ + assert(n->type == Node_val || n->type == Node_typedregex); + if (n->type == Node_val) { + if ((n->flags & MAYBE_NUM) != 0) + return force_number(n); + if ((n->flags & INTIND) != 0) + return force_string(n); + } + return n; +} + +/* boolval --- return true/false based on awk's criteria */ + +/* + * In awk, a value is considered to be true if it is nonzero _or_ + * non-null. Otherwise, the value is false. + */ + +static inline int +boolval(NODE *t) +{ + (void) fixtype(t); + if ((t->flags & NUMBER) != 0) + return ! iszero(t); + return (t->stlen > 0); +} + /* emalloc_real --- malloc with error checking */ static inline void * |