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Diffstat (limited to 'include/ruby/3/scan_args.h')
| -rw-r--r-- | include/ruby/3/scan_args.h | 392 |
1 files changed, 392 insertions, 0 deletions
diff --git a/include/ruby/3/scan_args.h b/include/ruby/3/scan_args.h new file mode 100644 index 0000000000..3944c8bebc --- /dev/null +++ b/include/ruby/3/scan_args.h @@ -0,0 +1,392 @@ +/** \noop-*-C++-*-vi:ft=cpp + * @file + * @author Ruby developers <ruby-core@ruby-lang.org> + * @copyright This file is a part of the programming language Ruby. + * Permission is hereby granted, to either redistribute and/or + * modify this file, provided that the conditions mentioned in the + * file COPYING are met. Consult the file for details. + * @warning Symbols prefixed with either `RUBY3` or `ruby3` are + * implementation details. Don't take them as canon. They could + * rapidly appear then vanish. The name (path) of this header file + * is also an implementation detail. Do not expect it to persist + * at the place it is now. Developers are free to move it anywhere + * anytime at will. + * @note To ruby-core: remember that this header can be possibly + * recursively included from extension libraries written in C++. + * Do not expect for instance `__VA_ARGS__` is always available. + * We assume C99 for ruby itself but we don't assume languages of + * extension libraries. They could be written in C++98. + * @brief Compile-time static implementation of ::rb_scan_args(). + * + * This is a beast. It statically analyses the argument spec string, and + * expands the assignment of variables into dedicated codes. + */ +#ifndef RUBY3_SCAN_ARGS_H +#define RUBY3_SCAN_ARGS_H +#include "ruby/3/attr/diagnose_if.h" +#include "ruby/3/attr/error.h" +#include "ruby/3/attr/forceinline.h" +#include "ruby/3/attr/noreturn.h" +#include "ruby/3/config.h" +#include "ruby/3/dllexport.h" +#include "ruby/3/has/attribute.h" +#include "ruby/3/intern/array.h" /* rb_ary_new_from_values */ +#include "ruby/3/intern/error.h" /* rb_error_arity */ +#include "ruby/3/intern/hash.h" /* rb_hash_dup */ +#include "ruby/3/intern/proc.h" /* rb_block_proc */ +#include "ruby/3/iterator.h" /* rb_block_given_p / rb_keyword_given_p */ +#include "ruby/3/static_assert.h" +#include "ruby/3/stdbool.h" +#include "ruby/3/value.h" +#include "ruby/assert.h" + +#define RB_SCAN_ARGS_PASS_CALLED_KEYWORDS 0 +#define RB_SCAN_ARGS_KEYWORDS 1 +#define RB_SCAN_ARGS_LAST_HASH_KEYWORDS 3 +#define RB_NO_KEYWORDS 0 +#define RB_PASS_KEYWORDS 1 +#define RB_PASS_CALLED_KEYWORDS rb_keyword_given_p() +/* rb_scan_args() format allows ':' for optional hash */ +#define HAVE_RB_SCAN_ARGS_OPTIONAL_HASH 1 + +RUBY3_SYMBOL_EXPORT_BEGIN() +int rb_scan_args(int, const VALUE*, const char*, ...); +int rb_scan_args_kw(int, int, const VALUE*, const char*, ...); + +RUBY3_ATTR_ERROR(("bad scan arg format")) +void rb_scan_args_bad_format(const char*); + +RUBY3_ATTR_ERROR(("variable argument length doesn't match")) +void rb_scan_args_length_mismatch(const char*,int); + +RUBY3_SYMBOL_EXPORT_END() + +/* If we could use constexpr the following macros could be inline functions + * ... but sadly we cannot. */ + +#define rb_scan_args_isdigit(c) (RUBY3_CAST((unsigned char)((c)-'0'))<10) + +#define rb_scan_args_count_end(fmt, ofs, vari) \ + ((fmt)[ofs] ? -1 : (vari)) + +#define rb_scan_args_count_block(fmt, ofs, vari) \ + ((fmt)[ofs]!='&' ? \ + rb_scan_args_count_end(fmt, ofs, vari) : \ + rb_scan_args_count_end(fmt, (ofs)+1, (vari)+1)) + +#define rb_scan_args_count_hash(fmt, ofs, vari) \ + ((fmt)[ofs]!=':' ? \ + rb_scan_args_count_block(fmt, ofs, vari) : \ + rb_scan_args_count_block(fmt, (ofs)+1, (vari)+1)) + +#define rb_scan_args_count_trail(fmt, ofs, vari) \ + (!rb_scan_args_isdigit((fmt)[ofs]) ? \ + rb_scan_args_count_hash(fmt, ofs, vari) : \ + rb_scan_args_count_hash(fmt, (ofs)+1, (vari)+((fmt)[ofs]-'0'))) + +#define rb_scan_args_count_var(fmt, ofs, vari) \ + ((fmt)[ofs]!='*' ? \ + rb_scan_args_count_trail(fmt, ofs, vari) : \ + rb_scan_args_count_trail(fmt, (ofs)+1, (vari)+1)) + +#define rb_scan_args_count_opt(fmt, ofs, vari) \ + (!rb_scan_args_isdigit((fmt)[ofs]) ? \ + rb_scan_args_count_var(fmt, ofs, vari) : \ + rb_scan_args_count_var(fmt, (ofs)+1, (vari)+(fmt)[ofs]-'0')) + +#define rb_scan_args_count_lead(fmt, ofs, vari) \ + (!rb_scan_args_isdigit((fmt)[ofs]) ? \ + rb_scan_args_count_var(fmt, ofs, vari) : \ + rb_scan_args_count_opt(fmt, (ofs)+1, (vari)+(fmt)[ofs]-'0')) + +#define rb_scan_args_count(fmt) rb_scan_args_count_lead(fmt, 0, 0) + +#if RUBY3_HAS_ATTRIBUTE(diagnose_if) +# /* Assertions done in the attribute. */ +# define rb_scan_args_verify(fmt, varc) RUBY3_ASSERT_NOTHING +#else +# /* At one sight it _seems_ the expressions below could be written using +# * static assrtions. The reality is no, they don't. Because fmt is a string +# * literal, any operations against fmt cannot produce the "integer constant +# * expression"s, as defined in ISO/IEC 9899:2018 section 6.6 paragraph #6. +# * Static assertions need such integer constant expressions as defined in +# * ISO/IEC 9899:2018 section 6.7.10 paragraph #3. +# * +# * GCC nontheless constant-folds this into no-op, though. */ +# define rb_scan_args_verify(fmt, varc) \ + (sizeof(char[1-2*(rb_scan_args_count(fmt)<0)])!=1 ? \ + rb_scan_args_bad_format(fmt) : \ + sizeof(char[1-2*(rb_scan_args_count(fmt)!=(varc))])!=1 ? \ + rb_scan_args_length_mismatch(fmt, varc) : \ + RUBY3_ASSERT_NOTHING) +#endif + +static inline bool +rb_scan_args_keyword_p(int kw_flag, VALUE last) +{ + switch (kw_flag) { + case RB_SCAN_ARGS_PASS_CALLED_KEYWORDS: + return !! rb_keyword_given_p(); + case RB_SCAN_ARGS_KEYWORDS: + return true; + case RB_SCAN_ARGS_LAST_HASH_KEYWORDS: + return RB_TYPE_P(last, T_HASH); + default: + return false; + } +} + +RUBY3_ATTR_FORCEINLINE() +static bool +rb_scan_args_lead_p(const char *fmt) +{ + return rb_scan_args_isdigit(fmt[0]); +} + +RUBY3_ATTR_FORCEINLINE() +static int +rb_scan_args_n_lead(const char *fmt) +{ + return (rb_scan_args_lead_p(fmt) ? fmt[0]-'0' : 0); +} + +RUBY3_ATTR_FORCEINLINE() +static bool +rb_scan_args_opt_p(const char *fmt) +{ + return (rb_scan_args_lead_p(fmt) && rb_scan_args_isdigit(fmt[1])); +} + +RUBY3_ATTR_FORCEINLINE() +static int +rb_scan_args_n_opt(const char *fmt) +{ + return (rb_scan_args_opt_p(fmt) ? fmt[1]-'0' : 0); +} + +RUBY3_ATTR_FORCEINLINE() +static int +rb_scan_args_var_idx(const char *fmt) +{ + return (!rb_scan_args_lead_p(fmt) ? 0 : !rb_scan_args_isdigit(fmt[1]) ? 1 : 2); +} + +RUBY3_ATTR_FORCEINLINE() +static bool +rb_scan_args_f_var(const char *fmt) +{ + return (fmt[rb_scan_args_var_idx(fmt)]=='*'); +} + +RUBY3_ATTR_FORCEINLINE() +static int +rb_scan_args_trail_idx(const char *fmt) +{ + const int idx = rb_scan_args_var_idx(fmt); + return idx+(fmt[idx]=='*'); +} + +RUBY3_ATTR_FORCEINLINE() +static int +rb_scan_args_n_trail(const char *fmt) +{ + const int idx = rb_scan_args_trail_idx(fmt); + return (rb_scan_args_isdigit(fmt[idx]) ? fmt[idx]-'0' : 0); +} + +RUBY3_ATTR_FORCEINLINE() +static int +rb_scan_args_hash_idx(const char *fmt) +{ + const int idx = rb_scan_args_trail_idx(fmt); + return idx+rb_scan_args_isdigit(fmt[idx]); +} + +RUBY3_ATTR_FORCEINLINE() +static bool +rb_scan_args_f_hash(const char *fmt) +{ + return (fmt[rb_scan_args_hash_idx(fmt)]==':'); +} + +RUBY3_ATTR_FORCEINLINE() +static int +rb_scan_args_block_idx(const char *fmt) +{ + const int idx = rb_scan_args_hash_idx(fmt); + return idx+(fmt[idx]==':'); +} + +RUBY3_ATTR_FORCEINLINE() +static bool +rb_scan_args_f_block(const char *fmt) +{ + return (fmt[rb_scan_args_block_idx(fmt)]=='&'); +} + +# if 0 +RUBY3_ATTR_FORCEINLINE() +static int +rb_scan_args_end_idx(const char *fmt) +{ + const int idx = rb_scan_args_block_idx(fmt); + return idx+(fmt[idx]=='&'); +} +# endif + +/* NOTE: Use `char *fmt` instead of `const char *fmt` because of clang's bug*/ +/* https://bugs.llvm.org/show_bug.cgi?id=38095 */ +# define rb_scan_args0(argc, argv, fmt, varc, vars) \ + rb_scan_args_set(RB_SCAN_ARGS_PASS_CALLED_KEYWORDS, argc, argv, \ + rb_scan_args_n_lead(fmt), \ + rb_scan_args_n_opt(fmt), \ + rb_scan_args_n_trail(fmt), \ + rb_scan_args_f_var(fmt), \ + rb_scan_args_f_hash(fmt), \ + rb_scan_args_f_block(fmt), \ + (rb_scan_args_verify(fmt, varc), vars), (char *)fmt, varc) +# define rb_scan_args_kw0(kw_flag, argc, argv, fmt, varc, vars) \ + rb_scan_args_set(kw_flag, argc, argv, \ + rb_scan_args_n_lead(fmt), \ + rb_scan_args_n_opt(fmt), \ + rb_scan_args_n_trail(fmt), \ + rb_scan_args_f_var(fmt), \ + rb_scan_args_f_hash(fmt), \ + rb_scan_args_f_block(fmt), \ + (rb_scan_args_verify(fmt, varc), vars), (char *)fmt, varc) + +RUBY3_ATTR_FORCEINLINE() +static int +rb_scan_args_set(int kw_flag, int argc, const VALUE *argv, + int n_lead, int n_opt, int n_trail, + bool f_var, bool f_hash, bool f_block, + VALUE *vars[], RB_UNUSED_VAR(const char *fmt), RB_UNUSED_VAR(int varc)) + RUBY3_ATTR_DIAGNOSE_IF(rb_scan_args_count(fmt) < 0, "bad scan arg format", "error") + RUBY3_ATTR_DIAGNOSE_IF(rb_scan_args_count(fmt) != varc, "variable argument length doesn't match", "error") +{ + int i, argi = 0, vari = 0; + VALUE *var, hash = Qnil; + const int n_mand = n_lead + n_trail; + + if (f_hash && argc > 0) { + VALUE last = argv[argc - 1]; + if (rb_scan_args_keyword_p(kw_flag, last)) { + hash = rb_hash_dup(last); + argc--; + } + } + + if (argc < n_mand) { + goto argc_error; + } + + /* capture leading mandatory arguments */ + for (i = n_lead; i-- > 0; ) { + var = vars[vari++]; + if (var) *var = argv[argi]; + argi++; + } + /* capture optional arguments */ + for (i = n_opt; i-- > 0; ) { + var = vars[vari++]; + if (argi < argc - n_trail) { + if (var) *var = argv[argi]; + argi++; + } + else { + if (var) *var = Qnil; + } + } + /* capture variable length arguments */ + if (f_var) { + int n_var = argc - argi - n_trail; + + var = vars[vari++]; + if (0 < n_var) { + if (var) *var = rb_ary_new_from_values(n_var, &argv[argi]); + argi += n_var; + } + else { + if (var) *var = rb_ary_new(); + } + } + /* capture trailing mandatory arguments */ + for (i = n_trail; i-- > 0; ) { + var = vars[vari++]; + if (var) *var = argv[argi]; + argi++; + } + /* capture an option hash - phase 2: assignment */ + if (f_hash) { + var = vars[vari++]; + if (var) *var = hash; + } + /* capture iterator block */ + if (f_block) { + var = vars[vari++]; + if (rb_block_given_p()) { + *var = rb_block_proc(); + } + else { + *var = Qnil; + } + } + + if (argi >= argc) { + return argc; + } + + argc_error: + rb_error_arity(argc, n_mand, f_var ? UNLIMITED_ARGUMENTS : n_mand + n_opt); +} + +#if ! defined(HAVE_BUILTIN___BUILTIN_CHOOSE_EXPR_CONSTANT_P) +# /* skip */ + +#elif ! defined(HAVE_VA_ARGS_MACRO) +# /* skip */ + +#elif ! defined(__OPTIMIZE__) +# /* skip */ + +#elif defined(HAVE___VA_OPT__) +# define rb_scan_args(argc, argvp, fmt, ...) \ + __builtin_choose_expr( \ + __builtin_constant_p(fmt), \ + rb_scan_args0( \ + argc, argvp, fmt, \ + (sizeof((VALUE*[]){__VA_ARGS__})/sizeof(VALUE*)), \ + ((VALUE*[]){__VA_ARGS__})), \ + (rb_scan_args)(argc, argvp, fmt __VA_OPT__(, __VA_ARGS__))) +# define rb_scan_args_kw(kw_flag, argc, argvp, fmt, ...) \ + __builtin_choose_expr( \ + __builtin_constant_p(fmt), \ + rb_scan_args_kw0( \ + kw_flag, argc, argvp, fmt, \ + (sizeof((VALUE*[]){__VA_ARGS__})/sizeof(VALUE*)), \ + ((VALUE*[]){__VA_ARGS__})), \ + (rb_scan_args_kw)(kw_flag, argc, argvp, fmt __VA_OPT__(, __VA_ARGS__))) + +#elif defined(__STRICT_ANSI__) +# /* skip */ + +#elif defined(__GNUC__) +# define rb_scan_args(argc, argvp, fmt, ...) \ + __builtin_choose_expr( \ + __builtin_constant_p(fmt), \ + rb_scan_args0( \ + argc, argvp, fmt, \ + (sizeof((VALUE*[]){__VA_ARGS__})/sizeof(VALUE*)), \ + ((VALUE*[]){__VA_ARGS__})), \ + (rb_scan_args)(argc, argvp, fmt, ## __VA_ARGS__)) +# define rb_scan_args_kw(kw_flag, argc, argvp, fmt, ...) \ + __builtin_choose_expr( \ + __builtin_constant_p(fmt), \ + rb_scan_args_kw0( \ + kw_flag, argc, argvp, fmt, \ + (sizeof((VALUE*[]){__VA_ARGS__})/sizeof(VALUE*)), \ + ((VALUE*[]){__VA_ARGS__})), \ + (rb_scan_args_kw)(kw_flag, argc, argvp, fmt, ## __VA_ARGS__)) +#endif + +#endif /* RUBY3_SCAN_ARGS_H */ |