| Message ID | 20231016001227.2717180-4-kmatsui@gcc.gnu.org |
|---|---|
| State | New |
| Headers | show |
| Series | Optimize type traits performance | expand |
On Sun, 15 Oct 2023, Ken Matsui wrote: > This patch accepts the use of built-in trait identifiers when they are > actually not used as traits. Specifically, we check if the subsequent token > is '(' for ordinary built-in traits or is '<' only for the special > __type_pack_element built-in trait. If those identifiers are used > differently, the parser treats them as normal identifiers. This allows > us to accept code like: struct __is_pointer {};. LGTM, thanks > > gcc/cp/ChangeLog: > > * parser.cc (cp_lexer_lookup_trait): Rename to ... > (cp_lexer_peek_trait): ... this. Handle a subsequent token for > the corresponding built-in trait. > (cp_lexer_lookup_trait_expr): Rename to ... > (cp_lexer_peek_trait_expr): ... this. > (cp_lexer_lookup_trait_type): Rename to ... > (cp_lexer_peek_trait_type): ... this. > (cp_lexer_next_token_is_decl_specifier_keyword): Call > cp_lexer_peek_trait_type. > (cp_parser_simple_type_specifier): Likewise. > (cp_parser_primary_expression): Call cp_lexer_peek_trait_expr. > > Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org> > --- > gcc/cp/parser.cc | 48 ++++++++++++++++++++++++++++++------------------ > 1 file changed, 30 insertions(+), 18 deletions(-) > > diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc > index eba5272be03..0f2a1baee6a 100644 > --- a/gcc/cp/parser.cc > +++ b/gcc/cp/parser.cc > @@ -246,12 +246,12 @@ static void cp_lexer_start_debugging > (cp_lexer *) ATTRIBUTE_UNUSED; > static void cp_lexer_stop_debugging > (cp_lexer *) ATTRIBUTE_UNUSED; > -static const cp_trait *cp_lexer_lookup_trait > - (const cp_token *); > -static const cp_trait *cp_lexer_lookup_trait_expr > - (const cp_token *); > -static const cp_trait *cp_lexer_lookup_trait_type > - (const cp_token *); > +static const cp_trait *cp_lexer_peek_trait > + (cp_lexer *lexer, const cp_token *); > +static const cp_trait *cp_lexer_peek_trait_expr > + (cp_lexer *lexer, const cp_token *); > +static const cp_trait *cp_lexer_peek_trait_type > + (cp_lexer *lexer, const cp_token *); > > static cp_token_cache *cp_token_cache_new > (cp_token *, cp_token *); > @@ -1195,19 +1195,31 @@ cp_keyword_starts_decl_specifier_p (enum rid keyword) > } > } > > -/* Look ups the corresponding built-in trait if a given token is > +/* Peeks the corresponding built-in trait if a given token is > a built-in trait. Otherwise, returns nullptr. */ > > static const cp_trait * > -cp_lexer_lookup_trait (const cp_token *token) > +cp_lexer_peek_trait (cp_lexer *lexer, const cp_token *token1) > { > - tree id = token->u.value; > + tree id = token1->u.value; > > - if (token->type == CPP_NAME > + if (token1->type == CPP_NAME > && TREE_CODE (id) == IDENTIFIER_NODE > && IDENTIFIER_TRAIT_P (id)) > - return &cp_traits[IDENTIFIER_CP_INDEX (id)]; > + { > + const cp_trait &trait = cp_traits[IDENTIFIER_CP_INDEX (id)]; > + const bool is_pack_element = (trait.kind == CPTK_TYPE_PACK_ELEMENT); > > + /* Check if the subsequent token is a `<' token to > + __type_pack_element or is a `(' token to everything else. */ > + const cp_token *token2 = cp_lexer_peek_nth_token (lexer, 2); > + if (is_pack_element && token2->type != CPP_LESS) > + return nullptr; > + if (!is_pack_element && token2->type != CPP_OPEN_PAREN) > + return nullptr; > + > + return &trait; > + } > return nullptr; > } > > @@ -1215,9 +1227,9 @@ cp_lexer_lookup_trait (const cp_token *token) > built-in trait. */ > > static const cp_trait * > -cp_lexer_lookup_trait_expr (const cp_token *token) > +cp_lexer_peek_trait_expr (cp_lexer *lexer, const cp_token *token1) > { > - const cp_trait *trait = cp_lexer_lookup_trait (token); > + const cp_trait *trait = cp_lexer_peek_trait (lexer, token1); > if (trait && !trait->type) > return trait; > > @@ -1228,9 +1240,9 @@ cp_lexer_lookup_trait_expr (const cp_token *token) > built-in trait. */ > > static const cp_trait * > -cp_lexer_lookup_trait_type (const cp_token *token) > +cp_lexer_peek_trait_type (cp_lexer *lexer, const cp_token *token1) > { > - const cp_trait *trait = cp_lexer_lookup_trait (token); > + const cp_trait *trait = cp_lexer_peek_trait (lexer, token1); > if (trait && trait->type) > return trait; > > @@ -1245,7 +1257,7 @@ cp_lexer_next_token_is_decl_specifier_keyword (cp_lexer *lexer) > cp_token *token; > > token = cp_lexer_peek_token (lexer); > - if (cp_lexer_lookup_trait_type (token)) > + if (cp_lexer_peek_trait_type (lexer, token)) > return true; > return cp_keyword_starts_decl_specifier_p (token->keyword); > } > @@ -6117,7 +6129,7 @@ cp_parser_primary_expression (cp_parser *parser, > keyword. */ > case CPP_NAME: > { > - const cp_trait* trait = cp_lexer_lookup_trait_expr (token); > + const cp_trait* trait = cp_lexer_peek_trait_expr (parser->lexer, token); > if (trait) > return cp_parser_trait (parser, trait); > } > @@ -20126,7 +20138,7 @@ cp_parser_simple_type_specifier (cp_parser* parser, > } > > /* If token is a type-yielding built-in traits, parse it. */ > - const cp_trait* trait = cp_lexer_lookup_trait_type (token); > + const cp_trait* trait = cp_lexer_peek_trait_type (parser->lexer, token); > if (trait) > { > type = cp_parser_trait (parser, trait); > -- > 2.42.0 > >
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc index eba5272be03..0f2a1baee6a 100644 --- a/gcc/cp/parser.cc +++ b/gcc/cp/parser.cc @@ -246,12 +246,12 @@ static void cp_lexer_start_debugging (cp_lexer *) ATTRIBUTE_UNUSED; static void cp_lexer_stop_debugging (cp_lexer *) ATTRIBUTE_UNUSED; -static const cp_trait *cp_lexer_lookup_trait - (const cp_token *); -static const cp_trait *cp_lexer_lookup_trait_expr - (const cp_token *); -static const cp_trait *cp_lexer_lookup_trait_type - (const cp_token *); +static const cp_trait *cp_lexer_peek_trait + (cp_lexer *lexer, const cp_token *); +static const cp_trait *cp_lexer_peek_trait_expr + (cp_lexer *lexer, const cp_token *); +static const cp_trait *cp_lexer_peek_trait_type + (cp_lexer *lexer, const cp_token *); static cp_token_cache *cp_token_cache_new (cp_token *, cp_token *); @@ -1195,19 +1195,31 @@ cp_keyword_starts_decl_specifier_p (enum rid keyword) } } -/* Look ups the corresponding built-in trait if a given token is +/* Peeks the corresponding built-in trait if a given token is a built-in trait. Otherwise, returns nullptr. */ static const cp_trait * -cp_lexer_lookup_trait (const cp_token *token) +cp_lexer_peek_trait (cp_lexer *lexer, const cp_token *token1) { - tree id = token->u.value; + tree id = token1->u.value; - if (token->type == CPP_NAME + if (token1->type == CPP_NAME && TREE_CODE (id) == IDENTIFIER_NODE && IDENTIFIER_TRAIT_P (id)) - return &cp_traits[IDENTIFIER_CP_INDEX (id)]; + { + const cp_trait &trait = cp_traits[IDENTIFIER_CP_INDEX (id)]; + const bool is_pack_element = (trait.kind == CPTK_TYPE_PACK_ELEMENT); + /* Check if the subsequent token is a `<' token to + __type_pack_element or is a `(' token to everything else. */ + const cp_token *token2 = cp_lexer_peek_nth_token (lexer, 2); + if (is_pack_element && token2->type != CPP_LESS) + return nullptr; + if (!is_pack_element && token2->type != CPP_OPEN_PAREN) + return nullptr; + + return &trait; + } return nullptr; } @@ -1215,9 +1227,9 @@ cp_lexer_lookup_trait (const cp_token *token) built-in trait. */ static const cp_trait * -cp_lexer_lookup_trait_expr (const cp_token *token) +cp_lexer_peek_trait_expr (cp_lexer *lexer, const cp_token *token1) { - const cp_trait *trait = cp_lexer_lookup_trait (token); + const cp_trait *trait = cp_lexer_peek_trait (lexer, token1); if (trait && !trait->type) return trait; @@ -1228,9 +1240,9 @@ cp_lexer_lookup_trait_expr (const cp_token *token) built-in trait. */ static const cp_trait * -cp_lexer_lookup_trait_type (const cp_token *token) +cp_lexer_peek_trait_type (cp_lexer *lexer, const cp_token *token1) { - const cp_trait *trait = cp_lexer_lookup_trait (token); + const cp_trait *trait = cp_lexer_peek_trait (lexer, token1); if (trait && trait->type) return trait; @@ -1245,7 +1257,7 @@ cp_lexer_next_token_is_decl_specifier_keyword (cp_lexer *lexer) cp_token *token; token = cp_lexer_peek_token (lexer); - if (cp_lexer_lookup_trait_type (token)) + if (cp_lexer_peek_trait_type (lexer, token)) return true; return cp_keyword_starts_decl_specifier_p (token->keyword); } @@ -6117,7 +6129,7 @@ cp_parser_primary_expression (cp_parser *parser, keyword. */ case CPP_NAME: { - const cp_trait* trait = cp_lexer_lookup_trait_expr (token); + const cp_trait* trait = cp_lexer_peek_trait_expr (parser->lexer, token); if (trait) return cp_parser_trait (parser, trait); } @@ -20126,7 +20138,7 @@ cp_parser_simple_type_specifier (cp_parser* parser, } /* If token is a type-yielding built-in traits, parse it. */ - const cp_trait* trait = cp_lexer_lookup_trait_type (token); + const cp_trait* trait = cp_lexer_peek_trait_type (parser->lexer, token); if (trait) { type = cp_parser_trait (parser, trait);
This patch accepts the use of built-in trait identifiers when they are actually not used as traits. Specifically, we check if the subsequent token is '(' for ordinary built-in traits or is '<' only for the special __type_pack_element built-in trait. If those identifiers are used differently, the parser treats them as normal identifiers. This allows us to accept code like: struct __is_pointer {};. gcc/cp/ChangeLog: * parser.cc (cp_lexer_lookup_trait): Rename to ... (cp_lexer_peek_trait): ... this. Handle a subsequent token for the corresponding built-in trait. (cp_lexer_lookup_trait_expr): Rename to ... (cp_lexer_peek_trait_expr): ... this. (cp_lexer_lookup_trait_type): Rename to ... (cp_lexer_peek_trait_type): ... this. (cp_lexer_next_token_is_decl_specifier_keyword): Call cp_lexer_peek_trait_type. (cp_parser_simple_type_specifier): Likewise. (cp_parser_primary_expression): Call cp_lexer_peek_trait_expr. Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org> --- gcc/cp/parser.cc | 48 ++++++++++++++++++++++++++++++------------------ 1 file changed, 30 insertions(+), 18 deletions(-)