Resent as plain text to appear on the patch tracker Hi all,
This is the beginning of a patch to introduce the extended attribute for asm declarations proposed in https://gcc.gnu.org/pipermail/gcc-patches/2023-November/636563.html. I will need some reviewer help in implementing this patch, as I am not very familiar with gcc's internals. The attribute in question looks as such (Example): [[gnu::extended([output] "=r" (output) [otheroutput] "=r" (otheroutput), [input] "r" (input) [otherinput] "r" (otherinput), "%rcx" "%rdx", label, volatile stack)]] asm (""); I would really appreciate any reviews, as well as help in implementing this patch best regards, Julian >From a189f2820025315b5574d0e9384b96301c6ba7e8 Mon Sep 17 00:00:00 2001 From: TheShermanTanker <tanksherma...@gmail.com> Date: Fri, 17 Nov 2023 11:09:50 +0800 Subject: [PATCH] Introduce the extended attribute for asm declarations --- gcc/cp/parser.cc | 25 +++++++++++++++++++++++++ gcc/cp/tree.cc | 11 +++++++++++ 2 files changed, 36 insertions(+) diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc index 5116bcb78f6..ecc5f2fabc1 100644 --- a/gcc/cp/parser.cc +++ b/gcc/cp/parser.cc @@ -15407,6 +15407,13 @@ cp_parser_block_declaration (cp_parser *parser, cp_parser_commit_to_tentative_parse (parser); cp_parser_asm_definition (parser); } + else if ((attr_idx = cp_parser_skip_std_attribute_spec_seq (parser, 1)) != 1 + && cp_lexer_nth_token_is_keyword (parser->lexer, attr_idx, RID_ASM)) + { + if (statement_p) + cp_parser_commit_to_tentative_parse (parser); + cp_parser_asm_definition (parser); + } /* If the next keyword is `namespace', we have a namespace-alias-definition. */ else if (token1->keyword == RID_NAMESPACE) @@ -22397,6 +22404,23 @@ cp_parser_asm_definition (cp_parser* parser) bool invalid_inputs_p = false; bool invalid_outputs_p = false; required_token missing = RT_NONE; + + tree attrs = cp_parser_std_attribute_spec_seq (parser); + tree extended = error_mark_node; + + if (cp_lexer_next_token_is (parser->lexer, CPP_SEMICOLON)) + { + /* Error during attribute parsing that resulted in skipping + to next semicolon. */ + cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON); + return; + } + + if (attrs != error_mark_node) + { + extended = lookup_attribute ("gnu", "extended", attrs); + } + location_t asm_loc = cp_lexer_peek_token (parser->lexer)->location; /* Look for the `asm' keyword. */ @@ -22511,6 +22535,7 @@ cp_parser_asm_definition (cp_parser* parser) two `:' tokens. */ if (cp_parser_allow_gnu_extensions_p (parser) && parser->in_function_body + && extended == error_mark_node && (cp_lexer_next_token_is (parser->lexer, CPP_COLON) || cp_lexer_next_token_is (parser->lexer, CPP_SCOPE))) { diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc index 417c92ba76f..1f081b3dfd8 100644 --- a/gcc/cp/tree.cc +++ b/gcc/cp/tree.cc @@ -46,6 +46,7 @@ static tree verify_stmt_tree_r (tree *, int *, void *); static tree handle_init_priority_attribute (tree *, tree, tree, int, bool *); static tree handle_abi_tag_attribute (tree *, tree, tree, int, bool *); +static tree handle_extended_attribute (tree *, tree, tree, int, bool *); static tree handle_contract_attribute (tree *, tree, tree, int, bool *); /* If REF is an lvalue, returns the kind of lvalue that REF is. @@ -5080,6 +5081,8 @@ const struct attribute_spec cxx_attribute_table[] = handle_init_priority_attribute, NULL }, { "abi_tag", 1, -1, false, false, false, true, handle_abi_tag_attribute, NULL }, + { "extended", 0, 5, true, false, false, false, + handle_extended_attribute, NULL }, { NULL, 0, 0, false, false, false, false, NULL, NULL } }; @@ -5350,6 +5353,14 @@ handle_abi_tag_attribute (tree* node, tree name, tree args, return NULL_TREE; } +static tree +handle_extended_attribute (tree *node, tree name, tree args, int flags, bool *no_add_attrs) +{ + /* TODO What could be done here? */ + *no_add_attrs = true; + return NULL_TREE; +} + /* Perform checking for contract attributes. */ tree -- 2.41.0
