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-rw-r--r--gcc/cp/parser.c81
1 files changed, 74 insertions, 7 deletions
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 168486c..5ec8b1b 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -10585,14 +10585,31 @@ cp_parser_statement (cp_parser* parser, tree in_statement_expr,
}
/* Look for an expression-statement instead. */
statement = cp_parser_expression_statement (parser, in_statement_expr);
+
+ /* Handle [[fallthrough]];. */
+ if (attribute_fallthrough_p (std_attrs))
+ {
+ /* The next token after the fallthrough attribute is ';'. */
+ if (statement == NULL_TREE)
+ {
+ /* Turn [[fallthrough]]; into FALLTHROUGH ();. */
+ statement = build_call_expr_internal_loc (statement_location,
+ IFN_FALLTHROUGH,
+ void_type_node, 0);
+ finish_expr_stmt (statement);
+ }
+ else
+ warning_at (statement_location, OPT_Wattributes,
+ "%<fallthrough%> attribute not followed by %<;%>");
+ std_attrs = NULL_TREE;
+ }
}
/* Set the line number for the statement. */
if (statement && STATEMENT_CODE_P (TREE_CODE (statement)))
SET_EXPR_LOCATION (statement, statement_location);
- /* Note that for now, we don't do anything with c++11 statements
- parsed at this level. */
+ /* Allow "[[fallthrough]];", but warn otherwise. */
if (std_attrs != NULL_TREE)
warning_at (attrs_location,
OPT_Wattributes,
@@ -10628,6 +10645,10 @@ cp_parser_label_for_labeled_statement (cp_parser* parser, tree attributes)
return;
}
+ /* Remember whether this case or a user-defined label is allowed to fall
+ through to. */
+ bool fallthrough_p = token->flags & PREV_FALLTHROUGH;
+
parser->colon_corrects_to_scope_p = false;
switch (token->keyword)
{
@@ -10659,7 +10680,11 @@ cp_parser_label_for_labeled_statement (cp_parser* parser, tree attributes)
expr_hi = NULL_TREE;
if (parser->in_switch_statement_p)
- finish_case_label (token->location, expr, expr_hi);
+ {
+ tree l = finish_case_label (token->location, expr, expr_hi);
+ if (l && TREE_CODE (l) == CASE_LABEL_EXPR)
+ FALLTHROUGH_LABEL_P (CASE_LABEL (l)) = fallthrough_p;
+ }
else
error_at (token->location,
"case label %qE not within a switch statement",
@@ -10672,7 +10697,11 @@ cp_parser_label_for_labeled_statement (cp_parser* parser, tree attributes)
cp_lexer_consume_token (parser->lexer);
if (parser->in_switch_statement_p)
- finish_case_label (token->location, NULL_TREE, NULL_TREE);
+ {
+ tree l = finish_case_label (token->location, NULL_TREE, NULL_TREE);
+ if (l && TREE_CODE (l) == CASE_LABEL_EXPR)
+ FALLTHROUGH_LABEL_P (CASE_LABEL (l)) = fallthrough_p;
+ }
else
error_at (token->location, "case label not within a switch statement");
break;
@@ -10680,6 +10709,8 @@ cp_parser_label_for_labeled_statement (cp_parser* parser, tree attributes)
default:
/* Anything else must be an ordinary label. */
label = finish_label_stmt (cp_parser_identifier (parser));
+ if (label && TREE_CODE (label) == LABEL_DECL)
+ FALLTHROUGH_LABEL_P (label) = fallthrough_p;
break;
}
@@ -10728,6 +10759,10 @@ cp_parser_expression_statement (cp_parser* parser, tree in_statement_expr)
{
tree statement = NULL_TREE;
cp_token *token = cp_lexer_peek_token (parser->lexer);
+ location_t loc = token->location;
+
+ /* There might be attribute fallthrough. */
+ tree attr = cp_parser_gnu_attributes_opt (parser);
/* If the next token is a ';', then there is no expression
statement. */
@@ -10742,6 +10777,25 @@ cp_parser_expression_statement (cp_parser* parser, tree in_statement_expr)
}
}
+ /* Handle [[fallthrough]];. */
+ if (attribute_fallthrough_p (attr))
+ {
+ /* The next token after the fallthrough attribute is ';'. */
+ if (statement == NULL_TREE)
+ /* Turn [[fallthrough]]; into FALLTHROUGH ();. */
+ statement = build_call_expr_internal_loc (loc, IFN_FALLTHROUGH,
+ void_type_node, 0);
+ else
+ warning_at (loc, OPT_Wattributes,
+ "%<fallthrough%> attribute not followed by %<;%>");
+ attr = NULL_TREE;
+ }
+
+ /* Allow "[[fallthrough]];", but warn otherwise. */
+ if (attr != NULL_TREE)
+ warning_at (loc, OPT_Wattributes,
+ "attributes at the beginning of statement are ignored");
+
/* Give a helpful message for "A<T>::type t;" and the like. */
if (cp_lexer_next_token_is_not (parser->lexer, CPP_SEMICOLON)
&& !cp_parser_uncommitted_to_tentative_parse_p (parser))
@@ -12980,6 +13034,7 @@ cp_parser_storage_class_specifier_opt (cp_parser* parser)
if (cxx_dialect != cxx98)
return NULL_TREE;
/* Fall through for C++98. */
+ gcc_fallthrough ();
case RID_REGISTER:
case RID_STATIC:
@@ -24116,7 +24171,7 @@ cp_parser_std_attribute (cp_parser *parser, tree attr_ns)
if (is_attribute_p ("noreturn", attr_id))
TREE_PURPOSE (TREE_PURPOSE (attribute)) = get_identifier ("gnu");
/* C++14 deprecated attribute is equivalent to GNU's. */
- else if (cxx_dialect >= cxx11 && is_attribute_p ("deprecated", attr_id))
+ else if (is_attribute_p ("deprecated", attr_id))
{
if (cxx_dialect == cxx11)
pedwarn (token->location, OPT_Wpedantic,
@@ -24124,6 +24179,15 @@ cp_parser_std_attribute (cp_parser *parser, tree attr_ns)
" use %<gnu::deprecated%>");
TREE_PURPOSE (TREE_PURPOSE (attribute)) = get_identifier ("gnu");
}
+ /* C++17 fallthrough attribute is equivalent to GNU's. */
+ else if (is_attribute_p ("fallthrough", attr_id))
+ {
+ if (cxx_dialect < cxx1z)
+ pedwarn (token->location, OPT_Wpedantic,
+ "%<fallthrough%> is a C++17 feature;"
+ " use %<gnu::fallthrough%>");
+ TREE_PURPOSE (TREE_PURPOSE (attribute)) = get_identifier ("gnu");
+ }
/* Transactional Memory TS optimize_for_synchronized attribute is
equivalent to GNU transaction_callable. */
else if (is_attribute_p ("optimize_for_synchronized", attr_id))
@@ -24182,11 +24246,11 @@ cp_parser_check_std_attribute (tree attributes, tree attribute)
tree name = get_attribute_name (attribute);
if (is_attribute_p ("noreturn", name)
&& lookup_attribute ("noreturn", attributes))
- error ("attribute noreturn can appear at most once "
+ error ("attribute %<noreturn%> can appear at most once "
"in an attribute-list");
else if (is_attribute_p ("deprecated", name)
&& lookup_attribute ("deprecated", attributes))
- error ("attribute deprecated can appear at most once "
+ error ("attribute %<deprecated%> can appear at most once "
"in an attribute-list");
}
}
@@ -27303,6 +27367,7 @@ cp_parser_skip_to_end_of_template_parameter_list (cp_parser* parser)
}
/* Fall through for C++0x, so we handle the second `>' in
the `>>'. */
+ gcc_fallthrough ();
case CPP_GREATER:
if (!nesting_depth && level-- == 0)
@@ -27760,6 +27825,7 @@ cp_parser_cache_defarg (cp_parser *parser, bool nsdmi)
/* Fall through for C++0x, which treats the `>>'
operator like two `>' tokens in certain
cases. */
+ gcc_fallthrough ();
case CPP_GREATER:
if (depth == 0)
@@ -33402,6 +33468,7 @@ cp_parser_omp_for_cond (cp_parser *parser, tree decl, enum tree_code code)
if (code == CILK_SIMD || code == CILK_FOR)
break;
/* Fall through: OpenMP disallows NE_EXPR. */
+ gcc_fallthrough ();
default:
return error_mark_node;
}
generated by cgit v1.1 at 2024-10-01 23:08:47 +0000