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-rw-r--r--gcc/c/ChangeLog19
-rw-r--r--gcc/c/c-decl.cc8
-rw-r--r--gcc/c/c-parser.cc48
-rw-r--r--gcc/c/c-typeck.cc31
4 files changed, 95 insertions, 11 deletions
diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index bd139a7..c303d2fb 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,3 +1,22 @@
+2025-07-15 Jakub Jelinek <jakub@redhat.com>
+ Jason Merrill <jason@redhat.com>
+
+ PR c/44677
+ * c-parser.cc (c_parser_unary_expression): Clear DECL_READ_P
+ after default_function_array_read_conversion for
+ -Wunused-but-set-{parameter,variable}={2,3} on
+ PRE{IN,DE}CREMENT_EXPR argument.
+ (c_parser_postfix_expression_after_primary): Similarly for
+ POST{IN,DE}CREMENT_EXPR.
+ * c-decl.cc (pop_scope): Use OPT_Wunused_but_set_variable_
+ instead of OPT_Wunused_but_set_variable.
+ (finish_function): Use OPT_Wunused_but_set_parameter_
+ instead of OPT_Wunused_but_set_parameter.
+ * c-typeck.cc (mark_exp_read): Handle {PRE,POST}{IN,DE}CREMENT_EXPR
+ and don't handle it when cast to void.
+ (build_modify_expr): Clear DECL_READ_P after build_binary_op
+ for -Wunused-but-set-{parameter,variable}=3.
+
2025-07-10 Qing Zhao <qing.zhao@oracle.com>
* c-typeck.cc (build_access_with_size_for_counted_by): Update comments.
diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
index 8bbd6eb..acbe2b88 100644
--- a/gcc/c/c-decl.cc
+++ b/gcc/c/c-decl.cc
@@ -1363,7 +1363,7 @@ pop_scope (void)
case VAR_DECL:
/* Warnings for unused variables. */
if ((!TREE_USED (p) || !DECL_READ_P (p))
- && !warning_suppressed_p (p, OPT_Wunused_but_set_variable)
+ && !warning_suppressed_p (p, OPT_Wunused_but_set_variable_)
&& !DECL_IN_SYSTEM_HEADER (p)
&& DECL_NAME (p)
&& !DECL_ARTIFICIAL (p)
@@ -1377,7 +1377,7 @@ pop_scope (void)
}
else if (DECL_CONTEXT (p) == current_function_decl)
warning_at (DECL_SOURCE_LOCATION (p),
- OPT_Wunused_but_set_variable,
+ OPT_Wunused_but_set_variable_,
"variable %qD set but not used", p);
}
@@ -11465,9 +11465,9 @@ finish_function (location_t end_loc)
&& !DECL_READ_P (decl)
&& DECL_NAME (decl)
&& !DECL_ARTIFICIAL (decl)
- && !warning_suppressed_p (decl, OPT_Wunused_but_set_parameter))
+ && !warning_suppressed_p (decl, OPT_Wunused_but_set_parameter_))
warning_at (DECL_SOURCE_LOCATION (decl),
- OPT_Wunused_but_set_parameter,
+ OPT_Wunused_but_set_parameter_,
"parameter %qD set but not used", decl);
}
diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index 0c3e3e2..5119841 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -10547,15 +10547,31 @@ c_parser_unary_expression (c_parser *parser)
c_parser_consume_token (parser);
exp_loc = c_parser_peek_token (parser)->location;
op = c_parser_cast_expression (parser, NULL);
-
- op = default_function_array_read_conversion (exp_loc, op);
+ if ((VAR_P (op.value) || TREE_CODE (op.value) == PARM_DECL)
+ && !DECL_READ_P (op.value)
+ && (VAR_P (op.value) ? warn_unused_but_set_variable
+ : warn_unused_but_set_parameter) > 1)
+ {
+ op = default_function_array_read_conversion (exp_loc, op);
+ DECL_READ_P (op.value) = 0;
+ }
+ else
+ op = default_function_array_read_conversion (exp_loc, op);
return parser_build_unary_op (op_loc, PREINCREMENT_EXPR, op);
case CPP_MINUS_MINUS:
c_parser_consume_token (parser);
exp_loc = c_parser_peek_token (parser)->location;
op = c_parser_cast_expression (parser, NULL);
-
- op = default_function_array_read_conversion (exp_loc, op);
+ if ((VAR_P (op.value) || TREE_CODE (op.value) == PARM_DECL)
+ && !DECL_READ_P (op.value)
+ && (VAR_P (op.value) ? warn_unused_but_set_variable
+ : warn_unused_but_set_parameter) > 1)
+ {
+ op = default_function_array_read_conversion (exp_loc, op);
+ DECL_READ_P (op.value) = 0;
+ }
+ else
+ op = default_function_array_read_conversion (exp_loc, op);
return parser_build_unary_op (op_loc, PREDECREMENT_EXPR, op);
case CPP_AND:
c_parser_consume_token (parser);
@@ -13933,7 +13949,17 @@ c_parser_postfix_expression_after_primary (c_parser *parser,
start = expr.get_start ();
finish = c_parser_peek_token (parser)->get_finish ();
c_parser_consume_token (parser);
- expr = default_function_array_read_conversion (expr_loc, expr);
+ if ((VAR_P (expr.value) || TREE_CODE (expr.value) == PARM_DECL)
+ && !DECL_READ_P (expr.value)
+ && (VAR_P (expr.value) ? warn_unused_but_set_variable
+ : warn_unused_but_set_parameter) > 1
+ && TREE_CODE (TREE_TYPE (expr.value)) != ARRAY_TYPE)
+ {
+ expr = default_function_array_read_conversion (expr_loc, expr);
+ DECL_READ_P (expr.value) = 0;
+ }
+ else
+ expr = default_function_array_read_conversion (expr_loc, expr);
expr.value = build_unary_op (op_loc, POSTINCREMENT_EXPR,
expr.value, false);
set_c_expr_source_range (&expr, start, finish);
@@ -13945,7 +13971,17 @@ c_parser_postfix_expression_after_primary (c_parser *parser,
start = expr.get_start ();
finish = c_parser_peek_token (parser)->get_finish ();
c_parser_consume_token (parser);
- expr = default_function_array_read_conversion (expr_loc, expr);
+ if ((VAR_P (expr.value) || TREE_CODE (expr.value) == PARM_DECL)
+ && !DECL_READ_P (expr.value)
+ && (VAR_P (expr.value) ? warn_unused_but_set_variable
+ : warn_unused_but_set_parameter) > 1
+ && TREE_CODE (TREE_TYPE (expr.value)) != ARRAY_TYPE)
+ {
+ expr = default_function_array_read_conversion (expr_loc, expr);
+ DECL_READ_P (expr.value) = 0;
+ }
+ else
+ expr = default_function_array_read_conversion (expr_loc, expr);
expr.value = build_unary_op (op_loc, POSTDECREMENT_EXPR,
expr.value, false);
set_c_expr_source_range (&expr, start, finish);
diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index 9a5eb0d..5d11e57 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -2310,14 +2310,30 @@ mark_exp_read (tree exp)
case PARM_DECL:
DECL_READ_P (exp) = 1;
break;
+ CASE_CONVERT:
+ if (VOID_TYPE_P (TREE_TYPE (exp)))
+ switch (TREE_CODE (TREE_OPERAND (exp, 0)))
+ {
+ case PREINCREMENT_EXPR:
+ case PREDECREMENT_EXPR:
+ case POSTINCREMENT_EXPR:
+ case POSTDECREMENT_EXPR:
+ return;
+ default:
+ break;
+ }
+ /* FALLTHRU */
case ARRAY_REF:
case COMPONENT_REF:
case MODIFY_EXPR:
case REALPART_EXPR:
case IMAGPART_EXPR:
- CASE_CONVERT:
case ADDR_EXPR:
case VIEW_CONVERT_EXPR:
+ case PREINCREMENT_EXPR:
+ case PREDECREMENT_EXPR:
+ case POSTINCREMENT_EXPR:
+ case POSTDECREMENT_EXPR:
mark_exp_read (TREE_OPERAND (exp, 0));
break;
case COMPOUND_EXPR:
@@ -7308,8 +7324,21 @@ build_modify_expr (location_t location, tree lhs, tree lhs_origtype,
newrhs = build1 (EXCESS_PRECISION_EXPR, TREE_TYPE (rhs),
newrhs);
}
+ bool clear_decl_read = false;
+ if ((VAR_P (lhs) || TREE_CODE (lhs) == PARM_DECL)
+ && !DECL_READ_P (lhs)
+ && (VAR_P (lhs) ? warn_unused_but_set_variable
+ : warn_unused_but_set_parameter) > 2)
+ {
+ mark_exp_read (newrhs);
+ if (!DECL_READ_P (lhs))
+ clear_decl_read = true;
+ }
+
newrhs = build_binary_op (location,
modifycode, lhs, newrhs, true);
+ if (clear_decl_read)
+ DECL_READ_P (lhs) = 0;
/* The original type of the right hand side is no longer
meaningful. */
generated by cgit v1.1 at 2025-07-16 18:26:02 +0000