[PATCH] Latest version of the -Wunused-but-set-{variable,parameter} patches (C part)
Jakub Jelinek
jakub@redhat.com
Fri Jan 22 16:11:00 GMT 2010
Hi!
Here is the C part of the -Wunused-but-set-* patchset,
bootstrapped/regtested on x86_64-linux and i686-linux with the other 2
patches.
Ok for 4.6?
Jakub
-------------- next part --------------
2010-01-22 Jakub Jelinek <jakub@redhat.com>
PR c/18624
* tree.h (DECL_READ_P): Define.
(struct tree_decl_common): Add decl_read_flag.
* c-decl.c (pop_scope): If TREE_USED but !DECL_READ_P, issue
a set but not used warning.
(merge_decls): Merge DECL_READ_P flag.
(finish_decl, build_compound_literal): Set DECL_READ_P flag.
(finish_function): Issue -Wunused-but-set-parameter diagnostics.
* c-common.c (handle_used_attribute, handle_unused_attribute):
Likewise.
* c-tree.h (default_function_array_read_conversion, mark_exp_read):
New prototypes.
* c-typeck.c (default_function_array_read_conversion, mark_exp_read):
New functions.
(default_conversion, c_process_expr_stmt): Call mark_exp_read.
* c-parser.c (c_parser_initializer, c_parser_expr_no_commas,
c_parser_binary_expression, c_parser_cast_expression,
c_parser_expr_list, c_parser_omp_atomic, c_parser_omp_for_loop):
Call default_function_array_read_conversion instead of
default_function_array_conversion where needed.
(c_parser_unary_expression, c_parser_conditional_expression,
c_parser_postfix_expression_after_primary, c_parser_initelt):
Likewise. Call mark_exp_read where needed.
(c_parser_statement_after_labels, c_parser_asm_operands,
c_parser_typeof_specifier, c_parser_sizeof_expression,
c_parser_alignof_expression, c_parser_initval): Call mark_exp_read
where needed.
* common.opt (Wunused-but-set-variable, Wunused-but-set-parameter):
New.
* toplev.c (warn_unused_but_set_variable): Default to warn_unused.
(warn_unused_but_set_parameter): Default to warn_unused
&& extra_warnings.
* doc/invoke.texi: Document -Wunused-but-set-variable and
-Wunused-but-set-parameter.
* objc-act.c (finish_var_decl, objc_begin_catch_clause,
really_start_method, get_super_receiver, handle_class_ref): Set
DECL_READ_P in addition to TREE_USED.
* gcc.dg/Wunused-var-1.c: New test.
* gcc.dg/Wunused-var-2.c: New test.
* gcc.dg/Wunused-var-3.c: New test.
* gcc.dg/Wunused-var-4.c: New test.
* gcc.dg/Wunused-var-5.c: New test.
* gcc.dg/Wunused-var-6.c: New test.
* gcc.dg/Wunused-parm-1.c: New test.
--- gcc/tree.h.jj 2009-11-27 12:25:18.000000000 +0100
+++ gcc/tree.h 2009-11-27 16:14:33.000000000 +0100
@@ -1317,6 +1317,9 @@ extern void omp_clause_range_check_faile
(TREE_CHECK3 (NODE, VAR_DECL, PARM_DECL, \
RESULT_DECL)->decl_common.decl_restricted_flag)
+#define DECL_READ_P(NODE) \
+ (TREE_CHECK2 (NODE, VAR_DECL, PARM_DECL)->decl_common.decl_read_flag)
+
/* In a CALL_EXPR, means that the call is the jump from a thunk to the
thunked-to function. */
#define CALL_FROM_THUNK_P(NODE) (CALL_EXPR_CHECK (NODE)->base.protected_flag)
@@ -2689,8 +2692,12 @@ struct GTY(()) tree_decl_common {
/* In VAR_DECL, PARM_DECL and RESULT_DECL, this is DECL_RESTRICTED_P. */
unsigned decl_restricted_flag : 1;
+ /* In VAR_DECL and PARM_DECL set when the decl has been used except for
+ being set. */
+ unsigned decl_read_flag : 1;
+
/* Padding so that 'off_align' can be on a 32-bit boundary. */
- unsigned decl_common_unused : 2;
+ unsigned decl_common_unused : 1;
/* DECL_OFFSET_ALIGN, used only for FIELD_DECLs. */
unsigned int off_align : 8;
--- gcc/c-decl.c.jj 2009-11-27 12:25:19.000000000 +0100
+++ gcc/c-decl.c 2009-11-27 18:06:33.000000000 +0100
@@ -1164,14 +1164,20 @@ pop_scope (void)
case VAR_DECL:
/* Warnings for unused variables. */
- if (!TREE_USED (p)
+ if ((!TREE_USED (p) || !DECL_READ_P (p))
&& !TREE_NO_WARNING (p)
&& !DECL_IN_SYSTEM_HEADER (p)
&& DECL_NAME (p)
&& !DECL_ARTIFICIAL (p)
&& scope != file_scope
&& scope != external_scope)
- warning (OPT_Wunused_variable, "unused variable %q+D", p);
+ {
+ if (!TREE_USED (p))
+ warning (OPT_Wunused_variable, "unused variable %q+D", p);
+ else if (DECL_CONTEXT (p) == current_function_decl)
+ warning (OPT_Wunused_but_set_variable,
+ "variable %q+D set but not used", p);
+ }
if (b->inner_comp)
{
@@ -2387,6 +2393,8 @@ merge_decls (tree newdecl, tree olddecl,
TREE_USED (newdecl) = 1;
else if (TREE_USED (newdecl))
TREE_USED (olddecl) = 1;
+ if (TREE_CODE (olddecl) == VAR_DECL || TREE_CODE (olddecl) == PARM_DECL)
+ DECL_READ_P (newdecl) |= DECL_READ_P (olddecl);
/* Copy most of the decl-specific fields of NEWDECL into OLDDECL.
But preserve OLDDECL's DECL_UID, DECL_CONTEXT and
@@ -4229,7 +4237,10 @@ finish_decl (tree decl, location_t init_
}
if (TREE_USED (type))
- TREE_USED (decl) = 1;
+ {
+ TREE_USED (decl) = 1;
+ DECL_READ_P (decl) = 1;
+ }
}
/* If this is a function and an assembler name is specified, reset DECL_RTL
@@ -4377,6 +4388,7 @@ finish_decl (tree decl, location_t init_
/* Don't warn about decl unused; the cleanup uses it. */
TREE_USED (decl) = 1;
TREE_USED (cleanup_decl) = 1;
+ DECL_READ_P (decl) = 1;
push_cleanup (decl, cleanup, false);
}
@@ -4468,6 +4480,7 @@ build_compound_literal (location_t loc,
TREE_STATIC (decl) = (current_scope == file_scope);
DECL_CONTEXT (decl) = current_function_decl;
TREE_USED (decl) = 1;
+ DECL_READ_P (decl) = 1;
TREE_TYPE (decl) = type;
TREE_READONLY (decl) = TYPE_READONLY (type);
store_init_value (loc, decl, init, NULL_TREE);
@@ -8031,6 +8044,24 @@ finish_function (void)
TREE_NO_WARNING (fndecl) = 1;
}
+ /* Complain about parameters that are only set, but never otherwise used. */
+ if (warn_unused_but_set_parameter)
+ {
+ tree decl;
+
+ for (decl = DECL_ARGUMENTS (fndecl);
+ decl;
+ decl = TREE_CHAIN (decl))
+ if (TREE_USED (decl)
+ && TREE_CODE (decl) == PARM_DECL
+ && !DECL_READ_P (decl)
+ && DECL_NAME (decl)
+ && !DECL_ARTIFICIAL (decl)
+ && !TREE_NO_WARNING (decl))
+ warning (OPT_Wunused_but_set_parameter,
+ "parameter %q+D set but not used", decl);
+ }
+
/* Store the end of the function, so that we get good line number
info for the epilogue. */
cfun->function_end_locus = input_location;
--- gcc/c-common.c.jj 2009-11-27 12:25:19.000000000 +0100
+++ gcc/c-common.c 2009-11-27 13:00:10.000000000 +0100
@@ -6116,6 +6116,8 @@ handle_used_attribute (tree *pnode, tree
{
TREE_USED (node) = 1;
DECL_PRESERVE_P (node) = 1;
+ if (TREE_CODE (node) == VAR_DECL)
+ DECL_READ_P (node) = 1;
}
else
{
@@ -6142,7 +6144,12 @@ handle_unused_attribute (tree *node, tre
|| TREE_CODE (decl) == FUNCTION_DECL
|| TREE_CODE (decl) == LABEL_DECL
|| TREE_CODE (decl) == TYPE_DECL)
- TREE_USED (decl) = 1;
+ {
+ TREE_USED (decl) = 1;
+ if (TREE_CODE (decl) == VAR_DECL
+ || TREE_CODE (decl) == PARM_DECL)
+ DECL_READ_P (decl) = 1;
+ }
else
{
warning (OPT_Wattributes, "%qE attribute ignored", name);
--- gcc/c-tree.h.jj 2009-11-27 12:25:19.000000000 +0100
+++ gcc/c-tree.h 2009-11-27 13:00:10.000000000 +0100
@@ -511,7 +511,10 @@ extern bool c_mark_addressable (tree);
extern void c_incomplete_type_error (const_tree, const_tree);
extern tree c_type_promotes_to (tree);
extern struct c_expr default_function_array_conversion (location_t,
- struct c_expr);
+ struct c_expr);
+extern struct c_expr default_function_array_read_conversion (location_t,
+ struct c_expr);
+extern void mark_exp_read (tree);
extern tree composite_type (tree, tree);
extern tree build_component_ref (location_t, tree, tree);
extern tree build_array_ref (location_t, tree, tree);
--- gcc/c-typeck.c.jj 2009-11-27 12:25:19.000000000 +0100
+++ gcc/c-typeck.c 2009-11-27 13:00:10.000000000 +0100
@@ -1763,6 +1763,35 @@ function_to_pointer_conversion (location
return build_unary_op (loc, ADDR_EXPR, exp, 0);
}
+/* Mark EXP as read, not just set, for set but not used -Wunused
+ warning purposes. */
+
+void
+mark_exp_read (tree exp)
+{
+ switch (TREE_CODE (exp))
+ {
+ case VAR_DECL:
+ case PARM_DECL:
+ DECL_READ_P (exp) = 1;
+ break;
+ case ARRAY_REF:
+ case COMPONENT_REF:
+ case MODIFY_EXPR:
+ case REALPART_EXPR:
+ case IMAGPART_EXPR:
+ CASE_CONVERT:
+ case ADDR_EXPR:
+ mark_exp_read (TREE_OPERAND (exp, 0));
+ break;
+ case COMPOUND_EXPR:
+ mark_exp_read (TREE_OPERAND (exp, 1));
+ break;
+ default:
+ break;
+ }
+}
+
/* Perform the default conversion of arrays and functions to pointers.
Return the result of converting EXP. For any other expression, just
return EXP.
@@ -1818,6 +1847,12 @@ default_function_array_conversion (locat
return exp;
}
+struct c_expr
+default_function_array_read_conversion (location_t loc, struct c_expr exp)
+{
+ mark_exp_read (exp.value);
+ return default_function_array_conversion (loc, exp);
+}
/* EXP is an expression of integer type. Apply the integer promotions
to it and return the promoted value. */
@@ -1879,6 +1914,8 @@ default_conversion (tree exp)
enum tree_code code = TREE_CODE (type);
tree promoted_type;
+ mark_exp_read (exp);
+
/* Functions and arrays have been converted during parsing. */
gcc_assert (code != FUNCTION_TYPE);
if (code == ARRAY_TYPE)
@@ -8738,6 +8775,7 @@ c_process_expr_stmt (location_t loc, tre
number, wrap the thing in a no-op NOP_EXPR. */
if (DECL_P (expr) || CONSTANT_CLASS_P (expr))
{
+ mark_exp_read (expr);
expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr);
SET_EXPR_LOCATION (expr, loc);
}
--- gcc/c-parser.c.jj 2009-11-27 12:25:19.000000000 +0100
+++ gcc/c-parser.c 2009-11-27 13:00:10.000000000 +0100
@@ -2171,6 +2171,7 @@ c_parser_typeof_specifier (c_parser *par
if (TREE_CODE (expr.value) == COMPONENT_REF
&& DECL_C_BIT_FIELD (TREE_OPERAND (expr.value, 1)))
error_at (here, "%<typeof%> applied to a bit-field");
+ mark_exp_read (expr.value);
ret.spec = TREE_TYPE (expr.value);
was_vm = variably_modified_type_p (ret.spec, NULL_TREE);
/* This is returned with the type so that when the type is
@@ -3073,7 +3074,7 @@ c_parser_initializer (c_parser *parser)
ret = c_parser_expr_no_commas (parser, NULL);
if (TREE_CODE (ret.value) != STRING_CST
&& TREE_CODE (ret.value) != COMPOUND_LITERAL_EXPR)
- ret = default_function_array_conversion (loc, ret);
+ ret = default_function_array_read_conversion (loc, ret);
return ret;
}
}
@@ -3229,6 +3230,7 @@ c_parser_initelt (c_parser *parser)
goto parse_message_args;
}
first = c_parser_expr_no_commas (parser, NULL).value;
+ mark_exp_read (first);
if (c_parser_next_token_is (parser, CPP_ELLIPSIS)
|| c_parser_next_token_is (parser, CPP_CLOSE_SQUARE))
goto array_desig_after_first;
@@ -3244,7 +3246,8 @@ c_parser_initelt (c_parser *parser)
c_parser_consume_token (parser);
exp_loc = c_parser_peek_token (parser)->location;
next = c_parser_expr_no_commas (parser, NULL);
- next = default_function_array_conversion (exp_loc, next);
+ next = default_function_array_read_conversion (exp_loc,
+ next);
rec = build_compound_expr (comma_loc, rec, next.value);
}
parse_message_args:
@@ -3264,12 +3267,14 @@ c_parser_initelt (c_parser *parser)
}
c_parser_consume_token (parser);
first = c_parser_expr_no_commas (parser, NULL).value;
+ mark_exp_read (first);
array_desig_after_first:
if (c_parser_next_token_is (parser, CPP_ELLIPSIS))
{
ellipsis_loc = c_parser_peek_token (parser)->location;
c_parser_consume_token (parser);
second = c_parser_expr_no_commas (parser, NULL).value;
+ mark_exp_read (second);
}
else
second = NULL_TREE;
@@ -3337,7 +3342,7 @@ c_parser_initval (c_parser *parser, stru
if (init.value != NULL_TREE
&& TREE_CODE (init.value) != STRING_CST
&& TREE_CODE (init.value) != COMPOUND_LITERAL_EXPR)
- init = default_function_array_conversion (loc, init);
+ init = default_function_array_read_conversion (loc, init);
}
process_init_element (init, false);
}
@@ -3840,6 +3845,7 @@ c_parser_statement_after_labels (c_parse
else
{
struct c_expr expr = c_parser_expression_conv (parser);
+ mark_exp_read (expr.value);
stmt = c_finish_return (loc, expr.value, expr.original_type);
goto expect_semicolon;
}
@@ -4455,6 +4461,7 @@ c_parser_asm_operands (c_parser *parser,
}
loc = c_parser_peek_token (parser)->location;
expr = c_parser_expression (parser);
+ mark_exp_read (expr.value);
if (convert_p)
expr = default_function_array_conversion (loc, expr);
expr.value = c_fully_fold (expr.value, false, NULL);
@@ -4605,7 +4612,7 @@ c_parser_expr_no_commas (c_parser *parse
c_parser_consume_token (parser);
exp_location = c_parser_peek_token (parser)->location;
rhs = c_parser_expr_no_commas (parser, NULL);
- rhs = default_function_array_conversion (exp_location, rhs);
+ rhs = default_function_array_read_conversion (exp_location, rhs);
ret.value = build_modify_expr (op_location, lhs.value, lhs.original_type,
code, exp_location, rhs.value,
rhs.original_type);
@@ -4647,7 +4654,7 @@ c_parser_conditional_expression (c_parse
if (c_parser_next_token_is_not (parser, CPP_QUERY))
return cond;
cond_loc = c_parser_peek_token (parser)->location;
- cond = default_function_array_conversion (cond_loc, cond);
+ cond = default_function_array_read_conversion (cond_loc, cond);
c_parser_consume_token (parser);
if (c_parser_next_token_is (parser, CPP_COLON))
{
@@ -4674,6 +4681,7 @@ c_parser_conditional_expression (c_parse
(cond_loc, default_conversion (cond.value));
c_inhibit_evaluation_warnings += cond.value == truthvalue_false_node;
exp1 = c_parser_expression_conv (parser);
+ mark_exp_read (exp1.value);
c_inhibit_evaluation_warnings +=
((cond.value == truthvalue_true_node)
- (cond.value == truthvalue_false_node));
@@ -4691,7 +4699,7 @@ c_parser_conditional_expression (c_parse
{
location_t exp2_loc = c_parser_peek_token (parser)->location;
exp2 = c_parser_conditional_expression (parser, NULL);
- exp2 = default_function_array_conversion (exp2_loc, exp2);
+ exp2 = default_function_array_read_conversion (exp2_loc, exp2);
}
c_inhibit_evaluation_warnings -= cond.value == truthvalue_true_node;
ret.value = build_conditional_expr (colon_loc, cond.value,
@@ -4844,10 +4852,11 @@ c_parser_binary_expression (c_parser *pa
break; \
} \
stack[sp - 1].expr \
- = default_function_array_conversion (stack[sp - 1].loc, \
- stack[sp - 1].expr); \
+ = default_function_array_read_conversion (stack[sp - 1].loc, \
+ stack[sp - 1].expr); \
stack[sp].expr \
- = default_function_array_conversion (stack[sp].loc, stack[sp].expr); \
+ = default_function_array_read_conversion (stack[sp].loc, \
+ stack[sp].expr); \
stack[sp - 1].expr = parser_build_binary_op (stack[sp].loc, \
stack[sp].op, \
stack[sp - 1].expr, \
@@ -4952,8 +4961,8 @@ c_parser_binary_expression (c_parser *pa
{
case TRUTH_ANDIF_EXPR:
stack[sp].expr
- = default_function_array_conversion (stack[sp].loc,
- stack[sp].expr);
+ = default_function_array_read_conversion (stack[sp].loc,
+ stack[sp].expr);
stack[sp].expr.value = c_objc_common_truthvalue_conversion
(stack[sp].loc, default_conversion (stack[sp].expr.value));
c_inhibit_evaluation_warnings += (stack[sp].expr.value
@@ -4961,8 +4970,8 @@ c_parser_binary_expression (c_parser *pa
break;
case TRUTH_ORIF_EXPR:
stack[sp].expr
- = default_function_array_conversion (stack[sp].loc,
- stack[sp].expr);
+ = default_function_array_read_conversion (stack[sp].loc,
+ stack[sp].expr);
stack[sp].expr.value = c_objc_common_truthvalue_conversion
(stack[sp].loc, default_conversion (stack[sp].expr.value));
c_inhibit_evaluation_warnings += (stack[sp].expr.value
@@ -5032,7 +5041,7 @@ c_parser_cast_expression (c_parser *pars
{
location_t expr_loc = c_parser_peek_token (parser)->location;
expr = c_parser_cast_expression (parser, NULL);
- expr = default_function_array_conversion (expr_loc, expr);
+ expr = default_function_array_read_conversion (expr_loc, expr);
}
ret.value = c_cast_expr (cast_loc, type_name, expr.value);
ret.original_code = ERROR_MARK;
@@ -5085,23 +5094,24 @@ c_parser_unary_expression (c_parser *par
c_parser_consume_token (parser);
exp_loc = c_parser_peek_token (parser)->location;
op = c_parser_cast_expression (parser, NULL);
- op = default_function_array_conversion (exp_loc, op);
+ 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_conversion (exp_loc, op);
+ 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);
- return parser_build_unary_op (op_loc, ADDR_EXPR,
- c_parser_cast_expression (parser, NULL));
+ op = c_parser_cast_expression (parser, NULL);
+ mark_exp_read (op.value);
+ return parser_build_unary_op (op_loc, ADDR_EXPR, op);
case CPP_MULT:
c_parser_consume_token (parser);
exp_loc = c_parser_peek_token (parser)->location;
op = c_parser_cast_expression (parser, NULL);
- op = default_function_array_conversion (exp_loc, op);
+ op = default_function_array_read_conversion (exp_loc, op);
ret.value = build_indirect_ref (op_loc, op.value, RO_UNARY_STAR);
return ret;
case CPP_PLUS:
@@ -5112,25 +5122,25 @@ c_parser_unary_expression (c_parser *par
c_parser_consume_token (parser);
exp_loc = c_parser_peek_token (parser)->location;
op = c_parser_cast_expression (parser, NULL);
- op = default_function_array_conversion (exp_loc, op);
+ op = default_function_array_read_conversion (exp_loc, op);
return parser_build_unary_op (op_loc, CONVERT_EXPR, op);
case CPP_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_conversion (exp_loc, op);
+ op = default_function_array_read_conversion (exp_loc, op);
return parser_build_unary_op (op_loc, NEGATE_EXPR, op);
case CPP_COMPL:
c_parser_consume_token (parser);
exp_loc = c_parser_peek_token (parser)->location;
op = c_parser_cast_expression (parser, NULL);
- op = default_function_array_conversion (exp_loc, op);
+ op = default_function_array_read_conversion (exp_loc, op);
return parser_build_unary_op (op_loc, BIT_NOT_EXPR, op);
case CPP_NOT:
c_parser_consume_token (parser);
exp_loc = c_parser_peek_token (parser)->location;
op = c_parser_cast_expression (parser, NULL);
- op = default_function_array_conversion (exp_loc, op);
+ op = default_function_array_read_conversion (exp_loc, op);
return parser_build_unary_op (op_loc, TRUTH_NOT_EXPR, op);
case CPP_AND_AND:
/* Refer to the address of a label as a pointer. */
@@ -5230,6 +5240,7 @@ c_parser_sizeof_expression (c_parser *pa
sizeof_expr:
c_inhibit_evaluation_warnings--;
in_sizeof--;
+ mark_exp_read (expr.value);
if (TREE_CODE (expr.value) == COMPONENT_REF
&& DECL_C_BIT_FIELD (TREE_OPERAND (expr.value, 1)))
error_at (expr_loc, "%<sizeof%> applied to a bit-field");
@@ -5290,6 +5301,7 @@ c_parser_alignof_expression (c_parser *p
struct c_expr ret;
expr = c_parser_unary_expression (parser);
alignof_expr:
+ mark_exp_read (expr.value);
c_inhibit_evaluation_warnings--;
in_alignof--;
ret.value = c_alignof_expr (loc, expr.value);
@@ -5495,6 +5507,7 @@ c_parser_postfix_expression (c_parser *p
break;
}
e1 = c_parser_expr_no_commas (parser, NULL);
+ mark_exp_read (e1.value);
e1.value = c_fully_fold (e1.value, false, NULL);
if (!c_parser_require (parser, CPP_COMMA, "expected %<,%>"))
{
@@ -5639,6 +5652,8 @@ c_parser_postfix_expression (c_parser *p
tree c;
c = e1.value;
+ mark_exp_read (e2.value);
+ mark_exp_read (e3.value);
if (TREE_CODE (c) != INTEGER_CST
|| !INTEGRAL_TYPE_P (TREE_TYPE (c)))
error_at (loc,
@@ -5883,6 +5898,7 @@ c_parser_postfix_expression_after_primar
c_parser_skip_until_found (parser, CPP_CLOSE_PAREN,
"expected %<)%>");
orig_expr = expr;
+ mark_exp_read (expr.value);
/* FIXME diagnostics: Ideally we want the FUNCNAME, not the
"(" after the FUNCNAME, which is what we have now. */
expr.value = build_function_call_vec (op_loc, expr.value, exprlist,
@@ -5965,7 +5981,7 @@ c_parser_postfix_expression_after_primar
case CPP_PLUS_PLUS:
/* Postincrement. */
c_parser_consume_token (parser);
- expr = default_function_array_conversion (expr_loc, expr);
+ expr = default_function_array_read_conversion (expr_loc, expr);
expr.value = build_unary_op (op_loc,
POSTINCREMENT_EXPR, expr.value, 0);
expr.original_code = ERROR_MARK;
@@ -5974,7 +5990,7 @@ c_parser_postfix_expression_after_primar
case CPP_MINUS_MINUS:
/* Postdecrement. */
c_parser_consume_token (parser);
- expr = default_function_array_conversion (expr_loc, expr);
+ expr = default_function_array_read_conversion (expr_loc, expr);
expr.value = build_unary_op (op_loc,
POSTDECREMENT_EXPR, expr.value, 0);
expr.original_code = ERROR_MARK;
@@ -6052,7 +6068,7 @@ c_parser_expr_list (c_parser *parser, bo
expr = c_parser_expr_no_commas (parser, NULL);
if (convert_p)
- expr = default_function_array_conversion (loc, expr);
+ expr = default_function_array_read_conversion (loc, expr);
if (fold_p)
expr.value = c_fully_fold (expr.value, false, NULL);
VEC_quick_push (tree, ret, expr.value);
@@ -6064,7 +6080,7 @@ c_parser_expr_list (c_parser *parser, bo
loc = c_parser_peek_token (parser)->location;
expr = c_parser_expr_no_commas (parser, NULL);
if (convert_p)
- expr = default_function_array_conversion (loc, expr);
+ expr = default_function_array_read_conversion (loc, expr);
if (fold_p)
expr.value = c_fully_fold (expr.value, false, NULL);
VEC_safe_push (tree, gc, ret, expr.value);
@@ -7887,7 +7903,7 @@ c_parser_omp_atomic (location_t loc, c_p
{
location_t rhs_loc = c_parser_peek_token (parser)->location;
rhs_expr = c_parser_expression (parser);
- rhs_expr = default_function_array_conversion (rhs_loc, rhs_expr);
+ rhs_expr = default_function_array_read_conversion (rhs_loc, rhs_expr);
}
rhs = rhs_expr.value;
rhs = c_fully_fold (rhs, false, NULL);
@@ -8034,7 +8050,8 @@ c_parser_omp_for_loop (location_t loc,
init_loc = c_parser_peek_token (parser)->location;
init_exp = c_parser_expr_no_commas (parser, NULL);
- init_exp = default_function_array_conversion (init_loc, init_exp);
+ init_exp = default_function_array_read_conversion (init_loc,
+ init_exp);
init = build_modify_expr (init_loc, decl, decl_exp.original_type,
NOP_EXPR, init_loc, init_exp.value,
init_exp.original_type);
--- gcc/common.opt.jj 2009-11-27 12:25:19.000000000 +0100
+++ gcc/common.opt 2009-11-27 18:07:20.000000000 +0100
@@ -208,6 +208,14 @@ Wunused
Common Var(warn_unused) Init(0) Warning
Enable all -Wunused- warnings
+Wunused-but-set-parameter
+Common Var(warn_unused_but_set_parameter) Init(-1) Warning
+Warn when a function parameter is only set, otherwise unused
+
+Wunused-but-set-variable
+Common Var(warn_unused_but_set_variable) Init(-1) Warning
+Warn when a variable is only set, otherwise unused
+
Wunused-function
Common Var(warn_unused_function) Init(-1) Warning
Warn when a function is unused
--- gcc/toplev.c.jj 2009-11-27 12:25:18.000000000 +0100
+++ gcc/toplev.c 2009-11-27 18:09:08.000000000 +0100
@@ -1785,6 +1785,12 @@ process_options (void)
warn_unused_parameter = (warn_unused && extra_warnings);
if (warn_unused_variable == -1)
warn_unused_variable = warn_unused;
+ /* Wunused-but-set-parameter is enabled if both -Wunused -Wextra are
+ enabled. */
+ if (warn_unused_but_set_parameter == -1)
+ warn_unused_but_set_parameter = (warn_unused && extra_warnings);
+ if (warn_unused_but_set_variable == -1)
+ warn_unused_but_set_variable = warn_unused;
if (warn_unused_value == -1)
warn_unused_value = warn_unused;
--- gcc/objc/objc-act.c.jj 2009-11-27 12:25:18.000000000 +0100
+++ gcc/objc/objc-act.c 2009-11-27 16:38:23.000000000 +0100
@@ -1524,6 +1524,7 @@ finish_var_decl (tree var, tree initiali
mark_decl_referenced (var);
/* Mark the decl to avoid "defined but not used" warning. */
TREE_USED (var) = 1;
+ DECL_READ_P (var) = 1;
}
/* Find the decl for the constant string class reference. This is only
@@ -3851,6 +3852,7 @@ objc_begin_catch_clause (tree decl)
/* ??? As opposed to __attribute__((unused))? Anyway, this appears to
be what the previous objc implementation did. */
TREE_USED (decl) = 1;
+ DECL_READ_P (decl) = 1;
/* Verify that the type of the catch is valid. It must be a pointer
to an Objective-C class, or "id" (which is catch-all). */
@@ -8719,7 +8721,9 @@ really_start_method (tree method,
/* Suppress unused warnings. */
TREE_USED (self_decl) = 1;
+ DECL_READ_P (self_decl) = 1;
TREE_USED (TREE_CHAIN (self_decl)) = 1;
+ DECL_READ_P (TREE_CHAIN (self_decl)) = 1;
#ifdef OBJCPLUS
pop_lang_context ();
#endif
@@ -8796,6 +8800,7 @@ get_super_receiver (void)
objc_super_template);
/* This prevents `unused variable' warnings when compiling with -Wall. */
TREE_USED (UOBJC_SUPER_decl) = 1;
+ DECL_READ_P (UOBJC_SUPER_decl) = 1;
lang_hooks.decls.pushdecl (UOBJC_SUPER_decl);
finish_decl (UOBJC_SUPER_decl, input_location, NULL_TREE, NULL_TREE,
NULL_TREE);
@@ -9419,6 +9424,7 @@ handle_class_ref (tree chain)
DECL_INITIAL (decl) = exp;
TREE_STATIC (decl) = 1;
TREE_USED (decl) = 1;
+ DECL_READ_P (decl) = 1;
/* Force the output of the decl as this forces the reference of the class. */
mark_decl_referenced (decl);
--- gcc/doc/invoke.texi.jj 2009-11-23 13:04:19.000000000 +0100
+++ gcc/doc/invoke.texi 2009-11-27 18:18:13.000000000 +0100
@@ -262,7 +262,7 @@ Objective-C and Objective-C++ Dialects}.
-Wunknown-pragmas -Wno-pragmas -Wunreachable-code @gol
-Wunsuffixed-float-constants -Wunused -Wunused-function @gol
-Wunused-label -Wunused-parameter -Wno-unused-result -Wunused-value -Wunused-variable @gol
--Wvariadic-macros -Wvla @gol
+-Wunused-but-set-parameter -Wunused-but-set-variable -Wvariadic-macros -Wvla @gol
-Wvolatile-register-var -Wwrite-strings}
@item C and Objective-C-only Warning Options
@@ -2895,7 +2895,8 @@ name is still supported, but the newer n
-Wsign-compare @gol
-Wtype-limits @gol
-Wuninitialized @gol
--Wunused-parameter @r{(only with} @option{-Wunused} @r{or} @option{-Wall}@r{)} @gol
+-Wunused-parameter @r{(only with} @option{-Wunused} @r{or} @option{-Wall}@r{)} @gol
+-Wunused-but-set-parameter @r{(only with} @option{-Wunused} @r{or} @option{-Wall}@r{)} @gol
}
The option @option{-Wextra} also prints warning messages for the
@@ -3285,6 +3286,25 @@ Warn if any trigraphs are encountered th
the program (trigraphs within comments are not warned about).
This warning is enabled by @option{-Wall}.
+@item -Wunused-but-set-parameter
+@opindex Wunused-but-set-parameter
+@opindex Wno-unused-but-set-parameter
+Warn whenever a function parameter is assigned to, but otherwise unused
+(aside from its declaration).
+
+To suppress this warning use the @samp{unused} attribute
+(@pxref{Variable Attributes}).
+
+@item -Wunused-but-set-variable
+@opindex Wunused-but-set-variable
+@opindex Wno-unused-but-set-variable
+Warn whenever a local variable is assigned to, but otherwise unused
+(aside from its declaration).
+This warning is enabled by @option{-Wall}.
+
+To suppress this warning use the @samp{unused} attribute
+(@pxref{Variable Attributes}).
+
@item -Wunused-function
@opindex Wunused-function
@opindex Wno-unused-function
--- gcc/testsuite/gcc.dg/Wunused-var-1.c.jj 2009-11-27 13:00:10.000000000 +0100
+++ gcc/testsuite/gcc.dg/Wunused-var-1.c 2009-11-27 13:00:10.000000000 +0100
@@ -0,0 +1,179 @@
+/* { dg-do compile } */
+/* { dg-options "-Wunused" } */
+
+void
+f1 (void)
+{
+ int a; /* { dg-warning "set but not used" } */
+ int b;
+ int c;
+ c = 1;
+ a = b = c;
+}
+
+void
+f2 (int x)
+{
+ int a; /* { dg-warning "set but not used" } */
+ int b;
+ int c; /* { dg-warning "set but not used" } */
+ c = (a = x, b = x);
+}
+
+int
+f3 (int x)
+{
+ int a;
+ return a = x;
+}
+
+int
+f4 (int x)
+{
+ int a;
+ a = x;
+ return a;
+}
+
+void
+f5 (int x)
+{
+ int a[2]; /* { dg-warning "set but not used" } */
+ int b;
+ int *c, d[2];
+ c = d;
+ b = x;
+ a[b] = 1;
+ c[b] = 1;
+}
+
+int
+f6 (int x)
+{
+ int a[2];
+ int b;
+ b = x;
+ a[b] = 1;
+ return a[b];
+}
+
+void
+f7 (int x, int *p)
+{
+ int *a[2];
+ a[x] = p;
+ a[x][x] = x;
+}
+
+struct S { int i; };
+
+void
+f8 (void)
+{
+ struct S s; /* { dg-warning "set but not used" } */
+ s.i = 6;
+}
+
+int
+f9 (void)
+{
+ struct S s;
+ s.i = 6;
+ return s.i;
+}
+
+struct S
+f10 (void)
+{
+ struct S s;
+ s.i = 6;
+ return s;
+}
+
+extern int foo11 (int *);
+
+void
+f11 (void)
+{
+ int a[2];
+ foo11 (a);
+}
+
+void
+f12 (void)
+{
+ int a;
+ a = 1;
+ a; /* { dg-warning "statement with no effect" } */
+}
+
+void
+f13 (void (*x) (void))
+{
+ void (*a) (void);
+ a = x;
+ a ();
+}
+
+void
+f14 (void (*x) (void))
+{
+ void (*a) (void); /* { dg-warning "set but not used" } */
+ a = x;
+}
+
+extern void foo15 (int *);
+
+void
+f15 (void)
+{
+ int a[10];
+ int *b = a + 2;
+ foo15 (b);
+}
+
+extern void foo16 (int **);
+
+void
+f16 (void)
+{
+ int a[10];
+ int *b[] = { a, a + 2 };
+ foo16 (b);
+}
+
+void
+f17 (int x)
+{
+ long a; /* { dg-warning "set but not used" } */
+ int b;
+ a = b = x;
+}
+
+void
+f18 (int x)
+{
+ int a; /* { dg-warning "set but not used" } */
+ int b;
+ a = (char) (b = x);
+}
+
+int
+f19 (int x, int y, int z)
+{
+ int a;
+ int b;
+ a = x;
+ b = y;
+ return z ? a : b;
+}
+
+int *
+f20 (int x)
+{
+ static int a[] = { 3, 4, 5, 6 };
+ static int b[] = { 4, 5, 6, 7 };
+ static int c[] = { 5, 6, 7, 8 }; /* { dg-warning "set but not used" } */
+ c[1] = 1;
+ return x ? a : b;
+}
--- gcc/testsuite/gcc.dg/Wunused-var-2.c.jj 2009-11-27 13:00:10.000000000 +0100
+++ gcc/testsuite/gcc.dg/Wunused-var-2.c 2009-11-27 13:00:10.000000000 +0100
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-Wunused" } */
+
+int
+f1 (void)
+{
+ int c = ({
+ int a;
+ a = 1;
+ a; });
+ return c;
+}
+
+void
+f2 (void)
+{
+ int f;
+ f = 0;
+ __asm__ __volatile__ ("" : "+r" (f));
+}
--- gcc/testsuite/gcc.dg/Wunused-var-3.c.jj 2009-11-27 13:00:10.000000000 +0100
+++ gcc/testsuite/gcc.dg/Wunused-var-3.c 2009-11-27 13:00:10.000000000 +0100
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-Wunused" } */
+
+void
+f1 (void)
+{
+ _Complex int a; /* { dg-warning "set but not used" } */
+ _Complex double b; /* { dg-warning "set but not used" } */
+ __real__ a = 1;
+ __imag__ a = 2;
+ __real__ b = 3.0;
+ __imag__ b = 4.0;
+}
+
+int
+f2 (void)
+{
+ _Complex int a;
+ _Complex double b;
+ __real__ a = 1;
+ __imag__ a = 2;
+ __real__ b = 3.0;
+ __imag__ b = 4.0;
+ return __real__ a + __imag__ b;
+}
+
+_Complex double
+f3 (void)
+{
+ _Complex int a;
+ _Complex double b;
+ __real__ a = 1;
+ __imag__ a = 2;
+ __real__ b = 3.0;
+ __imag__ b = 4.0;
+ return a + b;
+}
--- gcc/testsuite/gcc.dg/Wunused-var-4.c.jj 2009-11-27 13:00:10.000000000 +0100
+++ gcc/testsuite/gcc.dg/Wunused-var-4.c 2009-11-27 13:00:10.000000000 +0100
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-options "-Wunused" } */
+
+int
+f1 (void)
+{
+ int a;
+ int foo (void)
+ {
+ return a;
+ }
+ a = 1;
+ return foo ();
+}
+
+void
+f2 (void)
+{
+ int a; /* { dg-warning "set but not used" } */
+ void foo (void)
+ {
+ a = 2;
+ }
+ a = 1;
+ foo ();
+}
--- gcc/testsuite/gcc.dg/Wunused-var-5.c.jj 2009-11-27 13:00:10.000000000 +0100
+++ gcc/testsuite/gcc.dg/Wunused-var-5.c 2009-11-27 13:00:10.000000000 +0100
@@ -0,0 +1,33 @@
+/* { dg-do compile } */
+/* { dg-options "-Wunused" } */
+
+void
+f1 (void)
+{
+ extern int extvari;
+ extvari = 1;
+}
+
+int extvarj;
+
+void
+f2 (void)
+{
+ extern int extvarj;
+ extvarj = 1;
+}
+
+static int extvark;
+
+void
+f3 (void)
+{
+ extern int extvark;
+ extvark = 1;
+}
+
+int
+f4 (void)
+{
+ return extvark;
+}
--- gcc/testsuite/gcc.dg/Wunused-var-6.c.jj 2009-11-27 13:00:10.000000000 +0100
+++ gcc/testsuite/gcc.dg/Wunused-var-6.c 2009-11-27 13:00:10.000000000 +0100
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-Wunused" } */
+
+int
+f1 (void)
+{
+ int a;
+ int b;
+ int c;
+ int d;
+ int e;
+ a = 1;
+ b = 2;
+ c = 3;
+ d = 4;
+ e = 5;
+ return sizeof (a) + ((__typeof (b)) 1) + __alignof__ (c)
+ + __builtin_choose_expr (1, d, e);
+}
--- gcc/testsuite/gcc.dg/Wunused-parm-1.c.jj 2009-11-27 21:17:05.000000000 +0100
+++ gcc/testsuite/gcc.dg/Wunused-parm-1.c 2009-11-27 21:16:32.000000000 +0100
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+/* { dg-options "-Wunused -W" } */
+
+long
+f1 (unsigned long long x)
+{
+ unsigned long long a = 1;
+ const union { unsigned long long l; unsigned int p[2]; } b = { .l = x };
+ const union { unsigned long long l; unsigned int p[2]; } c = { .l = a };
+ return b.p[0] + c.p[0];
+}
+
+int
+f2 (int x, int y)
+{
+ int a = 1;
+ int b[] = { 1, 2, x, a, 3, 4 };
+ return b[y];
+}
+
+int
+f3 (int a, /* { dg-warning "unused parameter" } */
+ int b, /* { dg-warning "set but not used" } */
+ int c)
+{
+ b = 1;
+ c = 1;
+ return c;
+}
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