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.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@158086 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ff2857a..896a790 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,40 @@
 2010-04-07  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.
+
        * tree-ssa-pre.c (my_rev_post_order_compute): Remove set but not
        used count variable.
        * genemit.c (gen_expand, gen_split): Avoid set but not used warnings

diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index a9cd106..326fa86 100644 (file)
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -8869,6 +8869,7 @@ c_process_expr_stmt (location_t loc, tree expr)
      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);
     }

diff --git a/gcc/objc/ChangeLog b/gcc/objc/ChangeLog
index 3063af9..4307001 100644 (file)
--- a/gcc/objc/ChangeLog
+++ b/gcc/objc/ChangeLog
@@ -1,3 +1,10 @@
+2010-04-07  Jakub Jelinek  <jakub@redhat.com>
+
+       PR c/18624
+       * 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.
+
 2010-04-07  Iain Sandoe <iains@gcc.gnu.org>
 
        PR objc/35996

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 18cacee..3674a26 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,14 @@
 2010-04-07  Jakub Jelinek  <jakub@redhat.com>
 
+       PR c/18624
+       * 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.dg/builtin-choose-expr.c: Avoid set but not used warnings.
        * gcc.dg/trunc-1.c: Likewise.
        * gcc.dg/vla-9.c: Likewise.

diff --git a/gcc/testsuite/gcc.dg/Wunused-var-3.c b/gcc/testsuite/gcc.dg/Wunused-var-3.c
new file mode 100644 (file)
index 0000000..9b1fce7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wunused-var-3.c
@@ -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;
+}

diff --git a/gcc/testsuite/gcc.dg/Wunused-var-1.c b/gcc/testsuite/gcc.dg/Wunused-var-4.c
similarity index 100%
rename from gcc/testsuite/gcc.dg/Wunused-var-1.c
rename to gcc/testsuite/gcc.dg/Wunused-var-4.c

diff --git a/gcc/testsuite/gcc.dg/Wunused-var-5.c b/gcc/testsuite/gcc.dg/Wunused-var-5.c
new file mode 100644 (file)
index 0000000..747f58d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wunused-var-5.c
@@ -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;
+}

diff --git a/gcc/testsuite/gcc.dg/Wunused-var-2.c b/gcc/testsuite/gcc.dg/Wunused-var-6.c
similarity index 100%
rename from gcc/testsuite/gcc.dg/Wunused-var-2.c
rename to gcc/testsuite/gcc.dg/Wunused-var-6.c