[PATCH, ARM] attribute target (thumb,arm) [5/6]

[Christian Bruel <christian dot bruel at st dot com>]

Implements the hooks for #pragma GCC target

A test included to check that macros were correctly defined/undefined on 
pragma regions.

Thanks

Christian

2014-09-23  Christian Bruel  <christian.bruel@st.com>

	* config/arm/arm.h (REGISTER_TARGET_PRAGMAS):
	 Call arm_register_target_pragmas.
	* config/arm/arm-protos.h (arm_register_target_pragmas): Declare.
	* config/arm/arm-c.c (arm_register_target_pragmas): New function.
	(arm_pragma_target_parse): Likewise.

diff '--exclude=ChangeLog*' '--exclude=.svn' '--exclude=*~' '--exclude=#*#' -rupN e/gcc/gcc/config/arm/arm-c.c f/gcc/gcc/config/arm/arm-c.c
--- e/gcc/gcc/config/arm/arm-c.c	2014-11-13 13:03:27.000000000 +0100
+++ f/gcc/gcc/config/arm/arm-c.c	2014-11-13 13:53:45.000000000 +0100
@@ -20,9 +20,12 @@
 #include "system.h"
 #include "coretypes.h"
 #include "tm.h"
-#include "tm_p.h"
 #include "tree.h"
+#include "tm_p.h"
 #include "c-family/c-common.h"
+#include "target.h"
+#include "target-def.h"
+#include "c-family/c-pragma.h"
 
 /* Output C specific EABI object attributes.  These can not be done in
    arm.c because they require information from the C frontend.  */
@@ -112,3 +115,78 @@ arm_cpp_builtins (struct cpp_reader *in,
  cpp_def_or_undef (in, "__ARM_ASM_SYNTAX_UNIFIED__", inline_asm_unified);
 }
 
+/* Hook to validate the current #pragma GCC target and set the arch custom
+   mode state.  If ARGS is NULL, then POP_TARGET is used to reset
+   the options.  */
+static bool
+arm_pragma_target_parse (tree args, tree pop_target)
+{
+  tree prev_tree = build_target_option_node (&global_options);
+  tree cur_tree;
+  struct cl_target_option *prev_opt;
+  struct cl_target_option *cur_opt;
+  bool cur_mode, prev_mode;
+
+  if (! args)
+    {
+      cur_tree = ((pop_target) ? pop_target : target_option_default_node);
+      cl_target_option_restore (&global_options,
+				TREE_TARGET_OPTION (cur_tree));
+    }
+  else
+    {
+      cur_tree = arm_valid_target_attribute_tree (args,  &global_options);
+      if (cur_tree == NULL_TREE)
+	{
+	  cl_target_option_restore (&global_options,
+				    TREE_TARGET_OPTION (prev_tree));
+	  return false;
+	}
+    }
+
+  target_option_current_node = cur_tree;
+  arm_reset_previous_fndecl ();
+
+  /* Figure out the previous mode.  */
+  prev_opt  = TREE_TARGET_OPTION (prev_tree);
+  cur_opt   = TREE_TARGET_OPTION (cur_tree);
+
+  gcc_assert (prev_opt);
+  gcc_assert (cur_opt);
+
+  cur_mode = TARGET_THUMB_P (cur_opt->x_target_flags);
+  prev_mode = TARGET_THUMB_P (prev_opt->x_target_flags);
+
+  if (prev_mode != cur_mode)
+    {
+      /* For the definitions, ensure all newly defined macros are considered
+	 as used for -Wunused-macros.  There is no point warning about the
+	 compiler predefined macros.  */
+      cpp_options *cpp_opts = cpp_get_options (parse_in);
+      unsigned char saved_warn_unused_macros = cpp_opts->warn_unused_macros;
+      cpp_opts->warn_unused_macros = 0;
+
+      /* Update macros.  */
+      arm_cpp_builtins (parse_in, cur_mode);
+
+      cpp_opts->warn_unused_macros = saved_warn_unused_macros;
+    }
+
+  return true;
+}
+
+/* Register target pragmas.  We need to add the hook for parsing #pragma GCC
+   option here rather than in arm.c since it will pull in various preprocessor
+   functions, and those are not present in languages like fortran without a
+   preprocessor.  */
+
+void
+arm_register_target_pragmas (void)
+{
+  /* Update pragma hook to allow parsing #pragma GCC target.  */
+  targetm.target_option.pragma_parse = arm_pragma_target_parse;
+
+#ifdef REGISTER_SUBTARGET_PRAGMAS
+  REGISTER_SUBTARGET_PRAGMAS ();
+#endif
+}
diff '--exclude=ChangeLog*' '--exclude=.svn' '--exclude=*~' '--exclude=#*#' -rupN e/gcc/gcc/config/arm/arm.h f/gcc/gcc/config/arm/arm.h
--- e/gcc/gcc/config/arm/arm.h	2014-11-13 13:48:59.000000000 +0100
+++ f/gcc/gcc/config/arm/arm.h	2014-11-13 13:48:01.000000000 +0100
@@ -2097,7 +2097,8 @@ extern int making_const_table;
   c_register_pragma (0, "long_calls", arm_pr_long_calls);		\
   c_register_pragma (0, "no_long_calls", arm_pr_no_long_calls);		\
   c_register_pragma (0, "long_calls_off", arm_pr_long_calls_off);	\
-  arm_lang_object_attributes_init(); \
+  arm_lang_object_attributes_init();					\
+  arm_register_target_pragmas();                                       \
 } while (0)
 
 /* Condition code information.  */
diff '--exclude=ChangeLog*' '--exclude=.svn' '--exclude=*~' '--exclude=#*#' -rupN e/gcc/gcc/config/arm/arm-protos.h f/gcc/gcc/config/arm/arm-protos.h
--- e/gcc/gcc/config/arm/arm-protos.h	2014-11-13 13:07:47.000000000 +0100
+++ f/gcc/gcc/config/arm/arm-protos.h	2014-11-13 13:49:50.000000000 +0100
@@ -306,6 +306,7 @@ extern const char *arm_rewrite_selected_
 
 /* Defined in gcc/common/config/arm-c.c.  */
 extern void arm_lang_object_attributes_init(void);
+extern void arm_register_target_pragmas (void);
 extern void arm_cpp_builtins (struct cpp_reader *, bool);
 
 extern bool arm_is_constant_pool_ref (rtx);

2014-09-23  Christian Bruel  <christian.bruel@st.com>

	* gcc.target/arm/pragma_attribute.c: New test.

diff '--exclude=ChangeLog*' '--exclude=.svn' '--exclude=*~' '--exclude=#*#' -rupN e/gcc/gcc/testsuite/gcc.target/arm/pragma_attribute.c f/gcc/gcc/testsuite/gcc.target/arm/pragma_attribute.c
--- e/gcc/gcc/testsuite/gcc.target/arm/pragma_attribute.c	1970-01-01 01:00:00.000000000 +0100
+++ f/gcc/gcc/testsuite/gcc.target/arm/pragma_attribute.c	2014-11-18 11:13:19.000000000 +0100
@@ -0,0 +1,35 @@
+/* Test for #prama target macros.  */
+/* { dg-do compile } */
+/* { dg-require-effective-target arm_thumb1_ok } */
+
+#pragma GCC target ("thumb")
+
+#ifndef __thumb__
+#error "__thumb__ is not defined"
+#endif
+
+#ifdef __thumb2__
+#ifndef __ARM_32BIT_STATE
+#error  "__ARM_32BIT_STATE is not defined"
+#endif
+#else /* thumb1 */
+#ifdef __ARM_32BIT_STATE
+#error  "__ARM_32BIT_STATE is defined"
+#endif
+#endif /* thumb1 */
+
+#pragma GCC target ("arm")
+
+#ifdef __thumb__
+#error "__thumb__ is defined"
+#endif
+
+#if defined (__thumb2__) || defined (__thumb1__)
+#error "thumb is defined"
+#endif 
+
+#ifndef __ARM_32BIT_STATE
+#error  "__ARM_32BIT_STATE is not defined"
+#endif
+
+#pragma GCC reset_options