Target FP: Add string routines to target-float.{c,h}

This adds target_float_to_string and target_float_from_string,
which dispatch to the corresponding floatformat_ or decimal_ routines.

Existing users of those routines are changed to use the new
target-float routines instead (most of those places already handle
both binary and decimal FP).

In addition, two other places are changes to use target_float_from_string:

- define_symbol in stabsread.c, when parsing a floating-point literal
  from stabs debug info

- gdbarch-selftest.c when initializing a target format values (to
  eliminate use of DOUBLEST there).

gdb/ChangeLog:
2017-11-06  Ulrich Weigand  <uweigand@de.ibm.com>

	* target-float.c (target_float_to_string): New function.
	(target_float_from_string): New function.
	* target-float.h (target_float_to_string): Add prototype.
	(target_float_from_string): Add prototype.

	* valprint.c: Include "target-float.h".  Do not include
	"doublest.h" and "dfp.h".
	(print_floating): Use target_float_to_string.
	* printcmd.c: Include "target-float.h".  Do not include "dfp.h".
	(printf_floating): Use target_float_to_string.
	* i387-tdep.c: Include "target-float.h".  Do not include "doublest.h".
	(print_i387_value): Use target_float_to_string.
	* mips-tdep.c: Include "target-float.h".
	(mips_print_fp_register): Use target_float_to_string.
	* sh64-tdep.c: Include "target-float.h".
	(sh64_do_fp_register): Use target_float_to_string.

	* parse.c: Include "target-float.h".  Do not include
	"doublest.h" and "dfp.h".
	(parse_float): Use target_float_from_string.
	* stabsread.c: Include "target-float.h".  Do not include "doublest.h".
	(define_symbol): Use target_float_from_string.
	* gdbarch-selftests.c: Include "target-float.h".
	(register_to_value_test): Use target_float_from_string.

1 files changed, 3 insertions, 7 deletions

diff --git a/gdb/stabsread.c b/gdb/stabsread.c
index c51b3c7bf1..830138b1b3 100644
--- a/gdb/stabsread.c
+++ b/gdb/stabsread.c
@@ -41,7 +41,7 @@
 #include "demangle.h"
 #include "gdb-demangle.h"
 #include "language.h"
-#include "doublest.h"
+#include "target-float.h"
 #include "cp-abi.h"
 #include "cp-support.h"
 #include <ctype.h>
@@ -798,19 +798,15 @@ define_symbol (CORE_ADDR valu, const char *string, int desc, int type,
 	{
 	case 'r':
 	  {
-	    double d = atof (p);
 	    gdb_byte *dbl_valu;
 	    struct type *dbl_type;
 
-	    /* FIXME-if-picky-about-floating-accuracy: Should be using
-	       target arithmetic to get the value.  real.c in GCC
-	       probably has the necessary code.  */
-
 	    dbl_type = objfile_type (objfile)->builtin_double;
 	    dbl_valu
 	      = (gdb_byte *) obstack_alloc (&objfile->objfile_obstack,
 					    TYPE_LENGTH (dbl_type));
-	    store_typed_floating (dbl_valu, dbl_type, d);
+
+	    target_float_from_string (dbl_valu, dbl_type, std::string (p));
 
 	    SYMBOL_TYPE (sym) = dbl_type;
 	    SYMBOL_VALUE_BYTES (sym) = dbl_valu;