re PR c/39037 (FLOAT_CONST_DECIMAL64 pragma not supported)

gcc/
	PR c/39037
	* c-common.h (mark_valid_location_for_stdc_pragma,
	valid_location_for_stdc_pragma_p, set_float_const_decimal64,
	clear_float_const_decimal64, float_const_decimal64_p): New.
	* c.opt (Wunsuffixed-float-constants): New.
	* c-lex.c (interpret_float): Use pragma FLOAT_CONST_DECIMAL64 for
	unsuffixed float constant, handle new warning.
	* c-cppbuiltin.c (c_cpp_builtins): Use cast for double constants.
	* c-decl.c (c_scope): New flag float_const_decimal64.
	(set_float_const_decimal64, clear_float_const_decimal64,
	float_const_decimal64_p): New.
	(push_scope): Set new flag.
	* c-parser.c (c_parser_translation_unit): Mark when it's valid
	to use STDC pragmas.
	(c_parser_external_declaration): Ditto.
	(c_parser_compound_statement_nostart): Ditto.
	* c-pragma.c (valid_location_for_stdc_pragma,
	mark_valid_location_for_stdc_pragma,
	valid_location_for_stdc_pragma_p, handle_stdc_pragma,
	handle_pragma_float_const_decimal64): New.
	(init_pragma): Register new pragma FLOAT_CONST_DECIMAL64.
	* cp/semantics.c (valid_location_for_stdc_pragma_p,
	set_float_const_decimal64, clear_float_const_decimal64,
	float_const_decimal64_p): New dummy functions.
	* doc/extend.texi (Decimal Float): Remove statement that the
	pragma, and suffix for double constants, are not supported.
	* doc/invoke.texi (Warning Options): List new option.
	(-Wunsuffixed-float-constants): New.

gcc/testsuite
	PR c/39037
	* gcc.dg/Wunsuffixed-float-constants-1.c: New test.
	* gcc.dg/cpp/pragma-float-const-decimal64-1.c: New test.
	* gcc.dg/dfp/float-constant-double.c: New test.
	* gcc.dg/dfp/pragma-float-const-decimal64-1.c: New test.
	* gcc.dg/dfp/pragma-float-const-decimal64-2.c: New test.
	* gcc.dg/dfp/pragma-float-const-decimal64-3.c: New test.
	* gcc.dg/dfp/pragma-float-const-decimal64-4.c: New test.
	* gcc.dg/dfp/pragma-float-const-decimal64-5.c: New test.
	* gcc.dg/dfp/pragma-float-const-decimal64-6.c: New test.
	* gcc.dg/dfp/pragma-float-const-decimal64-7.c: New test.
	* gcc.dg/dfp/pragma-float-const-decimal64-8.c: New test.
	* g++.dg/cpp/pragma-float-const-decimal64-1.C: New test.

From-SVN: r147259

1 files changed, 40 insertions, 0 deletions

diff --git a/gcc/c-decl.c b/gcc/c-decl.c
index 85c4d6b..409c458 100644
--- a/gcc/c-decl.c
+++ b/gcc/c-decl.c
@@ -342,6 +342,9 @@ struct GTY((chain_next ("%h.outer"))) c_scope {
 
   /* True means make a BLOCK for this scope no matter what.  */
   BOOL_BITFIELD keep : 1;
+
+  /* True means that an unsuffixed float constant is _Decimal64.  */
+  BOOL_BITFIELD float_const_decimal64 : 1;
 };
 
 /* The scope currently in effect.  */
@@ -674,6 +677,30 @@ keep_next_level (void)
   keep_next_level_flag = true;
 }
 
+/* Set the flag for the FLOAT_CONST_DECIMAL64 pragma being ON.  */
+
+void
+set_float_const_decimal64 (void)
+{
+  current_scope->float_const_decimal64 = true;
+}
+
+/* Clear the flag for the FLOAT_CONST_DECIMAL64 pragma.  */
+
+void
+clear_float_const_decimal64 (void)
+{
+  current_scope->float_const_decimal64 = false;
+}
+
+/* Return nonzero if an unsuffixed float constant is _Decimal64.  */
+
+bool
+float_const_decimal64_p (void)
+{
+  return current_scope->float_const_decimal64;
+}
+
 /* Identify this scope as currently being filled with parameters.  */
 
 void
@@ -705,6 +732,13 @@ push_scope (void)
 
       keep_next_level_flag = false;
       next_is_function_body = false;
+
+      /* The FLOAT_CONST_DECIMAL64 pragma applies to nested scopes.  */
+      if (current_scope->outer)
+	current_scope->float_const_decimal64
+	  = current_scope->outer->float_const_decimal64;
+      else
+	current_scope->float_const_decimal64 = false;
     }
   else
     {
@@ -717,6 +751,12 @@ push_scope (void)
       else
 	scope = GGC_CNEW (struct c_scope);
 
+      /* The FLOAT_CONST_DECIMAL64 pragma applies to nested scopes.  */
+      if (current_scope)
+	scope->float_const_decimal64 = current_scope->float_const_decimal64;
+      else
+	scope->float_const_decimal64 = false;
+
       scope->keep          = keep_next_level_flag;
       scope->outer         = current_scope;
       scope->depth	   = current_scope ? (current_scope->depth + 1) : 0;