[multiple changes]

2011-11-21  Tristan Gingold  <gingold@adacore.com>

	* env.c: Remove unused declaration.

2011-11-21  Pascal Obry  <obry@adacore.com>

	* s-os_lib.ads: Minor style fix.

2011-11-21  Pascal Obry  <obry@adacore.com>

	* adaint.c (__gnat_dup2): When fd are stdout, stdin or stderr and
	identical, do nothing on Windows XP.

2011-11-21  Yannick Moy  <moy@adacore.com>

	* sem_ch3.adb (Constrain_Index, Process_Range_Expr_In_Decl):
	Use Full_Expander_Active instead of Expander_Active to control
	the forced evaluation of expressions for the sake of generating
	checks.

2011-11-21  Thomas Quinot  <quinot@adacore.com>

	* init.c: On FreeBSD, stack checking failures may raise SIGBUS.

2011-11-21  Tristan Gingold  <gingold@adacore.com>

	* sysdep.c (mode_read_text, mode_write_text, mode_append_text,
	mode_read_binary, mode_write_binary, mode_append_binary,
	mode_read_text_plus, mode_write_text_plus, mode_append_text_plus,
	mode_read_binary_plus, mode_write_binary_plus,
	mode_append_binary_plus): Remove unused declarations.

2011-11-21  Yannick Moy  <moy@adacore.com>

	* gnat_rm.texi: Minor rewording.

2011-11-21  Hristian Kirtchev  <kirtchev@adacore.com>

	* exp_imgv.adb (Expand_Width_Attribute): Emit
	an error message rather than a warning when pragma Discard_Names
	prevents the computation of 'Width. Do not emit an error through
	the use of RE_Null.

2011-11-21  Javier Miranda  <miranda@adacore.com>

	* exp_ch6.adb (Make_Build_In_Place_Call_In_Allocator): Add
	implicit type conversion when the type of the allocator is an
	interface. Done to force generation of displacement of the "this"
	pointer when required.

2011-11-21  Ed Schonberg  <schonberg@adacore.com>

	* sinfo.ads, sinfo.adb: Corresponding_Spec applies to expression
	functions, and is set when the expression is a completion of a
	previous declaration.
	* sem_ch6.adb (Analyze_Expression_Function): To determine properly
	whether an expression function completes a previous declaration,
	use Find_Corresponding_Spec, as when analyzing a subprogram body.

2011-11-21  Steve Baird  <baird@adacore.com>

	* sem_util.adb (Deepest_Type_Access_Level): Improve comment.
	(Type_Access_Level): Improve comment.

From-SVN: r181575

1 files changed, 16 insertions, 2 deletions

diff --git a/gcc/ada/sem_util.adb b/gcc/ada/sem_util.adb
index 8e6a2a2..edf1fec 100644
--- a/gcc/ada/sem_util.adb
+++ b/gcc/ada/sem_util.adb
@@ -2437,7 +2437,8 @@ package body Sem_Util is
                          (Defining_Identifier
                            (Associated_Node_For_Itype (Typ))));
 
-      --  For generic formal type, return Int'Last (infinite) (why ???)
+      --  For generic formal type, return Int'Last (infinite).
+      --  See comment preceding Is_Generic_Type call in Type_Access_Level.
 
       elsif Is_Generic_Type (Root_Type (Typ)) then
          return UI_From_Int (Int'Last);
@@ -12719,7 +12720,20 @@ package body Sem_Util is
          end if;
       end if;
 
-      --  Return library level for a generic formal type (why???)
+      --  Return library level for a generic formal type. This is done because
+      --  RM(10.3.2) says that "The statically deeper relationship does not
+      --  apply to ... a descendant of a generic formal type". Rather than
+      --  checking at each point where a static accessibility check is
+      --  performed to see if we are dealing with a formal type, this rule is
+      --  implemented by having Type_Access_Level and Deepest_Type_Access_Level
+      --  return extreme values for a formal type; Deepest_Type_Access_Level
+      --  returns Int'Last. By calling the appropriate function from among the
+      --  two, we ensure that the static accessibility check will pass if we
+      --  happen to run into a formal type. More specifically, we should call
+      --  Deepest_Type_Access_Level instead of Type_Access_Level whenever the
+      --  call occurs as part of a static accessibility check and the error
+      --  case is the case where the type's level is too shallow (as opposed
+      --  to too deep).
 
       if Is_Generic_Type (Root_Type (Btyp)) then
          return Scope_Depth (Standard_Standard);