2015-01-07 Hristian Kirtchev <kirtchev@adacore.com>

	* alloc.ads Alphabetize several declarations. Add constants
	Ignored_Ghost_Units_Initial and Ignored_Ghost_Units_Increment.
	* atree.adb Add with and use clauses for Opt.
	(Allocate_Initialize_Node): Mark a node as ignored Ghost
	if it is created in an ignored Ghost region.
	(Ekind_In): New variant.
	(Is_Ignored_Ghost_Node): New routine.
	(Set_Is_Ignored_Ghost_Node): New routine.
	* atree.adb Aplhabetize several subprograms declarations. Flag
	Spare0 is now known as Is_Ignored_Ghost_Node.
	(Ekind_In): New variant.
	(Is_Ignored_Ghost_Node): New routine.
	(Set_Is_Ignored_Ghost_Node): New routine.
	* einfo.adb: Flag 279 is now known as Contains_Ignored_Ghost_Code.
	(Contains_Ignored_Ghost_Code): New routine.
	(Set_Contains_Ignored_Ghost_Code): New routine.
	(Set_Is_Checked_Ghost_Entity, Set_Is_Ignored_Ghost_Entity):
	It is now possible to set this property on an unanalyzed entity.
	(Write_Entity_Flags): Output the status of flag
	Contains_Ignored_Ghost_Code.
	* einfo.ads New attribute Contains_Ignored_Ghost_Code along with
	usage in nodes.
	(Contains_Ignored_Ghost_Code): New routine
	along with pragma Inline.
	(Set_Contains_Ignored_Ghost_Code): New routine along with pragma Inline.
	* exp_ch3.adb Add with and use clauses for Ghost.
	(Freeze_Type): Capture/restore the value of Ghost_Mode on entry/exit.
	Set the Ghost_Mode in effect.
	(Restore_Globals): New routine.
	* exp_ch7.adb (Process_Declarations): Do not process a context
	that invoves an ignored Ghost entity.
	* exp_dbug.adb (Qualify_All_Entity_Names): Skip an ignored Ghost
	construct that has been rewritten as a null statement.
	* exp_disp.adb Add with and use clauses for Ghost.
	(Make_DT): Capture/restore the value of Ghost_Mode on entry/exit. Set
	the Ghost_Mode in effect.
	(Restore_Globals): New routine.
	* exp_util.adb (Requires_Cleanup_Actions): An ignored Ghost entity
	does not require any clean up. Add two missing cases that deal
	with block statements.
	* freeze.adb Add with and use clauses for Ghost.
	(Freeze_Entity): Capture/restore the value of Ghost_Mode on entry/exit.
	Set the Ghost_Mode in effect.
	(Restore_Globals): New routine.
	* frontend.adb Add with and use clauses for Ghost. Remove any
	ignored Ghost code from all units that qualify.
	* ghost.adb New unit.
	* ghost.ads New unit.
	* gnat1drv.adb Add with clause for Ghost. Initialize and lock
	the table in package Ghost.
	* lib.ads: Alphabetize several subprogram declarations.
	* lib-xref.adb (Output_References): Do not generate reference
	information for ignored Ghost entities.
	* opt.ads Add new type Ghost_Mode_Type and new global variable
	Ghost_Mode.
	* rtsfind.adb (Load_RTU): Provide a clean environment when
	loading a runtime unit.
	* sem.adb (Analyze): Capture/restore the value of Ghost_Mode on
	entry/exit as the node may set a different mode.
	(Do_Analyze):
	Capture/restore the value of Ghost_Mode on entry/exit as the
	unit may be withed from a unit with a different Ghost mode.
	* sem_ch3.adb Add with and use clauses for Ghost.
	(Analyze_Full_Type_Declaration, Analyze_Incomplete_Type_Decl,
	Analyze_Number_Declaration, Analyze_Private_Extension_Declaration,
	Analyze_Subtype_Declaration): Set the Ghost_Mode in effect. Mark
	the entity as Ghost when there is a Ghost_Mode in effect.
	(Array_Type_Declaration): The implicit base type inherits the
	"ghostness" from the array type.
	(Derive_Subprogram): The
	alias inherits the "ghostness" from the parent subprogram.
	(Make_Implicit_Base): The implicit base type inherits the
	"ghostness" from the parent type.
	* sem_ch5.adb Add with and use clauses for Ghost.
	(Analyze_Assignment): Set the Ghost_Mode in effect.
	* sem_ch6.adb Add with and use clauses for Ghost.
	(Analyze_Abstract_Subprogram_Declaration, Analyze_Procedure_Call,
	Analyze_Subprogram_Body_Helper, Analyze_Subprogram_Declaration):
	Set the Ghost_Mode in effect. Mark the entity as Ghost when
	there is a Ghost_Mode in effect.
	* sem_ch7.adb Add with and use clauses for Ghost.
	(Analyze_Package_Body_Helper, Analyze_Package_Declaration,
	Analyze_Private_Type_Declaration): Set the Ghost_Mode in
	effect. Mark the entity as Ghost when there is a Ghost_Mode
	in effect.
	* sem_ch8.adb Add with and use clauses for Ghost.
	(Analyze_Exception_Renaming, Analyze_Generic_Renaming,
	Analyze_Object_Renaming, Analyze_Package_Renaming,
	Analyze_Subprogram_Renaming): Set the Ghost_Mode in effect. Mark
	the entity as Ghost when there is a Ghost_Mode in effect.
	(Find_Type): Check the Ghost context of a type.
	* sem_ch11.adb Add with and use clauses for Ghost.
	(Analyze_Exception_Declaration): Set the Ghost_Mode in
	effect. Mark the entity as Ghost when there is a Ghost_Mode
	in effect.
	* sem_ch12.adb Add with and use clauses for Ghost.
	(Analyze_Generic_Package_Declaration,
	Analyze_Generic_Subprogram_Declaration): Set the Ghost_Mode in effect.
	Mark the entity as Ghost when there is a Ghost_Mode in effect.
	* sem_prag.adb Add with and use clauses for Ghost.
	(Analyze_Pragma): Ghost-related checks are triggered when there
	is a Ghost mode in effect.
	(Create_Abstract_State): Mark the
	entity as Ghost when there is a Ghost_Mode in effect.
	* sem_res.adb Add with and use clauses for Ghost.
	(Check_Ghost_Context): Removed.
	* sem_util.adb (Check_Ghost_Completion): Removed.
	(Check_Ghost_Derivation): Removed.
	(Incomplete_Or_Partial_View):
	Add a guard in case the entity has not been analyzed yet
	and does carry a scope.
	(Is_Declaration): New routine.
	(Is_Ghost_Entity): Removed.
	(Is_Ghost_Statement_Or_Pragma):
	Removed.
	(Is_Subject_To_Ghost): Removed.
	(Set_Is_Ghost_Entity):
	Removed.
	(Within_Ghost_Scope): Removed.
	* sem_util.adb (Check_Ghost_Completion): Removed.
	(Check_Ghost_Derivation): Removed.
	(Is_Declaration): New routine.
	(Is_Ghost_Entity): Removed.
	(Is_Ghost_Statement_Or_Pragma): Removed.
	(Is_Subject_To_Ghost): Removed.
	(Set_Is_Ghost_Entity): Removed.
	(Within_Ghost_Scope): Removed.
	* sinfo.ads Add a section on Ghost mode.
	* treepr.adb (Print_Header_Flag): New routine.
	(Print_Node_Header): Factor out code. Output flag
	Is_Ignored_Ghost_Node.
	* gcc-interface/Make-lang.in: Add dependency for unit Ghost.

From-SVN: r219280

1 files changed, 115 insertions, 0 deletions

diff --git a/gcc/ada/ghost.ads b/gcc/ada/ghost.ads
new file mode 100644
index 0000000..436e84f
--- /dev/null
+++ b/gcc/ada/ghost.ads
@@ -0,0 +1,115 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT COMPILER COMPONENTS                         --
+--                                                                          --
+--                                G H O S T                                 --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--            Copyright (C) 2014-2015, Free Software Foundation, Inc.       --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
+-- for  more details.  You should have  received  a copy of the GNU General --
+-- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
+-- http://www.gnu.org/licenses for a complete copy of the license.          --
+--                                                                          --
+-- GNAT was originally developed  by the GNAT team at  New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This package contains routines that deal with the static and runtime
+--  semantics of Ghost entities.
+
+with Types; use Types;
+
+package Ghost is
+
+   procedure Add_Ignored_Ghost_Unit (Unit : Node_Id);
+   --  Add a single ignored Ghost compilation unit to the internal table for
+   --  post processing.
+
+   procedure Check_Ghost_Completion
+     (Partial_View : Entity_Id;
+      Full_View    : Entity_Id);
+   --  Verify that the Ghost policy of a full view or a completion is the same
+   --  as the Ghost policy of the partial view. Emit an error if this is not
+   --  the case.
+
+   procedure Check_Ghost_Context (Ghost_Id : Entity_Id; Ghost_Ref : Node_Id);
+   --  Determine whether node Ghost_Ref appears within a Ghost-friendly context
+   --  where Ghost entity Ghost_Id can safely reside.
+
+   procedure Check_Ghost_Derivation (Typ : Entity_Id);
+   --  Verify that the parent type and all progenitors of derived type or type
+   --  extension Typ are Ghost. If this is not the case, issue an error.
+
+   function Implements_Ghost_Interface (Typ : Entity_Id) return Boolean;
+   --  Determine whether type Typ implements at least one Ghost interface
+
+   procedure Initialize;
+   --  Initialize internal tables
+
+   function Is_Ghost_Entity (Id : Entity_Id) return Boolean;
+   --  Determine whether entity Id is Ghost. To qualify as such, the entity
+   --  must be subject to pragma Ghost.
+
+   function Is_Subject_To_Ghost (N : Node_Id) return Boolean;
+   --  Determine whether declarative node N is subject to aspect or pragma
+   --  Ghost. Use this routine in cases where [source] pragma Ghost has not
+   --  been analyzed yet, but the context needs to establish the "ghostness"
+   --  of N.
+
+   procedure Lock;
+   --  Lock internal tables before calling backend
+
+   procedure Remove_Ignored_Ghost_Code;
+   --  Remove all code marked as ignored Ghost from the trees of all qualifying
+   --  units.
+   --
+   --  WARNING: this is a separate front end pass, care should be taken to keep
+   --  it optimized.
+
+   procedure Set_Ghost_Mode (N : Node_Id; Prev_Id : Entity_Id := Empty);
+   --  Set the value of global variable Ghost_Mode depending on the following
+   --  scenarios:
+   --
+   --    If N is a declaration, determine whether N is subject to pragma Ghost.
+   --    If this is the case, the Ghost_Mode is set based on the current Ghost
+   --    policy in effect. Special cases:
+   --
+   --      N is the completion of a deferred constant, Prev_Id denotes the
+   --      entity of the partial declaration.
+   --
+   --      N is the full view of a private type, Prev_Id denotes the entity
+   --      of the partial declaration.
+   --
+   --    If N is an assignment statement or a procedure call, determine whether
+   --    the name of N denotes a reference to a Ghost entity. If this is the
+   --    case, the Global_Mode is set based on the mode of the name.
+   --
+   --    If N denotes a package or a subprogram body, determine whether the
+   --    corresponding spec Prev_Id is a Ghost entity or the body is subject
+   --    to pragma Ghost. If this is the case, the Global_Mode is set based on
+   --    the current Ghost policy in effect.
+   --
+   --  WARNING: the caller must save and restore the value of Ghost_Mode in a
+   --  a stack-like fasion as this routine may override the existing value.
+
+   procedure Set_Ghost_Mode_For_Freeze (Id : Entity_Id; N : Node_Id);
+   --  Set the value of global variable Ghost_Mode depending on the mode of
+   --  entity Id. N denotes the context of the freeze.
+   --
+   --  WARNING: the caller must save and restore the value of Ghost_Mode in a
+   --  a stack-like fasion as this routine may override the existing value.
+
+   procedure Set_Is_Ghost_Entity (Id : Entity_Id);
+   --  Set the relevant ghost attribute of entity Id depending on the current
+   --  Ghost assertion policy in effect.
+
+end Ghost;