[Ada] Forced elaboration order in Elaboration order v4.0

This patch refactors the forced elaboration order functionality,
reintegrates it in Binde, and impelements it in Bindo.

------------
-- Source --
------------

--  server.ads

package Server is
end Server;

--  client.ads

with Server;

package Client is
end Client;

--  main.adb

with Client;

procedure Main is begin null; end Main;

--  duplicate_1.txt

server (spec)
client (spec)
server (spec)

--  error_unit_1.txt

no such unit
client (spec)

--  error_unit_2.txt

no such unit
client (spec)

--  error_unit_3.txt

no such unit     --  comment
client (spec)

--  error_unit_4.txt

         no such unit     --  comment

client (spec)

--  error_unit_5.txt

no such unit (body)
client (spec)

--  error_unit_6.txt

    no such unit (body)
client (spec)

--  error_unit_7.txt

    no such unit (body)    --  comment
client (spec)

--  error_unit_8.txt

    no such unit (body)--  comment
client (spec)

--  error_unit_9.txt

    no such unit--  comment
client (spec)

--  no_unit_1.txt

--  no_unit_2.txt

--  no_unit_3.txt

      --  comment

--  no_unit_4.txt

--  no_unit_5.txt

--  no_unit_6.txt

       --  comment

--  no_unit_7.txt

--  no_unit_8.txt

    --  comment
--  comment

--  ok_unit_1.txt

server (spec)
client (spec)

--  ok_unit_2.txt

    server (spec)
client (spec)

--  ok_unit_3.txt

    server (spec)
client (spec)

--  ok_unit_4.txt

    server (spec)      --  comment
client (spec)

--  ok_unit_5.txt

server (spec)
client (spec)

--  ok_unit_6.txt

server (spec)
client (spec)    --  comment

--  ok_unit_7.txt

server (spec)
client (spec)    --  comment

--  ok_unit_8.txt

    --  comment
--  comment
    server (spec)

   --  comment
--  comment

client (spec)    --  comment

--  ok_unit_9.txt

server (spec)--  comment
client (spec)

----------------------------
-- Compilation and output --
----------------------------
$ gnatmake -q main.adb
$ gnatbind -fno_unit_1.txt main.ali
$ gnatbind -fno_unit_2.txt main.ali
$ gnatbind -fno_unit_3.txt main.ali
$ gnatbind -fno_unit_4.txt main.ali
$ gnatbind -fno_unit_5.txt main.ali
$ gnatbind -fno_unit_6.txt main.ali
$ gnatbind -fno_unit_7.txt main.ali
$ gnatbind -fno_unit_8.txt main.ali
$ gnatbind -ferror_unit_1.txt main.ali
$ gnatbind -ferror_unit_2.txt main.ali
$ gnatbind -ferror_unit_3.txt main.ali
$ gnatbind -ferror_unit_4.txt main.ali
$ gnatbind -ferror_unit_5.txt main.ali
$ gnatbind -ferror_unit_6.txt main.ali
$ gnatbind -ferror_unit_7.txt main.ali
$ gnatbind -ferror_unit_8.txt main.ali
$ gnatbind -ferror_unit_9.txt main.ali
$ gnatbind -fduplicate_1.txt main.ali
$ gnatbind -fok_unit_1.txt main.ali
$ gnatbind -fok_unit_2.txt main.ali
$ gnatbind -fok_unit_3.txt main.ali
$ gnatbind -fok_unit_4.txt main.ali
$ gnatbind -fok_unit_5.txt main.ali
$ gnatbind -fok_unit_6.txt main.ali
$ gnatbind -fok_unit_7.txt main.ali
$ gnatbind -fok_unit_8.txt main.ali
$ gnatbind -fok_unit_9.txt main.ali
"no such unit": not present; ignored
"no such unit": not present; ignored
"no such unit": not present; ignored
"no such unit": not present; ignored
"no such unit%b": not present; ignored
"no such unit%b": not present; ignored
"no such unit%b": not present; ignored
"no such unit%b": not present; ignored
"no such unit": not present; ignored
server (spec) <-- client (spec)
error: duplicate_1.txt:3: duplicate unit name "server (spec)" from line 1
server (spec) <-- client (spec)
server (spec) <-- client (spec)
server (spec) <-- client (spec)
server (spec) <-- client (spec)
server (spec) <-- client (spec)
server (spec) <-- client (spec)
server (spec) <-- client (spec)
server (spec) <-- client (spec)
server (spec) <-- client (spec)

2019-07-03  Hristian Kirtchev  <kirtchev@adacore.com>

gcc/ada/

	* binde.adb: Remove with clause for System.OS_Lib.
	(Force_Elab_Order): Refactor the majority of the code in Butil.
	Use the new forced units iterator to obtain unit names.
	* bindo-builders.adb: Add with and use clauses for Binderr,
	Butil, Opt, Output, Types, GNAT, and GNAT.Dynamic_HTables.  Add
	a hash table which maps units to line number in the forced
	elaboration order file.
	(Add_Unit): New routine.
	(Build_Library_Graph): Create forced edges between pairs of
	units listed in the forced elaboration order file.
	(Create_Forced_Edge, Create_Forced_Edges, Destroy_Line_Number,
	Duplicate_Unit_Error, Hash_Unit, Internal_Unit_Info,
	Is_Duplicate_Unit, Missing_Unit_Info): New routines.
	* bindo-graphs.adb (Is_Internal_Unit, Is_Predefined_Unit):
	Refactor some of the behavior to Bindo-Units.
	* bindo-graphs.ads: Enable the enumeration literal for forced
	edges.
	* bindo-units.adb, bindo-units.ads (Is_Internal_Unit,
	Is_Predefined_Unit): New routines.
	* butil.adb: Add with and use clauses for Opt, GNAT, and
	System.OS_Lib.  Add with clause for Unchecked_Deallocation.
	(Has_Next, Iterate_Forced_Units, Next, Parse_Next_Unit_Name,
	Read_Forced_Elab_Order_File): New routines.
	* butil.ads: Add with and use clauses for Types.  Add new
	iterator over the units listed in the forced elaboration order
	file.
	(Has_Next, Iterate_Forced_Units, Next): New routine.
	* namet.adb, namet.ads (Present): New routine.

From-SVN: r272987

1 files changed, 51 insertions, 2 deletions

diff --git a/gcc/ada/butil.ads b/gcc/ada/butil.ads
index 80eb2a5..3ce2f1e 100644
--- a/gcc/ada/butil.ads
+++ b/gcc/ada/butil.ads
@@ -23,12 +23,13 @@
 --                                                                          --
 ------------------------------------------------------------------------------
 
+--  This package contains utility routines for the binder
+
 with Namet; use Namet;
+with Types; use Types;
 
 package Butil is
 
---  This package contains utility routines for the binder
-
    function Is_Predefined_Unit return Boolean;
    --  Given a unit name stored in Name_Buffer with length in Name_Len,
    --  returns True if this is the name of a predefined unit or a child of
@@ -51,4 +52,52 @@ package Butil is
    --  Output unit name with (body) or (spec) after as required. On return
    --  Name_Len is set to the number of characters which were output.
 
+   ---------------
+   -- Iterators --
+   ---------------
+
+   --  The following type represents an iterator over all units that are
+   --  specified in the forced-elaboration-order file supplied by the binder
+   --  via switch -f.
+
+   type Forced_Units_Iterator is private;
+
+   function Has_Next (Iter : Forced_Units_Iterator) return Boolean;
+   pragma Inline (Has_Next);
+   --  Determine whether iterator Iter has more units to examine
+
+   function Iterate_Forced_Units return Forced_Units_Iterator;
+   pragma Inline (Iterate_Forced_Units);
+   --  Obtain an iterator over all units in the forced-elaboration-order file
+
+   procedure Next
+     (Iter      : in out Forced_Units_Iterator;
+      Unit_Name : out Unit_Name_Type;
+      Unit_Line : out Logical_Line_Number);
+   pragma Inline (Next);
+   --  Return the current unit referenced by iterator Iter along with the
+   --  line number it appears on, and advance to the next available unit.
+
+private
+   First_Line_Number : constant Logical_Line_Number := No_Line_Number + 1;
+
+   type Forced_Units_Iterator is record
+      Order : String_Ptr := null;
+      --  A reference to the contents of the forced-elaboration-order file,
+      --  read in as a string.
+
+      Order_Index : Positive := 1;
+      --  Index into the order string
+
+      Order_Line : Logical_Line_Number := First_Line_Number;
+      --  Logical line number within the order string
+
+      Unit_Line : Logical_Line_Number := No_Line_Number;
+      --  The logical line number of the current unit name within the order
+      --  string.
+
+      Unit_Name : Unit_Name_Type := No_Unit_Name;
+      --  The current unit name parsed from the order string
+   end record;
+
 end Butil;