frontend.adb (Frontend): Skip -gnatec=gnat.adc switch, because we've already…

frontend.adb (Frontend): Skip -gnatec=gnat.adc switch, because we've already read gnat.adc by default.

2017-09-06  Bob Duff  <duff@adacore.com>

	* frontend.adb (Frontend): Skip -gnatec=gnat.adc
	switch, because we've already read gnat.adc by default.

2017-09-06  Bob Duff  <duff@adacore.com>

	* exp_ch5.adb (Get_Default_Iterator): Replace
	"Assert(False)" with "return Iter", because if an iterable
	type is derived from a noniterable one, then we won't find an
	overriding or inherited default iterator.

From-SVN: r251774

gcc/ada/ChangeLog

+2017-09-06  Bob Duff  <duff@adacore.com>
+
+	* frontend.adb (Frontend): Skip -gnatec=gnat.adc
+	switch, because we've already read gnat.adc by default.
+
+2017-09-06  Bob Duff  <duff@adacore.com>
+
+	* exp_ch5.adb (Get_Default_Iterator): Replace
+	"Assert(False)" with "return Iter", because if an iterable
+	type is derived from a noniterable one, then we won't find an
+	overriding or inherited default iterator.
+
 2017-09-06  Yannick Moy  <moy@adacore.com>
 
 	* sem_warn.adb (Warn_On_Suspicious_Index): Improve warning when the

gcc/ada/exp_ch5.adb

@@ -3934,9 +3934,9 @@ package body Exp_Ch5 is
 
             function Get_Default_Iterator
               (T : Entity_Id) return Entity_Id;
-            --  If the container is a derived type, the aspect holds the parent
-            --  operation. The required one is a primitive of the derived type
-            --  and is either inherited or overridden. Also sets Container_Arg.
+            --  Return the default iterator for a specific type. If the type is
+            --  derived, we return the inherited or overridden one if
+            --  appropriate.
 
             --------------------------
             -- Get_Default_Iterator --
@@ -3953,11 +3953,11 @@ package body Exp_Ch5 is
             begin
                Container_Arg := New_Copy_Tree (Container);
 
-               --  A previous version of GNAT allowed indexing aspects to
-               --  be redefined on derived container types, while the
-               --  default iterator was inherited from the parent type.
-               --  This non-standard extension is preserved temporarily for
-               --  use by the modelling project under debug flag d.X.
+               --  A previous version of GNAT allowed indexing aspects to be
+               --  redefined on derived container types, while the default
+               --  iterator was inherited from the parent type. This
+               --  nonstandard extension is preserved for use by the
+               --  modelling project under debug flag -gnatd.X.
 
                if Debug_Flag_Dot_XX then
                   if Base_Type (Etype (Container)) /=
@@ -3995,9 +3995,11 @@ package body Exp_Ch5 is
                      Next_Elmt (Prim);
                   end loop;
 
-                  --  Default iterator must exist
+                  --  If we didn't find it, then our parent type is not
+                  --  iterable, so we return the Default_Iterator aspect of
+                  --  this type.
 
-                  pragma Assert (False);
+                  return Iter;
 
                --  Otherwise not a derived type
 

gcc/ada/frontend.adb

@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 1992-2016, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2017, 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- --
@@ -68,9 +68,6 @@ with Tbuild;   use Tbuild;
 with Types;    use Types;
 
 procedure Frontend is
-   Config_Pragmas : List_Id;
-   --  Gather configuration pragmas
-
 begin
    --  Carry out package initializations. These are initializations which might
    --  logically be performed at elaboration time, were it not for the fact
@@ -136,6 +133,12 @@ begin
    --  Read and process configuration pragma files if present
 
    declare
+      Config_Pragmas : List_Id := Empty_List;
+      --  Gather configuration pragmas
+
+      Gnat_Adc : constant File_Name_Type := Name_Find ("gnat.adc");
+      Dot_Gnat_Adc : constant File_Name_Type := Name_Find ("./gnat.adc");
+
       Save_Style_Check : constant Boolean := Opt.Style_Check;
       --  Save style check mode so it can be restored later
 
@@ -144,8 +147,6 @@ begin
 
       Prag : Node_Id;
 
-      Temp_File : Boolean;
-
    begin
       --  We always analyze config files with style checks off, since we
       --  don't want a miscellaneous gnat.adc that is around to discombobulate
@@ -162,9 +163,7 @@ begin
       --  First deal with gnat.adc file
 
       if Opt.Config_File then
-         Name_Buffer (1 .. 8) := "gnat.adc";
-         Name_Len := 8;
-         Source_gnat_adc := Load_Config_File (Name_Enter);
+         Source_gnat_adc := Load_Config_File (Gnat_Adc);
 
          --  Case of gnat.adc file present
 
@@ -175,20 +174,11 @@ begin
             Initialize_Scanner (No_Unit, Source_gnat_adc);
             Config_Pragmas := Par (Configuration_Pragmas => True);
 
-            --  We unconditionally add a compilation dependency for gnat.adc
-            --  so that if it changes, we force a recompilation. This is a
-            --  fairly recent (2014-03-28) change.
+            --  We add a compilation dependency for gnat.adc so that if it
+            --  changes, we force a recompilation.
 
             Prepcomp.Add_Dependency (Source_gnat_adc);
-
-         --  Case of no gnat.adc file present
-
-         else
-            Config_Pragmas := Empty_List;
          end if;
-
-      else
-         Config_Pragmas := Empty_List;
       end if;
 
       --  Now deal with specified config pragmas files if there are any
@@ -198,32 +188,38 @@ begin
          --  Loop through config pragmas files
 
          for Index in Opt.Config_File_Names'Range loop
-
-            --  See if extension is .TMP/.tmp indicating a temporary config
-            --  file (which we ignore from the dependency point of view).
-
-            Name_Len := Config_File_Names (Index)'Length;
-            Name_Buffer (1 .. Name_Len) := Config_File_Names (Index).all;
-            Temp_File :=
-              Name_Len > 4
+            declare
+               Len : constant Natural := Config_File_Names (Index)'Length;
+               Str : constant String (1 .. Len) :=
+                 Config_File_Names (Index).all;
+               Config_Name : constant File_Name_Type := Name_Find (Str);
+               Temp_File : constant Boolean := Len > 4
                  and then
-                  (Name_Buffer (Name_Len - 3 .. Name_Len) = ".TMP"
+                  (Str (Len - 3 .. Len) = ".TMP"
                      or else
-                   Name_Buffer (Name_Len - 3 .. Name_Len) = ".tmp");
+                   Str (Len - 3 .. Len) = ".tmp");
+               --  Extension indicating a temporary config file?
+
+            begin
+               --  Skip it if it's the default name, already loaded above.
+               --  Otherwise, we get confusing warning messages about
+               --  seeing the same thing twice.
 
+               if Config_Name /= Gnat_Adc
+                 and then Config_Name /= Dot_Gnat_Adc
+               then
                   --  Load the file, error if we did not find it
 
-            Source_Config_File := Load_Config_File (Name_Enter);
+                  Source_Config_File := Load_Config_File (Config_Name);
 
                   if Source_Config_File = No_Source_File then
                      Osint.Fail
                        ("cannot find configuration pragmas file "
                         & Config_File_Names (Index).all);
 
-            --  If we did find the file, and it is not a temporary file, then
-            --  we unconditionally add a compilation dependency for it so
-            --  that if it changes, we force a recompilation. This is a
-            --  fairly recent (2014-03-28) change.
+                  --  If we did find the file, and it is not a temporary file,
+                  --  then we add a compilation dependency for it so that if it
+                  --  changes, we force a recompilation.
 
                   elsif not Temp_File then
                      Prepcomp.Add_Dependency (Source_Config_File);
@@ -234,6 +230,8 @@ begin
                   Initialize_Scanner (No_Unit, Source_Config_File);
                   Append_List_To
                     (Config_Pragmas, Par (Configuration_Pragmas => True));
+               end if;
+            end;
          end loop;
       end if;
 
@@ -260,10 +258,9 @@ begin
       --  Capture any modifications to suppress options from config pragmas
 
       Opt.Suppress_Options := Scope_Suppress;
-   end;
 
-   --  If a target dependency info file has been read through switch -gnateT=,
-   --  add it to the dependencies.
+      --  If a target dependency info file has been read through switch
+      --  -gnateT=, add it to the dependencies.
 
       if Target_Dependent_Info_Read_Name /= null then
          declare
@@ -276,14 +273,15 @@ begin
          end;
       end if;
 
-   --  This is where we can capture the value of the compilation unit specific
-   --  restrictions that have been set by the config pragma files (or from
-   --  Targparm), for later restoration when processing e.g. subunits.
+      --  This is where we can capture the value of the compilation unit
+      --  specific restrictions that have been set by the config pragma
+      --  files (or from Targparm), for later restoration when processing
+      --  e.g. subunits.
 
       Save_Config_Cunit_Boolean_Restrictions;
 
-   --  If there was a -gnatem switch, initialize the mappings of unit names to
-   --  file names and of file names to path names from the mapping file.
+      --  If there was a -gnatem switch, initialize the mappings of unit names
+      --  to file names and of file names to path names from the mapping file.
 
       if Mapping_File_Name /= null then
          Fmap.Initialize (Mapping_File_Name.all);
@@ -297,9 +295,10 @@ begin
          Optimize_Alignment := 'T';
       end if;
 
-   --  We have now processed the command line switches, and the configuration
-   --  pragma files, so this is the point at which we want to capture the
-   --  values of the configuration switches (see Opt for further details).
+      --  We have now processed the command line switches, and the
+      --  configuration pragma files, so this is the point at which we want to
+      --  capture the values of the configuration switches (see Opt for further
+      --  details).
 
       Opt.Register_Opt_Config_Switches;
 
@@ -334,16 +333,16 @@ begin
       if Config_Pragmas /= Error_List
         and then Operating_Mode /= Check_Syntax
 
-     --  Do not attempt to process deferred configuration pragmas if the main
-     --  unit failed to load, to avoid cascaded inconsistencies that can lead
-     --  to a compiler crash.
+        --  Do not attempt to process deferred configuration pragmas if the
+        --  main unit failed to load, to avoid cascaded inconsistencies that
+        --  can lead to a compiler crash.
 
         and then Fatal_Error (Main_Unit) /= Error_Detected
       then
-      --  Pragmas that require some semantic activity, such as Interrupt_State,
-      --  cannot be processed until the main unit is installed, because they
-      --  require a compilation unit on which to attach with_clauses, etc. So
-      --  analyze them now.
+         --  Pragmas that require some semantic activity, such as
+         --  Interrupt_State, cannot be processed until the main unit is
+         --  installed, because they require a compilation unit on which to
+         --  attach with_clauses, etc. So analyze them now.
 
          declare
             Prag : Node_Id;
@@ -367,9 +366,10 @@ begin
          end;
       end if;
 
-   --  If we have restriction No_Exception_Propagation, and we did not have an
-   --  explicit switch turning off Warn_On_Non_Local_Exception, then turn on
-   --  this warning by default if we have encountered an exception handler.
+      --  If we have restriction No_Exception_Propagation, and we did not have
+      --  an explicit switch turning off Warn_On_Non_Local_Exception, then turn
+      --  on this warning by default if we have encountered an exception
+      --  handler.
 
       if Restriction_Check_Required (No_Exception_Propagation)
         and then not No_Warn_On_Non_Local_Exception
@@ -384,7 +384,8 @@ begin
 
          --  Install the configuration pragmas in the tree
 
-      Set_Config_Pragmas (Aux_Decls_Node (Cunit (Main_Unit)), Config_Pragmas);
+         Set_Config_Pragmas
+           (Aux_Decls_Node (Cunit (Main_Unit)), Config_Pragmas);
 
          --  Following steps are skipped if we had a fatal error during parsing
 
@@ -462,6 +463,7 @@ begin
             Sem_Warn.Output_Unused_Warnings_Off_Warnings;
          end if;
       end if;
+   end;
 
    --  Qualify all entity names in inner packages, package bodies, etc