2016-04-27 Hristian Kirtchev <kirtchev@adacore.com>

	* sem_ch13.adb (Analyze_Aspect_Export_Import): Signal that there is no
	corresponding pragma.

2016-04-27  Bob Duff  <duff@adacore.com>

	* exp_ch3.adb: Minor comment improvement.

2016-04-27  Ed Schonberg  <schonberg@adacore.com>

	* exp_ch6.adb (Make_Build_In_Place_Call_In_Object_Declaration): If the
	return type is an untagged limited record with only access
	discriminants and no controlled components, the return value does not
	need to use the secondary stack.

2016-04-27  Javier Miranda  <miranda@adacore.com>

	* exp_util.adb (Remove_Side_Effects): When
	generating C code handle object declarations that have
	discriminants and are initialized by means of a call to a
	function.

2016-04-27  Ed Schonberg  <schonberg@adacore.com>

	* a-textio.adb (Get_Line function): Handle properly the case of
	a line that has the same length as the buffer (or a multiple
	thereof) and there is no line terminator.
	* a-tigeli.adb (Get_Line procedure): Do not store an end_of_file
	in the string when there is no previous line terminator and we
	need at most one additional character.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@235492 138bc75d-0d04-0410-961f-82ee72b054a4

7 files changed, 142 insertions, 20 deletions

diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index b04b513777c..4b39a4d8542 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,3 +1,35 @@
+2016-04-27  Hristian Kirtchev  <kirtchev@adacore.com>
+
+	* sem_ch13.adb (Analyze_Aspect_Export_Import): Signal that there is no
+	corresponding pragma.
+
+2016-04-27  Bob Duff  <duff@adacore.com>
+
+	* exp_ch3.adb: Minor comment improvement.
+
+2016-04-27  Ed Schonberg  <schonberg@adacore.com>
+
+	* exp_ch6.adb (Make_Build_In_Place_Call_In_Object_Declaration): If the
+	return type is an untagged limited record with only access
+	discriminants and no controlled components, the return value does not
+	need to use the secondary stack.
+
+2016-04-27  Javier Miranda  <miranda@adacore.com>
+
+	* exp_util.adb (Remove_Side_Effects): When
+	generating C code handle object declarations that have
+	discriminants and are initialized by means of a call to a
+	function.
+
+2016-04-27  Ed Schonberg  <schonberg@adacore.com>
+
+	* a-textio.adb (Get_Line function): Handle properly the case of
+	a line that has the same length as the buffer (or a multiple
+	thereof) and there is no line terminator.
+	* a-tigeli.adb (Get_Line procedure): Do not store an end_of_file
+	in the string when there is no previous line terminator and we
+	need at most one additional character.
+
 2016-04-27  Arnaud Charlet  <charlet@adacore.com>
 
 	* s-rident.ads: Make No_Implicit_Loops non partition wide.
diff --git a/gcc/ada/a-textio.adb b/gcc/ada/a-textio.adb
index dc0b45358fe..61d6accc078 100644
--- a/gcc/ada/a-textio.adb
+++ b/gcc/ada/a-textio.adb
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 1992-2015, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2016, 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- --
@@ -704,9 +704,6 @@ package body Ada.Text_IO is
    end Get_Line;
 
    function Get_Line (File : File_Type) return String is
-      Buffer : String (1 .. 500);
-      Last   : Natural;
-
       function Get_Rest (S : String) return String;
       --  This is a recursive function that reads the rest of the line and
       --  returns it. S is the part read so far.
@@ -732,12 +729,19 @@ package body Ada.Text_IO is
          begin
             if Last < Buffer'Last then
                return R;
+
             else
                return Get_Rest (R);
             end if;
          end;
       end Get_Rest;
 
+      --  Local variables
+
+      Buffer : String (1 .. 500);
+      ch     : int;
+      Last   : Natural;
+
    --  Start of processing for Get_Line
 
    begin
@@ -745,6 +749,22 @@ package body Ada.Text_IO is
 
       if Last < Buffer'Last then
          return Buffer (1 .. Last);
+
+      --  If the String has the same length as the buffer, and there is no end
+      --  of line, check whether we are at the end of file, in which case we
+      --  have the full String in the buffer.
+
+      elsif Last = Buffer'Last then
+         ch := Getc (File);
+
+         if ch = EOF then
+            return Buffer;
+
+         else
+            Ungetc (ch, File);
+            return Get_Rest (Buffer (1 .. Last));
+         end if;
+
       else
          return Get_Rest (Buffer (1 .. Last));
       end if;
diff --git a/gcc/ada/a-tigeli.adb b/gcc/ada/a-tigeli.adb
index 8273b050775..d4aedcdd7d1 100644
--- a/gcc/ada/a-tigeli.adb
+++ b/gcc/ada/a-tigeli.adb
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 1992-2015, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2016, 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- --
@@ -187,8 +187,13 @@ begin
          --  If we get EOF after already reading data, this is an incomplete
          --  last line, in which case no End_Error should be raised.
 
-         if ch = EOF and then Last < Item'First then
-            raise End_Error;
+         if ch = EOF then
+            if  Last < Item'First then
+               raise End_Error;
+
+            else  --  All done
+               return;
+            end if;
 
          elsif ch /= LM then
 
diff --git a/gcc/ada/exp_ch3.adb b/gcc/ada/exp_ch3.adb
index 09253290f09..e76db7eeeb7 100644
--- a/gcc/ada/exp_ch3.adb
+++ b/gcc/ada/exp_ch3.adb
@@ -7108,8 +7108,10 @@ package body Exp_Ch3 is
          end;
       end if;
 
-      --  Final transformation - turn the object declaration into a renaming if
-      --  appropriate.
+      --  Final transformation - turn the object declaration into a renaming
+      --  if appropriate. If this is the completion of a deferred constant
+      --  declaration, then this transformation generates what would be
+      --  illegal code if written by hand, but that's OK.
 
       if Present (Expr) then
          if Rewrite_As_Renaming then
diff --git a/gcc/ada/exp_ch6.adb b/gcc/ada/exp_ch6.adb
index 4e996a16411..60c2ce034ea 100644
--- a/gcc/ada/exp_ch6.adb
+++ b/gcc/ada/exp_ch6.adb
@@ -7783,7 +7783,12 @@ package body Exp_Ch6 is
       Result_Subt     : Entity_Id;
 
       Definite : Boolean;
-      --  True for definite function result subtype
+      --  True if result subtype is definite, or has a size that does not
+      --  require secondary stack usage (i.e. no variant part or components
+      --  whose type depends on discriminants). In particular, untagged types
+      --  with only access discriminants do not require secondary stack use.
+      --  Note that if the return type is tagged we must always use the sec.
+      --  stack because the call may dispatch on result.
 
    begin
       --  Step past qualification or unchecked conversion (the latter can occur
@@ -7818,7 +7823,10 @@ package body Exp_Ch6 is
       end if;
 
       Result_Subt := Etype (Function_Id);
-      Definite    := Is_Definite_Subtype (Underlying_Type (Result_Subt));
+      Definite :=
+        (Is_Definite_Subtype (Underlying_Type (Result_Subt))
+             and then not Is_Tagged_Type (Result_Subt))
+          or else not Requires_Transient_Scope (Underlying_Type (Result_Subt));
 
       --  Create an access type designating the function's result subtype. We
       --  use the type of the original call because it may be a call to an
diff --git a/gcc/ada/exp_util.adb b/gcc/ada/exp_util.adb
index 2e8e1d6966f..7591c3afd27 100644
--- a/gcc/ada/exp_util.adb
+++ b/gcc/ada/exp_util.adb
@@ -7944,13 +7944,35 @@ package body Exp_Util is
       else
          --  An expression which is in SPARK mode is considered side effect
          --  free if the resulting value is captured by a variable or a
-         --  constant. Same reasoning when generating C code.
-         --  Why can't we apply this test in general???
+         --  constant.
 
-         if (GNATprove_Mode or Generate_C_Code)
+         if GNATprove_Mode
            and then Nkind (Parent (Exp)) = N_Object_Declaration
          then
             goto Leave;
+
+         --  When generating C code we cannot consider side effect free object
+         --  declarations that have discriminants and are initialized by means
+         --  of a function call since on this target there is no secondary
+         --  stack to store the return value and the expander may generate an
+         --  extra call to the function to compute the discriminant value. In
+         --  addition, for targets that have secondary stack, the expansion of
+         --  functions with side effects involves the generation of an access
+         --  type to capture the return value stored in the secondary stack;
+         --  by contrast when generating C code such expansion generates an
+         --  internal object declaration (no access type involved) which must
+         --  be identified here to avoid entering into a never-ending loop
+         --  generating internal object declarations.
+
+         elsif Generate_C_Code
+           and then Nkind (Parent (Exp)) = N_Object_Declaration
+           and then
+             (Nkind (Exp) /= N_Function_Call
+                or else not Has_Discriminants (Exp_Type)
+                or else Is_Internal_Name
+                          (Chars (Defining_Identifier (Parent (Exp)))))
+         then
+            goto Leave;
          end if;
 
          --  Special processing for function calls that return a limited type.
@@ -8063,12 +8085,39 @@ package body Exp_Util is
             Set_Analyzed (E, False);
          end if;
 
-         Insert_Action (Exp,
-           Make_Object_Declaration (Loc,
-             Defining_Identifier => Def_Id,
-             Object_Definition   => New_Occurrence_Of (Ref_Type, Loc),
-             Constant_Present    => True,
-             Expression          => New_Exp));
+         --  Generating C code of object declarations that have discriminants
+         --  and are initialized by means of a function call we propagate the
+         --  discriminants of the parent type to the internally built object.
+         --  This is needed to avoid generating an extra call to the called
+         --  function.
+
+         --  For example, if we generate here the following declaration, it
+         --  will be expanded later adding an extra call to evaluate the value
+         --  of the discriminant (needed to compute the size of the object).
+         --
+         --     type Rec (D : Integer) is ...
+         --     Obj : constant Rec := SomeFunc;
+
+         if Generate_C_Code
+           and then Nkind (Parent (Exp)) = N_Object_Declaration
+           and then Has_Discriminants (Exp_Type)
+           and then Nkind (Exp) = N_Function_Call
+         then
+            Insert_Action (Exp,
+              Make_Object_Declaration (Loc,
+                Defining_Identifier => Def_Id,
+                Object_Definition   => New_Copy_Tree
+                                         (Object_Definition (Parent (Exp))),
+                Constant_Present    => True,
+                Expression          => New_Exp));
+         else
+            Insert_Action (Exp,
+              Make_Object_Declaration (Loc,
+                Defining_Identifier => Def_Id,
+                Object_Definition   => New_Occurrence_Of (Ref_Type, Loc),
+                Constant_Present    => True,
+                Expression          => New_Exp));
+         end if;
       end if;
 
       --  Preserve the Assignment_OK flag in all copies, since at least one
diff --git a/gcc/ada/sem_ch13.adb b/gcc/ada/sem_ch13.adb
index 5e4368e563c..d42b7cad79e 100644
--- a/gcc/ada/sem_ch13.adb
+++ b/gcc/ada/sem_ch13.adb
@@ -1691,6 +1691,12 @@ package body Sem_Ch13 is
                   --  into account Conversion, External_Name, and Link_Name.
 
                   Aitem := Build_Export_Import_Pragma (Aspect, E);
+
+               --  Otherwise the expression is either False or erroneous. There
+               --  is no corresponding pragma.
+
+               else
+                  Aitem := Empty;
                end if;
             end Analyze_Aspect_Export_Import;