+2009-04-29 Vincent Celier <celier@adacore.com>
+
+ * sinput-l.adb (Load_File): When preprocessing, set temporarily the
+ Source_File_Index_Table entries for the source, to avoid crash when
+ reporting an error.
+
+ * gnatcmd.adb (Test_If_Relative_Path): Use
+ Makeutl.Test_If_Relative_Path.
+
+ * makeutl.adb:(Test_If_Relative_Path): Process switches --RTS= only if
+ Including_RTS is True.
+
+ * makeutl.ads (Test_If_Relative_Path): New Boolean parameter
+ Including_RTS defaulted to False.
+
+ * sinput.ads, scans.ads, err_vars.ads: Initialize some variables with
+ a default value.
+
+2009-04-29 Javier Miranda <miranda@adacore.com>
+
+ * gnat_ugn.texi: Adding documentation for non-default C++ constructors.
+
2009-04-29 Javier Miranda <miranda@adacore.com>
* sem_ch3.adb (Analyze_Object_Declaration): Disable error message
-- --
-- S p e c --
-- --
--- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2009, 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- --
package Err_Vars is
+ -- Some variables are initialized so that some tools (such as gprbuild)
+ -- can be built with -gnatVa and pragma Initialized_Scalars without
+ -- problems.
+
------------------
-- Error Counts --
------------------
- Serious_Errors_Detected : Nat;
+ Serious_Errors_Detected : Nat := 0;
-- This is a count of errors that are serious enough to stop expansion,
-- and hence to prevent generation of an object file even if the
-- switch -gnatQ is set. Initialized to zero at the start of compilation.
- Total_Errors_Detected : Nat;
+ Total_Errors_Detected : Nat := 0;
-- Number of errors detected so far. Includes count of serious errors and
-- non-serious errors, so this value is always greater than or equal to the
-- Serious_Errors_Detected value. Initialized to zero at the start of
-- compilation.
- Warnings_Detected : Nat;
+ Warnings_Detected : Nat := 0;
-- Number of warnings detected. Initialized to zero at the start of
-- compilation.
-- generated on the instantiation (referring to the template) rather
-- than on the template itself.
- Raise_Exception_On_Error : Nat;
+ Raise_Exception_On_Error : Nat := 0;
-- If this value is non-zero, then any attempt to generate an error
-- message raises the exception Error_Msg_Exception, and the error
-- message is not output. This is used for defending against junk
* Interfacing to C++::
* Linking a Mixed C++ & Ada Program::
* A Simple Example::
+* Interfacing with C++ constructors::
* Interfacing with C++ at the Class Level::
@end menu
end Simple_Cpp_Interface;
@end smallexample
+@node Interfacing with C++ constructors
+@subsection Interfacing with C++ constructors
+@noindent
+
+In order to interface with C++ constructors GNAT provides the
+@code{pragma CPP_Constructor} (@xref{Interfacing to C++,,,
+gnat_rm, GNAT Reference Manual}, for additional information).
+In this section we present some common uses of C++ constructors
+in mixed-languages programs in GNAT.
+
+Let us assume that we need to interface with the following
+C++ class:
+
+@smallexample
+@b{class} Root @{
+@b{public}:
+ int a_value;
+ int b_value;
+ @b{virtual} int Get_Value ();
+ Root(); // Default constructor
+ Root(int v); // 1st non-default constructor
+ Root(int v, int w); // 2nd non-default constructor
+@};
+@end smallexample
+
+For this purpose we can write the following package spec (further
+information on how to build this spec is available in
+@ref{Interfacing with C++ at the Class Level} and
+@ref{Generating Ada Bindings for C and C++ headers}).
+
+@smallexample @c ada
+with Interfaces.C; use Interfaces.C;
+package Pkg_Root is
+ type Root is tagged limited record
+ A_Value : int;
+ B_Value : int;
+ end record;
+ pragma Import (CPP, Root);
+
+ function Get_Value (Obj : Root) return int;
+ pragma Import (CPP, Get_Value);
+
+ function Constructor return Root'Class;
+ pragma Cpp_Constructor (Constructor, "_ZN4RootC1Ev");
+
+ function Constructor (v : Integer) return Root'Class;
+ pragma Cpp_Constructor (Constructor, "_ZN4RootC1Ei");
+
+ function Constructor (v, w : Integer) return Root'Class;
+ pragma Cpp_Constructor (Constructor, "_ZN4RootC1Eii");
+end Pkg_Root;
+@end smallexample
+
+On the Ada side the constructor is represented by a function (whose
+name is arbitrary) that returns the classwide type corresponding to
+the imported C++ class.
+
+In a declaration of an object whose type is a class imported from C++,
+either the default C++ constructor is implicitly called by GNAT, or
+else the required C++ constructor must be explicitly called in the
+expression that initializes the object. For example:
+
+@smallexample @c ada
+ Obj1 : Root;
+ Obj2 : Root := Constructor;
+ Obj3 : Root := Constructor (v => 10);
+ Obj4 : Root := Constructor (30, 40);
+@end smallexample
+
+The first two declarations are equivalent: in both cases the default C++
+constructor is invoked (in the former case the call to the constructor is
+implicit, and in the latter case the call is explicit in the object
+declaration). @code{Obj3} is initialized by the C++ non-default constructor
+that takes an integer argument, and @code{Obj4} is initialized by the
+non-default C++ constructor that takes two integers.
+
+Let us derive the imported C++ class in the Ada side. For example:
+
+@smallexample @c ada
+ type DT is new Root with record
+ C_Value : Natural := 2009;
+ end record;
+@end smallexample
+
+In this case the components DT inherited from the C++ side must be
+initialized by a C++ constructor, and the additional Ada components
+of type DT are initialized by GNAT. The initialization of such an
+object is done either by default, or by means of a function returning
+an aggregate of type DT, or by means of an extended aggregate.
+
+@smallexample @c ada
+ Obj5 : DT;
+ Obj6 : DT := Function_Returning_DT (50);
+ Obj7 : DT := (Constructor (30,40) with (C_Value => 50));
+@end smallexample
+
+The declaration of @code{Obj5} invokes the default constructors: the
+C++ default constructor of the parent type takes care of the initialization
+of the components inherited from Root, and GNAT takes care of the default
+initialization of the additional Ada components of type DT (that is,
+@code{C_Value} is initialized to value 2009). The order of invocation of
+the constructors is consistent with the order of elaboration required by
+Ada and C++. That is, the constructor of the parent type is always called
+before the constructor of the derived type.
+
+Let us now consider a record that has components whose type is imported
+from C++. For example:
+
+@smallexample @c ada
+ type Rec1 is limited record
+ Data1 : Root := Constructor (10);
+ Value : Natural := 1000;
+ end record;
+
+ type Rec2 (D : Integer := 20) is limited record
+ Rec : Rec1;
+ Data2 : Root := Constructor (D, 30);
+ end record;
+@end smallexample
+
+The initialization of an object of type @code{Rec2} will call the
+non-default C++ constructors specified for the imported components.
+For example:
+
+@smallexample @c ada
+ Obj8 : Rec2 (40);
+@end smallexample
+
+Using Ada 2005 we can use limited aggregates to initialize an object
+invoking C++ constructors that differ from those specified in the type
+declarations. For example:
+
+@smallexample @c ada
+ Obj9 : Rec2 := (Rec => (Data1 => Constructor (15, 16),
+ others => <>),
+ others => <>);
+@end smallexample
+
+The above declaration uses an Ada 2005 limited aggregate to
+initialize @code{Obj9}, and the C++ constructor that has two integer
+arguments is invoked to initialize the @code{Data1} component instead
+of the constructor specified in the declaration of type @code{Rec1}. In
+Ada 2005 the box in the aggregate indicates that unspecified components
+are initialized using the expression (if any) available in the component
+declaration. That is, in this case discriminant @code{D} is initialized
+to value @code{20}, @code{Value} is initialized to value 1000, and the
+non-default C++ constructor that handles two integers takes care of
+initializing component @code{Data2} with values @code{20,30}.
+
+In Ada 2005 we can use the extended return statement to build the Ada
+equivalent to C++ non-default constructors. For example:
+
+@smallexample @c ada
+ function Constructor (V : Integer) return Rec2 is
+ begin
+ return Obj : Rec2 := (Rec => (Data1 => Constructor (V, 20),
+ others => <>),
+ others => <>) do
+ -- Further actions required for construction of
+ -- objects of type Rec2
+ ...
+ end record;
+ end Constructor;
+@end smallexample
+
+In this example the extended return statement construct is used to
+build in place the returned object whose components are initialized
+by means of a limited aggregate. Any further action associated with
+the constructor can be placed inside the construct.
+
@node Interfacing with C++ at the Class Level
@subsection Interfacing with C++ at the Class Level
@noindent
with GNAT.Directory_Operations; use GNAT.Directory_Operations;
with Csets;
+with Makeutl;
with MLib.Tgt; use MLib.Tgt;
with MLib.Utl;
with MLib.Fil;
Parent : String)
is
begin
- if Switch /= null then
-
- declare
- Sw : String (1 .. Switch'Length);
- Start : Positive := 1;
-
- begin
- Sw := Switch.all;
-
- if Sw (1) = '-' then
- if Sw'Length >= 3
- and then (Sw (2) = 'A' or else
- Sw (2) = 'I' or else
- Sw (2) = 'L')
- then
- Start := 3;
-
- if Sw = "-I-" then
- return;
- end if;
-
- elsif Sw'Length >= 4
- and then (Sw (2 .. 3) = "aL" or else
- Sw (2 .. 3) = "aO" or else
- Sw (2 .. 3) = "aI")
- then
- Start := 4;
-
- elsif Sw'Length >= 7
- and then Sw (2 .. 6) = "-RTS="
- then
- Start := 7;
- else
- return;
- end if;
- end if;
-
- -- If the path is relative, test if it includes directory
- -- information. If it does, prepend Parent to the path.
-
- if not Is_Absolute_Path (Sw (Start .. Sw'Last)) then
- for J in Start .. Sw'Last loop
- if Sw (J) = Directory_Separator then
- Switch :=
- new String'
- (Sw (1 .. Start - 1) &
- Parent &
- Directory_Separator &
- Sw (Start .. Sw'Last));
- return;
- end if;
- end loop;
- end if;
- end;
- end if;
+ Makeutl.Test_If_Relative_Path
+ (Switch, Parent, Including_Non_Switch => False, Including_RTS => True);
end Test_If_Relative_Path;
-------------------
(Switch : in out String_Access;
Parent : String;
Including_L_Switch : Boolean := True;
- Including_Non_Switch : Boolean := True)
+ Including_Non_Switch : Boolean := True;
+ Including_RTS : Boolean := False)
is
begin
if Switch /= null then
then
Start := 4;
+ elsif Including_RTS
+ and then Sw'Length >= 7
+ and then Sw (2 .. 6) = "-RTS="
+ then
+ Start := 7;
+
else
return;
end if;
-- Because relative path arguments to --RTS= may be relative
-- to the search directory prefix, those relative path
- -- arguments are not converted.
+ -- arguments are converted only when they include directory
+ -- information.
if not Is_Absolute_Path (Sw (Start .. Sw'Last)) then
if Parent'Length = 0 then
& Sw
& """) are not allowed");
+ elsif Including_RTS then
+ for J in Start .. Sw'Last loop
+ if Sw (J) = Directory_Separator then
+ Switch :=
+ new String'
+ (Sw (1 .. Start - 1) &
+ Parent &
+ Directory_Separator &
+ Sw (Start .. Sw'Last));
+ return;
+ end if;
+ end loop;
+
else
Switch :=
new String'
(Switch : in out String_Access;
Parent : String;
Including_L_Switch : Boolean := True;
- Including_Non_Switch : Boolean := True);
+ Including_Non_Switch : Boolean := True;
+ Including_RTS : Boolean := False);
-- Test if Switch is a relative search path switch.
-- If it is, fail if Parent is the empty string, otherwise prepend the path
-- with Parent. This subprogram is only called when using project files.
-- For gnatbind switches, Including_L_Switch is False, because the
- -- argument of the -L switch is not a path.
+ -- argument of the -L switch is not a path. If Including_RTS is True,
+ -- process also switches --RTS=.
function Path_Or_File_Name (Path : Path_Name_Type) return String;
-- Returns a file name if -df is used, otherwise return a path name
-- Note: these variables can only be referenced during the parsing of a
-- file. Reference to any of them from Sem or the expander is wrong.
+ -- Some of these variables are initialized so that some tools (such as
+ -- gprbuild) can be built with -gnatVa and pragma Initialized_Scalars
+ -- without problems.
- Scan_Ptr : Source_Ptr;
+ Scan_Ptr : Source_Ptr := No_Location;
-- Current scan pointer location. After a call to Scan, this points
-- just past the end of the token just scanned.
- Token : Token_Type;
+ Token : Token_Type := No_Token;
-- Type of current token
- Token_Ptr : Source_Ptr;
+ Token_Ptr : Source_Ptr := No_Location;
-- Pointer to first character of current token
- Current_Line_Start : Source_Ptr;
+ Current_Line_Start : Source_Ptr := No_Location;
-- Pointer to first character of line containing current token
- Start_Column : Column_Number;
+ Start_Column : Column_Number := No_Column_Number;
-- Starting column number (zero origin) of the first non-blank character
-- on the line containing the current token. This is used for error
-- recovery circuits which depend on looking at the column line up.
- Type_Token_Location : Source_Ptr;
+ Type_Token_Location : Source_Ptr := No_Location;
-- Within a type declaration, gives the location of the TYPE keyword that
-- opened the type declaration. Used in checking the end column of a record
-- declaration, which can line up either with the TYPE keyword, or with the
-- start of the line containing the RECORD keyword.
- Checksum : Word;
+ Checksum : Word := 0;
-- Used to accumulate a CRC representing the tokens in the source
-- file being compiled. This CRC includes only program tokens, and
-- excludes comments.
- First_Non_Blank_Location : Source_Ptr;
+ First_Non_Blank_Location : Source_Ptr := No_Location;
-- Location of first non-blank character on the line containing the
-- current token (i.e. the location of the character whose column number
-- is stored in Start_Column).
-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2008, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2009, 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- --
-- Preprocess the source if it needs to be preprocessed
if Preprocessing_Needed then
+ -- Set temporarily the Source_File_Index_Table entries for the
+ -- source, to avoid crash when reporting an error.
+
+ Set_Source_File_Index_Table (X);
+
if Opt.List_Preprocessing_Symbols then
Get_Name_String (N);
-- Global Data --
-----------------
- Current_Source_File : Source_File_Index;
- -- Source_File table index of source file currently being scanned
+ Current_Source_File : Source_File_Index := No_Source_File;
+ -- Source_File table index of source file currently being scanned.
+ -- Initialized so that some tools (such as gprbuild) can be built with
+ -- -gnatVa and pragma Initialized_Scalars without problems.
Current_Source_Unit : Unit_Number_Type;
-- Unit number of source file currently being scanned. The special value
projects / thirdparty / gcc.git / commitdiff
