re PR fortran/34112 (Add $!DEC ATTRIBUTE support for 32bit Windows' STDCALL)

2009-06-28  Tobias Burnus  <burnus@net-b.de>
	    Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>

	PR fortran/34112
	* symbol.c (gfc_add_ext_attribute): New function.
	(gfc_get_sym_tree): New argument allow_subroutine.
	(gfc_get_symbol,gfc_get_ha_sym_tree,gen_cptr_param,gen_fptr_param
	gen_shape_param,generate_isocbinding_symbol): Use it.
	* decl.c (find_special): New argument allow_subroutine.
	(add_init_expr_to_sym,add_hidden_procptr_result,attr_decl1,
	match_procedure_in_type,gfc_match_final_decl): Use it.
	(gfc_match_gcc_attributes): New function.
	* gfortran.texi (Mixed-Language Programming): New section
	"GNU Fortran Compiler Directives".
	* gfortran.h (ext_attr_t): New struct.
	(symbol_attributes): Use it.
	(gfc_add_ext_attribute): New prototype.
	(gfc_get_sym_tree): Update pototype.
	* expr.c (gfc_check_pointer_assign): Check whether call
	convention is the same.
	* module.c (import_iso_c_binding_module, create_int_parameter,
	use_iso_fortran_env_module): Update gfc_get_sym_tree call.
	* scanner.c (skip_gcc_attribute): New function.
	(skip_free_comments,skip_fixed_comments): Use it.
	(gfc_next_char_literal): Support !GCC$ lines.
	* resolve.c (check_host_association): Update
	gfc_get_sym_tree call.
	* match.c (gfc_match_sym_tree,gfc_match_call): Update
	gfc_get_sym_tree call.
	* trans-decl.c (add_attributes_to_decl): New function.
	(gfc_get_symbol_decl,get_proc_pointer_decl,
	gfc_get_extern_function_decl,build_function_decl: Use it.
	* match.h (gfc_match_gcc_attributes): Add prototype.
	* parse.c (decode_gcc_attribute): New function.
	(next_free,next_fixed): Support !GCC$ lines.
	* primary.c (match_actual_arg,check_for_implicit_index,
	gfc_match_rvalue,gfc_match_rvalue): Update
	gfc_get_sym_tree call.

2009-06-28  Tobias Burnus  <burnus@net-b.de>

	PR fortran/34112
	* gfortran.dg/compiler-directive_1.f90: New test.
	* gfortran.dg/compiler-directive_2.f: New test.


Co-Authored-By: Francois-Xavier Coudert <fxcoudert@gcc.gnu.org>

From-SVN: r149036

1 files changed, 55 insertions, 0 deletions

diff --git a/gcc/fortran/gfortran.texi b/gcc/fortran/gfortran.texi
index ab69c0a..f0b1c67 100644
--- a/gcc/fortran/gfortran.texi
+++ b/gcc/fortran/gfortran.texi
@@ -1851,6 +1851,7 @@ c
 
 @menu
 * Interoperability with C::
+* GNU Fortran Compiler Directives::
 * Non-Fortran Main Program::
 @end menu
 
@@ -2097,6 +2098,60 @@ C-interoperable @code{OPTIONAL} and for assumed-rank and assumed-type
 dummy arguments. However, the TR has neither been approved nor implemented
 in GNU Fortran; therefore, these features are not yet available.
 
+
+
+@node GNU Fortran Compiler Directives
+@section GNU Fortran Compiler Directives
+
+The Fortran standard standard describes how a conforming program shall
+behave; however, the exact implementation is not standardized. In order
+to allow the user to choose specific implementation details, compiler
+directives can be used to set attributes of variables and procedures
+which are not part of the standard. Whether a given attribute is
+supported and its exact effects depend on both the operating system and
+on the processor; see
+@ref{Top,,C Extensions,gcc,Using the GNU Compiler Collection (GCC)}
+for details.
+
+For procedures and procedure pointers, the following attributes can
+be used to change the calling convention:
+
+@itemize
+@item @code{CDECL} -- standard C calling convention
+@item @code{STDCALL} -- convention where the called procedure pops the stack
+@item @code{FASTCALL} -- part of the arguments are passed via registers
+instead using the stack
+@end itemize
+
+Besides changing the calling convention, the attributes also influence
+the decoration of the symbol name, e.g., by a leading underscore or by
+a trailing at-sign followed by the number of bytes on the stack. When
+assigning a procedure to a procedure pointer, both should use the same
+calling convention.
+
+On some systems, procedures and global variables (module variables and
+@code{COMMON} blocks) need special handling to be accessible when they
+are in a shared library. The following attributes are available:
+
+@itemize
+@item @code{DLLEXPORT} -- provide a global pointer to a pointer in the DLL
+@item @code{DLLIMPORT} -- reference the function or variable using a global pointer 
+@end itemize
+
+The attributes are specified using the syntax
+
+@code{!GCC$ ATTRIBUTES} @var{attribute-list} @code{::} @var{variable-list}
+
+where in free-form source code only whitespace is allowed before @code{!GCC$}
+and in fixed-form source code @code{!GCC$}, @code{cGCC$} or @code{*GCC$} shall
+start in the first column.
+
+For procedures, the compiler directives shall be placed into the body
+of the procedure; for variables and procedure pointers, they shall be in
+the same declaration part as the variable or procedure pointer.
+
+
+
 @node Non-Fortran Main Program
 @section Non-Fortran Main Program