[gfortran] Add comments about strlen

[Paul Brook <paul at codesourcery dot com>]

The patch below adds a comment describing gfc_strlen_type_node, as pointed out 
be RTH.

It also removes a could of unused #defines left over from when we did builtin 
functions differently.

Tested on i686-linux.
Applied to mainline.

Paul

2004-08-31  Paul Brook  <paul@codesourcery.com>

 * trans-types.h: Add comments.
 (intmax_type_node, string_type_node, const_string_type_node): Remove.
libgfortran/
 * libgfortran.h: Add comments.

Index: gcc/fortran/trans-types.h
===================================================================
RCS file: /var/cvsroot/gcc-cvs/gcc/gcc/fortran/trans-types.h,v
retrieving revision 1.6
diff -u -p -r1.6 trans-types.h
--- gcc/fortran/trans-types.h 30 Aug 2004 21:59:08 -0000 1.6
+++ gcc/fortran/trans-types.h 30 Aug 2004 23:20:38 -0000
@@ -45,15 +45,13 @@ extern GTY(()) tree gfc_character1_type_
 extern GTY(()) tree ppvoid_type_node;
 extern GTY(()) tree pvoid_type_node;
 extern GTY(()) tree pchar_type_node;
+/* This is the type used to hold string lengths.  It has nothing to do with
+   the C strlen(3) function.  It must be the same as the corresponding
+   definition in gfortran.h.  */
+/* TODO: This is still hardcoded as kind=4 in some bits of the compiler
+   and runtime library.  */
 extern GTY(()) tree gfc_strlen_type_node;
 
-/* These C-specific types are used while building builtin function decls.
-   For now it doesn't really matter what these are defined to as we don't
-   need any of the builtins that use them.  */
-#define intmax_type_node gfc_int8_type_node
-#define string_type_node pchar_type_node
-#define const_string_type_node pchar_type_node
-
 /* be-function.c */
 void gfc_convert_function_code (gfc_namespace *);
 
Index: libgfortran/libgfortran.h
===================================================================
RCS file: /var/cvsroot/gcc-cvs/gcc/libgfortran/libgfortran.h,v
retrieving revision 1.10
diff -u -p -r1.10 libgfortran.h
--- libgfortran/libgfortran.h 28 Aug 2004 19:48:02 -0000 1.10
+++ libgfortran/libgfortran.h 30 Aug 2004 22:49:15 -0000
@@ -87,7 +87,11 @@ typedef double GFC_REAL_8;
 typedef complex float GFC_COMPLEX_4;
 typedef complex double GFC_COMPLEX_8;
 
+/* The following two definitions must be consistent with the types used
+   by the compiler.  */
+/* The type used of array indices, amongst other things.  */
 typedef size_t index_type;
+/* The type used for string lengths.  Nothing to do with strlen(3).  */
 typedef GFC_INTEGER_4 gfc_strlen_type;
 
 /* This will be 0 on little-endian machines and one on big-endian machines.  
*/