[RFC]: Document patch for F90 derived type support

[Wu Zhou]

Eli,

Thanks for your quick review!  Please see my answers below.

On Fri, 24 Feb 2006, Eli Zaretskii wrote:

> > Date: Fri, 24 Feb 2006 02:54:16 -0500 (EST)
> > From: Wu Zhou <woodzltc@cn.ibm.com>
> > 
> > Here is the modified document patch for F90 derived type support.  Please 
> > review and comment.
> 
> Reviewed; comments below.
> 
> > + Fortran 90 and later support derived type (a.k.a structure).  For a
>                                                ^^^^^
> This should be "a.k.a.@:".  You forgot the last period, and @: tells
> TeX that this period does not end a sentence, so that TeX typeset it
> correctly.

Thanks for the correction.  Modified.

> > + type = Type bar
> > +     int4 :: c
> > +     real*4 :: d
> > + End Type bar
> 
> Btw, isn't it more consistent to print "integer*4" instead of "int4"?
> Either that, or just "integer", I think.  Or is "int4" a valid type
> name in f90?  (The last Fortran I used was f77, so please forgive my
> ignorance.)

Yes. I also think so.  But the name of "int4" is got from the DWARF tag:

 <1><e6>: Abbrev Number: 4 (DW_TAG_base_type)
     DW_AT_name        : int4
     DW_AT_byte_size   : 4
     DW_AT_encoding    : 5      (signed)

Maybe we can suggest the compiler to generate integer or integer*4 
instead.

> > + For example, for variable q of type foo defined above:
> 
> "q" and "foo" should be in @code (they are program symbols).

Modified.

> 
> > + Please be noted that in the above example, the result of @code{print q}
>     ^^^^^^^^^^^^^^^
> "Please note".

Thanks.  The modified patch is appended below:

2006-02-27  Wu Zhou  <woodzltc@cn.ibm.com>

	* gdb.texinfo (Fortran): Document the "%" operator for member
	access.  Document the type-print and value-print operation of
	Fortran 90 derived types.

Index: gdb.texinfo
===================================================================
RCS file: /cvs/src/src/gdb/doc/gdb.texinfo,v
retrieving revision 1.314
diff -c -p -r1.314 gdb.texinfo
*** gdb.texinfo	18 Feb 2006 20:45:01 -0000	1.314
--- gdb.texinfo	27 Feb 2006 02:59:47 -0000
*************** of the second one.
*** 9399,9404 ****
--- 9399,9408 ----
  @item :
  The range operator.  Normally used in the form of array(low:high) to
  represent a section of array.
+ 
+ @item %
+ Fortran 90 and later use this to access the members of derived
+ type, which is also introduced after the Fortran 90.
  @end table
  
  @node Fortran Defaults
*************** This command prints the values contained
*** 9427,9432 ****
--- 9431,9506 ----
  block whose name is @var{common-name}.  With no argument, the names of
  all @code{COMMON} blocks visible at current program location are
  printed.
+ 
+ @cindex structure type-print
+ @item ptype @var{derived-type}
+ Fortran 90 and later support derived type (a.k.a.@: structure).  For a
+ variable of derived type, the @code{ptype} command will output all its
+ members, including nested derived type.
+ 
+ For example, for this derived type declaration:
+ 
+ @smallexample
+ type bar
+   integer :: c
+   real :: d
+ end type
+ 
+ type foo
+   real :: a
+   type(bar) :: x
+   character*7 :: b
+ end type foo
+ @end smallexample
+ 
+ @noindent
+ the @code{ptype} commands give this output:
+ 
+ @smallexample
+ @group
+ (@value{GDBP}) ptype bar
+ type = Type bar
+     int4 :: c
+     real*4 :: d
+ End Type bar
+ (@value{GDBP}) ptype foo
+ type = Type foo
+     real*4 :: a
+     Type bar
+         int4  :: c
+         real*4 :: d
+     End Type bar :: x
+     character (7) :: b
+ End Type foo
+ @end group
+ @end smallexample
+ 
+ @cindex structure value-print
+ @item print @var{derived-type}
+ For a variable of derived type, the @code{print} command will output the
+ value of all its members, including its nested derived type .
+ 
+ For example, for variable @code{q} of type @code{foo} defined above:
+ 
+ @smallexample
+ type(foo) :: q
+ @end smallexample
+ 
+ @noindent
+ the @code{print} command will output this:
+ 
+ @smallexample
+ @group
+ (@value{GDBP}) print q
+ $1 = @{ 3.125, @{ 1, 2.375@}, 
+        (97 'a', 98 'b', 99 'c', 100 'd', 101 'e', 102 'f', 103 'g')@}
+ @end group
+ @end smallexample
+ 
+ Please note that in the above example, the result of @code{print q} is
+ a single long line, broken only for clarity.
+ @noindent
+ 
  @end table
  
  @node Pascal


Regards
- Wu Zhou