-to do:
+-*- text -*-
+
+PORTING:
+
+Sorry, no description of the interfaces is written up yet. Look at existing
+back ends and work from there.
+
+New hosts: The configure script, which is generated by autoconf,
+should handle all host specific configuration.
+
+New target formats: Look at the BFD_ASSEMBLER code. The a.out or ELF
+code might be a fair example. There are no "good" examples yet,
+unfortunately, nor any good documentation of the changes.
+
+New target processors: Check first to see if the BFD_ASSEMBLER interface is
+supported by the file format code you need to use.
+
+DOCUMENTATION:
+
+The internals of gas need documenting.
+
+The documentation should also contain a "Trouble" section similar to gcc's
+manual: real bugs, common problems, incompatibilities, etc.
+
+Anyone want to offer to maintain a man page?
+
+BFD CONVERSION:
+
+The "#ifdef BFD_ASSEMBLER" code is on its way in; the "#ifndef BFD_ASSEMBLER"
+code is on its way out. The new code uses BFD data structures, and calls BFD
+for anything that needs to be written to the output file. The old code did all
+the writing itself, or in a couple of cases, used BFD as a slightly higher
+level than stdio (i.e., bfd_seek, bfd_write -- these are not the preferred
+interface).
+
+Because of this, some of this code is messy. Lots of ifdef's, and the
+non-BFD_ASSEMBLER version often has multiple conditional tests inside it for
+various processors or formats. As the various targets get converted over,
+these will gradually go away.
+
+TO DO:
+
+Remove DONTDEF code, commented-out code.
+
+Eliminate, as much as possible, anything not in config that is conditionalized
+on a CPU, format, or environment.
+
+Merge COFF support into one version, supporting all the pseudo-ops used in
+either versions now, but using BFD for high-level operations. (See second
+following item.) Currently there are two versions (plus the new BFD code),
+which support different features, and are used on different targets.
+
+Convert remaining a.out/b.out targets to using the BFD_ASSEMBLER code by
+default.
+
+Finish conversion to using BFD for all object file writing. (This is the
+BFD_ASSEMBLER code, not BFD or BFD_HEADERS.) VMS might be the tough one here,
+since there's no BFD support for it at all yet. Eliminate the old code. Some
+of this can be done target by target, so doing a target where the CPU or
+format already supports BFD_ASSEMBLER mode may be easiest.
+
+Fix lots of uses of empty strings to use null pointers. Will improve
+efficiency, and should make code clearer too.
+
+Clean up comments; lots of 'em are one previous maintainer griping about
+another previous maintainer, unrelated to the code. (And with no names,
+they're not so fun to read. :-)
+
+For sparc: "call 0" becomes "jmpl %g0,%l7", and similarly for absolute
+addresses in -4096...4095. (Solaris assembler does this. No
+relocation required, no absolute symbol needed.) For addresses
+outside the range, for COFF, keep generating an absolute symbol to use
+for relocs.
+
+Get Steve to document H8/500 stuff (and others).
+
+Improve test suite. Incorporate more reported net bugs, and non-confidential
+Cygnus customer bugs, and anything else.
+
+Add support for i386/i486 16-bit mode, so operating system initialization code
+doesn't require a separate assembler nor lots of `.byte' directives.
+
+See if it's more maintainable (and not too much of a performance loss) to use
+a yacc grammar for parsing input. The lexer will have to be flexible, and the
+grammar will have to contain any construct used on any platform, but it may be
+easier to maintain, instead of having code in most of the back ends.
+
+PIC support.
+
+Torbjorn Granlund <tege@cygnus.com> writes, regarding alpha .align:
+
+ Please make sure the .align directive works as in digital's assembler.
+ They fill the space with a sequence of "bis $31,$31,$31;ldq_u $31,0($30)"
+ since these two instructions can dual-issue. Since .align is ued a lot by
+ gcc, it is an important optimization.
+
+(From old "NOTES" file to-do list, not really reviewed:)
+
+fix relocation types for i860, perhaps by adding a ref pointer to fixS?
-fucked up on a.out.gnu.h, etc.
-fucked up on foo-opcode.h.
remove the ifdef's from fx_callj tests?
-what are callj tests?
-search for (), build prototypes.
-space tighten sparc alignment.
-convert md_ri_to_chars to not pass structs.
-convert md_ri_to_chars to emit fixP's.
-fix number_to_chars, & family to have no side effects.
-prototype.
-md_ => tp_
-use CROSS_ASSEMBLE
-multiple segments.
-share b.out with a.out.
+space tighten sparc alignment?
-stack:
+md_ => tc_
+
+share b.out with a.out.
projects / deliverable / binutils-gdb.git / blobdiff