GCC 4.6.0 optimizes based on type-based alias analysis. For
example, if b is of type struct buffer * and v of type struct
Lisp_Vector *, then gcc -O2 was incorrectly assuming that &b->size
!= &v->size, and therefore "v->size = 1; b->size = 2; return
v->size;" must therefore return 1. This assumption is incorrect
for Emacs, since it type-puns struct Lisp_Vector * with many other
types. To fix this problem, this patch adds a new type struct
vector_header that documents the constraints on layout of vectors
and pseudovectors, and helps optimizing compilers not get fooled
by Emacs's type punning. It also adds the macros XSETTYPED_PVECTYPE
XSETTYPED_PSEUDOVECTOR, TYPED_PSEUDOVECTORP, for similar reasons.
* lisp.h (XVECTOR_SIZE): New convenience macro. All previous uses of
XVECTOR (foo)->size replaced to use this macro, to avoid the hassle
of writing XVECTOR (foo)->header.size.
(XVECTOR_HEADER_SIZE): New macro, for use in XSETPSEUDOVECTOR.
(XSETTYPED_PVECTYPE): New macro, specifying the name of the size
member.
(XSETPVECTYPE): Rewrite in terms of new macro.
(XSETPVECTYPESIZE): New macro, specifying both type and size.
This is a bit clearer, and further avoids the possibility of
undesirable aliasing.
(XSETTYPED_PSEUDOVECTOR): New macro, specifying the size.
(XSETPSEUDOVECTOR): Rewrite in terms of XSETTYPED_PSEUDOVECTOR
and XVECTOR_HEADER_SIZE.
(XSETSUBR): Rewrite in terms of XSETTYPED_PSEUDOVECTOR and XSIZE,
since Lisp_Subr is a special case (no "next" field).
(ASIZE): Rewrite in terms of XVECTOR_SIZE.
(struct vector_header): New type.
(TYPED_PSEUDOVECTORP): New macro, also specifying the C type of the
object, to help avoid aliasing.
(PSEUDOVECTORP): Rewrite in terms of TYPED_PSEUDOVECTORP.
(SUBRP): Likewise, since Lisp_Subr is a special case.
* lisp.h (struct Lisp_Vector, struct Lisp_Char_Table):
(struct Lisp_Sub_Char_Table, struct Lisp_Bool_Vector):
(struct Lisp_Hash_Table): Combine first two members into a single
struct vector_header member. All uses of "size" and "next" members
changed to be "header.size" and "header.next".
* buffer.h (struct buffer): Likewise.
* font.h (struct font_spec, struct font_entity, struct font): Likewise.
* frame.h (struct frame): Likewise.
* process.h (struct Lisp_Process): Likewise.
* termhooks.h (struct terminal): Likewise.
* window.c (struct save_window_data, struct saved_window): Likewise.
* window.h (struct window): Likewise.
* alloc.c (allocate_buffer, Fmake_bool_vector, allocate_pseudovector):
Use XSETPVECTYPESIZE, not XSETPVECTYPE, to avoid aliasing problems.
* buffer.c (init_buffer_once): Likewise.
* lread.c (defsubr): Use XSETTYPED_PVECTYPE, since Lisp_Subr is a
special case.
* process.c (Fformat_network_address): Use local var for size,
for brevity.
This makes it easier for human readers (and static analyzers)
to see whether these variables are used from other modules.
* alloc.c, buffer.c, bytecode.c, callint.c, casetab.c, category.c:
* ccl.c, character.c, charset.c, cmds.c, coding.c, composite.c:
* data.c, dbusbind.c, dired.c, editfns.c, eval.c, fileio.c, fns.c:
* font.c, frame.c, fringe.c, ftfont.c, image.c, keyboard.c, keymap.c:
* lread.c, macros.c, minibuf.c, print.c, process.c, search.c:
* sound.c, syntax.c, textprop.c, window.c, xdisp.c, xfaces.c, xfns.c:
* xmenu.c, xselect.c:
Declare Q* vars static if they are not used in other modules.
* ccl.h, character.h, charset.h, coding.h, composite.h, font.h:
* frame.h, intervals.h, keyboard.h, lisp.h, process.h, syntax.h:
Remove decls of unexported vars.
* keyboard.h (EVENT_HEAD_UNMODIFIED): Remove now-unused macro.
This makes it easier for human readers (and static analyzers)
to see whether these functions can be called from other modules.
DEFUN now defines a static function. To make the function external
so that it can be used in other C modules, use the new macro DEFUE.
* lisp.h (DEFINE_FUNC): New macro, with the old contents of DEFUN.
(DEFUN): Rewrite in terms of DEFINE_FUNC. It now generates a
static function definition. Use DEFUE if you want an extern one.
(DEFUE, INFUN): New macros.
(Funibyte_char_to_multibyte, Fsyntax_table_p, Finit_image_library):
(Feval_region, Fbacktrace, Ffetch_bytecode, Fswitch_to_buffer):
(Ffile_executable_p, Fmake_symbolic_link, Fcommand_execute):
(Fget_process, Fdocumentation_property, Fbyte_code, Ffile_attributes):
Remove decls, since these functions are now static.
(Funintern, Fget_internal_run_time): New decls, since these functions
were already external.
* alloc.c, buffer.c, callint.c, callproc.c, casefiddle.c, casetab.c:
* ccl.c, character.c, chartab.c, cmds.c, coding.c, data.c, dispnew.c:
* doc.c, editfns.c, emacs.c, eval.c, fileio.c, filelock.c, floatfns.c:
* fns.c, font.c, fontset.c, frame.c, image.c, indent.c:
* keyboard.c, keymap.c, lread.c:
* macros.c, marker.c, menu.c, minibuf.c, print.c, process.c, search.c:
* syntax.c, term.c, terminal.c, textprop.c, undo.c:
* window.c, xdisp.c, xfaces.c, xfns.c, xmenu.c, xsettings.c:
Mark functions with DEFUE instead of DEFUN,
if they are used in other modules.
* buffer.c (Fset_buffer_major_mode, Fdelete_overlay): New forward
decls for now-static functions.
* buffer.h (Fdelete_overlay): Remove decl.
* callproc.c (Fgetenv_internal): Mark as internal.
* composite.c (Fremove_list_of_text_properties): Remove decl.
(Fcomposition_get_gstring): New forward static decl.
* composite.h (Fcomposite_get_gstring): Remove decl.
* dired.c (Ffile_attributes): New forward static decl.
* doc.c (Fdocumntation_property): New forward static decl.
* eval.c (Ffetch_bytecode): New forward static decl.
(Funintern): Remove extern decl; now in .h file where it belongs.
* fileio.c (Fmake_symbolic_link): New forward static decl.
* image.c (Finit_image_library): New forward static decl.
* insdel.c (Fcombine_after_change_execute): Make forward decl static.
* intervals.h (Fprevious_property_change):
(Fremove_list_of_text_properties): Remove decls.
* keyboard.c (Fthis_command_keys): Remove decl.
(Fcommand_execute): New forward static decl.
* keymap.c (Flookup_key): New forward static decl.
(Fcopy_keymap): Now static.
* keymap.h (Flookup_key): Remove decl.
* process.c (Fget_process): New forward static decl.
(Fprocess_datagram_address): Mark as internal.
* syntax.c (Fsyntax_table_p): New forward static decl.
(skip_chars): Remove duplicate decl.
* textprop.c (Fprevious_property_change): New forward static decl.
* window.c (Fset_window_fringes, Fset_window_scroll_bars):
Now internal.
(Fset_window_margins, Fset_window_vscroll): New forward static decls.
* window.h (Fset_window_vscroll, Fset_window_margins): Remove decls.
* buffer.h (BUF_BEGV, BUF_BEGV_BYTE, BUF_ZV, BUF_ZV_BYTE, BUF_PT)
(BUF_PT_BYTE): Rewrite to handle indirect buffers (Bug#8219).
These macros can no longer be used for assignment.
* buffer.c (Fget_buffer_create, Fmake_indirect_buffer): Assign
struct members directly, instead of using BUF_BEGV etc.
(record_buffer_markers, fetch_buffer_markers): New functions for
recording and fetching special buffer markers.
(set_buffer_internal_1, set_buffer_temp): Use them.
* lread.c (unreadchar): Use SET_BUF_PT_BOTH.
* insdel.c (adjust_point): Use SET_BUF_PT_BOTH.
* intervals.c (temp_set_point_both): Use SET_BUF_PT_BOTH.
(get_local_map): Use SET_BUF_BEGV_BOTH and SET_BUF_ZV_BOTH.
* xdisp.c (hscroll_window_tree):
(reconsider_clip_changes): Use PT instead of BUF_PT.
* buffer.h (BUF_BEGV, BUF_BEGV_BYTE, BUF_ZV, BUF_ZV_BYTE, BUF_PT)
(BUF_PT_BYTE): Rewrite to handle indirect buffers (Bug#8219).
These macros can no longer be used for assignment.
* buffer.c (Fget_buffer_create, Fmake_indirect_buffer): Assign
struct members directly, instead of using BUF_BEGV etc.
(record_buffer_markers, fetch_buffer_markers): New functions for
recording and fetching special buffer markers.
(set_buffer_internal_1, set_buffer_temp): Use them.
* lread.c (unreadchar): Use SET_BUF_PT_BOTH.
* insdel.c (adjust_point): Use SET_BUF_PT_BOTH.
* intervals.c (temp_set_point_both): Use SET_BUF_PT_BOTH.
(get_local_map): Use SET_BUF_BEGV_BOTH and SET_BUF_ZV_BOTH.
* xdisp.c (hscroll_window_tree):
(reconsider_clip_changes): Use PT instead of BUF_PT.
dired.c (directory_files_internal):
fileio.c (Finsert_file_contents):
insdel.c (prepare_to_modify_buffer):
xdisp.c (pos_visible_p):
s/ms-w32.h (MODE_LINE_BINARY_TEXT):
w32fns.c (Fw32_shell_execute, Fx_show_tip, x_create_tip_frame):
Use B_ for the MS-Windows build.
From Tom Tromey:
buffer.c (init_buffer_once, syms_of_buffer): Use B_ in DOS_NT case.
* configure: Rebuild.
* configure.in (NS_OBJC_OBJ): New subst.
lib-src
* make-docfile.c: Unconditionally include stdlib.h.
(generate_globals): New global.
(xrealloc): New function.
(main): Handle '-g'. Call start_globals, write_globals.
(scan_file): Conditionally call put_filename.
(start_globals): New function.
(struct global): New.
(num_globals, globals): New globals.
(add_global, compare_globals, write_globals): New functions.
(scan_c_file): Update for "-g".
(scan_lisp_file): Fail if "-g".
(enum global_type): New.
src
* Makefile.in (NS_OBJC_OBJ): New variable.
(base_obj): Rename from 'obj'.
(obj): New variable.
(globals.h, gl-stamp, $(obj)): New targets.
(GLOBAL_SOURCES): New variable.
* globals.h: Remove.
* nsselect.m (Vselection_alist): Define. Reverts part of
2011-01-19T22:11:33Z!jan.h.d@swipnet.se.
* buffer.c: Don't use "no_cell" for name of kill-buffer-hook's
variable.
* xselect.c (Vselection_alist): Define. Reverts part of 2011-01-19T23:32:42Z!eggert@cs.ucla.edu.
