GitLab

Remove __BOUNDED_POINTERS__ code, which does not work with
-fcheck-pointer-bound and which has undefined behavior anyway.
Problem found when trying to port to gcc -fcheck-pointer-bounds.
(This code was removed from glibc and gnulib regex.c many years ago.)
* src/regex.c (ELSE_EXTEND_BUFFER_HIGH_BOUND): Remove.
(EXTEND_BUFFER): Use a more-portable approach that avoids
undefined behavior due to inspecting pointers to freed storage.

The fix was not complete, and completing it was proving too complicated.

- Revert "* src/regex.c (re_search_2): Make new code safe for
          -Wjump-misses-init."
  This reverts commit c2a17924.
- Revert "Port to GCC 6.2.1 + --enable-gcc-warnings"
  This reverts commit f6134bbd.
- Revert "Fix handling of allocation in regex matching"
  This reverts commit ad66b3fa.
- Revert "Fix handling of buffer relocation in regex.c functions"
  This reverts commit ee04aedc.

This finishes the merge of the recent emacs-25 regex changes into
master.

* src/regex.c (ENSURE_FAIL_STACK, re_search_2):
Redo recent regex changes to avoid complaints from GCC 6.2.1 when
Emacs is configured with --enable-gcc-warnings.  Also, work around
GCC bug 78081, which was uncovered by this new code.

`re_match_2_internal' uses pointers to the lisp objects that it
searches.  Since it may call malloc when growing the "fail stack", these
pointers may be invalidated while searching, resulting in memory
curruption (Bug #24358).

To fix this, we check the pointer that the lisp object (as specified by
re_match_object) points to before and after growing the stack, and
update existing pointers accordingly.

* src/regex.c (STR_BASE_PTR): New macro.
(ENSURE_FAIL_STACK, re_search_2): Use it to convert pointers into
offsets before possible malloc call, and back into pointers again
afterwards.
(POS_AS_IN_BUFFER): Add explanatory comment about punning trick.
* src/search.c (search_buffer): Instead of storing search location as
pointers, store them as pointers and recompute the corresponding address
for each call to `re_search_2'.
(string_match_1, fast_string_match_internal, fast_looking_at):
* src/dired.c (directory_files_internal): Set `re_match_object' to Qnil
after calling `re_search' or `re_match_2'.
* src/regex.h (re_match_object): Mention new usage in commentary.

This follows up on recent problems with the fact that config.h
includes stdlib.h etc.; some files need to include stdlib.h later.
config.h generally should limit itself to includes that are
universally safe; outside of MS-Windows, only stdbool.h makes
the cut among the files currently included.  So, move the
other includes to just the files that need them (Bug#24506).
* configure.ac (config_opsysfile): Remove, as this generic hook
is no longer needed.
* lib-src/etags.c, src/unexmacosx.c, src/w32.c, src/w32notify.c:
* src/w32proc.c (_GNU_SOURCE):
Remove, as it’s OK for config.h to do this now.
* src/conf_post.h: Include <ms-w32.h>, instead of the generic
config_opsysfile, for simplicity as this old way of configuring is
now done only for the MS-Windows port.  Do not include <ms-w32.h>
if DEFER_MS_W32_H, for the benefit of the few files that want its
effects later.  Do not include <alloca.h>, <string.h>, or
<stdlib.h>.  Other files modified to include these headers as
needed, or to not include headers that are no longer needed.
* src/lisp.h: Include <alloca.h> and <string.h> here, since
some of the inline functions need them.
* src/regex.c: Include <alloca.h> if not emacs.  (If emacs,
we can rely on SAFE_ALLOCA.)  There is no longer any need to
worry about HAVE_ALLOCA_H.
* src/unexmacosx.c: Rely on config.h not including stdlib.h.
* src/w32.c, src/w32notify.c, src/w32proc.c (DEFER_MS_W32_H):
Define before including <config.h> first, and include <ms-w32.h>
after the troublesome headers.

RE_CHAR_TO_MULTIBYTE(c) yields c for ASCII characters and a byte8
character for c ≥ 0x80.  Furthermore, CHAR_BYTE8_P(c) is true only
for byte8 characters.  This means that

	c = RE_CHAR_TO_MULTIBYTE (ch);
	if (! CHAR_BYTE8_P (c) && re_iswctype (c, cc))

is equivalent to:

	c = c;
	if (! false && re_iswctype (c, cc))

for 0 ⪬ c < 0x80, and

	c = BYTE8_TO_CHAR (c);
	if (! true && re_iswctype (c, cc))

for 0x80 ⪬ c < 0x100.  In other words, the loop never executes for
c ≥ 0x80 and RE_CHAR_TO_MULTIBYTE call is unnecessary for c < 0x80.

* src/regex.c (regex_compile): Simplyfy a for loop by eliminating
dead iterations and unnecessary macro calls.

decimalnump was used in regex.c only in ISALNUM macro which ored it with
alphabeticp.  Because both of those functions require Unicode general
category lookup, this resulted in unnecessary lookups (if alphabeticp
return false decimalp had to perform another lookup).  Drop decimalnump
in favour of alphanumericp which combines decimelnump with alphabeticp.

* src/character.c (decimalnump): Remove in favour of…
(alphanumericp): …new function.

* src/regex.c (ISALNUM): Use alphanumericp.

* src/regex.c (regex_compile): Remove comment indicating that wctype of
some character classes may be negative.  All wctypes are in fact
non-negative.

* test/file-organization.org: Rename from test/file-organisation.org.

* src/regex.c (regex_compile): Redo casts.

This fixes the following compilation warning:

    regex.c:516:0: warning: macro "STREQ" is not used [-Wunused-macros]
     #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
     ^

* src/regex.c (STREQ): Remove unused macro.  It should have been removed
in a [4538a5e3: Refactor regex character class parsing in [:name:]]
commit but was mistakenly left out.

Emacs only ever uses its own regex syntax so support for other syntaxes
is never used.  Hardcode the syntax so that the compilar can detect such
dead code and remove it from compiled code.

The only exception is RE_NO_POSIX_BACKTRACKING which can be separatelly
specified.  Handle this separatelly with a function argument (replacing
now unnecessary syntax argument).

With this patchset, size of Emacs binary on x86_64 machine is reduced by
around 60 kB:

	new-sizes:-rwx------ 3 mpn eng 30254720 Jul 27 23:31 src/emacs
	old-sizes:-rwx------ 3 mpn eng 30314828 Jul 27 23:29 src/emacs

* src/regex.h (re_pattern_buffer): Don’t define syntax field #ifdef emacs.
(re_compile_pattern): Replace syntax with posix_backtracking argument.

* src/regex.c (print_compiled_pattern): Don’t print syntax #ifdef emacs.
(regex_compile): #ifdef emacs, replace syntax argument with
posix_backtracking which is now used instead of testing for
RE_NO_POSIX_BACKTRACKING syntax.
(re_match_2_internal): Don’t access bufp->syntax #ifndef emacs.
(re_compile_pattern): Replace syntax with posix_backtracking argument.

* src/search.c (compile_pattern_1): Pass boolean posix_backtracking
instead of syntax to re_compile_pattern.

* src/regex.h (re_set_whitespace_regexp): Delete.
(re_compile_pattern): Add whitespace_regexp argument #ifdef emacs.

* src/regex.c (re_set_whitespace_regexp, whitespace_regexp): Delete.
(regex_compile): Add whitespace_regexp argument #ifdef emacs and wrap
whitespace_regexp-related code in an #ifdef emacs so it’s compiled out
unless building Emacs.
(re_compile_pattern): Pass whitespace_regexp argument to regex_compile

* src/search.c (compile_pattern_1): Don’t use re_set_whitespace_regexp,
pass the regex as argument to re_compile_pattern instead.

Instead of using a global variable for storing regex syntax, pass it
to re_compile_pattern.  This is only enabled when compiling Emacs (i.e.
‘#ifdef emacs’).

* src/regex.h (re_set_syntax): Declare only #ifndef emacs.
(re_compile_pattern): Now takes syntax argument #ifdef emacs.

* src/regex.c (re_syntax_options): Define only #ifndef emacs.
(re_compile_pattern): Use the new syntax argument #ifdef emacs.

* src/search.c (compile_pattern_1): Don’t use re_set_syntax and
instead pass syntax to re_compile_pattern directly.

There is no way to specify before_dot and after_dot opcodes in a regex
so code handling those ends up being dead.  Remove it.

* src/regex.c (print_partial_compiled_pattern, regex_compile,
analyze_first, re_match_2_internal): Remove handling and references to
before_dot and after_dot opcodes.

re_wctype function is used in three separate places and in all of
those places almost exact code extracting the name from [:name:]
surrounds it.  Furthermore, re_wctype requires a NUL-terminated
string, so the name of the character class is copied to a temporary
buffer.

The code duplication and unnecessary memory copying can be avoided by
pushing the responsibility of parsing the whole [:name:] sequence to
the function.

Furthermore, since now the function has access to the length of the
character class name (since it’s doing the parsing), it can take
advantage of that information in skipping some string comparisons and
using a constant-length memcmp instead of strcmp which needs to take
care of NUL bytes.

* src/regex.c (re_wctype): Delete function.  Replace it with:
(re_wctype_parse): New function which parses a whole [:name:] string
and returns a RECC_* constant or -1 if the string is not of [:name:]
format.
(regex_compile): Use re_wctype_parse.
* src/syntax.c (skip_chars): Use re_wctype_parse.

* src/regex.c (mutually_exclusive_p): Fix how whether character is
unibyte is tested when calling execute_charset function.  This bug has
been introduced by [6dc6b007: Fix ‘[[🇨🇨]]*literal’ regex failing to
match ‘literal’] which dropped a call to IS_REAL_ASCII (c) macro.
Reinstitute it.

The regex engine tries to optimise Kleene star by avoiding backtracking
when it can detect that star’s operand cannot match what follows it in
the pattern.

For example, when ‘[[:alpha:]]*1’ tries to match a ‘foo’, the engine
will test the longest match for ‘[[:alpha:]]*’, namely ’foo’ which is
the entire string.  Literal digit one still present in the pattern will
however not match the remaining empty string.

Normally, backtracking would be performed trying a shorter match for the
character class (namely ‘fo’ leaving ‘o’ in the string), but since the
engine knows whatever would be put back into the string cannot possibly
match literal digit one so no backtracking will be attempted.

In the regexes of the form ‘[[:CC:]]*X’, the optimisation can be applied
if the character class CC does not match character X.  In the above
example, this holds because digit one is not in alpha character class.

This test is performed by mutually_exclusive_p function but it did not
check class bits of a charset opcode.  This resulted in an assumption
that character classes do not match multibyte characters.  For example,
it would incorrectly conclude that [[:alpha:]] doesn’t match ‘ż’.

This, in turn, led to the aforementioned Kleene star optimisation being
incorrectly applied in patterns such as ‘[[:graph:]]*☠’ (which should
match ‘☠’ but doesn’t as can be tested by executing
    (string-match-p "[[:graph:]]*☠" "☠")
which should return 0 but instead yields nil.

This issue affects any class witch matches multibyte characters, i.e.
if ‘[[🇨🇨]]’ matches a multibyte character X then ‘[[🇨🇨]]*X’ will
fail to match ‘X’.

* src/regex.c (executing_charset): A new function for executing the
charset and charset_not opcodes.  It performs check on the character
taking into consideration existing bitmap, range table and class bits.
It also advances the pointer in the regex bytecode past the parsed
opcode.
(CHARSET_LOOKUP_RANGE_TABLE_RAW, CHARSET_LOOKUP_RANGE_TABLE): Removed.
Code now included in executing_charset.
(mutually_exclusive_p, re_match_2_internal): Changed to take advantage
of executing_charset function.

* test/src/regex-tests.el: New file with tests for the character class
matching.

Inspired by a suggestion from RMS in: http://bugs.gnu.org/23640#58
* .dir-locals.el (c-mode): Adjust to macro changes.
* src/conf_post.h (NONVOLATILE, UNINIT): New macros (Bug#23640).
(IF_LINT): Remove.  All uses replaced by the new macros.

Nowadays GCC is smarter, or the Emacs code has mutated, or both,
and now is as good a time as any to remove uses of IF_LINT that
now seem to be unnecessary.
* lib-src/emacsclient.c (set_local_socket):
* lib-src/movemail.c (main) [MAIL_USE_MAILLOCK && HAVE_TOUCHLOCK]:
* src/buffer.c (fix_start_end_in_overlays, fix_overlays_before):
* src/casefiddle.c (casify_region):
* src/charset.c (load_charset_map):
* src/coding.c (decode_coding_object, encode_coding_object):
* src/data.c (Fmake_variable_buffer_local, Fmake_local_variable)
(cons_to_unsigned, cons_to_signed):
* src/frame.c (make_frame, x_set_frame_parameters):
* src/keyboard.c (read_event_from_main_queue):
* src/regex.c (regex_compile):
* src/syntax.c (back_comment):
* src/window.c (Frecenter):
* src/xfaces.c (Fx_list_fonts):
Remove IF_LINT that no longer seems necessary.
* src/image.c (png_load_body, jpeg_load_body): Simplify use of IF_LINT.
* src/keyboard.c (read_char): Use IF_LINT (volatile) rather than
a pragma dance to pacify GCC -Wclobbered.
* src/xdisp.c (x_produce_glyphs): Rewrite to avoid need for IF_LINT.

* src/xterm.c (x_connection_closed): Now _Noreturn, which should
mean we do not need IF_LINT any more.
(x_io_error_quitter): Now _Noreturn.  Put an 'assume (false)’
at the end, to forestall warnings from older compilers.

Problem reported by Kylie McClain for musl in:
http://lists.gnu.org/archive/html/emacs-devel/2016-03/msg01592.html
* etc/DEBUG, etc/NEWS: Mention this.
* src/callproc.c (child_setup) [!MSDOS]:
* src/dispnew.c (init_display):
* src/emacs.c (main, Fdaemon_initialized):
* src/minibuf.c (read_minibuf_noninteractive):
* src/regex.c (xmalloc, xrealloc):
Prefer symbolic names like STDERR_FILENO to magic numbers like 2,
to make file-descriptor manipulation easier to follow.
* src/emacs.c (relocate_fd) [!WINDOWSNT]: Remove; no longer needed
now that we make sure stdin, stdout and stderr are open.  All uses
removed.
(main): Make sure standard FDs are OK.  Prefer symbolic names like
EXIT_FAILURE to magic numbers like 1.  Use bool for boolean.
* src/lisp.h (init_standard_fds): New decl.
* src/print.c (WITH_REDIRECT_DEBUGGING_OUTPUT) [GNU_LINUX]:
Remove; no longer needed.
(Fredirect_debugging_output): Define on all platforms, not just
GNU/Linux.  Redirect file descriptor, not stream, so that the code
works even if stderr is not an lvalue.  Report an error if the
file arg is neither a string nor nil.
(syms_of_print): Always define redirect-debugging-output.
* src/sysdep.c (force_open, init_standard_fds): New functions.

When configuring with --enable-gcc-warnings, also enable
-Wjump-misses-init, as it’s confusing to use a goto to skip over
an initialization.  Fix the few places in the code that run afoul
of this warning.
* configure.ac (WERROR_CFLAGS): Add -Wjump-misses-init.
* src/doc.c (Fsubstitute_command_keys):
* src/image.c (svg_load_image):
* src/regex.c (re_match_2_internal):
* src/xdisp.c (redisplay_internal, redisplay_window):
Don’t jump over initialization.

* src/regex.c (re_match_2_internal): Support [:upper:] and
[:lower:] for non-ASCII characters.  (Bug#18150)

Run admin/update-copyright.

The problem was in:
  * src/syntax.c (update_syntax_table_forward): Propertize even when truncated
which is hence not unreverted.
The rest is:
* src/syntax.h (UPDATE_SYNTAX_TABLE_FORWARD_FAST):
(UPDATE_SYNTAX_TABLE_FAST): Re-introduce.
All callers in regex.c changed back to the _FAST versions.

* test/automated/message-mode-tests.el: Tweak the test to rely on auto
propertization in backward-sexp.

Although the patch does fix Bug#21688 and prevents a core dump,
it also makes the message-mode-propertize test fail; see:
http://lists.gnu.org/archive/html/emacs-devel/2015-11/msg01667.html
Perhaps someone else can come up with a better fix some day.
* src/syntax.c (update_syntax_table_forward):
Propertize even when truncated.
* src/syntax.h (UPDATE_SYNTAX_TABLE_FORWARD_FAST):
(UPDATE_SYNTAX_TABLE_FAST): Remove.
All callers changed back to the non-_FAST versions.

Problem reported by Ken Raeburn.
Solution suggested by Stefan Monnier (Bug#21688).
* src/regex.c (re_match_2_internal):
Use new _FAST functions to avoid regex code reentering itself.
* src/syntax.c (update_syntax_table_forward): New arg PROPERTIZE.
All callers changed.
* src/syntax.h (UPDATE_SYNTAX_TABLE_FORWARD_FAST)
(UPDATE_SYNTAX_TABLE_FAST): New inline functions.

* src/dispnew.c (add_window_display_history) [GLYPH_DEBUG]:
Remove redundant quotes.
* src/doc.c (uLSQM, uRSQM): New macros.
* src/doc.c (Fsubstitute_command_keys):
* src/syntax.c (Finternal_describe_syntax_value): Follow the user
preference for quotes rather than hardcoding the ‘grave’ style.
* src/regex.c (PUSH_FAILURE_POINT, POP_FAILURE_POINT)
(re_match_2_internal) [DEBUG]: In debugging output, quote C
strings with "...", not `...'.

* doc/lispref/searching.texi (Char Classes):
* lisp/emacs-lisp/rx.el (rx): Document [:graph:] to be [:print:]
sans whitespace (not sans space).
* src/character.c (graphicp): Exclude all Unicode whitespace chars,
not just space.
* src/regex.c (ISGRAPH): Exclude U+00A0 (NO-BREAK SPACE).

In POSIX [[:print:]] is equivalent to [ [:graph:]], so change
[:graph:] so that it matches everything that [:print:] does,
except for space.
* doc/lispref/searching.texi (Char Classes):
* etc/NEWS:
* lisp/emacs-lisp/rx.el (rx):
Document [:graph:] to be [:print:] sans ' '.
* src/character.c, src/character.h (graphicp): New function.
* src/regex.c (ISGRAPH) [emacs]: Use it.
(BIT_GRAPH): New macro.
(BIT_PRINT): Increase to 0x200, to make room for BIT_GRAPH.
(re_wctype_to_bit) [! WIDE_CHAR_SUPPORT]:
Return BIT_GRAPH for RECC_GRAPH.
(re_match_2_internal) [emacs]: Use ISGRAPH if BIT_GRAPH,
and ISPRINT if BIT_PRINT.

* src/regex.c (ISPRINT): Call 'printablep' for multibyte characters.
(BIT_PRINT): New bit mask.
(re_wctype_to_bit): Return BIT_PRINT for RECC_PRINT.
* src/character.c (printablep): New function.
* src/character.h (printablep): Add prototype.

* lisp/emacs-lisp/rx.el (rx): Doc fix: document the new behavior
of 'print', 'alnum', and 'alphabetic'.

* doc/lispref/searching.texi (Char Classes): Document the new
behavior of [:print:].

* etc/NEWS: Mention the new behavior of [:print:].

 src/character.c (alphabeticp, decimalnump): New functions.
 src/character.h (alphabeticp, decimalnump): Add prototypes.
 src/regex.c (ISALNUM, ISALPHA): Check Unicode character properties
 for multibyte characters by calling alphabeticp and decimalnump.
 (BIT_ALPHA, BIT_ALNUM): New bit masks.
 (re_wctype_to_bit): Return them when the class is RECC_ALPHA or
 RECC_ALNUM.
 (re_match_2_internal): Call ISALPHA and ISALNUM when appropriate.

 doc/lispref/searching.texi (Char Classes): Update the documentation of
 [:alpha:] and [:alnum:].

 etc/NEWS: Mention the changes in [:alpha:] and [:alnum:].

Run admin/update-copyright.

Run admin/update-copyright.

All uses changed.
* lib-src/etags.c (analyze_regex): Rename from analyse_regex.
* lisp/cedet/semantic/lex-spp.el:
(semantic-lex-spp-analyzer-do-replace):
Rename from semantic-lex-spp-anlyzer-do-replace.
* lisp/emacs-lisp/cconv.el (cconv--analyze-use):
Rename from cconv--analyse-use.
(cconv--analyze-function): Rename from cconv--analyse-function.
(cconv-analyze-form): Rename from cconv-analyse-form.
* src/regex.c (analyze_first): Rename from analyze_first.

* coding.c (min, max):
* font.c (MAX):
* unexhp9k800.c (min):
* unexw32.c (min, max): Use definitions from lisp.h.
* regex.c (MAX, MIN) [!emacs]: Define own max and min as such.
Adjust users.
* gmalloc.c (min): Tiny style change.

This follows up on the recent thread in emacs-devel on alloca; see:
http://lists.gnu.org/archive/html/emacs-devel/2014-09/msg00042.html
This patch also cleans up alloca-related glitches noted while
examining the code looking for unbounded alloca.
* alloc.c (listn):
* callproc.c (init_callproc):
Rewrite to avoid need for alloca.
* buffer.c (mouse_face_overlay_overlaps)
(report_overlay_modification):
* buffer.h (GET_OVERLAYS_AT):
* coding.c (make_subsidiaries):
* doc.c (Fsnarf_documentation):
* editfns.c (Fuser_full_name):
* fileio.c (Ffile_name_directory, Fexpand_file_name)
(search_embedded_absfilename, Fsubstitute_in_file_name):
* fns.c (Fmake_hash_table):
* font.c (font_vconcat_entity_vectors, font_update_drivers):
* fontset.c (fontset_pattern_regexp, Ffontset_info):
* frame.c (Fmake_terminal_frame, x_set_frame_parameters)
(xrdb_get_resource, x_get_resource_string):
* ftfont.c (ftfont_get_charset, ftfont_check_otf, ftfont_drive_otf):
* ftxfont.c (ftxfont_draw):
* image.c (xbm_load, xpm_load, jpeg_load_body):
* keyboard.c (echo_add_key, menu_bar_items, tool_bar_items):
* keymap.c (Fdescribe_buffer_bindings, describe_map):
* lread.c (openp):
* menu.c (digest_single_submenu, find_and_call_menu_selection)
(find_and_return_menu_selection):
* print.c (PRINTFINISH):
* process.c (Fformat_network_address):
* scroll.c (do_scrolling, do_direct_scrolling, scrolling_1):
* search.c (search_buffer, Fmatch_data, Fregexp_quote):
* sound.c (wav_play, au_play):
* syntax.c (skip_chars):
* term.c (tty_menu_activate, tty_menu_show):
* textprop.c (get_char_property_and_overlay):
* window.c (Fset_window_configuration):
* xdisp.c (safe__call, next_overlay_change, vmessage)
(compute_overhangs_and_x, draw_glyphs, note_mouse_highlight):
* xfaces.c (face_at_buffer_position):
* xmenu.c (x_menu_show):
Use SAFE_ALLOCA etc. instead of plain alloca, since the
allocation size isn't bounded.
* callint.c (Fcall_interactively): Redo memory_full check
so that it can be done at compile-time on some platforms.
* coding.c (MAX_LOOKUP_MAX): New constant.
(get_translation_table): Use it.
* callproc.c (call_process): Use SAFE_NALLOCA instead of
SAFE_ALLOCA, to catch integer overflows on size calculation.
(exec_failed) [!DOS_NT]: New function.
(child_setup) [!DOS_NT]: Use it.
* editfns.c (Ftranspose_regions):
Hoist USE_SAFE_ALLOC + SAFE_FREE out of 'if'.
* editfns.c (check_translation):
Allocate larger buffers on the heap.
* eval.c (internal_lisp_condition_case):
Check for MAX_ALLOCA overflow.
* fns.c (sort_vector): Use SAFE_ALLOCA_LISP rather than Fmake_vector.
(Fbase64_encode_region, Fbase64_decode_region):
Avoid unnecessary calls to SAFE_FREE before 'error'.
* buffer.c (mouse_face_overlay_overlaps):
* editfns.c (Fget_pos_property, check_translation):
* eval.c (Ffuncall):
* font.c (font_unparse_xlfd, font_find_for_lface):
* ftfont.c (ftfont_drive_otf):
* keyboard.c (echo_add_key, read_decoded_event_from_main_queue)
(menu_bar_items, tool_bar_items):
* sound.c (Fplay_sound_internal):
* xdisp.c (load_overlay_strings, dump_glyph_row):
Use an ordinary auto buffer rather than alloca, since the
allocation size is fixed and small.
* ftfont.c: Include <c-strcase.h>.
(matching_prefix): New function.
(get_adstyle_property): Use it, to avoid need for alloca.
* keyboard.c (echo_add_key):
* keymap.c (describe_map): Use ptrdiff_t, not int.
* keyboard.c (echo_add_key): Prefer sizeof to strlen.
* keymap.c (Fdescribe_buffer_bindings): Use SBYTES, not SCHARS,
when counting bytes.
* lisp.h (xlispstrdupa): Remove, replacing with ...
(SAFE_ALLOCA_STRING): ... new macro with different API.
This fixes a portability problem, namely, alloca result
passed to another function.  All uses changed.
(SAFE_ALLOCA, SAFE_ALLOCA_LISP): Check for MAX_ALLOCA,
not MAX_ALLOCA - 1.
* regex.c (REGEX_USE_SAFE_ALLOCA, REGEX_SAFE_FREE)
(REGEX_ALLOCATE): New macros.
(REGEX_REALLOCATE, REGEX_ALLOCATE_STACK, REGEX_REALLOCATE_STACK)
(REGEX_FREE_STACK, FREE_VARIABLES, re_match_2_internal):
Use them.
* xdisp.c (message3): Use SAFE_ALLOCA_STRING rather than doing it
by hand.
(decode_mode_spec_coding): Store directly into buf rather than
into an alloca temporary and copying the temporary to the buf.

Fixes: debbugs:18410