Package: emacs;
Reported by: Stefan Kangas <stefankangas <at> gmail.com>
Date: Sun, 12 Jan 2025 17:56:02 UTC
Severity: wishlist
Done: Stefan Kangas <stefankangas <at> gmail.com>
Bug is archived. No further changes may be made.
View this message in rfc822 format
From: Pip Cet <pipcet <at> protonmail.com> To: Eli Zaretskii <eliz <at> gnu.org> Cc: 75521 <at> debbugs.gnu.org, stefankangas <at> gmail.com Subject: bug#75521: scratch/igc: Delete unused macro DEFVAR_LISP_NOPROX Date: Mon, 13 Jan 2025 14:16:04 +0000
"Eli Zaretskii" <eliz <at> gnu.org> writes:
>> Date: Mon, 13 Jan 2025 12:57:03 +0000
>> From: Pip Cet <pipcet <at> protonmail.com>
>> Cc: 75521 <at> debbugs.gnu.org, stefankangas <at> gmail.com
>>
>> "Eli Zaretskii" <eliz <at> gnu.org> writes:
>>
>> > According to this comment:
>> >
>> > /* Vector of Vfont_weight_table, Vfont_slant_table, and Vfont_width_table. */
>> > static Lisp_Object font_style_table;
>> >
>> > Vfont_weight_table is actually an element of font_style_table, and
>> > that one is protected:
>>
>> But then font_style_table is sometimes modified so it points to
>> (i.e. contains as its element) a new vector, and I don't see how
>> Vfont_weight_table is protected then.
>
> Modified where?
font_style_to_value:
if (! noerror)
return -1;
eassert (len < 255);
elt = make_vector (2, make_fixnum (100));
ASET (elt, 1, val);
ASET (font_style_table, prop - FONT_WEIGHT_INDEX,
CALLN (Fvconcat, table, make_vector (1, elt)));
return (100 << 8) | (i << 4);
It's not clear to me when this code is reached (usually, noerror is
false and we don't modify font_style_table), but if it ever is reached,
we lose (at least when --enable-checking or in temacs).
The crash is easy to fix, but it's not at all clear to me that modifying
font_style_table shouldn't also modify Vfont_weight_table etc.
However, it is clear that the _NOPRO isn't required or helpful, and
since that's the last usage, let's just remove this remnant of GCPRO
times.
If, in addition, we want to keep Vfont_weight_table synchronized with
the table used by the font code to resolve weight symbols, we can do
this (this would change behavior in those cases that previously resulted
in a crash):
diff --git a/src/font.c b/src/font.c
index e6c41e41258..9b3d294640e 100644
--- a/src/font.c
+++ b/src/font.c
@@ -47,7 +47,22 @@ Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011
#define DEFAULT_ENCODING Qiso8859_1
/* Vector of Vfont_weight_table, Vfont_slant_table, and Vfont_width_table. */
-static Lisp_Object font_style_table;
+static Lisp_Object *font_style_table (int index)
+{
+ Lisp_Object *ret;
+ if (index == FONT_WEIGHT_INDEX)
+ ret = &Vfont_weight_table;
+ else if (index == FONT_SLANT_INDEX)
+ ret = &Vfont_slant_table;
+ else if (index == FONT_WIDTH_INDEX)
+ ret = &Vfont_width_table;
+ else
+ emacs_abort ();
+
+ CHECK_VECTOR (*ret);
+
+ return ret;
+}
/* Structure used for tables mapping weight, slant, and width numeric
values and their names. */
@@ -376,10 +391,9 @@ font_pixel_size (struct frame *f, Lisp_Object spec)
font_style_to_value (enum font_property_index prop, Lisp_Object val,
bool noerror)
{
- Lisp_Object table = AREF (font_style_table, prop - FONT_WEIGHT_INDEX);
+ Lisp_Object table = *font_style_table (prop);
int len;
- CHECK_VECTOR (table);
len = ASIZE (table);
if (SYMBOLP (val))
@@ -418,8 +432,8 @@ font_style_to_value (enum font_property_index prop, Lisp_Object val,
eassert (len < 255);
elt = make_vector (2, make_fixnum (100));
ASET (elt, 1, val);
- ASET (font_style_table, prop - FONT_WEIGHT_INDEX,
- CALLN (Fvconcat, table, make_vector (1, elt)));
+ *font_style_table(prop) =
+ CALLN (Fvconcat, table, make_vector (1, elt));
return (100 << 8) | (i << 4);
}
else
@@ -461,8 +475,7 @@ font_style_symbolic (Lisp_Object font, enum font_property_index prop,
if (NILP (val))
return Qnil;
- table = AREF (font_style_table, prop - FONT_WEIGHT_INDEX);
- CHECK_VECTOR (table);
+ table = *font_style_table (prop);
i = XFIXNUM (val) & 0xFF;
eassert (((i >> 4) & 0xF) < ASIZE (table));
elt = AREF (table, ((i >> 4) & 0xF));
@@ -588,13 +601,12 @@ font_prop_validate_style (Lisp_Object style, Lisp_Object val)
if (FIXNUMP (val))
{
EMACS_INT n = XFIXNUM (val);
- CHECK_VECTOR (AREF (font_style_table, prop - FONT_WEIGHT_INDEX));
if (((n >> 4) & 0xF)
- >= ASIZE (AREF (font_style_table, prop - FONT_WEIGHT_INDEX)))
+ >= ASIZE (*font_style_table (prop)))
val = Qerror;
else
{
- Lisp_Object elt = AREF (AREF (font_style_table, prop - FONT_WEIGHT_INDEX), (n >> 4) & 0xF);
+ Lisp_Object elt = AREF (*font_style_table (prop), (n >> 4) & 0xF);
CHECK_VECTOR (elt);
if ((n & 0xF) + 1 >= ASIZE (elt))
@@ -5949,11 +5961,6 @@ syms_of_font (void)
gets the repertory information by an opened font and ENCODING. */);
Vfont_encoding_alist = Qnil;
- /* FIXME: These 3 vars are not quite what they appear: setq on them
- won't have any effect other than disconnect them from the style
- table used by the font display code. So we make them read-only,
- to avoid this confusing situation. */
-
DEFVAR_LISP ("font-weight-table", Vfont_weight_table,
doc: /* Vector of valid font weight values.
Each element has the form:
@@ -5961,25 +5968,18 @@ syms_of_font (void)
NUMERIC-VALUE is an integer, and SYMBOLIC-NAME and ALIAS-NAME are symbols.
This variable cannot be set; trying to do so will signal an error. */);
Vfont_weight_table = BUILD_STYLE_TABLE (weight_table);
- make_symbol_constant (intern_c_string ("font-weight-table"));
DEFVAR_LISP ("font-slant-table", Vfont_slant_table,
doc: /* Vector of font slant symbols vs the corresponding numeric values.
See `font-weight-table' for the format of the vector.
This variable cannot be set; trying to do so will signal an error. */);
Vfont_slant_table = BUILD_STYLE_TABLE (slant_table);
- make_symbol_constant (intern_c_string ("font-slant-table"));
DEFVAR_LISP ("font-width-table", Vfont_width_table,
doc: /* Alist of font width symbols vs the corresponding numeric values.
See `font-weight-table' for the format of the vector.
This variable cannot be set; trying to do so will signal an error. */);
Vfont_width_table = BUILD_STYLE_TABLE (width_table);
- make_symbol_constant (intern_c_string ("font-width-table"));
-
- staticpro (&font_style_table);
- font_style_table = CALLN (Fvector, Vfont_weight_table, Vfont_slant_table,
- Vfont_width_table);
DEFVAR_LISP ("font-log", Vfont_log, doc: /*
A list that logs font-related actions and results, for debugging.
GNU bug tracking system
Copyright (C) 1999 Darren O. Benham,
1997,2003 nCipher Corporation Ltd,
1994-97 Ian Jackson.