To support WASM targets with slow or unsupported setjmp and longjmp,
we eliminate these calls in favor of an error propagation model.
When gray_set_cell is out of cells, it raises an exception which is
later handled in gray_convert_glyph_inner.
This is a less invasive alternative to !385.
* src/smooth/ftgrays.c (gray_set_cell): Raise the overflow exception
and redirect all work to `cell_null`.
(gray_move,line,conic,cubic_to): Return the exception.
(gray_convert_glyph, gray_convert_glyph_inner): Handle the exception.
The previous code had a fundamental flaw: it didn't validate the necessary
parts of the 'GPOS' table before accessing it, causing crashes with
malformed data (since `TT_CONFIG_OPTION_GPOS_KERNING` is off by default,
standard fuzzers don't catch these problems). Additionally, it did a lot of
parsing while accessing kerning data, making it rather slow.
The new implementation fixes this. After validation, offsets to the 'GPOS'
lookup subtables used in the 'kern' feature that correspond to 'simple'
kerning (i.e., similar to 'kern' table kerning) are stored in `TT_Face`;
this greatly simplifies and accelerates access to the kerning data.
Testing with font `SF-Pro.ttf` version '1.00', the validation time for the
'GPOS' table increases the start-up time of `FT_New_Face` by less than 1%,
while calls to `FT_Get_Kerning` become about 3.5 times faster.
* include/freetype/internal (gpos_kerning_available): Replace with...
(gpos_lookups_kerning, num_gpos_lookups_kerning): ... these new fields.
Update callers.
* src/ttgpos.c [TT_CONFIG_OPTION_GPOS_KERNING]: A new implementation.
Given that we also support (limited) 'GPOS' table kerning if
`TT_CONFIG_OPTION_GPOS_KERNING` is defined, the name of this macro is
misleading since it only is true for 'kern' table kerning.
* src/sfnt/sfobjs.c (sfn_load_face): Replace `TT_FACE_HAS_KERNING` with
plain code.
We completely validate the accessed data from the 'GSUB' table, making this
field unnecessary.
* src/autofit/afglobal.h (AF_FaceGlobalsRec): Remove `gsub_length` field.
* src/autofit/afglobal.c (af_face_globals_new), src/autofit/afgsub.c
(af_parse_gsub): Updated.
As reported by clang 19.
* src/autofit/afadjust.c (add_substitute): Make first argument unsigned.
Update all callers.
Other minor signedness fixes.
(af_reverse_character_map_new): Minor signedness fixes.
* src/autofit/afgsub.c (af_hash_insert): Minor signedness fixes.
* src/autofit/aflatin.c
(af_glyph_hints_apply_vertical_separation_adjustments): Make third
argument unsigned.
Update all callers.
Other minor signedness fixes.
(af_latin_hints_apply): Minor signedness fixes.
* src/bdf/bdflib.c (bdf_parse_bitmap_): Minor signedness fix.
* src/truetype/ttobjs.c (tt_size_init_bytecode): Minor signedness fix.
Due to the new GSUB parsing we no longer need
`hb_ot_layout_lookup_get_glyph_alternates`.
This partially reverts commit 5d2fd7608a.
* CMakeLists.txt (HARFBUZZ_MIN_VERSION), meson.build (harfbuzz_dep),
builds/unix/configure.raw (harfbuzz_pkg): Set version to 2.0.0.
* src/autofit/ft-hb-decls.h: Remove entry for
`hb_ot_layout_lookup_get_glyph_alternates`.
With this commit, the start-up time for creating the reverse character map
gets reduced from more than 300% to about 25% (as tested with `arial.ttf`
version 7.00).
* src/autofit/afadjust.c [FT_CONFIG_OPTION_USE_HARFBUZZ]: Include
`afgsub.h`.
(add_substitute): New auxiliary function to recursively add elements to
the reverse cmap.
(af_reverse_character_map_new): New code that replaces the old code
removed in the previous commit.
Rip out some HarfBuzz code of `af_reverse_character_map_new`. The new code
comes immediately in a follow-up commit, making it easier to follow the
changes.
* src/autofit/afadjust.c (af_get_glyph_alternates_helper,
af_get_glyph_alternates): Remove.
(af_reverse_character_map_new): Remove code to create the `*map` hash.
Create an array of GSUB lookup indices for `SingleSubst` and
`AlternateSubst` lookup types to exit early if we have different types.
Also improve tracing.
* src/autofit/afglobal.h (AF_FaceGlobals) [FT_CONFIG_OPTION_USE_HARFBUZZ]:
New fields `gsub_length`, `gsub`, and `gsub_lookups_single_alternate`.
* src/autofit/afglobal.c [FT_CONFIG_OPTION_USE_HARFBUZZ]: Include
`afgsub.h`.
(af_face_globals_new) [FT_CONFIG_OPTION_USE_HARFBUZZ]: Call
`af_parse_gsub` to fill `gsub_lookups_single_alternate`.
(af_face_globals_free): Updated.
* src/autofit/afadjust.c (af_get_glyph_alternates_helper): Exit early if we
possible.
(af_reverse_character_map_new): Trace GSUB lookup indices to be checked.
Using HarfBuzz's API functions to construct the reverse map is too slow; we
have to call `hb_ot_layout_lookup_get_glyph_alternates` far too often
because it can only handle a single glyph at a time. For this reason we are
going to parse the GSUB table by ourselves.
The new non-local functions are `af_parse_gsub` and `af_map_lookup`.
* src/autofit/afgsub.c, src/autofit/afgsub.h: New files for parsing,
validating, and mapping the `SingleSubst` and `AlternateSubst` subtable
types of a GSUB table.
* src/autofit/autofit.c, src/autofit/rules.mk (AUTOF_DRV_SRC): Updated.
According to specifications, CVT and storage area may or may not be
persistent after modifications by a glyf program. FreeType had always
reset them, which was broken by the last commit.
* src/truetype/ttinterp.c (TT_Load_Context): Set CVT and storage here.
* src/truetype.ttobjs.c (tt_size_run_prep): Prioritize TT_Load_Context.
(tt_size_init_bytecode): Allocate but not set CVT and storage area.
To avoid repeated synchronization, some TT_Size allocations are moved
TT_ExecContext for good. The memory blocks are also consolidated.
* src/truetype/ttinterp.c (TT_{Load,Save,Done}_Context): Remove
synchronization and stack management.
* src/truetype/ttobjs.c (tt_size_{init,done}_bytecode): Manage allocations
and assign them to the execution context.
(tt_size_run_prep): Updated.
This replaces a large number of confusing boolean constructs that
describe the target rendering mode in the execution context with
the straight mode variable. It might fix some hidden bugs when
FT_LOAD_TARGET_XXX were used as flags, which they are not.
The condition that triggers the CV program re-execution is simplified.
These events due the rendering mode change are rather rare and unexpected
and, therefore, should not be over-analyzed. In v40, all mode changes
now trigger the CV program. In v35, only switches to/from mono do.
* src/truetype/ttinterp.h (TT_ExecContext): Replace 'grayscale',
'grayscale_cleartype', 'subpixel_hinting_lean', and 'vertical_lcd_lean'
with the rendering 'mode'.
* src/truetype/ttinterp.c (Ins_GETINFO): Updated.
* src/truetype/ttgload.c (tt_loader_init): Replace 'prep' re-execution
trigger and update 'backward_compatibility' condition.
(tt_loader_set_pp): Updated.
This avoids executing the CV program twice and cleans up the use of
'fpgm' and 'prep' triggers
* src/truetype/ttgload.c (tt_loader_init): Call 'tt_size_init_bytecode'
and 'tt_size_run_prep' explicitly and avoid the call repetition.
* src/truetype/ttobjs.c (tt_size_ready_bytecode): Removed as unused.
(tt_size_init, tt_size_init_bytecode, tt_size_done_bytecode): Remove some
'fpgm' and 'prep' triggers and update.
(tt_size_run_fpgm, tt_size_run_prep): Do not set the pedantic flag here.
* src/truetype/ttobjs.h: Update signatures.
This commit actually implements what commit 43ec023e1a describes.
* src/autofit/ft-hb.c (FT_RTLD_FLAGS): New macro for `dlopen`; it uses
`RTLD_GLOBAL` only if `RTLD_DEFAULT` is available.
This assures that twilight zone is reset before each CV program
execution, including after the rendering mode switch. Fixes#1344.
* src/truetype/ttobjs.c (tt_size_ready_bytecode): Relocate the GS
the twilight zone initiation from here...
(tt_size_run_prep): ... to this function, sho that it is always
done prior to the CV program execution.
* src/truetype/ttobjs.c (TT_Run_Context): Set twilight zone here...
(TT_Load_Context): ... rather than here, as it used to be.
This is a minor change with large code rearrangements.
* src/truetype/ttinterp.c (TT_RunIns): Just loop through instructions
and move all setup to...
(TT_Run_Context): ... here; relocated.
(Compute_Round): Replaced by simple assignment, removed.
This reduces dereferencing when calling the interpreter.
* include/freetype/internal/tttypes.h (TT_Face): Move it from here...
* src/truetype/ttinterp.h (TT_ExecContext): ... to here.
* src/truetype/ttobjs.c (tt_size_init_bytecode): Move its initialization
* src/truetype/ttinterp.c (TT_New_Context): ... to here.
(TT_Run_Context): Updated.
This reduces the number of function calls and data copying events.
* src/truetype/ttinterp.c (TT_Goto_CodeRange): Merge into...
(TT_Set_CodeRange): ... this function.
(TT_Load_Context): Do not set up any zones, copy GS, or prepare the
execution...
(TT_Run_Context): ... do this here instead..
* src/truetype/ttinterp.c (TT_Set_CodeRange): Update signature.
* src/truetype/ttobjs.c (tt_size_run_fpgm, tt_size_run_prep): Call
TT_Run_Context.
* src/truetype/ttgload.c (TT_Hint_Glyph, tt_loader_init): Updated.
Instead of restoring persistent GS variables, we only save modifications
permitted by the CVT program. This reduces the context manipulations.
* src/truetype/ttobjs.h (TT_GraphicsState): Reorder fields.
* src/truetype/ttobjs.c (tt_size_run_fpgm, tt_size_run_prep):
Do not alter the context.
* src/truetype/ttgload.c (TT_Hint_Glyph): Do not reset GS.
(tt_loader_init): Fix potential issue in 'instruct_control' handling.
* src/truetype/ttinterp.c (TT_Run_Context): Fully reset GS.
(TT_Load_Conext): Rearrange and remove the 'size' check, already
performed in FT_Load_Glyph.
(TT_Save_Context): Save only modifiable GS parts.
(tt_default_graphics_state): Updated.
* src/truetype/ttinterp.h (TT_Run_Context): Update signature.
With this commit, the following warning gets removed.
```
In file included from src/autofit/autofit.c:21:0:
src/autofit/ft-hb.c: In function 'ft_hb_funcs_init':
src/autofit/ft-hb.c:75:35: warning:
variable 'version_atleast' set but not used [-Wunused-but-set-variable]
ft_hb_version_atleast_func_t version_atleast = NULL;
^~~~~~~~~~~~~~~
```
* src/autofit/ft-hb.c (ft_hb_funcs_init): Move `NULL` check of
`version_atleast` out of ifdefs.
* CMakeLists.txt: Set `C_VISIBILITY_PRESET` to hidden for non-Windows only.
Windows handles exports with `DLL_EXPORT` defined, and old MinGW
toolchains emit a lot of warnings about visibility attributes not being
supported in this configuration.
* build/unix/configure.raw: Revise visibility attributes checks by compiling a
better test program with `-Werror` in `CFLAGS` so that warnings correctly
indicate unsupported configurations.
