43752ec17d
There are several gcc/ld flags that optimize size and performance without requiring explicit code changes. In no particular order, this adds: - gcc -pipe to avoid temporary files and use pipes during compilation - gcc -fno-common avoids putting uninitialized global variables not marked as "extern" into a common section. This catches compilation errors if we didn't mark global variables explicitly as "extern". - gcc -fno-strict-aliasing allows us to use unions for some binary magic. Otherwise, -O2 might assume that two different types never point at the same memory. We currently don't rely on this but it's common practice so avoid any non-obvious runtime errors later. - gcc -ffunction-sections and -fdata-sections put each function and variable into a separate section. This enables ld's --gc-sections to drop any unused sections (sections which aren't referenced from an exported section). This is very useful to avoid putting dead code into DSOs. We can now link any helper function into libevdev and the linker removes all of them if they're unused. - gcc -fstack-protector adds small stack-corruption protectors in functions which have big buffers on the stack (>8bytes). If the stack-protectors are corrupted, the process is aborted. This is highly useful to debug stack-corruption issues which often are nearly impossible to catch without this. - ld --as-needed drops all linked libraries that are not actually required by libevdev. So we can link to whatever we want and the linker will drop everything which is not actually used. - ld -z now, resolve symbols during linking, not during runtime. - ld -z relro, add relocation-read-only section. This allows to put read-only global variables and alike into a read-only section. This is useful for variables that need a relocation and thus cannot be explicitly put into a read-only section. This option tells the linker to mark them read-only after relocations are done. (that's why -z now makes sense in combination with this) All of these options are common in other open-source projects, including systemd and weston. Don't ask me why they are not marked as default.. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net> Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net> |
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| doc | ||
| libevdev | ||
| test | ||
| tools | ||
| .gitignore | ||
| configure.ac | ||
| COPYING | ||
| libevdev.pc.in | ||
| Makefile.am | ||
| README.md | ||
libevdev - wrapper library for evdev input devices
libevdev is a wrapper library for evdev devices. it moves the common tasks when dealing with evdev devices into a library and provides a library interface to the callers, thus avoiding erroneous ioctls, etc.
git://git.freedesktop.org/git/libevdev http://cgit.freedesktop.org/libevdev/
libevdev is currently in early stages of development. Use at your own risk
The eventual goal is that libevdev wraps all ioctls available to evdev devices, thus making direct access unnecessary.
Go here for the API documentation: http://www.freedesktop.org/software/libevdev/doc/latest/
File bugs in the freedesktop.org bugzilla: https://bugs.freedesktop.org/enter_bug.cgi?product=libevdev
Patches, questions and general comments should be submitted to the input-tools@lists.freedesktop.org mailing list: http://lists.freedesktop.org/mailman/listinfo/input-tools