Add shared library support to the CMake build.
This is enabled via:
$ cmake path/to/aom -DBUILD_SHARED_LIBS=1
Currently supports only Linux and MacOS targets. Symbol visibility
is handled by exports.cmake and its helpers exports_sources.cmake
and generate_exports.cmake.
Some sweeping changes were required to properly support shared libs
and control symbol visibility:
- Object libraries are always linked privately into static
libraries.
- Static libraries are always linked privately into eachother
in the many cases where the CMake build merges multiple library
targets.
- aom_dsp.cmake now links all its targets into the aom_dsp static
library target, and privately links aom_dsp into the aom target.
- av1.cmake now links all its targets into the aom_av1 static library
target, and privately links in aom_dsp and aom_scale as well. It
then privately links aom_av1 into the aom target.
- The aom_mem, aom_ports, aom_scale, and aom_util targets are now
static libs that are privately linked into the aom target.
- In CMakeLists.txt libyuv and libwebm are now privately linked into
app targets.
- The ASM and intrinsic library functions in aom_optimization.cmake
now both require a dependent target argument. This facilitates the
changes noted above regarding new privately linked static library
targets for ASM and intrinsics sources.
BUG=aomedia:76,aomedia:556
Change-Id: I4892059880c5de0f479da2e9c21d8ba2fa7390c3
diff --git a/README.md b/README.md
index 1fc764d..69b7f88 100644
--- a/README.md
+++ b/README.md
@@ -46,6 +46,16 @@
in the root of the AV1 repository, and AV1 codec configuration options can
currently be found in the file `build/cmake/aom_config_defaults.cmake`.
+### Dylib builds
+
+A dylib (shared object) build of the AV1 codec library can be enabled via the
+CMake built in variable BUILD\_SHARED\_LIBS:
+
+ $ cmake path/to/aom -D BUILD_SHARED_LIBS=1
+ $ make
+
+This is currently only supported on non-Windows targets.
+
### Cross compiling
For the purposes of building the AV1 codec and applications and relative to the
