Visual Studio always uses a complete NDK and not a standalone toolchain.
Let CMake handle the NDK and related logic correctly, avoid trying to
find the standalone toolchain version from the unified clang toolchain
in newer NDKs.
In commit 97bca2f9fa (Android: Use unified toolchain in NDK r19+,
2019-07-26, v3.16.0-rc1~342^2) we hard-coded use of the unified
toolchain for NDK r19+ and skipped most of the old detection logic.
However, in that fast path we left out setting `_CMAKE_TOOLCHAIN_PREFIX`
for `CMakeFindBinutils` to select the matching binutils. Add it.
Fixes: #20038
The CMake support for Android assumes cross-compilation using the NDK,
so stub out that Android NDK support and use the Linux support that's
already invoked. Set CMAKE_HOST_SYSTEM_NAME to "Android", rather than
"Linux".
Issue: #19840
The NDK build system now uses only a single toolchain in
<ndk>/toolchains/llvm/prebuilt/<host>
Its compilers are always `bin/{clang,clang++}` and its binutils are
always `bin/<triple>-*`. It is a standalone toolchain:
* The Anrdoid API level is specified at the end of `--target=`.
* The standard library may be specified via `-stdlib=`.
* No need to pass system includes or libraries explicitly.
* No need to pass `--sysroot` or `-gcc-toolchain`.
Teach CMake to recognize NDK versions that have a unified
toolchain with its own sysroot and use the above approach.
Fixes: #18739
In commit c4b4d8b3a6 (POSITION_INDEPENDENT_CODE: Manage link flags for
executables, 2018-10-02, v3.14.0-rc1~395^2) we accidentally removed our
Android-specific logic for PIE under the CMP0083 OLD behavior. Restore
it and also implement Android-specific logic for CMP0083 NEW behavior.
Fixes: #19393
NDK r18 drops GCC toolchains and some STL types. We need to choose a
clang toolchain by default when no gcc toolchains are available. Switch
the STL type default to `c++_static` when the old `gnustl_static`
default is not available.
Update the test suite to not run tests for STL types that do not exist.
Also do not expect the gcc toolchain `cpp` tool to be available because
r18 does not provide it. Also teach it to tolerate `gcc -dumpmachine`
output like `arm--linux-android` that differs from the toolchain prefix.
Fixes: #18301
Since NDK commit 90ec78ffd96b87cd75d82575587ead14d6494df1 (Remove Clang
toolchain path from setup.mk, 2017-05-31) the `setup.mk` files for Clang
no longer hold the path to the `toolchains/llvm` directory. It has been
the same since NDK r11, so use that as the default.
Fixes: #17253
The unified headers are preferred as of NDK r15, so use them by default
if available and provide an option to use the deprecated headers.
Inspired-by: Florent Castelli <florent.castelli@gmail.com>
Fixes: #16584
The NDK's own build files:
<ndk>/build/tools/build-cxx-stl.sh
<ndk>/build/cmake/android.toolchain.cmake
for the `c++_static` and `c++_shared` build types add the
`<ndk>/sources/android/support/include` include directory
between the two `<ndk>/sources/cxx-stl/llvm-libc++*` directories.
Re-order our own include directory generation to match.
Issue: #16536
Expose the binutils' machine name (typically used as a prefix on the
tool names) publicly. This is expected to match the `gcc -dumpmachine`
value.
Suggested-by: Ruslan Baratov <ruslan_baratov@yahoo.com>
The NDK provides prebuilt toolchain files in directories named for the
host architecture. The NDK build system calls this `HOST_TAG`.
Expose the value publicly for use by clients that need to pass it
to external tools.
Suggested-by: Ruslan Baratov <ruslan_baratov@yahoo.com>
When this variable is not set by the user or toolchain file, set it to
the default selected. This will be useful for client code that needs to
pass the value to an external tool that needs to find the same toolchain
in the NDK. Leave it empty for a standalone toolchain.
Suggested-by: Ruslan Baratov <ruslan_baratov@yahoo.com>
Add `-fPIE -pie` to the default executable link flags when
`CMAKE_POSITION_INDEPENDENT_CODE` is enabled. This is required by
Android 16 and above for executables to run on the device.
Closes: #16382
If the toolchain file or cache does not set this, enable it
automatically based on the Android API version. Versions 16
and above expect position independent code.
Use the main `CMAKE_POSITION_INDEPENDENT_CODE` setting in favor of
hard-coding `-fpic` or `-fPIC` in the compiler flags for each ABI.
This allows CMake to use `-fpie` or `-fPIE` as needed when sources
are meant for executables, and `-fpic` or `-fPIC` for other sources.
See `${ndk}/build/core/default-build-commands.mk` for link flags the NDK
uses for executables. Add them to our default executable link flags.
Suppress `nocopyreloc` on `arm64-v8a` because it does not work with
some STL types.
Closes: #16380
Add missing "unwind" and "atomic" libraries needed for this combination.
See `${ndk}/sources/cxx-stl/llvm-libc++/libs/armeabi/libc++.a` for the
libraries the NDK uses.
Issue: #16380
Per-source copyright/license notice headers that spell out copyright holder
names and years are hard to maintain and often out-of-date or plain wrong.
Precise contributor information is already maintained automatically by the
version control tool. Ultimately it is the receiver of a file who is
responsible for determining its licensing status, and per-source notices are
merely a convenience. Therefore it is simpler and more accurate for
each source to have a generic notice of the license name and references to
more detailed information on copyright holders and full license terms.
Our `Copyright.txt` file now contains a list of Contributors whose names
appeared source-level copyright notices. It also references version control
history for more precise information. Therefore we no longer need to spell
out the list of Contributors in each source file notice.
Replace CMake per-source copyright/license notice headers with a short
description of the license and links to `Copyright.txt` and online information
available from "https://cmake.org/licensing". The online URL also handles
cases of modules being copied out of our source into other projects, so we
can drop our notices about replacing links with full license text.
Run the `Utilities/Scripts/filter-notices.bash` script to perform the majority
of the replacements mechanically. Manually fix up shebang lines and trailing
newlines in a few files. Manually update the notices in a few files that the
script does not handle.
Populate standard include directories and link libraries for the
platform. Select the STL corresponding to CMAKE_ANDROID_STL_TYPE and
matching the current ABI and toolchain to be used. Refer to the NDK
sources/cxx-stl/*/Android.mk files for the needed file locations.
The Android NDK source repository at
https://android.googlesource.com/platform/ndk.git
has `<ndk>/build/core/toolchains/*/setup.mk` files that store tables of
information for their build system. Add an equivalent file for each
compiler/abi combination.
Commonly used Android toolchain files that pre-date CMake upstream
support may need to be updated to work with our new functionality.
They typically set CMAKE_SYSTEM_VERSION to 1, so detect that and
skip our upstream Android settings. When such toolchain files are
updated to account for our upstream support, they can then set
CMAKE_SYSTEM_VERSION to a valid Android API and get new behavior.
Support for NVIDIA Nsight Tegra Visual Studio Edition was previously
implemented in the CMake VS IDE generators. Avoid interfering with
that functionality for now. Later we may try to integrate this.
