Since commit c5dd2ca538 (DetermineCompiler: Relax
_CMAKE_TOOLCHAIN_PREFIX detection, 2020-03-25, v3.18.0-rc1~430^2),
`_CMAKE_TOOLCHAIN_PREFIX` may be set even when not cross-compiling.
In this case we may still need to use binutils without any prefix.
Fixes: #21103
When updates are disconnected, don't depend on skip-update because that
target is always considered out of date. Depend directly on the patch target
instead because it already depends on the appropriate target regardless of
whether updates are disconnected or not. This in turn means nothing depends
on the skip-update target, so it has also been removed.
Relates: #21086
The skip-update target is always considered out-of-date. The change in
7249ba9677 (ExternalProject: Enforce that patch depends on update, 2020-04-03)
made the patch target depend on skip-update, which in turn made it
always out of date too. The patch command should only be re-run if the download
needs to be performed again where updates are disconnected.
Fixes: #21086
Since commit e672db628b (FindRuby: Rename variables to match case of
module name, 2020-03-11, v3.18.0-rc1~546^2), the upper-case-prefixed
variable names are for compatibility only but still exist. Put them
back in the documentation.
Issue: #21064
In order to shorten the download failure of ExternalProject download
steps, a download retry is only done when a recoverable network
error is encountered.
A valid HDF5 installation with the "high level" extensions not
configured will *fail* to be correctly detected by CMake since
commit d9e39f3f89 (FindHDF5: check that compiler wrapper can
compile a minimal program, 2020-02-10, v3.18.0-rc1~744^2~1):
```
/.../hdf5/cmake_hdf5_test.c:2:10: fatal error: 'hdf5_hl.h' file not found
```
This does not stop the configuration but does prevent flags and
libraries from being recognized.
Change the default value of `CMAKE_AUTOMOC_PATH_PREFIX` to `OFF` to
restore compatibility with behavior of CMake 3.15 and below.
C++ source files that are generated by Qt's meta object compiler (moc)
include the header file that was passed as input argument to moc. This
is usually a path relative to the source directory, for example
#include "../../source/dir/myobject.h"
That is problematic for reproducible builds as described in #18815.
To cope with that, the target property AUTOMOC_PATH_PREFIX was
introduced in CMake 3.16 by commit d018d27c10 (Autogen: Add moc path
prefix generation (AUTOMOC_PATH_PREFIX), 2019-09-13, v3.16.0-rc1~94^2~4).
The property is default-initialized from the variable
`CMAKE_AUTOMOC_PATH_PREFIX`, which defaults to `ON`.
If this property is ON, and myobject.h is located in an include
directory of the target, moc-generated C++ files include the file
without the "path prefix":
#include "myobject.h"
This behavior, however, can break projects that have equally named
header files in different include directories. As "not breaking
existing projects" trumps "have reproducible builds by default" we
change the default of `CMAKE_AUTOMOC_PATH_PREFIX` to `OFF`.
Also, it is now possible to pass `-DCMAKE_AUTOMOC_PATH_PREFIX=ON` on the
CMake command line. Before, it was overridden in `CMakeGenericSystem`.
Fixes: #20598
Issue: #18815
Starting with Xcode 12 the arm64 architecture is supported
as an iOS device as well as simulator architecture.
But the fat macho file format does not distinguish by SDK,
only by architecture. That makes lipo (rightfully) complain
that it cannot add both architectures to a single file.
To work around we make sure that both SDKs are built for a
disjoint set of architectures. If an architecture is present
for both SDKs we prefer the currently configured one.
The log output has been extended to reflect that:
```
[iOS combined] Architectures (iphoneos): arm64 arm64e armv7 armv7s
[iOS combined] Architectures (iphonesimulator): arm64 arm64e i386 x86_64
[iOS combined] Architectures (iphonesimulator) after pruning: i386 x86_64
```
Brad King