The implementation we currently use from OpenSSL prevents the compiler from optimizing away clensing operations on blocks of memory that are about to be released, but this protection is not extended to link-time optimization. This commit copies the solution cooked up by Google compiler engineers which uses inline assembly directives to instruct the compiler not to optimize out the call under any circumstances. As the code is in-lined, this has the added advantage of removing one more OpenSSL dependency.
Regarding license compatibility, Google's contributions to BoringSSL library, including this code, is made available under the ISC license, which is MIT compatible.
BoringSSL git commit: ad1907fe73334d6c696c8539646c21b11178f20f
Make splash screen queue its own deletion when it receives the finished
command, instead of relying on WA_DeleteOnClose which doesn't work under
these circumstances.
This contains a few hacks very specific to Qt's buildsystem. These can be
reverted once we split the build between native and target builds.
Qt's build contains a circular dependency when not using a system zlib.
By far the easiest fix is to switch to a system zlib, rather than Qt's own.
However, that confuses Qt's cross build which assumes that when using a system
zlib, it should also find a system (native) zlib for native tools. The build
breaks if that zlib is not present.
To solve this:
1. Always use a system zlib rather than the one provided by qt
2. Set force_bootstrap, which instructs the build tools to be built as though
we're cross-compiling (build != target)
3. For build tools, use qt's internal zlib so that a native zlib is not
required.
Step 3 means that if any zlib headers are found by the native build, it will
confuse Qt's internal zlib build. So we also need to make sure that the target
headers/libs aren't found. To do so, specify that our
cflags/cxxflags/cppflags/ldflags only apply for non-host builds.
# Conflicts:
# depends/patches/qt/mac-qmake.conf
