Allow Ninja to rebuild build.ninja any time a SCons tool or the compiler
is changed between iterative rebuilds. This change allows us to ensure
that we don't have any stale object files lying around that may have
been produced by an incompatible toolchain.
Allow Ninja to rebuild build.ninja any time a SCons tool or the compiler
is changed between iterative rebuilds. This change allows us to ensure
that we don't have any stale object files lying around that may have
been produced by an incompatible toolchain.
Some versions of ccache do not know how to handle clang's
-fsanitizer-blacklist flags. Some versions don't handle it at all, while
others only handle one instance, even though it can appear multiple
times on the command line. Because the argument can change the resulting
compiled object, not taking the flags into account properly can cause
ccache to pull an incorrect object file from its cache. The exact
behavior depends on the ccache version and how the arguments are changed
on the command line. We implement a workaround suggested by the ccache
developers until a newer version of ccache with all the required fixes
is in common use.
* Workaround ref: https://github.com/ccache/ccache/issues/174
If CCACHE or ICECC are specified on the SCons command line but the paths
given don't exist, the associated tool would simply be skipped. This
caused confusion when users were expecting the tool to run and the
compile would proceed without it. Now specifying an incorrect path to
the tool will cause a configure failure.
The toolchain llvm-symbolizer was never actually in PATH despite the
toolchain being appended to it in evergreen.yml, causing confusion while
attempting to diagnose an apparent symbolization failure. This change
explicitly sets the path to llvm-symbolizer for all sanitizer build
variants and removes the last vestiges of the non-working discovery
method.
The sanitizer flags in evergreen.yml were not being reflected in
SConstruct. This change simply synchronizes the two locations so
developers can build with sanitizers locally and get the same
results as with Evergreen builds. We also remove the separation between
LSAN and ASAN, since no evergreen builds use them separately anyway.
Before this point, remote builds did not work because Icecream did not
copy sanitizer blacklist files to the remote hosts. We had a check in
place that silently turned Icecream builds with sanitizers into local
builds. Now we build the sanitizer blacklist files into the environment
tarball that Icecream uses for remote builds.
A bug spotted in Icecream 1.2+ can cause build failures when building
with gcc. This is, in turn, due to a bug in GCC where the preprocessor
executed via `gcc -E` has different behavior than the one used
internally during compilation. We are working with Icecream, and GCC
to address these problems. For now, we work around the bugs.
* GCC bug report: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88475
* Icecream bug report: icecc/icecream#550
A bug spotted in Icecream 1.2+ can cause build failures when building
with gcc. This is, in turn, due to a bug in GCC where the preprocessor
executed via `gcc -E` has different behavior than the one used
internally during compilation. We are working with Icecream, and GCC
to address these problems. For now, we work around the bugs.
* GCC bug report: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88475
* Icecream bug report: https://github.com/icecc/icecream/issues/550
The death tests fork() a new thread in a multithreaded test harness so
we can test thread death behavior. Unfortunately TSAN does not support
fork() after spawning a thread and will kill the thread by default,
causing a test failure. This sets an unsupported TSAN flag that disables
the behavior, allowing the tests to proceed. There is currently no means
to limit the change to only the death tests, but the change only applies
to the death tests for now.
Minimizing the list of NEEDED entries directly attached to the core
programs reduces startup time for dynamically linked binaries by
approximately 40 percent.
