The new bare metal support only supports the single thread model. This causes
the builtin atomic functions (e.g.: __atomic_fetch_add) to not generate
thread-safe assembly for these operations, which breaks our firmware. We target
bare metal, and need to atomically modify variables in our interrupt routines,
and task threads.
Internally, the -mthread-model flag determines whether to lower or expand
atomic operations (see D4984).
This change removes the overridden thread model methods, and instead relies on
the base ToolChain class to validate the thread model (which already includes
logic to validate single thread model support). If the single thread model is
required, the -mthread-model flag will have to be provided.
As a workaround "-mthread-model posix" could be provided, but it only works due
to a bug in the validation of the -mthread-model flag (separate patch coming to
fix this).
https://reviews.llvm.org/D37493
Patch by: Ian Tessier!
llvm-svn: 312651
The baremetal test (r303873) has been added with expectance of very
specific -resource-dir. However, the test itself nor the BareMetal
driver does not enforce any specific -resource-dir, making this
constraint invalid. It already has been altered twice -- in r303910 for
Windows compatibility, and in r304085 for systems using lib64. To
account for even more systems, just use [[RESOURCE_DIR]] like a number
of other tests do. This is needed for Gentoo where RESOURCE_DIR starts
with ../ (uses relative path to a parent directory).
Differential Revision: https://reviews.llvm.org/D33877
llvm-svn: 304715
Also comes with a cmake cache for building the runtime bits:
$ cmake <normal cmake flags> \
-DBAREMETAL_ARMV6M_SYSROOT=/path/to/sysroot \
-DBAREMETAL_ARMV7M_SYSROOT=/path/to/sysroot \
-DBAREMETAL_ARMV7EM_SYSROOT=/path/to/sysroot \
-C /path/to/clang/cmake/caches/BaremetalARM.cmake \
/path/to/llvm
https://reviews.llvm.org/D33259
llvm-svn: 303873
Jonathan Roelofs