Updating to LLVM 7 mainly involved the following steps:
* Upgrade APIs for folding ConstantExpr.
* Upgrade APIs for GraphTraits.
* Upgrade APIs for DominatorTreeBase.
* Upgrade APIs for BinaryFormat to parse ELFs.
* Fix the LLVM Linker to properly link the QEMU helpers.
* Disable the new optnone attribute even with optimization -O0. This is
necessary to allow SROA to do its job properly.
* Upgrade APIs to delete Instructions.
* Properly cleaning up orphaned metadata still referring to Instructions
that have been destroyed. Recent versions of LLVM are more strict in
this respect, and will assert when compiled in debug.
* Avoid using LLVM `getGlobalContext` which has been removed from newer
versions of LLVM.
* Upgrade tests to use the new APIs.
* Upgrade APIs for instruction iterators and reverse iterators.
This commit introduces `revng_log`, a macro analagous to `revng_assert`,
which basically allows to have the benefit of the `Logger` class without
having to compute the expression to log if the logger is disabled.
This commit also completely dismisses the `DBG` macro, converting all
the old code to `Logger` + `revng_log`.
This commit moves around most files. The new directory structure is as
follows:
* `lib/$LIBRARY/`: contains a library, i.e., a set of `.cpp` files used
by multiple libraries/tools.
* `include/revng/$LIBRARY/`: contains the public headers associated to
the library in `lib/$LIBRARY/`.
* `tools/$TOOL/`: directory where all the `.cpp` files (and private
headers) for a tool reside. Currently we have two tools: `revamb` and
`revamb-dump`.
On top of this, all file names are now in camel case.