The generic binary loading interface is instantiated once for each
architecture/binary container pair. This isn't great, but there is enough
custom work in each setting to justify it.
The binary loading interface isn't finished yet, and needs to learn some
additional operations to support relocation. It already supports additional
information that is architecture specific and binary container format
specific (that operations will have to use on a per-format basis).
On the PowerPC side, the Table of Contents (TOC) is now architecture-specific
information constructed by the loader (currently from ELF binaries). The new
TOC data type is in place to support this more easily (the old format was just a
function).
Except for Attn, these are all no-ops since we don't have a concurrency model.
That could change later - we might want to model them as both failing and
succeeding in some cases (esp the transactional memory instructions).
This change is in the core generator monad and applied in the PowerPC backend.
This change includes some macaw updates (which required a new elf-edit version).
Now test to ensure that no blocks end in a classification failure (or a
disassembly failure). Before, many blocks were not classified, which causes
problems downstream. This required some changes in macaw core in two places:
1. The simplifier needed some additional rules to remove some redundant
constructions that threw off the abstract interpretation of values. This was
particularly an issue while reading return values off of the stack in
PowerPC.
2. Extending the abstract interpretation to be able to handle more operations (shiftl)
We need special treatment of the return, as the low two bits are cleared on
PowerPC, so we can't just rely on pattern matching against the ReturnAddr in the
IP register.
The Macaw Discovery now calls the identifyReturn to identify return
statements. Supply this for ARM, but at present this simply
replicates the original inline code which does not properly detect ARM
return operations because the low bit(s) of the address are always
cleared when writing to the instruction pointer in ARM.
The identifyReturn was previously unused because the Macaw Discovery
performed this test inline, but some architectures have different
semantics so the identifyReturn is now used by the Discovery process.
This implements the return discovery that should be sufficient for the
PPC.
