This commit switches the approach with which we run the ABI analyses: we
now run them until we reach a fixed point. This enables proper
interprocedural propagation of arguments and return values.
Basically, we now inject reads before call sites, so that, if a function
immediately calls another one, the arguments of the callee are
propagated to the caller.
This commit also updates the logic with which we propagate function
prototypes (and names) to callers. The main advantage of this, is that
function wrappers (in particular, PLT entries) now have the same name as
the function they wrap.
This commit drops the `CallToLifted` tag in favor of a
`getCallToIsolatedFunction` function which checks if the call has the
`IsolatedFunction` tag. The function also assumes that indirect calls
are calls to lifted functions.
SimplifyCFG with instruction sinking enabled sometimes can merge two
call sites that are identical at LLVM IR level, but originally come from
two distinct addresses in the original binary.
The nomerge attribute prevents this type of problematic deduplication.
This commit introduces `BasicBlockID` as the unique identifier for a
`efa::BasicBlock` into the CFG. A `BasicBlockID` is defined by a
`MetaAddress` plus an incremental integer. This enables us to have
multiple instances of the same block in a single function, which is
particularly useful when inlining multiple times the same function.
Apart from this, the commit also does the following:
* It drops representing `MetaAddress`es a `structs` in the IR. This created
several issues related to ABI. We now represent them as strings.
* It defines more functions in `support.h`, instead of defining prototypes
by hand in `CodeGenerator.cpp` and the like. Specifically, `unknownPC`
and `raise_exception_helper`. We also introduce a C "constructor" for
`PlainMetaAddress`.
* It significantly reduces the API of `GeneratedCodeBasicInfo`, which
was supposed to be put on a diet since a long time. Specifically,
many jump target related methods have been moved to free functions in
`IRHelpers.h`. Also `GCBI::getSuccessors` has been pushed into its
only user, `PruneRetSuccessors`, to prevent further usage of a
deprecated API. In the future, it would be nice to drop it entirely.
* It introduces `efa::BasicBlock::InlinedFrom`.
* Introduce an enum to represent named argument indices for `newpc`.
This enables us to more effectively manipulate its argument list.
* It improves the verification and error reporting for
`efa::FunctionMetadata`.
* Update tests.
This commit is preliminary to another piece of work to improve the
generality of inlining beyond the simple "fake function" scenario, for
which the feature was originally conceived.
This change makes sure that CollectCFG is always intertwined
with FunctionIsolation, as it needs to run before the latter
executed. To avoid possible rearrangements on the pipeline
in the future, CollectCFG pass is now registered within FI.
FunctionMetadata was being deserialized every time they were
inspected. This commit introduces a cache structure to prevent this
excessive deserializations.
The control-flow graph and all its hierarchy components
have been moved from `model` to `efa`. The CFG is now
serialized onto the LLVM IR module as a metadata.
FunctionIsolation used to expect the model to adhere too much to what
is on the IR. We relax some assumptions, particularly: 1) if there is
a leftover direct boundary, `IndirectBoundary` is set to it regardless;
2) in `handleDirectBoundary`, the actual successors of a block should
include all those in the model, however, we permit extra successors,
if they exist.
1. Hoist the logic to retrieve a model CallEdge from an llvm::CallInst
out of `getCallSitePrototype()`, in a separate `getCallEdge()`
function.
2. Modify `getCallSitePrototype()` so that the parent function's type is
optional.
This commit imports all the revng pipes (and other support utilities) to
be used with `revng-pipeline`. In particular, the pipes necessary for
binary translations have been introduced.
The goal of `OriginalName` is to keep track of the original name of a
symbol upon import.
In future, this will also be used to promote it to `CustomName`.
Model classes are now described by a YAML document, which is used to
generate C++ headers containing classes and all the boilerplate
required for YAML serialization/deserialization, usage in
SortedVectors, etc. See the README in include/revng/Model for more
info.
Ivan Krysak