This commit ensures that FunctionIsolation and EnforceABI do only
thing. This means that they no longer modify `root`.
Instead, we have a new pass, `invoke-isolated-functions` that needs to
be run after them and replaces the entry point of the functions with
invokes to the isolated functions, possibly with the appropriate
arguments.
This commit extracts a plain `struct` from the `MetaAddress` class. This
enables us to use `MetaAddress` from C and therefore, runtime.
The definition of such `struct`, `PlainMetaAddress`, is in
`PlainMetaAddress.h`, which is included by `early-linked.c`.
A function to print the content of a `PlainMetaAddress` has also been
introduced.
Also, anticipating the linkage of `early-linked.c` triggered a
superflous assertion in `CPUStateAccessAnalysis`. This commit removes
it.
* Introduce GCBI::buildDispatcher
* Introduce GCBI::getJumpTarget{,Block} and GCBI::getBlocksGeneratedByPC
to easily map `BasicBlock *` to jump targets and viceversa.
* PCH::buildDispatcher now returns a list of the newly created basic
blocks.
* Other minor changes
This commit fixes the following issues:
1. It introduces `getNameFromYAMLEnumScalar` which returns a
`llvm::StringRef` instead of a `std::string`.
2. Lets users decide what to do when `getValueFromYAMLScalar` does not
get any match (abort by defaul, or return an "Invalid" value).
Enable quotes around MetaAddress during serialization, since ':' is a
valid YAML separator, which causes wrong deserialization when a vector
of MetaAddress is serialized as a list
Changes include:
- `getFunctionCall` has been moved in IRHelpers.h
- `getFallthrough` and `getFunctionCallCallee`
have been simplified and added in IRHelpers.h (their old versions
have been removed respectively from FCI.h and revng.h)
- `FCI::getCall` and `FCI::isCall` have been removed
due to redundancy with `getFunctionCall`.
This commit fixes a bug that lead to be unable to instantiate from a
`Module` `ProgramCounterHandler`. The reason for this was that
`ProgramCounterHandler` was using `Module::getGlobalVariable` which, by
default, ignores variables with internal linkage.
FunctionIsolation used to base its work on calls to the marker function
`function_call`, as opposed to information provided by the StackAnalysis
(i.e., `revng.member.type` along with `func.call`).
This also affected EnforceABI, which took care of finishing the work
left over by FunctionIsolation. This was hackish and inelegant.
This commit makes FunctionIsolation work exclusively employing
information from StackAnalysis and purges away code that is no longer
necessary from EnforceABI.
EnforceABI promotes global variables representing parts of the CPU
states to arguments and return values of isolated functions.
This commit enables the promotion of CSV that are used in isolated
functions only indirectly, through `ConstantExpr`s casts.
This helper function is now able to replace also uses that are inside
`ConstantExpr`s.
Before this commit they were not substituted correctly, causing problems
down the decompilation pipeline.
Rationale: it is a widespread practice, both in revng and in projects
that depend on it, to write verification functions that check specific
properties hold after different transformations on various data
structures.
Often, these verification function are very useful for debugging and
during development, but they can be very costly and we don't want to
always execute them at runtime.
This patch adds a global public Logger, called VerifyLog, that can be
enabled with the --debug-log=verify command line argument.
This Logger is intended to be used in revng and in projects that depend
on it, as a guard for costly calls to verification functions that do not
need to be performed on a typical execution, but only when debugging.
For now the only user is JumpTargetManager, but other uses are already
envisioned.
AVI and InstCombine are the bottleneck of the lifting process.
This commit introduces a whitelist of jump targets that are considered
by AVI during harvesting.
The whitelist is initialized by the jump targets that are new with
respect to the last run of AVI. Then, it's expanded with all the jump
targets that can reach the initial set of jump targets through direct
jumps.
When translation of code overflows into an unmapped page, we can get a
SIGSEGV. To avoid this, for each set of contiguous pages, we add "guard
page" containing an architecture-specific pattern that ensure basic
block termination.
Unlike the previous iteration of `MetaAddress`, which tried to stuff all
the parts of `MetaAddress` within the existing `PC` CSV, this
implementation adds a set of new CSVs (or marks some existing ones as) to
represent the four portions of the current PC's `MetaAddress`.
* Introduce `ProgramCounterHandler`: a class responsible to maintain the
PC-related CSVs. This class is also used to manipulate the new
dispatcher.
* `AdvancedValueInfo`: update for new MetaAddress.
* External jump handler: do not clobber registers.
When introducing support for dynamic binaries, we didn't realize that
in x86-64 we were clobbering `r11`. To avoid this, we have to jump to
an address stored in memory. However, due to the new `MetaAddress`,
obtaining a *jumpable* address from the PC-related CSVs might require
some computations (and it does in ARM). Therefore, we introduce a new
global variable, `jumpablepc`, whose only role is to contain the
jumpable version of the program counter and then be the target of the
memory-indirect jump instruction.
* Labels care only about absolute addresses.
* CSAA: mark call site, even if no accesses.
Alessandro Di Federico