We used to accidentaly call `resetCacheMustHit` on the just popped
element of the set, resulting in an out-of-bounds access within the
container.
This bug has been spotted thanks to AddressSanitizer.
Add an additional opaque store the the `pc` after each function call in
the enforced functions. In this way, when the `pc` will be promoted to
an alloca, we won't have an inconsistent state of the IR (the callee
cannot propagate the correct value of pc, the safety check introduced by
the function isolation will always be false, and llvm will place a
`llvm.assume` which will in turn make the rest of the code dead and
purged by an additional `-simplifycfg`).
This commit drops the `--isolate-no-safety-checks` flags since we
adopted a new approach later on in the decompilation pipeline, i.e.,
dropping calls to `raise_exception_helper` and running dead code
elimination.
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.
We used to detect callee-saved registers only by checking if their final
value was identical to the initial one. However, the need for a more
precise heuristic emerged: we now also check if at least on of the stack
slots contains that same value.
This commit fixes a subtle bug that was preventing us from correctly
considering the effects of function calls during ABI analysis.
Specifically, when merging information from the call site to the caller,
in case the caller did not provide any information about a certain
slots, we used the `DefaultMap::Default` field, which is the correct
thing to do, except for the fact that, in two methods, the `Default`
field was being updated to early.
This basically had the effect of not considering arguments of function
calls as used, e.g., in URAOF.
When the `--enforce-no-safety-checks` flag is passed during the
enforcing, we avoid emitting the inlined `function_dispatcher` and we
emit instead a call to an `indirect_handle` disposable call created on
the fly to respect the ABI information on the callsite.
Under certain conditions, we ended up having code in the ABI IR which
was not reachable. This was due to the fact that a certain instruction
was initially detected as an indirect call, triggering inclusion in the
function of the fallthrough code, and then as a return, which has no
successors within the function.
This commit simply prunes the ABI IR in the finalization method.
We recently bumped the GCC version used for the x86-64 toolchain. The
newer version makes slightly different choices of instruction breaking
the names of basic blocks.
This commit drops them, since they are not really necessary: checking
the order is already more than enough.
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.
Fix an out-of-scope issue, where the `_Unwind_Exception` object was used
after the destruction of `raise_exception_helper`'s stackframe.
This issue has been addressed by placing the object into the `.bss`
segment.
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.
Before this commit, the exit status was not really taken care of.
Now the exit status is set to error whenever some of the checks fail,
and to success only if all the checks succeed.
This commit adds two helper functions that run two set of checks:
- `run_clang_format` runs clang format
- `run_revng_checks` runs revng-specific checks
This is a preliminary commit to ease extension of `check-conventions.sh`
so that it can be better integrated with bash scripts and git hooks.
Alessandro Di Federico