mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-13 04:30:23 +00:00
0556900b26
This occurs due to an alloca representing a separate ownership from the
original pointer. Thus consider the following pseudo-IR:
objc_retain(%a)
for (...) {
objc_retain(%a)
%block <- %a
F(%block)
objc_release(%block)
}
objc_release(%a)
From the perspective of the optimizer, the %block is a separate
provenance from the original %a. Thus the optimizer pairs up the inner
retain for %a and the outer release from %a, resulting in segfaults.
This is fixed by noting that the signature of a mismatch of
retain/releases inside the for loop is a Use/CanRelease top down with an
None bottom up (since bottom up the Retain-CanRelease-Use-Release
sequence is completed by the inner objc_retain, but top down due to the
differing provenance from the objc_release said sequence is not
completed). In said case in CheckForCFGHazards, we now clear the state
of %a implying that no pairing will occur.
Additionally a test case is included.
rdar://12969722
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179747 91177308-0d34-0410-b5e6-96231b3b80d8
|
||
|---|---|---|
| .. | ||
| Analysis | ||
| Archive | ||
| Assembler | ||
| Bindings/Ocaml | ||
| Bitcode | ||
| BugPoint | ||
| CodeGen | ||
| DebugInfo | ||
| ExecutionEngine | ||
| Feature | ||
| FileCheck | ||
| Instrumentation | ||
| Integer | ||
| JitListener | ||
| Linker | ||
| MC | ||
| Object | ||
| Other | ||
| TableGen | ||
| tools | ||
| Transforms | ||
| Unit | ||
| Verifier | ||
| YAMLParser | ||
| CMakeLists.txt | ||
| lit.cfg | ||
| lit.site.cfg.in | ||
| Makefile | ||
| Makefile.tests | ||
| TestRunner.sh | ||