mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-25 00:29:20 +00:00
LLVM backend for 6502
This is likely only the tip of the ice berg, but this particular bug caused any double-free on a glibc system to turn into a deadlock! It is not generally safe to either allocate or release heap memory from within the signal handler. The 'pop_back()' in RemoveFilesToRemove was deleting memory and causing the deadlock. What's worse, eraseFromDisk in PathV1 has lots of allocation and deallocation paths. We even passed 'true' in a place that would have caused the *signal handler* to try to run the 'system' system call and shell out to 'rm -rf'. That was never going to work... This patch switches the file removal to use a vector of strings so that the exact text needed for the 'unlink' system call can be stored there. It switches the loop to be a boring indexed loop, and directly calls unlink without looking at the error. It also works quite hard to ensure that calling 'c_str()' is safe, by ensuring that the non-signal-handling code path that manipulates the vector always leaves it in a state where every element has already had 'c_str()' called at least once. I dunno exactly how overkill this is, but it fixes the deadlock-on-double free issue, and seems likely to prevent any other issues from sneaking up. Sorry for not having a test case, but I *really* don't know how to test signal handling code easily.... git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158580 91177308-0d34-0410-b5e6-96231b3b80d8 |
||
---|---|---|
autoconf | ||
bindings | ||
cmake | ||
docs | ||
examples | ||
include | ||
lib | ||
projects | ||
runtime | ||
test | ||
tools | ||
unittests | ||
utils | ||
.gitignore | ||
CMakeLists.txt | ||
configure | ||
CREDITS.TXT | ||
LICENSE.TXT | ||
llvm.spec.in | ||
LLVMBuild.txt | ||
Makefile | ||
Makefile.common | ||
Makefile.config.in | ||
Makefile.rules | ||
README.txt |
Low Level Virtual Machine (LLVM) ================================ This directory and its subdirectories contain source code for the Low Level Virtual Machine, a toolkit for the construction of highly optimized compilers, optimizers, and runtime environments. LLVM is open source software. You may freely distribute it under the terms of the license agreement found in LICENSE.txt. Please see the HTML documentation provided in docs/index.html for further assistance with LLVM. If you're writing a package for LLVM, see docs/Packaging.html for our suggestions.