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
Calling checkRegMaskInterference(VirtReg) checks if VirtReg crosses any
regmask operands, regardless of the registers they clobber.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158563 91177308-0d34-0410-b5e6-96231b3b80d8
This patch will optimize abs(x-y)
FROM
sub, movs, rsbmi
TO
subs, rsbmi
For abs, we will use cmp instead of movs. This is necessary because we already
have an existing peephole pass which optimizes away cmp following sub.
rdar: 11633193
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158551 91177308-0d34-0410-b5e6-96231b3b80d8
For non-address users, Base and Scaled registers are not specially
associated to fit an address mode, so SCEVExpander should apply normal
expansion rules. Otherwise we may sink computation into inner loops
that have already been optimized.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158537 91177308-0d34-0410-b5e6-96231b3b80d8
linkonce linkage. For example, it is not valid to add unnamed_addr.
This also fixes a crash in g++.dg/opt/static5.C.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158528 91177308-0d34-0410-b5e6-96231b3b80d8
We only do very limited physreg coalescing now, but we still merge
virtual registers into reserved registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158526 91177308-0d34-0410-b5e6-96231b3b80d8
Patch extracted from a larger one by the PaX team. I added the testcases
and tightened error handling a bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158523 91177308-0d34-0410-b5e6-96231b3b80d8
example degenerate phi nodes and binops that use themselves in unreachable code.
Thanks to Charles Davis for the testcase that uncovered this can of worms.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158508 91177308-0d34-0410-b5e6-96231b3b80d8
to load an immediate that does not fit into 16-bit. Also, take into
consideration the global base register slot on the stack when computing the
stack size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158430 91177308-0d34-0410-b5e6-96231b3b80d8
compute the size of basic blocks in a function. Also, define a function which
emits a series of instructions to load an immediate.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158429 91177308-0d34-0410-b5e6-96231b3b80d8
object for the global base register.
This is the first of a series of patches which implements long branch expansion
for MIPS.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158427 91177308-0d34-0410-b5e6-96231b3b80d8
delay slot filler pass of MIPS, per suggestion of Jakob Stoklund Olesen.
This change, along with the fix in r158154, enables machine verification
to be run after delay slot filling.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158426 91177308-0d34-0410-b5e6-96231b3b80d8
