Summary:
Patch by Klaus Kretzschmar
We would like to introduce a new type of llvm error handler for handling
bad alloc fault situations. LLVM already provides a fatal error handler
for serious non-recoverable error situations which by default writes
some error information to stderr and calls exit(1) at the end (functions
are marked as 'noreturn').
For long running processes (e.g. a server application), exiting the
process is not an acceptable option, especially not when the system is
in a temporary resource bottleneck with a good chance to recover from
this fault situation. In such a situation you would rather throw an
exception to stop the current compilation and try to overcome the
resource bottleneck. The user should be aware of the problem of throwing
an exception in bad alloc situations, e.g. you must not do any
allocations in the unwind chain. This is especially true when adding
exceptions in existing unfamiliar code (as already stated in the comment
of the current fatal error handler)
So the new handler can also be used to distinguish from general fatal
error situations where recovering is no option. It should be used in
cases where a clean unwind after the allocation is guaranteed.
This patch contains:
- A report_bad_alloc function which calls a user defined bad alloc
error handler. If no user handler is registered the
report_fatal_error function is called. This function is not marked as
'noreturn'.
- A install/restore_bad_alloc_error_handler to install/restore the bad
alloc handler.
- An example (in Mutex.cpp) where the report_bad_alloc function is
called in case of a malloc returns a nullptr.
If this patch gets accepted we would create similar patches to fix
corresponding malloc/calloc usages in the llvm code.
Reviewers: chandlerc, greened, baldrick, rnk
Reviewed By: rnk
Subscribers: llvm-commits, MatzeB
Differential Revision: https://reviews.llvm.org/D34753
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307673 91177308-0d34-0410-b5e6-96231b3b80d8
The patch is generated using this command:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/
Thanks to Eugene Kosov for the original patch!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240137 91177308-0d34-0410-b5e6-96231b3b80d8
Prior to this change, error handling functions must be installed
and removed only inside of an llvm_[start/stop]_multithreading
pair. This change allows error handling functions to be installed
any time, and from any thread.
Reviewed by: chandlerc
Differential Revision: http://reviews.llvm.org/D4140
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210937 91177308-0d34-0410-b5e6-96231b3b80d8
There are a couple of interesting things here that we want to check over
(particularly the expecting asserts in StringRef) and get right for general use
in ADT so hold back on this one. For clang we have a workable templated
solution to use in the meanwhile.
This reverts commit r200187.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200194 91177308-0d34-0410-b5e6-96231b3b80d8
(1) Add llvm_expect(), an asserting macro that can be evaluated as a constexpr
expression as well as a runtime assert or compiler hint in release builds. This
technique can be used to construct functions that are both unevaluated and
compiled depending on usage.
(2) Update StringRef using llvm_expect() to preserve runtime assertions while
extending the same checks to static asserts in C++11 builds that support the
feature.
(3) Introduce ConstStringRef, a strong subclass of StringRef that references
compile-time constant strings. It's convertible to, but not from, ordinary
StringRef and thus can be used to add compile-time safety to various interfaces
in LLVM and clang that only accept fixed inputs such as diagnostic format
strings that tend to get misused.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200187 91177308-0d34-0410-b5e6-96231b3b80d8
AKA: Recompile *ALL* the source code!
This one went much better. No manual edits here. I spot-checked for
silliness and grep-checked for really broken edits and everything seemed
good. It all still compiles. Yell if you see something that looks goofy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169133 91177308-0d34-0410-b5e6-96231b3b80d8
doesn't return, so just go back to using the old runtime function instead
of trying to use abort() when __builtin_unreachable (or an equivalent) isn't
supported.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127629 91177308-0d34-0410-b5e6-96231b3b80d8
This adds location info for all llvm_unreachable calls (which is a macro now) in
!NDEBUG builds.
In NDEBUG builds location info and the message is off (it only prints
"UREACHABLE executed").
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75640 91177308-0d34-0410-b5e6-96231b3b80d8
Make llvm_unreachable take an optional string, thus moving the cerr<< out of
line.
LLVM_UNREACHABLE is now a simple wrapper that makes the message go away for
NDEBUG builds.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75379 91177308-0d34-0410-b5e6-96231b3b80d8
This will replace exit()/abort() style error handling with an API
that allows clients to register custom error handling hooks.
The default is to call exit(1) when no error handler is provided.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74922 91177308-0d34-0410-b5e6-96231b3b80d8
