hanchenye-llvm-project/llvm/include
Reid Kleckner ada8c398d0 [Support] - Add bad alloc error handler for handling allocation malfunctions
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

llvm-svn: 307673
2017-07-11 16:45:30 +00:00
..
llvm [Support] - Add bad alloc error handler for handling allocation malfunctions 2017-07-11 16:45:30 +00:00
llvm-c [ORC] Errorize the ORC APIs. 2017-07-07 02:59:13 +00:00