Added a TaskSignalledCallback to TaskQueue, which will be called instead of
TaskFinishedCallback if the task exited abnormally.
In Unix/TaskQueue.inc, check WIFSIGNALED if the task did not pass WIFEXITED,
and call the TaskSignalledCallback if necessary. In Default/TaskQueue.inc, check
for a return code of -2; if present, call the TaskSignalledCallback instead of
the TaskFinishedCallback.
Updated Compilation to pass a TaskSignalledCallback.
Added diagnostics to indicate when a command signalled as well as when a command
failed with either poor diagnostics or a non-1 exit code. (These match Clang’s
diagnostics.) Added tests to ensure these diagnostics are emitted when the
frontend crashes or fails an assertion (if assertions are available).
This fixes <rdar://problem/16012199>.
Swift SVN r13654
For the Unix implementation, this returns NumberOfParallelTasks (unless that value is 0, in which case it returns the default value of 1).
For the Default implementation, this always returns 1, since it does not support parallelism.
Swift SVN r12348
Due to the nature of this class, there are two implementations of TaskQueue:
a Unix-specific implementation which supports both parallel execution and output
buffering, and a default implementation which supports neither of these features.
(The default implementation uses the functions from llvm/Support/Program.h for execution.)
TaskQueue allows clients to provide a TaskBeganCallback and a TaskFinishedCallback,
each of which will be called when a new task begins or when a task finishes execution,
respectively. Clients may add tasks to the TaskQueue in either of these callbacks,
and clients can stop further execution by returning TaskFinishedResponse::StopExecution
from the TaskFinishedCallback.
Swift SVN r12059
