When using `setsid()` in a child process created by `fork()`, a new
session is created, and the child becomes a session leader. If the
parent process terminates before the child, the child becomes an orphan
and is adopted by the `init` process. The `init` process will eventually
clean up the child process once it exits.
However, killing the parent does not automatically kill the child; the
child will continue running until it exits.
Proper cleanup involves waiting for the child process to exit using
`wait()` or `waitpid()` in the parent process to avoid zombie processes,
but this approach is not valid for `EXECUTE_COMMAND_LINE` with async
mode.
Fix: https://github.com/llvm/llvm-project/issues/77803
The FreeMemory function only accepts a void pointer, but it was being
called with a const char pointer, resulting in a type-casting issue.
To address this, the const was removed, use char * instead.
Linux defines WEXITSTATUS in stdlib.h, but at least FreeBSD and NetBSD
only define it in sys/wait.h. Include this header unconditionally, since
it is required on the BSDs and should be harmless on other platforms.
Fixes FreeBSD build after #74077.
This patch add support of intrinsics Fortran 2008 EXECUTE_COMMAND_LINE.
The patch contains both the lowering and the runtime code and works on
both Windows and Linux. The patch contains a list of commits, to convey
the authorship and the history of changes. Some implementation specifics
or status has been added to `flang/docs/Intrinsics.md`.
I have provided a summary of the usage and the options required for the
`EXECUTE_COMMAND_LINE intrinsic`. The intrinsic supports both a
synchronous
(by default) and an asynchronous option.
| System | Mode | Implemention |
|---------|-------|---------------------------|
| Linux | Sync | std::system() |
| Windows | Sync | std::system() |
| Linux | Async | fork() |
| Windows | Async | CreateProcess |
Support for the SYSTEM GNU extension will be added in a separate PR.
Co-authored with @jeffhammond
---------
Signed-off-by: Jeff Hammond <jeff.science@gmail.com>
Co-authored-by: Jeff Hammond <jeff.science@gmail.com>
Co-authored-by: Yi Wu <yiwu02@wdev-yiwu02.arm.com>
