# Benefit
This patch fixes:
1. After `platform select ios-simulator`, `platform process list` will
now print processes which are running in the iOS simulator. Previously,
no process will be listed.
2. After `platform select ios-simulator`, `platform attach --name
<name>` will succeed. Previously, it will error out saying no process is
found.
# Several bugs that is being fixed
1. During the process listing, add `aarch64` to the list of CPU types
for which iOS simulators are checked for.
2. Given a candidate process, when checking for simulators, the original
code will find the desired environment variable (`SIMULATOR_UDID`) and
set the OS to iOS, but then the immediate next environment variable will
set it back to macOS.
3. For processes running on simulator, set the triple's `Environment` to
`Simulator`, so that such processes can pass the filtering [in this
line](https://fburl.com/8nivnrjx). The original code leave it as the
default `UnknownEnvironment`.
# Manual test
**With this patch:**
```
royshi-mac-home ~/public_llvm/build % bin/lldb
(lldb) platform select ios-simulator
(lldb) platform process list
240 matching processes were found on "ios-simulator"
PID PARENT USER TRIPLE NAME
====== ====== ========== ============================== ============================
40511 28844 royshi arm64-apple-ios-simulator FocusPlayground // my toy iOS app running on simulator
... // omit
28844 1 royshi arm64-apple-ios-simulator launchd_sim
(lldb) process attach --name FocusPlayground
Process 40511 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGSTOP
frame #0: 0x0000000104e3cb70 libsystem_kernel.dylib`mach_msg2_trap + 8
libsystem_kernel.dylib`mach_msg2_trap:
-> 0x104e3cb70 <+8>: ret
... // omit
```
**Without this patch:**
```
$ bin/lldb
(lldb) platform select ios-simulator
(lldb) platform process list
error: no processes were found on the "ios-simulator" platform
(lldb) process attach --name FocusPlayground
error: attach failed: could not find a process named FocusPlayground
```
# Unittest
See PR.
f63bc84b0d