Describe the bug
In hhvm 4.27, forgetting to use the $$ variable on the RHS of a |> operator, would be a typechecker error.
Naming[2069] This expression does not contain a usage of the special pipe variable. Did you forget to use the ($$) variable?
Hhvm 4.28 and above do not report an error for this code.
Standalone code, or other way to reproduce the problem
function main(): void {
$x = 0 |> \intval(0);
// or
$x = 0 |> 0;
}Steps to reproduce the behavior:
- Create an empty hack project
- Copy the example shown above to a src file.
- Run hh_client under hhvm 4.27, observe two typechecker errors.
- Run hh_client under hhvm 4.28, observe zero typechecker errors.
Expected behavior
The typechecker behavior of 4.27 is preferable.
Terminal output
$ docker run --tty --interactive -v /path/to/code:/mnt/code hhvm/hhvm:4.27.0 /bin/bash -l
root@bce64dc9fdce:/# cd /mnt/code/
root@bce64dc9fdce:/mnt/code# hh_client
For more detailed logs, try `tail -f $(hh_client --monitor-logname) $(hh_client --logname)`
Server launched with the following command:
'/opt/hhvm/4.27.0/bin/hh_server' '-d' '/mnt/code' '--waiting-client' '6'
Spawned typechecker (child pid=20)
Logs will go to /tmp/hh_server/monitor_logs/zSmntzScode-2020-05-13-21-05-39.monitor_log
Naming[2069] This expression does not contain a usage of the special pipe variable. Did you forget to use the ($$) variable?
--> src/main.hack
2 | $x = 0 |> \intval(0);
| ^^^^^^^^^^
Naming[2069] This expression does not contain a usage of the special pipe variable. Did you forget to use the ($$) variable?
--> src/main.hack
4 | $x = 0 |> 0;
| ^
2 errors found.
root@bce64dc9fdce:/mnt/code# exit
logout
$ docker run --tty --interactive -v /path/to/code:/mnt/code hhvm/hhvm:4.28.0 /bin/bash -l
root@d532c47e7f03:/# cd /mnt/code/
root@d532c47e7f03:/mnt/code# hh_client
For more detailed logs, try `tail -f $(hh_client --monitor-logname) $(hh_client --logname)`
Server launched with the following command:
'/opt/hhvm/4.28.0/bin/hh_server' '-d' '/mnt/code' '--waiting-client' '6'
Spawned typechecker (child pid=22)
Logs will go to /tmp/hh_server/monitor_logs/zSmntzScode-2020-05-13-21-05-59.monitor_log
No errors!
root@d532c47e7f03:/mnt/code# exit
logout
Desktop (please complete the following information):
- OS: Ubuntu 18.04 with docker
- HHVM Version: 4.27.0 |> 4.28.0+
hackc-f89bc3b7246753b2cdea6205005e1d49038d68f4-4.27.0
HipHop VM 4.27.0 (rel)
Compiler: 1571072038_021874391
Repo schema: 8bb24baf4d626dbff09412d248269b46ebf11e93
Additional context
Add any other context about the problem here.
Between hhvm 4.27 and 4.28, there is one commit that mentions the pipe variable, which I believe may be the cause of this change:
commit f1e5724
Author: Andrew Kennedy akenn@fb.com
Date: Wed Oct 16 05:02:42 2019 -0700
Analyse scope of pipe variable in typing, not naming
Summary:
The naming phase now does very little scope analysis, using the integer first component of a `Local_id.t` only for (a) the experimental let-bound variables, and (b) pipe variables `$$`.
But these latter variables also don't need the integer: it's easy to scope them properly during typing, with the expression `e1 |> e2` typed by adding `$$` of type `t` (where `t` is the type of `e1`) to the environment when typing `e2`, and then restoring `$$` (or unsetting it) to its original state.
We also need to remove the variable under a lambda, as this is not supported by HackC.
Reviewed By: CatherineGasnier
Differential Revision: D17880302
fbshipit-source-id: 2e28d3909e339e52dbc5a094c16d185489857138
Describe the bug
In hhvm 4.27, forgetting to use the
$$variable on the RHS of a|>operator, would be a typechecker error.Naming[2069] This expression does not contain a usage of the special pipe variable. Did you forget to use the ($$) variable?
Hhvm 4.28 and above do not report an error for this code.
Standalone code, or other way to reproduce the problem
Steps to reproduce the behavior:
Expected behavior
The typechecker behavior of 4.27 is preferable.
Terminal output
Desktop (please complete the following information):
Additional context
Add any other context about the problem here.
Between hhvm 4.27 and 4.28, there is one commit that mentions the pipe variable, which I believe may be the cause of this change:
commit f1e5724
Author: Andrew Kennedy akenn@fb.com
Date: Wed Oct 16 05:02:42 2019 -0700