run-make: arm command wrappers with drop bombs
This PR is one in a series of cleanups to run-make tests and the run-make-support library.
### Summary
It's easy to forget to actually executed constructed command wrappers, e.g. `rustc().input("foo.rs")` but forget the `run()`, so to help catch these mistakes, we arm command wrappers with drop bombs on construction to force them to be executed by test code.
This PR also removes the `Deref`/`DerefMut` impl for our custom `Command` which derefs to `std::process::Command` because it can cause issues when trying to use a custom command:
```rs
htmldocck().arg().run()
```
fails to compile because the `arg()` is resolved to `std::process::Command::arg`, which returns `&mut std::process::Command` that doesn't have a `run()` command.
This PR also:
- Removes `env_var` on the `impl_common_helper` macro that was wrongly named and is a footgun (no users).
- Bumps the run-make-support library to version `0.1.0`.
- Adds a changelog to the support library.
### Details
Especially for command wrappers like `Rustc`, it's very easy to build up
a command invocation but forget to actually execute it, e.g. by using
`run()`. This commit adds "drop bombs" to command wrappers, which are
armed on command wrapper construction, and only defused if the command
is executed (through `run`, `run_fail`).
If the test writer forgets to execute the command, the drop bomb will
"explode" and panic with an error message. This is so that tests don't
silently pass with constructed-but-not-executed command wrappers.
This PR is best reviewed commit-by-commit.
try-job: x86_64-msvc
The run-make test suite contains tests which are the most flexible out of all
the rust-lang/rust test suites. run-make
tests can basically contain arbitrary code, and are supported by the
run_make_support library.
Infrastructure
There are two kinds of run-make tests:
The new rmake.rs version: this allows run-make tests to be written in Rust
(with rmake.rs as the main test file).
The legacy Makefile version: this is what run-make tests were written with
before support for rmake.rs was introduced.
The implementation for collecting and building the rmake.rs recipes (or
Makefiles) are in
src/tools/compiletest/src/runtest.rs,
in run_rmake_v2_test and run_rmake_legacy_test.
Rust-based run-make tests: rmake.rs
The setup for the rmake.rs version is a 3-stage process:
First, we build the run_make_support library in bootstrap as a tool lib.
Then, we compile the rmake.rs "recipe" linking the support library and its
dependencies in, and provide a bunch of env vars. We setup a directory
structure within build/<target>/test/run-make/
<test-name>/
rmake.exe # recipe binary
rmake_out/ # sources from test sources copied over
and copy non-rmake.rs input support files over to rmake_out/. The
support library is made available as an extern prelude.
Finally, we run the recipe binary and set rmake_out/ as the working
directory.
20ba13c38e