Auto merge of #122036 - alexcrichton:test-wasm-with-wasi, r=oli-obk

Test wasm32-wasip1 in CI, not wasm32-unknown-unknown

This commit changes CI to no longer test the `wasm32-unknown-unknown` target and instead test the `wasm32-wasip1` target. There was some discussion of this in a [Zulip thread], and the motivations for this PR are:

* Runtime failures on `wasm32-unknown-unknown` print nothing, meaning all you get is "something failed". In contrast `wasm32-wasip1` can print to stdout/stderr.

* The unknown-unknown target is missing lots of pieces of libstd, and while `wasm32-wasip1` is also missing some pieces (e.g. threads) it's missing fewer pieces. This means that many more tests can be run.

Overall my hope is to improve the debuggability of wasm failures on CI and ideally be a bit less of a maintenance burden.

This commit specifically removes the testing of `wasm32-unknown-unknown` and replaces it with testing of `wasm32-wasip1`. Along the way there were a number of other archiectural changes made as well, including:

* A new `target.*.runtool` option can now be specified in `config.toml` which is passed as `--runtool` to `compiletest`. This is used to reimplement execution of WebAssembly in a less-wasm-specific fashion.

* The default value for `runtool` is an ambiently located WebAssembly runtime found on the system, if any. I've implemented logic for Wasmtime.

* Existing testing support for `wasm32-unknown-unknown` and Emscripten has been removed. I'm not aware of Emscripten testing being run any time recently and otherwise `wasm32-wasip1` is in theory the focus now.

* I've added a new `//@ needs-threads` directive for `compiletest` and classified a bunch of wasm-ignored tests as needing threads. In theory these tests can run on `wasm32-wasi-preview1-threads`, for example.

* I've tried to audit all existing tests that are either `ignore-emscripten` or `ignore-wasm*`. Many now run on `wasm32-wasip1` due to being able to emit error messages, for example. Many are updated with comments as to why they can't run as well.

* The `compiletest` output matching for `wasm32-wasip1` automatically uses "match a subset" mode implemented in `compiletest`. This is because WebAssembly runtimes often add extra information on failure, such as the `unreachable` instruction in `panic!`, which isn't able to be matched against the golden output from native platforms.

* I've ported most existing `run-make` tests that use custom Node.js wrapper scripts to the new run-make-based-in-Rust infrastructure. To do this I added `wasmparser` as a dependency of `run-make-support` for the various wasm tests to use that parse wasm files. The one test that executed WebAssembly now uses `wasmtime`-the-CLI to execute the test instead. I have not ported over an exception-handling test as Wasmtime doesn't implement this yet.

* I've updated the `test` crate to print out timing information for WASI targets as it can do that (gets a previously ignored test now passing).

* The `test-various` image now builds a WASI sysroot for the WASI target and additionally downloads a fixed release of Wasmtime, currently the latest one at 18.0.2, and uses that for testing.

[Zulip thread]: https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/Have.20wasm.20tests.20ever.20caused.20problems.20on.20CI.3F/near/424317944

3 files changed, 34 insertions, 82 deletions

diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index 9fd83c507ed..7be0571b111 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -493,12 +493,8 @@ impl<'test> TestCx<'test> {
         let expected_coverage_dump = self.load_expected_output(kind);
         let actual_coverage_dump = self.normalize_output(&proc_res.stdout, &[]);
 
-        let coverage_dump_errors = self.compare_output(
-            kind,
-            &actual_coverage_dump,
-            &expected_coverage_dump,
-            self.props.compare_output_lines_by_subset,
-        );
+        let coverage_dump_errors =
+            self.compare_output(kind, &actual_coverage_dump, &expected_coverage_dump);
 
         if coverage_dump_errors > 0 {
             self.fatal_proc_rec(
@@ -591,12 +587,8 @@ impl<'test> TestCx<'test> {
                 self.fatal_proc_rec(&err, &proc_res);
             });
 
-        let coverage_errors = self.compare_output(
-            kind,
-            &normalized_actual_coverage,
-            &expected_coverage,
-            self.props.compare_output_lines_by_subset,
-        );
+        let coverage_errors =
+            self.compare_output(kind, &normalized_actual_coverage, &expected_coverage);
 
         if coverage_errors > 0 {
             self.fatal_proc_rec(
@@ -2632,9 +2624,7 @@ impl<'test> TestCx<'test> {
         // double the length.
         let mut f = self.output_base_dir().join("a");
         // FIXME: This is using the host architecture exe suffix, not target!
-        if self.config.target.contains("emscripten") {
-            f = f.with_extra_extension("js");
-        } else if self.config.target.contains("wasm32") {
+        if self.config.target.starts_with("wasm") {
             f = f.with_extra_extension("wasm");
         } else if self.config.target.contains("spirv") {
             f = f.with_extra_extension("spv");
@@ -2649,32 +2639,6 @@ impl<'test> TestCx<'test> {
         // then split apart its command
         let mut args = self.split_maybe_args(&self.config.runner);
 
-        // If this is emscripten, then run tests under nodejs
-        if self.config.target.contains("emscripten") {
-            if let Some(ref p) = self.config.nodejs {
-                args.push(p.into());
-            } else {
-                self.fatal("emscripten target requested and no NodeJS binary found (--nodejs)");
-            }
-        // If this is otherwise wasm, then run tests under nodejs with our
-        // shim
-        } else if self.config.target.contains("wasm32") {
-            if let Some(ref p) = self.config.nodejs {
-                args.push(p.into());
-            } else {
-                self.fatal("wasm32 target requested and no NodeJS binary found (--nodejs)");
-            }
-
-            let src = self
-                .config
-                .src_base
-                .parent()
-                .unwrap() // chop off `ui`
-                .parent()
-                .unwrap(); // chop off `tests`
-            args.push(src.join("src/etc/wasm32-shim.js").into_os_string());
-        }
-
         let exe_file = self.make_exe_name();
 
         args.push(exe_file.into_os_string());
@@ -4079,35 +4043,17 @@ impl<'test> TestCx<'test> {
         match output_kind {
             TestOutput::Compile => {
                 if !self.props.dont_check_compiler_stdout {
-                    errors += self.compare_output(
-                        stdout_kind,
-                        &normalized_stdout,
-                        &expected_stdout,
-                        self.props.compare_output_lines_by_subset,
-                    );
+                    errors +=
+                        self.compare_output(stdout_kind, &normalized_stdout, &expected_stdout);
                 }
                 if !self.props.dont_check_compiler_stderr {
-                    errors += self.compare_output(
-                        stderr_kind,
-                        &normalized_stderr,
-                        &expected_stderr,
-                        self.props.compare_output_lines_by_subset,
-                    );
+                    errors +=
+                        self.compare_output(stderr_kind, &normalized_stderr, &expected_stderr);
                 }
             }
             TestOutput::Run => {
-                errors += self.compare_output(
-                    stdout_kind,
-                    &normalized_stdout,
-                    &expected_stdout,
-                    self.props.compare_output_lines_by_subset,
-                );
-                errors += self.compare_output(
-                    stderr_kind,
-                    &normalized_stderr,
-                    &expected_stderr,
-                    self.props.compare_output_lines_by_subset,
-                );
+                errors += self.compare_output(stdout_kind, &normalized_stdout, &expected_stdout);
+                errors += self.compare_output(stderr_kind, &normalized_stderr, &expected_stderr);
             }
         }
         errors
@@ -4201,12 +4147,7 @@ impl<'test> TestCx<'test> {
                 )
             });
 
-            errors += self.compare_output(
-                "fixed",
-                &fixed_code,
-                &expected_fixed,
-                self.props.compare_output_lines_by_subset,
-            );
+            errors += self.compare_output("fixed", &fixed_code, &expected_fixed);
         } else if !expected_fixed.is_empty() {
             panic!(
                 "the `//@ run-rustfix` directive wasn't found but a `*.fixed` \
@@ -4701,17 +4642,19 @@ impl<'test> TestCx<'test> {
         }
     }
 
-    fn compare_output(
-        &self,
-        kind: &str,
-        actual: &str,
-        expected: &str,
-        compare_output_by_lines: bool,
-    ) -> usize {
+    fn compare_output(&self, kind: &str, actual: &str, expected: &str) -> usize {
         if actual == expected {
             return 0;
         }
 
+        // If `compare-output-lines-by-subset` is not explicitly enabled then
+        // auto-enable it when a `runner` is in use since wrapper tools might
+        // provide extra output on failure, for example a WebAssembly runtime
+        // might print the stack trace of an `unreachable` instruction by
+        // default.
+        let compare_output_by_lines =
+            self.props.compare_output_lines_by_subset || self.config.runner.is_some();
+
         let tmp;
         let (expected, actual): (&str, &str) = if compare_output_by_lines {
             let actual_lines: HashSet<_> = actual.lines().collect();
diff --git a/src/tools/run-make-support/Cargo.toml b/src/tools/run-make-support/Cargo.toml
index 178deae6499..958aef69572 100644
--- a/src/tools/run-make-support/Cargo.toml
+++ b/src/tools/run-make-support/Cargo.toml
@@ -4,3 +4,4 @@ version = "0.0.0"
 edition = "2021"
 
 [dependencies]
+wasmparser = "0.118.2"
diff --git a/src/tools/run-make-support/src/lib.rs b/src/tools/run-make-support/src/lib.rs
index 820218732ce..674860f8413 100644
--- a/src/tools/run-make-support/src/lib.rs
+++ b/src/tools/run-make-support/src/lib.rs
@@ -2,13 +2,16 @@ use std::env;
 use std::path::{Path, PathBuf};
 use std::process::{Command, Output};
 
+pub use wasmparser;
+
+pub fn out_dir() -> PathBuf {
+    env::var_os("TMPDIR").unwrap().into()
+}
+
 fn setup_common_build_cmd() -> Command {
     let rustc = env::var("RUSTC").unwrap();
     let mut cmd = Command::new(rustc);
-    cmd.arg("--out-dir")
-        .arg(env::var("TMPDIR").unwrap())
-        .arg("-L")
-        .arg(env::var("TMPDIR").unwrap());
+    cmd.arg("--out-dir").arg(out_dir()).arg("-L").arg(out_dir());
     cmd
 }
 
@@ -45,6 +48,11 @@ impl RustcInvocationBuilder {
         self
     }
 
+    pub fn args(&mut self, args: &[&str]) -> &mut RustcInvocationBuilder {
+        self.cmd.args(args);
+        self
+    }
+
     #[track_caller]
     pub fn run(&mut self) -> Output {
         let caller_location = std::panic::Location::caller();