Rollup merge of rust-lang#155630 - Zalathar:skip-filecheck, r=jieyouxu

Make `//@ skip-filecheck` a normal compiletest directive

The `skip-filecheck` directive is currently used by mir-opt tests, to suppress the default behaviour of running LLVM's `FileCheck` tool to check MIR output against FileCheck rules in the test file.

The `skip-filecheck` directive was not included in the big migration to `//@` directive syntax (rust-lang#121370), perhaps because it was parsed and processed in the *miropt-test-tools* helper crate, not in compiletest itself.

Recently I noticed that a small number of *codegen-llvm* tests were using the `//@ build-pass` directive, which has the non-obvious effect of skipping FileCheck in codegen tests. That's quite confusing, so I decided to have the mir-opt tests migrate over to a proper `//@ skip-filecheck` directive, which could then be used by codegen tests as well.

(I also added skip-filecheck support to assembly tests, which are very similar to codegen tests, though there are currently no assembly tests that actually use `//@ skip-filecheck`.)

---

Support for using `//@ build-pass` in codegen tests to skip FileCheck was introduced in rust-lang#113603. With hindsight, I think doing things that way was pretty clearly a  mistake, and we'll be better off with `//@ skip-filecheck`.

r? jieyouxu

Author: JonathanBrouwer

src/doc/rustc-dev-guide/src/tests/directives.md

@@ -195,6 +195,9 @@ pub(crate) struct TestProps {
     /// Extra flags to pass to `llvm-cov` when producing coverage reports.
     /// Only used by the "coverage-run" test mode.
     pub(crate) llvm_cov_flags: Vec<String>,
+    /// Don't run LLVM's `filecheck` tool to check compiler output,
+    /// in tests that would normally run it.
+    pub(crate) skip_filecheck: bool,
     /// Extra flags to pass to LLVM's `filecheck` tool, in tests that use it.
     pub(crate) filecheck_flags: Vec<String>,
     /// Don't automatically insert any `--check-cfg` args
@@ -308,6 +311,7 @@ impl TestProps {
             mir_unit_test: None,
             remap_src_base: false,
             llvm_cov_flags: vec![],
+            skip_filecheck: false,
             filecheck_flags: vec![],
             no_auto_check_cfg: false,
             add_minicore: false,
@@ -438,7 +442,6 @@ impl TestProps {
         let check_no_run = |s| match (config.mode, s) {
             (TestMode::Ui, _) => (),
             (TestMode::Crashes, _) => (),
-            (TestMode::Codegen, "build-pass") => (),
             (mode, _) => panic!("`{s}` directive is not supported in `{mode}` tests"),
         };
         let pass_mode = if config.parse_name_directive(ln, "check-pass") {

src/tools/compiletest/src/directives.rs

@@ -286,6 +286,7 @@ pub(crate) const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     "rustc-env",
     "rustfix-only-machine-applicable",
     "should-fail",
+    "skip-filecheck",
     "stderr-per-bitwidth",
     "test-mir-pass",
     "unique-doc-out-dir",

src/tools/compiletest/src/directives/directive_names.rs

@@ -1,7 +1,7 @@
 use std::collections::HashMap;
 use std::sync::{Arc, LazyLock};
 
-use crate::common::Config;
+use crate::common::{Config, TestMode};
 use crate::directives::{
     DirectiveLine, NormalizeKind, NormalizeRule, TestProps, parse_and_update_aux,
     parse_edition_range, split_flags,
@@ -312,6 +312,18 @@ fn make_directive_handlers_map() -> HashMap<&'static str, Handler> {
                 props.llvm_cov_flags.extend(split_flags(&flags));
             }
         }),
+        handler("skip-filecheck", |config, ln, props| {
+            let directive_name = ln.name;
+            // FIXME(Zalathar): Someday we should add unified support for declaring
+            // and checking which modes are supported by each directive.
+            if !matches!(config.mode, TestMode::Assembly | TestMode::Codegen | TestMode::MirOpt) {
+                panic!(
+                    "directive `//@ {directive_name}` is not supported by this test suite (mode: {mode:?})",
+                    mode = config.mode
+                );
+            }
+            config.set_name_directive(ln, directive_name, &mut props.skip_filecheck);
+        }),
         handler(FILECHECK_FLAGS, |config, ln, props| {
             if let Some(flags) = config.parse_name_value_directive(ln, FILECHECK_FLAGS) {
                 props.filecheck_flags.extend(split_flags(&flags));

src/tools/compiletest/src/directives/handlers.rs

@@ -13,9 +13,11 @@ impl TestCx<'_> {
             self.fatal_proc_rec("compilation failed!", &proc_res);
         }
 
-        let proc_res = self.verify_with_filecheck(&output_path);
-        if !proc_res.status.success() {
-            self.fatal_proc_rec("verification with 'FileCheck' failed", &proc_res);
+        if !self.props.skip_filecheck {
+            let proc_res = self.verify_with_filecheck(&output_path);
+            if !proc_res.status.success() {
+                self.fatal_proc_rec("verification with 'FileCheck' failed", &proc_res);
+            }
         }
     }
 

src/tools/compiletest/src/runtest/assembly.rs

@@ -1,4 +1,4 @@
-use super::{PassMode, TestCx};
+use super::TestCx;
 
 impl TestCx<'_> {
     pub(super) fn run_codegen_test(&self) {
@@ -11,12 +11,11 @@ impl TestCx<'_> {
             self.fatal_proc_rec("compilation failed!", &proc_res);
         }
 
-        if let Some(PassMode::Build) = self.pass_mode() {
-            return;
-        }
-        let proc_res = self.verify_with_filecheck(&output_path);
-        if !proc_res.status.success() {
-            self.fatal_proc_rec("verification with 'FileCheck' failed", &proc_res);
+        if !self.props.skip_filecheck {
+            let proc_res = self.verify_with_filecheck(&output_path);
+            if !proc_res.status.success() {
+                self.fatal_proc_rec("verification with 'FileCheck' failed", &proc_res);
+            }
         }
     }
 }

src/tools/compiletest/src/runtest/codegen.rs

@@ -40,7 +40,7 @@ impl TestCx<'_> {
         let test_dir = self.testpaths.file.parent().unwrap();
         let test_crate = self.testpaths.file.file_stem().unwrap().replace('-', "_");
 
-        let MiroptTest { run_filecheck, suffix, files, passes: _ } = test_info;
+        let MiroptTest { suffix, files, passes: _ } = test_info;
 
         if self.config.bless {
             for e in glob(&format!("{}/{}.*{}.mir", test_dir, test_crate, suffix)).unwrap() {
@@ -89,7 +89,7 @@ impl TestCx<'_> {
             }
         }
 
-        if run_filecheck {
+        if !self.props.skip_filecheck {
             let output_path = self.output_base_name().with_extension("mir");
             let proc_res = self.verify_with_filecheck(&output_path);
             if !proc_res.status.success() {

src/tools/compiletest/src/runtest/mir_opt.rs

@@ -8,7 +8,6 @@ pub struct MiroptTestFile {
 }
 
 pub struct MiroptTest {
-    pub run_filecheck: bool,
     pub suffix: String,
     pub files: Vec<MiroptTestFile>,
     /// Vec of passes under test to be dumped
@@ -57,13 +56,15 @@ pub fn files_for_miropt_test(
     let test_crate = testfile.file_stem().unwrap().to_str().unwrap().replace('-', "_");
 
     let suffix = output_file_suffix(testfile, bit_width, panic_strategy);
-    let mut run_filecheck = true;
     let mut passes = Vec::new();
 
     for l in test_file_contents.lines() {
+        // FIXME(Zalathar): Remove this `skip-filecheck` migration error in 2027,
+        // or perhaps earlier if it seems no longer useful.
         if l.starts_with("// skip-filecheck") {
-            run_filecheck = false;
-            continue;
+            panic!(
+                "error: `// skip-filecheck` is no longer supported, use `//@ skip-filecheck` instead."
+            );
         }
         if l.starts_with("// EMIT_MIR ") {
             let test_name = l.trim_start_matches("// EMIT_MIR ").trim();
@@ -128,10 +129,7 @@ pub fn files_for_miropt_test(
 
             out.push(MiroptTestFile { expected_file, from_file, to_file });
         }
-        if !run_filecheck && l.trim_start().starts_with("// CHECK") {
-            panic!("error: test contains filecheck directive but is marked `skip-filecheck`");
-        }
     }
 
-    MiroptTest { run_filecheck, suffix, files: out, passes }
+    MiroptTest { suffix, files: out, passes }
 }

src/tools/miropt-test-tools/src/lib.rs

@@ -1,4 +1,5 @@
-//@ build-pass
+// FIXME: The FileCheck directives in this test are unchecked and probably broken.
+//@ skip-filecheck
 //@ only-aarch64
 #![crate_type = "lib"]
 #![allow(incomplete_features, internal_features)]

tests/codegen-llvm/scalable-vectors/tuple-intrinsics.rs

@@ -3,7 +3,7 @@
 //@ edition: 2021
 //@ only-x86_64
 //@ [mir-opt3]compile-flags: -Zmir-opt-level=3
-//@ [mir-opt3]build-pass
+//@ [mir-opt3] skip-filecheck
 
 // mir-opt3 is a regression test for https://github.com/rust-lang/rust/issues/98016