Rollup merge of rust-lang#137074 - jieyouxu:rustc_abi, r=onur-ozkan

compiletest: add `{ignore,only}-rustc_abi-x86-sse2` directives

As requested in https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/compiletest.20target.20selection.20is.20way.20too.20rigid, cc `@RalfJung`

r? bootstrap (or compiler)

Author: matthiaskrgr

Diff for: src/doc/rustc-dev-guide/src/tests/directives.md

@@ -154,6 +154,7 @@ Some examples of `X` in `ignore-X` or `only-X`:
   `ignore-coverage-map`, `ignore-coverage-run`
 - When testing a dist toolchain: `dist`
   - This needs to be enabled with `COMPILETEST_ENABLE_DIST_TESTS=1`
+- The `rustc_abi` of the target: e.g. `rustc_abi-x86_64-sse2`
 
 The following directives will check rustc build settings and target
 settings:

Diff for: src/tools/compiletest/src/common.rs

@@ -517,6 +517,7 @@ pub struct TargetCfgs {
     pub all_abis: HashSet<String>,
     pub all_families: HashSet<String>,
     pub all_pointer_widths: HashSet<String>,
+    pub all_rustc_abis: HashSet<String>,
 }
 
 impl TargetCfgs {
@@ -536,6 +537,9 @@ impl TargetCfgs {
         let mut all_abis = HashSet::new();
         let mut all_families = HashSet::new();
         let mut all_pointer_widths = HashSet::new();
+        // NOTE: for distinction between `abi` and `rustc_abi`, see comment on
+        // `TargetCfg::rustc_abi`.
+        let mut all_rustc_abis = HashSet::new();
 
         // If current target is not included in the `--print=all-target-specs-json` output,
         // we check whether it is a custom target from the user or a synthetic target from bootstrap.
@@ -576,7 +580,9 @@ impl TargetCfgs {
                 all_families.insert(family.clone());
             }
             all_pointer_widths.insert(format!("{}bit", cfg.pointer_width));
-
+            if let Some(rustc_abi) = &cfg.rustc_abi {
+                all_rustc_abis.insert(rustc_abi.clone());
+            }
             all_targets.insert(target.clone());
         }
 
@@ -590,6 +596,7 @@ impl TargetCfgs {
             all_abis,
             all_families,
             all_pointer_widths,
+            all_rustc_abis,
         }
     }
 
@@ -676,6 +683,10 @@ pub struct TargetCfg {
     pub(crate) xray: bool,
     #[serde(default = "default_reloc_model")]
     pub(crate) relocation_model: String,
+    // NOTE: `rustc_abi` should not be confused with `abi`. `rustc_abi` was introduced in #137037 to
+    // make SSE2 *required* by the ABI (kind of a hack to make a target feature *required* via the
+    // target spec).
+    pub(crate) rustc_abi: Option<String>,
 
     // Not present in target cfg json output, additional derived information.
     #[serde(skip)]

Diff for: src/tools/compiletest/src/directive-list.rs

@@ -87,6 +87,7 @@ const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     "ignore-remote",
     "ignore-riscv64",
     "ignore-rustc-debug-assertions",
+    "ignore-rustc_abi-x86-sse2",
     "ignore-s390x",
     "ignore-sgx",
     "ignore-sparc64",
@@ -198,6 +199,7 @@ const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     "only-nvptx64",
     "only-powerpc",
     "only-riscv64",
+    "only-rustc_abi-x86-sse2",
     "only-s390x",
     "only-sparc",
     "only-sparc64",

Diff for: src/tools/compiletest/src/header/cfg.rs

@@ -234,6 +234,14 @@ fn parse_cfg_name_directive<'a>(
         allowed_names: ["coverage-map", "coverage-run"],
         message: "when the test mode is {name}",
     }
+    condition! {
+        name: target_cfg.rustc_abi.as_ref().map(|abi| format!("rustc_abi-{abi}")).unwrap_or_default(),
+        allowed_names: ContainsPrefixed {
+            prefix: "rustc_abi-",
+            inner: target_cfgs.all_rustc_abis.clone(),
+        },
+        message: "when the target `rustc_abi` is {name}",
+    }
 
     condition! {
         name: "dist",

Diff for: src/tools/compiletest/src/header/tests.rs

@@ -889,3 +889,17 @@ fn test_needs_target_has_atomic() {
     assert!(!check_ignore(&config, "//@ needs-target-has-atomic: 8, ptr"));
     assert!(check_ignore(&config, "//@ needs-target-has-atomic: 8, ptr, 128"));
 }
+
+#[test]
+// FIXME: this test will fail against stage 0 until #137037 changes reach beta.
+#[cfg_attr(bootstrap, ignore)]
+fn test_rustc_abi() {
+    let config = cfg().target("i686-unknown-linux-gnu").build();
+    assert_eq!(config.target_cfg().rustc_abi, Some("x86-sse2".to_string()));
+    assert!(check_ignore(&config, "//@ ignore-rustc_abi-x86-sse2"));
+    assert!(!check_ignore(&config, "//@ only-rustc_abi-x86-sse2"));
+    let config = cfg().target("x86_64-unknown-linux-gnu").build();
+    assert_eq!(config.target_cfg().rustc_abi, None);
+    assert!(!check_ignore(&config, "//@ ignore-rustc_abi-x86-sse2"));
+    assert!(check_ignore(&config, "//@ only-rustc_abi-x86-sse2"));
+}