Only run the new default-hidden-visibility test on x86_64/linux.

Author: anforowicz

config.example.toml

@@ -207,7 +207,7 @@ change-id = 118703
 # Defaults to `host`. If you set this explicitly, you likely want to add all
 # host triples to this list as well in order for those host toolchains to be
 # able to compile programs for their native target.
-#target = build.host (list of triples)
+target = ["x86_64-unknown-linux-gnu", "x86_64-pc-windows-msvc", "i686-unknown-linux-gnu", "i686-pc-windows-msvc"]
 
 # Use this directory to store build artifacts. Paths are relative to the current directory, not to
 # the root of the repository.

tests/codegen/default-hidden-visibility.rs

@@ -3,30 +3,9 @@
 // also https://github.com/rust-lang/rust/issues/73295 and
 // https://github.com/rust-lang/rust/issues/37530.
 
-// We test 3 combinations of command-line flags:
-// * No extra command-line flag: DEFAULT
-// * Overriding to "yes": YES
-// * Overriding to "no": NO
-//
-//     revisions:DEFAULT YES NO
-//     [YES] compile-flags: -Zdefault-hidden-visibility=yes
-//     [NO]  compile-flags: -Zdefault-hidden-visibility=no
-
-// `compiler/rustc_target/src/spec/base/wasm.rs` has a different default value of
-// `default_hidden_visibility` - it wouldn't match the test expectations below.
-// And therefore we skip this test on WASM:
-//
-//     ignore-wasm32
-
-// We verify that using the command line marks the `exported_symbol` as `hidden`
-// and that it is not `hidden` otherwise.  We don't verify other attributes of
-// the symbol, because they vary depending on the target (e.g. in the `DEFAULT`
-// behavior on `i686-unknown-linux-musl` the symbol is `internal constant` while
-// on `x86_64-unknown-linux-gnu` it is just `constant`).
-//
-// DEFAULT-NOT: @{{.*}}default_hidden_visibility{{.*}}exported_symbol{{.*}} ={{.*}} hidden
-// NO-NOT:      @{{.*}}default_hidden_visibility{{.*}}exported_symbol{{.*}} ={{.*}} hidden
-// YES:         @{{.*}}default_hidden_visibility{{.*}}exported_symbol{{.*}} ={{.*}} hidden
+// revisions:DEFAULT YES NO
+//[YES] compile-flags: -Zdefault-hidden-visibility=yes
+//[NO]  compile-flags: -Zdefault-hidden-visibility=no
 
 // The test scenario is specifically about visibility of symbols exported out of dynamically linked
 // libraries.
@@ -37,4 +16,17 @@
 // the symbol should be exported;  we don't want that - we want to test the *default*
 // export setting instead).
 #[used]
-pub static exported_symbol: [u8; 6] = *b"foobar";
+pub static tested_symbol: [u8; 6] = *b"foobar";
+
+// Exact LLVM IR differs depending on the target triple (e.g. `hidden constant`
+// vs `internal constant` vs `constant`).  Because of this, we only apply the
+// specific test expectations below to one specific target triple.  If needed,
+// additional targets can be covered by adding copies of this test file with
+// a different `only-X` directive.
+//
+//     only-x86_64
+//     only-linux
+
+// DEFAULT: @{{.*}}default_hidden_visibility{{.*}}tested_symbol{{.*}} = constant
+// YES:     @{{.*}}default_hidden_visibility{{.*}}tested_symbol{{.*}} = hidden constant
+// NO:      @{{.*}}default_hidden_visibility{{.*}}tested_symbol{{.*}} = constant