Do not print linker command in linker error by default

Only print the entire linker command that failed if `--verbose` is set.

CC #110763. Fix #109979.

Author: estebank

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1004,6 +1004,7 @@ fn link_natively(
                     exit_status: prog.status,
                     command: &cmd,
                     escaped_output,
+                    verbose: sess.opts.verbose,
                 };
                 sess.dcx().emit_err(err);
                 // If MSVC's `link.exe` was expected but the return code

compiler/rustc_codegen_ssa/src/errors.rs

@@ -349,6 +349,7 @@ pub(crate) struct LinkingFailed<'a> {
     pub exit_status: ExitStatus,
     pub command: &'a Command,
     pub escaped_output: String,
+    pub verbose: bool,
 }
 
 impl<G: EmissionGuarantee> Diagnostic<'_, G> for LinkingFailed<'_> {
@@ -359,7 +360,17 @@ impl<G: EmissionGuarantee> Diagnostic<'_, G> for LinkingFailed<'_> {
 
         let contains_undefined_ref = self.escaped_output.contains("undefined reference to");
 
-        diag.note(format!("{:?}", self.command)).note(self.escaped_output);
+        let command = format!("{:?}", self.command);
+        let width = 100;
+        match (self.verbose, command.len() > width) {
+            (false, true) => {
+                diag.note("to see the full command that was run, rerun with `--verbose` flag");
+            }
+            (true, _) | (_, false) => {
+                diag.note(command);
+            }
+        }
+        diag.note(format!("output:\n{}", self.escaped_output));
 
         // Trying to match an error from OS linkers
         // which by now we have no way to translate.

src/tools/run-make-support/src/external_deps/rustc.rs

@@ -221,6 +221,11 @@ impl Rustc {
         self
     }
 
+    pub fn verbose(&mut self) -> &mut Self {
+        self.cmd.arg("--verbose");
+        self
+    }
+
     /// Specify json messages printed by the compiler
     pub fn json(&mut self, items: &str) -> &mut Self {
         self.cmd.arg(format!("--json={items}"));

tests/run-make/linkage-attr-framework/rmake.rs

@@ -2,7 +2,7 @@
 
 //@ only-apple
 
-use run_make_support::{Rustc, run, rustc};
+use run_make_support::{Rustc, diff, run, rustc};
 
 fn compile(cfg: &str) -> Rustc {
     let mut rustc = rustc();
@@ -16,11 +16,15 @@ fn main() {
         run("main");
     }
 
-    let errs = compile("omit").run_fail();
+    let errs = compile("omit").verbose().run_fail();
     // The linker's exact error output changes between Xcode versions, depends on
     // linker invocation details, and the linker sometimes outputs more warnings.
     errs.assert_stderr_contains_regex(r"error: linking with `.*` failed");
     errs.assert_stderr_contains_regex(r"(Undefined symbols|ld: symbol[^\s]* not found)");
     errs.assert_stderr_contains_regex(r".?_CFRunLoopGetTypeID.?, referenced from:");
     errs.assert_stderr_contains("clang: error: linker command failed with exit code 1");
+    // Ensure we don't show the full linker command by default.
+    let errs = compile("omit").run_fail().assert_stderr_contains(
+        "to see the full command that was run, rerun with `--verbose` flag",
+    );
 }