Unify passing of flags to rustdoc

Author: Kobzol

src/bootstrap/bin/rustdoc.rs

@@ -3,7 +3,6 @@
 //! See comments in `src/bootstrap/rustc.rs` for more information.
 
 use std::env;
-use std::ffi::OsString;
 use std::path::PathBuf;
 use std::process::{exit, Command};
 
@@ -48,15 +47,6 @@ fn main() {
     if env::var_os("RUSTC_FORCE_UNSTABLE").is_some() {
         cmd.arg("-Z").arg("force-unstable-if-unmarked");
     }
-    if let Some(linker) = env::var_os("RUSTDOC_LINKER") {
-        let mut arg = OsString::from("-Clinker=");
-        arg.push(&linker);
-        cmd.arg(arg);
-    }
-    if let Ok(no_threads) = env::var("RUSTDOC_LLD_NO_THREADS") {
-        cmd.arg("-Clink-arg=-fuse-ld=lld");
-        cmd.arg(format!("-Clink-arg=-Wl,{no_threads}"));
-    }
     // Cargo doesn't pass RUSTDOCFLAGS to proc_macros:
     // https://github.com/rust-lang/cargo/issues/4423
     // Thus, if we are on stage 0, we explicitly set `--cfg=bootstrap`.

src/bootstrap/builder.rs

@@ -22,7 +22,9 @@ use crate::run;
 use crate::setup;
 use crate::test;
 use crate::tool::{self, SourceType};
-use crate::util::{self, add_dylib_path, add_link_lib_path, exe, libdir, output, t};
+use crate::util::{
+    self, add_dylib_path, add_link_lib_path, add_rustdoc_lld_flags, exe, libdir, output, t,
+};
 use crate::EXTRA_CHECK_CFGS;
 use crate::{check, compile, Crate};
 use crate::{clean, dist};
@@ -1171,12 +1173,7 @@ impl<'a> Builder<'a> {
         cmd.env_remove("MAKEFLAGS");
         cmd.env_remove("MFLAGS");
 
-        if let Some(linker) = self.linker(compiler.host) {
-            cmd.env("RUSTDOC_LINKER", linker);
-        }
-        if self.is_fuse_ld_lld(compiler.host) {
-            cmd.env("RUSTDOC_FUSE_LD_LLD", "1");
-        }
+        add_rustdoc_lld_flags(&mut cmd, self, compiler.host, false);
         cmd
     }
 

src/bootstrap/test.rs

@@ -27,7 +27,10 @@ use crate::render_tests::add_flags_and_try_run_tests;
 use crate::synthetic_targets::MirOptPanicAbortSyntheticTarget;
 use crate::tool::{self, SourceType, Tool};
 use crate::toolstate::ToolState;
-use crate::util::{self, add_link_lib_path, dylib_path, dylib_path_var, output, t, up_to_date};
+use crate::util::{
+    self, add_link_lib_path, add_rustdoc_lld_flags, dylib_path, dylib_path_var, output, t,
+    up_to_date,
+};
 use crate::{envify, CLang, DocTests, GitRepo, Mode};
 
 const ADB_TEST_DIR: &str = "/data/local/tmp/work";
@@ -853,15 +856,8 @@ impl Step for RustdocTheme {
             .env("CFG_RELEASE_CHANNEL", &builder.config.channel)
             .env("RUSTDOC_REAL", builder.rustdoc(self.compiler))
             .env("RUSTC_BOOTSTRAP", "1");
-        if let Some(linker) = builder.linker(self.compiler.host) {
-            cmd.env("RUSTDOC_LINKER", linker);
-        }
-        if builder.is_fuse_ld_lld(self.compiler.host) {
-            cmd.env(
-                "RUSTDOC_LLD_NO_THREADS",
-                util::lld_flag_no_threads(self.compiler.host.contains("windows")),
-            );
-        }
+        add_rustdoc_lld_flags(&mut cmd, builder, self.compiler.host, true);
+
         builder.run_delaying_failure(&mut cmd);
     }
 }

src/bootstrap/util.rs

@@ -495,3 +495,22 @@ pub fn lld_flag_no_threads(is_windows: bool) -> &'static str {
 pub fn dir_is_empty(dir: &Path) -> bool {
     t!(std::fs::read_dir(dir)).next().is_none()
 }
+
+pub fn add_rustdoc_lld_flags(
+    cmd: &mut Command,
+    builder: &Builder,
+    target: TargetSelection,
+    single_threaded: bool,
+) {
+    if let Some(linker) = builder.linker(target) {
+        let mut flag = std::ffi::OsString::from("-Clinker=");
+        flag.push(linker);
+        cmd.arg(flag);
+    }
+    if builder.is_fuse_ld_lld(target) {
+        cmd.arg("-Clink-arg=-fuse-ld=lld");
+        if single_threaded {
+            cmd.arg(format!("-Clink-arg=-Wl,{}", lld_flag_no_threads(target.contains("windows"))));
+        }
+    }
+}