Auto merge of #139244 - jieyouxu:exp/auto-cross-run-make, r=<try>

[WIP] Enable automatic cross-compilation in run-make tests

> [!CAUTION]
>
> Stacked on top of #142414, needs rebase.

Supersedes #138066.

Blocker for #141856.

Based on #138066 with #139242 + #139239 cherry-picked in, plus `rustdoc()` cross-compile changes.

r? `@ghost`

try-job: armhf-gnu
try-job: test-various

Author: rust-bors[bot]

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

@@ -6,7 +6,7 @@ use crate::command::Command;
 use crate::env::env_var;
 use crate::path_helpers::cwd;
 use crate::util::set_host_compiler_dylib_path;
-use crate::{is_aix, is_darwin, is_msvc, is_windows, uname};
+use crate::{is_aix, is_darwin, is_msvc, is_windows, target, uname};
 
 /// Construct a new `rustc` invocation. This will automatically set the library
 /// search path as `-L cwd()`. Use [`bare_rustc`] to avoid this.
@@ -27,9 +27,15 @@ pub fn bare_rustc() -> Rustc {
 #[must_use]
 pub struct Rustc {
     cmd: Command,
+    target: Option<String>,
 }
 
-crate::macros::impl_common_helpers!(Rustc);
+// Only fill in the target just before execution, so that it can be overridden.
+crate::macros::impl_common_helpers!(Rustc, |rustc: &mut Rustc| {
+    if let Some(target) = &rustc.target {
+        rustc.cmd.arg(&format!("--target={target}"));
+    }
+});
 
 pub fn rustc_path() -> String {
     env_var("RUSTC")
@@ -46,19 +52,22 @@ impl Rustc {
     // `rustc` invocation constructor methods
 
     /// Construct a new `rustc` invocation. This will automatically set the library
-    /// search path as `-L cwd()`. Use [`bare_rustc`] to avoid this.
+    /// search path as `-L cwd()` and also the compilation target.
+    /// Use [`bare_rustc`] to avoid this.
     #[track_caller]
     pub fn new() -> Self {
         let mut cmd = setup_common();
         cmd.arg("-L").arg(cwd());
-        Self { cmd }
+
+        // Automatically default to cross-compilation
+        Self { cmd, target: Some(target()) }
     }
 
     /// Construct a bare `rustc` invocation with no flags set.
     #[track_caller]
     pub fn bare() -> Self {
         let cmd = setup_common();
-        Self { cmd }
+        Self { cmd, target: None }
     }
 
     // Argument provider methods
@@ -234,8 +243,9 @@ impl Rustc {
 
     /// Specify the target triple, or a path to a custom target json spec file.
     pub fn target<S: AsRef<str>>(&mut self, target: S) -> &mut Self {
-        let target = target.as_ref();
-        self.cmd.arg(format!("--target={target}"));
+        // We store the target as a separate field, so that it can be specified multiple times.
+        // This is in particular useful to override the default target set in Rustc::new().
+        self.target = Some(target.as_ref().to_string());
         self
     }
 

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

@@ -3,21 +3,36 @@ use std::path::Path;
 
 use crate::command::Command;
 use crate::env::env_var;
+use crate::target;
 use crate::util::set_host_compiler_dylib_path;
 
-/// Construct a new `rustdoc` invocation. This will configure the host compiler runtime libs.
+/// Construct a new `rustdoc` invocation with target automatically set to cross-compile target and
+/// with host compiler runtime libs configured. Use [`bare_rustdoc`] to avoid automatically setting
+/// cross-compile target.
 #[track_caller]
 pub fn rustdoc() -> Rustdoc {
     Rustdoc::new()
 }
 
+/// Bare `rustdoc` invocation, no args set.
+#[track_caller]
+pub fn bare_rustdoc() -> Rustdoc {
+    Rustdoc::bare()
+}
+
 #[derive(Debug)]
 #[must_use]
 pub struct Rustdoc {
     cmd: Command,
+    target: Option<String>,
 }
 
-crate::macros::impl_common_helpers!(Rustdoc);
+// Only fill in the target just before execution, so that it can be overridden.
+crate::macros::impl_common_helpers!(Rustdoc, |rustdoc: &mut Rustdoc| {
+    if let Some(target) = &rustdoc.target {
+        rustdoc.cmd.arg(&format!("--target={target}"));
+    }
+});
 
 #[track_caller]
 fn setup_common() -> Command {
@@ -28,11 +43,20 @@ fn setup_common() -> Command {
 }
 
 impl Rustdoc {
-    /// Construct a bare `rustdoc` invocation. This will configure the host compiler runtime libs.
+    /// Construct a new `rustdoc` invocation with target automatically set to cross-compile target
+    /// and with host compiler runtime libs configured. Use [`bare_rustdoc`] to avoid automatically
+    /// setting cross-compile target.
     #[track_caller]
     pub fn new() -> Self {
         let cmd = setup_common();
-        Self { cmd }
+        Self { cmd, target: Some(target()) }
+    }
+
+    /// Bare `rustdoc` invocation, no args set.
+    #[track_caller]
+    pub fn bare() -> Self {
+        let cmd = setup_common();
+        Self { cmd, target: None }
     }
 
     /// Specify where an external library is located.
@@ -85,8 +109,9 @@ impl Rustdoc {
 
     /// Specify the target triple, or a path to a custom target json spec file.
     pub fn target<S: AsRef<str>>(&mut self, target: S) -> &mut Self {
-        let target = target.as_ref();
-        self.cmd.arg(format!("--target={target}"));
+        // We store the target as a separate field, so that it can be specified multiple times.
+        // This is in particular useful to override the default target set in `Rustdoc::new()`.
+        self.target = Some(target.as_ref().to_string());
         self
     }