run-make-support: add support for stdin input with rustc/rustdoc

src/tools/run-make-support/src/cc.rs

@@ -71,6 +71,11 @@ impl Cc {
 
         self
     }
+
+    /// Get the [`Output`][::std::process::Output] of the finished process.
+    pub fn output(&mut self) -> ::std::process::Output {
+        self.cmd.output().expect("failed to get output of finished process")
+    }
 }
 
 /// `EXTRACFLAGS`

src/tools/run-make-support/src/clang.rs

@@ -70,4 +70,9 @@ impl Clang {
         self.cmd.arg(format!("-fuse-ld={ld}"));
         self
     }
+
+    /// Get the [`Output`][::std::process::Output] of the finished process.
+    pub fn output(&mut self) -> ::std::process::Output {
+        self.cmd.output().expect("failed to get output of finished process")
+    }
 }

src/tools/run-make-support/src/lib.rs

@@ -144,7 +144,7 @@ pub fn set_host_rpath(cmd: &mut Command) {
 }
 
 /// Implement common helpers for command wrappers. This assumes that the command wrapper is a struct
-/// containing a `cmd: Command` field. The provided helpers are:
+/// containing a `cmd: Command` field and a `output` function. The provided helpers are:
 ///
 /// 1. Generic argument acceptors: `arg` and `args` (delegated to [`Command`]). These are intended
 ///    to be *fallback* argument acceptors, when specific helpers don't make sense. Prefer to add
@@ -160,7 +160,12 @@ pub fn set_host_rpath(cmd: &mut Command) {
 /// Example usage:
 ///
 /// ```ignore (illustrative)
-/// struct CommandWrapper { cmd: Command }
+/// struct CommandWrapper { cmd: Command } // <- required `cmd` field
+///
+/// impl CommandWrapper {
+///     /// Get the [`Output`][::std::process::Output] of the finished process.
+///     pub fn output(&mut self) -> Output { /* ... */ } // <- required `output()` method
+/// }
 ///
 /// crate::impl_common_helpers!(CommandWrapper);
 ///
@@ -231,18 +236,13 @@ macro_rules! impl_common_helpers {
                 self
             }
 
-            /// Get the [`Output`][::std::process::Output] of the finished process.
-            pub fn output(&mut self) -> ::std::process::Output {
-                self.cmd.output().expect("failed to get output of finished process")
-            }
-
             /// Run the constructed command and assert that it is successfully run.
             #[track_caller]
             pub fn run(&mut self) -> ::std::process::Output {
                 let caller_location = ::std::panic::Location::caller();
                 let caller_line_number = caller_location.line();
 
-                let output = self.cmd.output().unwrap();
+                let output = self.output();
                 if !output.status.success() {
                     handle_failed_output(&self.cmd, output, caller_line_number);
                 }
@@ -255,7 +255,7 @@ macro_rules! impl_common_helpers {
                 let caller_location = ::std::panic::Location::caller();
                 let caller_line_number = caller_location.line();
 
-                let output = self.cmd.output().unwrap();
+                let output = self.output();
                 if output.status.success() {
                     handle_failed_output(&self.cmd, output, caller_line_number);
                 }

src/tools/run-make-support/src/llvm_readobj.rs

@@ -41,4 +41,10 @@ impl LlvmReadobj {
         self.cmd.arg("--file-header");
         self
     }
+
+    /// Get the [`Output`][::std::process::Output] of the finished process.
+    #[track_caller]
+    pub fn output(&mut self) -> ::std::process::Output {
+        self.cmd.output().expect("failed to get output of finished process")
+    }
 }

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

@@ -1,7 +1,8 @@
 use std::env;
 use std::ffi::OsString;
+use std::io::Write;
 use std::path::Path;
-use std::process::{Command, Output};
+use std::process::{Command, Output, Stdio};
 
 use crate::{handle_failed_output, set_host_rpath, tmp_dir};
 
@@ -19,6 +20,7 @@ pub fn aux_build() -> Rustc {
 #[derive(Debug)]
 pub struct Rustc {
     cmd: Command,
+    stdin: Option<Box<[u8]>>,
 }
 
 crate::impl_common_helpers!(Rustc);
@@ -37,14 +39,14 @@ impl Rustc {
     /// Construct a new `rustc` invocation.
     pub fn new() -> Self {
         let cmd = setup_common();
-        Self { cmd }
+        Self { cmd, stdin: None }
     }
 
     /// Construct a new `rustc` invocation with `aux_build` preset (setting `--crate-type=lib`).
     pub fn new_aux_build() -> Self {
         let mut cmd = setup_common();
         cmd.arg("--crate-type=lib");
-        Self { cmd }
+        Self { cmd, stdin: None }
     }
 
     // Argument provider methods
@@ -161,12 +163,40 @@ impl Rustc {
         self
     }
 
+    /// Specify a stdin input
+    pub fn stdin<I: AsRef<[u8]>>(&mut self, input: I) -> &mut Self {
+        self.stdin = Some(input.as_ref().to_vec().into_boxed_slice());
+        self
+    }
+
+    /// Get the [`Output`][::std::process::Output] of the finished process.
+    #[track_caller]
+    pub fn output(&mut self) -> ::std::process::Output {
+        // let's make sure we piped all the input and outputs
+        self.cmd.stdin(Stdio::piped());
+        self.cmd.stdout(Stdio::piped());
+        self.cmd.stderr(Stdio::piped());
+
+        if let Some(input) = &self.stdin {
+            let mut child = self.cmd.spawn().unwrap();
+
+            {
+                let mut stdin = child.stdin.take().unwrap();
+                stdin.write_all(input.as_ref()).unwrap();
+            }
+
+            child.wait_with_output().expect("failed to get output of finished process")
+        } else {
+            self.cmd.output().expect("failed to get output of finished process")
+        }
+    }
+
     #[track_caller]
     pub fn run_fail_assert_exit_code(&mut self, code: i32) -> Output {
         let caller_location = std::panic::Location::caller();
         let caller_line_number = caller_location.line();
 
-        let output = self.cmd.output().unwrap();
+        let output = self.output();
         if output.status.code().unwrap() != code {
             handle_failed_output(&self.cmd, output, caller_line_number);
         }

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

@@ -1,6 +1,7 @@
 use std::env;
+use std::io::Write;
 use std::path::Path;
-use std::process::{Command, Output};
+use std::process::{Command, Output, Stdio};
 
 use crate::{handle_failed_output, set_host_rpath};
 
@@ -17,6 +18,7 @@ pub fn rustdoc() -> Rustdoc {
 #[derive(Debug)]
 pub struct Rustdoc {
     cmd: Command,
+    stdin: Option<Box<[u8]>>,
 }
 
 crate::impl_common_helpers!(Rustdoc);
@@ -32,7 +34,7 @@ impl Rustdoc {
     /// Construct a bare `rustdoc` invocation.
     pub fn bare() -> Self {
         let cmd = setup_common();
-        Self { cmd }
+        Self { cmd, stdin: None }
     }
 
     /// Construct a `rustdoc` invocation with `-L $(TARGET_RPATH_DIR)` set.
@@ -40,7 +42,7 @@ impl Rustdoc {
         let mut cmd = setup_common();
         let target_rpath_dir = env::var_os("TARGET_RPATH_DIR").unwrap();
         cmd.arg(format!("-L{}", target_rpath_dir.to_string_lossy()));
-        Self { cmd }
+        Self { cmd, stdin: None }
     }
 
     /// Specify path to the input file.
@@ -62,12 +64,41 @@ impl Rustdoc {
         self
     }
 
+    /// Specify a stdin input
+    pub fn stdin<I: AsRef<[u8]>>(&mut self, input: I) -> &mut Self {
+        self.cmd.stdin(Stdio::piped());
+        self.stdin = Some(input.as_ref().to_vec().into_boxed_slice());
+        self
+    }
+
+    /// Get the [`Output`][::std::process::Output] of the finished process.
+    #[track_caller]
+    pub fn output(&mut self) -> ::std::process::Output {
+        // let's make sure we piped all the input and outputs
+        self.cmd.stdin(Stdio::piped());
+        self.cmd.stdout(Stdio::piped());
+        self.cmd.stderr(Stdio::piped());
+
+        if let Some(input) = &self.stdin {
+            let mut child = self.cmd.spawn().unwrap();
+
+            {
+                let mut stdin = child.stdin.take().unwrap();
+                stdin.write_all(input.as_ref()).unwrap();
+            }
+
+            child.wait_with_output().expect("failed to get output of finished process")
+        } else {
+            self.cmd.output().expect("failed to get output of finished process")
+        }
+    }
+
     #[track_caller]
     pub fn run_fail_assert_exit_code(&mut self, code: i32) -> Output {
         let caller_location = std::panic::Location::caller();
         let caller_line_number = caller_location.line();
 
-        let output = self.cmd.output().unwrap();
+        let output = self.output();
         if output.status.code().unwrap() != code {
             handle_failed_output(&self.cmd, output, caller_line_number);
         }