From 8c93de6a827952ab1341e28be923a2aab221f3c7 Mon Sep 17 00:00:00 2001
From: Dario Gonzalez <dario.gonzalez@fortanix.com>
Date: Fri, 26 Apr 2019 14:05:37 -0700
Subject: [PATCH] Added ability to crosscompile doctests

---
 src/cargo/core/compiler/compilation.rs |  2 +-
 src/cargo/ops/cargo_test.rs            | 18 +++++++++++++-----
 tests/testsuite/cross_compile.rs       |  7 +++++--
 3 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/src/cargo/core/compiler/compilation.rs b/src/cargo/core/compiler/compilation.rs
index dcd2e1923bf..35dc7e26656 100644
--- a/src/cargo/core/compiler/compilation.rs
+++ b/src/cargo/core/compiler/compilation.rs
@@ -163,7 +163,7 @@ impl<'cfg> Compilation<'cfg> {
         self.fill_env(process(cmd), pkg, true)
     }
 
-    fn target_runner(&self) -> &Option<(PathBuf, Vec<String>)> {
+    pub fn target_runner(&self) -> &Option<(PathBuf, Vec<String>)> {
         &self.target_runner
     }
 
diff --git a/src/cargo/ops/cargo_test.rs b/src/cargo/ops/cargo_test.rs
index 1079df47efa..0bb3a65c687 100644
--- a/src/cargo/ops/cargo_test.rs
+++ b/src/cargo/ops/cargo_test.rs
@@ -140,10 +140,7 @@ fn run_doc_tests(
     let mut errors = Vec::new();
     let config = options.compile_opts.config;
 
-    // We don't build/run doc tests if `target` does not equal `host`.
-    if compilation.host != compilation.target {
-        return Ok((Test::Doc, errors));
-    }
+    let runtool = compilation.target_runner();
 
     for doctest_info in &compilation.to_doc_test {
         let Doctest {
@@ -158,6 +155,18 @@ fn run_doc_tests(
             .arg("--crate-name")
             .arg(&target.crate_name());
 
+        p.arg("-Z");
+        p.arg("unstable-options");
+        p.arg("--enable-per-target-ignores");
+
+        runtool.as_ref().map(|(runtool, runtool_args)| {
+            p.arg("--target").arg(&compilation.target);
+            p.arg("--runtool").arg(runtool);
+            for arg in runtool_args {
+                p.arg("--runtool-arg").arg(arg);
+            }
+        });
+
         for &rust_dep in &[&compilation.deps_output] {
             let mut arg = OsString::from("dependency=");
             arg.push(rust_dep);
@@ -194,7 +203,6 @@ fn run_doc_tests(
         if let Some(flags) = compilation.rustdocflags.get(&package.package_id()) {
             p.args(flags);
         }
-
         config
             .shell()
             .verbose(|shell| shell.status("Running", p.to_string()))?;
diff --git a/tests/testsuite/cross_compile.rs b/tests/testsuite/cross_compile.rs
index 671afe7003a..c7121d9a077 100644
--- a/tests/testsuite/cross_compile.rs
+++ b/tests/testsuite/cross_compile.rs
@@ -535,7 +535,8 @@ fn cross_tests() {
 [COMPILING] foo v0.0.0 ([CWD])
 [FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
 [RUNNING] target/{triple}/debug/deps/foo-[..][EXE]
-[RUNNING] target/{triple}/debug/deps/bar-[..][EXE]",
+[RUNNING] target/{triple}/debug/deps/bar-[..][EXE]
+[DOCTEST] Skipping doctests, no runner defined for target",
             triple = target
         ))
         .with_stdout_contains("test test_foo ... ok")
@@ -595,6 +596,7 @@ fn no_cross_doctests() {
 [COMPILING] foo v0.0.1 ([CWD])
 [FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
 [RUNNING] target/{triple}/debug/deps/foo-[..][EXE]
+[DOCTEST] Skipping doctests, no runner defined for target
 ",
             triple = target
         ))
@@ -1223,7 +1225,8 @@ fn cross_test_dylib() {
 [COMPILING] foo v0.0.1 ([CWD])
 [FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
 [RUNNING] target/{arch}/debug/deps/foo-[..][EXE]
-[RUNNING] target/{arch}/debug/deps/test-[..][EXE]",
+[RUNNING] target/{arch}/debug/deps/test-[..][EXE]
+[DOCTEST] Skipping doctests, no runner defined for target",
             arch = cross_compile::alternate()
         ))
         .with_stdout_contains_n("test foo ... ok", 2)