Auto merge of #5121 - lzutao:comptest, r=flip1995

Improve compile_test and dogfood tests

* Hopefully this finally resolves the "multiple matching crates" error, e.g. #4015
* This handle some convenient CARGO env like CARGO_TARGET_DIR and CARGO_BUILD_TARGET

changelog: none

3 files changed, 124 insertions, 83 deletions

diff --git a/tests/cargo/mod.rs b/tests/cargo/mod.rs
new file mode 100644
index 00000000000..5b2de05cb17
--- /dev/null
+++ b/tests/cargo/mod.rs
@@ -0,0 +1,75 @@
+use cargo_metadata::{Message::CompilerArtifact, MetadataCommand};
+use std::env;
+use std::ffi::OsStr;
+use std::mem;
+use std::path::PathBuf;
+use std::process::Command;
+
+pub struct BuildInfo {
+    cargo_target_dir: PathBuf,
+}
+
+impl BuildInfo {
+    pub fn new() -> Self {
+        let data = MetadataCommand::new().exec().unwrap();
+        Self {
+            cargo_target_dir: data.target_directory,
+        }
+    }
+
+    pub fn host_lib(&self) -> PathBuf {
+        if let Some(path) = option_env!("HOST_LIBS") {
+            PathBuf::from(path)
+        } else {
+            self.cargo_target_dir.join(env!("PROFILE"))
+        }
+    }
+
+    pub fn target_lib(&self) -> PathBuf {
+        if let Some(path) = option_env!("TARGET_LIBS") {
+            path.into()
+        } else {
+            let mut dir = self.cargo_target_dir.clone();
+            if let Some(target) = env::var_os("CARGO_BUILD_TARGET") {
+                dir.push(target);
+            }
+            dir.push(env!("PROFILE"));
+            dir
+        }
+    }
+
+    pub fn clippy_driver_path(&self) -> PathBuf {
+        if let Some(path) = option_env!("CLIPPY_DRIVER_PATH") {
+            PathBuf::from(path)
+        } else {
+            self.target_lib().join("clippy-driver")
+        }
+    }
+
+    // When we'll want to use `extern crate ..` for a dependency that is used
+    // both by the crate and the compiler itself, we can't simply pass -L flags
+    // as we'll get a duplicate matching versions. Instead, disambiguate with
+    // `--extern dep=path`.
+    // See https://github.com/rust-lang/rust-clippy/issues/4015.
+    pub fn third_party_crates() -> Vec<(&'static str, PathBuf)> {
+        const THIRD_PARTY_CRATES: [&str; 4] = ["serde", "serde_derive", "regex", "clippy_lints"];
+        let cargo = env::var_os("CARGO");
+        let cargo = cargo.as_deref().unwrap_or_else(|| OsStr::new("cargo"));
+        let output = Command::new(cargo)
+            .arg("build")
+            .arg("--test=compile-test")
+            .arg("--message-format=json")
+            .output()
+            .unwrap();
+
+        let mut crates = Vec::with_capacity(THIRD_PARTY_CRATES.len());
+        for message in cargo_metadata::parse_messages(output.stdout.as_slice()) {
+            if let CompilerArtifact(mut artifact) = message.unwrap() {
+                if let Some(&krate) = THIRD_PARTY_CRATES.iter().find(|&&krate| krate == artifact.target.name) {
+                    crates.push((krate, mem::take(&mut artifact.filenames[0])));
+                }
+            }
+        }
+        crates
+    }
+}
diff --git a/tests/compile-test.rs b/tests/compile-test.rs
index 5c05e74dcb6..7cfbfcf16a9 100644
--- a/tests/compile-test.rs
+++ b/tests/compile-test.rs
@@ -1,36 +1,15 @@
 #![feature(test)]
 
 use compiletest_rs as compiletest;
-extern crate tester as test;
+use compiletest_rs::common::Mode as TestMode;
 
-use std::env::{set_var, var};
+use std::env::{self, set_var};
 use std::ffi::OsStr;
 use std::fs;
 use std::io;
 use std::path::{Path, PathBuf};
 
-#[must_use]
-fn clippy_driver_path() -> PathBuf {
-    if let Some(path) = option_env!("CLIPPY_DRIVER_PATH") {
-        PathBuf::from(path)
-    } else {
-        PathBuf::from(concat!("target/", env!("PROFILE"), "/clippy-driver"))
-    }
-}
-
-#[must_use]
-fn host_libs() -> PathBuf {
-    if let Some(path) = option_env!("HOST_LIBS") {
-        PathBuf::from(path)
-    } else {
-        Path::new("target").join(env!("PROFILE"))
-    }
-}
-
-#[must_use]
-fn target_libs() -> Option<PathBuf> {
-    option_env!("TARGET_LIBS").map(PathBuf::from)
-}
+mod cargo;
 
 #[must_use]
 fn rustc_test_suite() -> Option<PathBuf> {
@@ -42,73 +21,52 @@ fn rustc_lib_path() -> PathBuf {
     option_env!("RUSTC_LIB_PATH").unwrap().into()
 }
 
-fn config(mode: &str, dir: PathBuf) -> compiletest::Config {
+fn default_config() -> compiletest::Config {
+    let build_info = cargo::BuildInfo::new();
     let mut config = compiletest::Config::default();
 
-    let cfg_mode = mode.parse().expect("Invalid mode");
-    if let Ok(name) = var::<&str>("TESTNAME") {
-        config.filter = Some(name)
+    if let Ok(name) = env::var("TESTNAME") {
+        config.filter = Some(name);
     }
 
     if rustc_test_suite().is_some() {
-        config.run_lib_path = rustc_lib_path();
-        config.compile_lib_path = rustc_lib_path();
+        let path = rustc_lib_path();
+        config.run_lib_path = path.clone();
+        config.compile_lib_path = path;
     }
 
-    // When we'll want to use `extern crate ..` for a dependency that is used
-    // both by the crate and the compiler itself, we can't simply pass -L flags
-    // as we'll get a duplicate matching versions. Instead, disambiguate with
-    // `--extern dep=path`.
-    // See https://github.com/rust-lang/rust-clippy/issues/4015.
-    let needs_disambiguation = ["serde", "regex", "clippy_lints"];
-    // This assumes that deps are compiled (they are for Cargo integration tests).
-    let deps = fs::read_dir(target_libs().unwrap_or_else(host_libs).join("deps")).unwrap();
-    let disambiguated = deps
-        .filter_map(|dep| {
-            let path = dep.ok()?.path();
-            let name = path.file_name()?.to_string_lossy();
-            // NOTE: This only handles a single dep
-            // https://github.com/laumann/compiletest-rs/issues/101
-            needs_disambiguation.iter().find_map(|dep| {
-                if name.starts_with(&format!("lib{}-", dep)) && name.ends_with(".rlib") {
-                    Some(format!("--extern {}={}", dep, path.display()))
-                } else {
-                    None
-                }
-            })
-        })
-        .collect::<Vec<_>>();
+    let disambiguated: Vec<_> = cargo::BuildInfo::third_party_crates()
+        .iter()
+        .map(|(krate, path)| format!("--extern {}={}", krate, path.display()))
+        .collect();
 
     config.target_rustcflags = Some(format!(
-        "-L {0} -L {0}/deps {1} -Dwarnings -Zui-testing {2}",
-        host_libs().display(),
-        target_libs().map_or_else(String::new, |path| format!("-L {0} -L {0}/deps", path.display())),
+        "-L {0} -L {1} -Dwarnings -Zui-testing {2}",
+        build_info.host_lib().join("deps").display(),
+        build_info.target_lib().join("deps").display(),
         disambiguated.join(" ")
     ));
 
-    config.mode = cfg_mode;
     config.build_base = if rustc_test_suite().is_some() {
         // we don't need access to the stderr files on travis
         let mut path = PathBuf::from(env!("OUT_DIR"));
         path.push("test_build_base");
         path
     } else {
-        let mut path = std::env::current_dir().unwrap();
-        path.push("target/debug/test_build_base");
-        path
+        build_info.host_lib().join("test_build_base")
     };
-    config.src_base = dir;
-    config.rustc_path = clippy_driver_path();
+    config.rustc_path = build_info.clippy_driver_path();
     config
 }
 
-fn run_mode(mode: &str, dir: PathBuf) {
-    let cfg = config(mode, dir);
+fn run_mode(cfg: &mut compiletest::Config) {
+    cfg.mode = TestMode::Ui;
+    cfg.src_base = Path::new("tests").join("ui");
     compiletest::run_tests(&cfg);
 }
 
 #[allow(clippy::identity_conversion)]
-fn run_ui_toml_tests(config: &compiletest::Config, mut tests: Vec<test::TestDescAndFn>) -> Result<bool, io::Error> {
+fn run_ui_toml_tests(config: &compiletest::Config, mut tests: Vec<tester::TestDescAndFn>) -> Result<bool, io::Error> {
     let mut result = true;
     let opts = compiletest::test_opts(config);
     for dir in fs::read_dir(&config.src_base)? {
@@ -137,15 +95,16 @@ fn run_ui_toml_tests(config: &compiletest::Config, mut tests: Vec<test::TestDesc
                 .iter()
                 .position(|test| test.desc.name == test_name)
                 .expect("The test should be in there");
-            result &= test::run_tests_console(&opts, vec![tests.swap_remove(index)])?;
+            result &= tester::run_tests_console(&opts, vec![tests.swap_remove(index)])?;
         }
     }
     Ok(result)
 }
 
-fn run_ui_toml() {
-    let path = PathBuf::from("tests/ui-toml").canonicalize().unwrap();
-    let config = config("ui", path);
+fn run_ui_toml(config: &mut compiletest::Config) {
+    config.mode = TestMode::Ui;
+    config.src_base = Path::new("tests").join("ui-toml").canonicalize().unwrap();
+
     let tests = compiletest::make_tests(&config);
 
     let res = run_ui_toml_tests(&config, tests);
@@ -167,6 +126,7 @@ fn prepare_env() {
 #[test]
 fn compile_test() {
     prepare_env();
-    run_mode("ui", "tests/ui".into());
-    run_ui_toml();
+    let mut config = default_config();
+    run_mode(&mut config);
+    run_ui_toml(&mut config);
 }
diff --git a/tests/dogfood.rs b/tests/dogfood.rs
index 944f3c2c013..5458143ab1c 100644
--- a/tests/dogfood.rs
+++ b/tests/dogfood.rs
@@ -1,16 +1,26 @@
+use lazy_static::lazy_static;
+use std::path::PathBuf;
+use std::process::Command;
+
+#[allow(dead_code)]
+mod cargo;
+
+lazy_static! {
+    static ref CLIPPY_PATH: PathBuf = {
+        let build_info = cargo::BuildInfo::new();
+        build_info.target_lib().join("cargo-clippy")
+    };
+}
+
 #[test]
 fn dogfood_clippy() {
     // run clippy on itself and fail the test if lint warnings are reported
     if option_env!("RUSTC_TEST_SUITE").is_some() || cfg!(windows) {
         return;
     }
-    let root_dir = std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"));
-    let clippy_binary = std::path::Path::new(&root_dir)
-        .join("target")
-        .join(env!("PROFILE"))
-        .join("cargo-clippy");
+    let root_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
 
-    let output = std::process::Command::new(clippy_binary)
+    let output = Command::new(&*CLIPPY_PATH)
         .current_dir(root_dir)
         .env("CLIPPY_DOGFOOD", "1")
         .env("CARGO_INCREMENTAL", "0")
@@ -37,11 +47,7 @@ fn dogfood_subprojects() {
     if option_env!("RUSTC_TEST_SUITE").is_some() || cfg!(windows) {
         return;
     }
-    let root_dir = std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"));
-    let clippy_binary = std::path::Path::new(&root_dir)
-        .join("target")
-        .join(env!("PROFILE"))
-        .join("cargo-clippy");
+    let root_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
 
     for d in &[
         "clippy_workspace_tests",
@@ -51,7 +57,7 @@ fn dogfood_subprojects() {
         "clippy_dev",
         "rustc_tools_util",
     ] {
-        let output = std::process::Command::new(&clippy_binary)
+        let output = Command::new(&*CLIPPY_PATH)
             .current_dir(root_dir.join(d))
             .env("CLIPPY_DOGFOOD", "1")
             .env("CARGO_INCREMENTAL", "0")