Improve test suite for -Zbuild-std

Cargo.toml

@@ -103,6 +103,7 @@ features = [
 
 [dev-dependencies]
 cargo-test-macro = { path = "crates/cargo-test-macro", version = "0.1.0" }
+cargo-test-support = { path = "crates/cargo-test-support", version = "0.1.0" }
 
 [[bin]]
 name = "cargo"

azure-pipelines.yml

@@ -43,6 +43,7 @@ jobs:
       x86_64-msvc:
         TOOLCHAIN: stable-x86_64-pc-windows-msvc
         OTHER_TARGET: i686-pc-windows-msvc
+
 - job: rustfmt
   pool:
     vmImage: ubuntu-16.04
@@ -54,6 +55,8 @@ jobs:
       displayName: "Check rustfmt (cargo)"
     - bash: cd crates/cargo-test-macro && cargo fmt --all -- --check
       displayName: "Check rustfmt (cargo-test-macro)"
+    - bash: cd crates/cargo-test-support && cargo fmt --all -- --check
+      displayName: "Check rustfmt (cargo-test-support)"
     - bash: cd crates/crates-io && cargo fmt --all -- --check
       displayName: "Check rustfmt (crates-io)"
     - bash: cd crates/resolver-tests && cargo fmt --all -- --check
@@ -71,6 +74,20 @@ jobs:
   variables:
     TOOLCHAIN: stable
 
+- job: build_std
+  pool:
+    vmImage: ubuntu-16.04
+  steps:
+    - template: ci/azure-install-rust.yml
+    - bash: rustup component add rust-src
+      displayName: "Install rust-src"
+    - bash: cargo build
+    - bash: cargo test --test build-std
+      displayName: "tests"
+  variables:
+    TOOLCHAIN: nightly
+    CARGO_RUN_BUILD_STD_TESTS: 1
+
 - job: docs
   pool:
     vmImage: ubuntu-16.04
@@ -88,4 +105,3 @@ jobs:
       displayName: "Build mdbook documentation"
   variables:
     TOOLCHAIN: stable
-

ci/azure-test-all.yml

@@ -16,11 +16,6 @@ steps:
 - bash: rustup component add clippy || echo "clippy not available"
   displayName: "Install clippy (maybe)"
 
-# This is needed for standard library tests.
-- bash: rustup component add rust-src
-  condition: and(succeeded(), eq(variables['TOOLCHAIN'], 'nightly'))
-  displayName: "Install rust-src (maybe)"
-
 # Deny warnings on CI to avoid warnings getting into the codebase, and note the
 # `force-system-lib-on-osx` which is intended to fix compile issues on OSX where
 # compiling curl from source on OSX yields linker errors on Azure.
@@ -31,3 +26,6 @@ steps:
 # fix the link errors.
 - bash: cargo test --features 'deny-warnings curl/force-system-lib-on-osx'
   displayName: "cargo test"
+
+- bash: cargo test -p cargo-test-support
+  displayName: "cargo test -p cargo-test-support"

crates/cargo-test-macro/src/lib.rs

@@ -3,7 +3,7 @@ extern crate proc_macro;
 use proc_macro::*;
 
 #[proc_macro_attribute]
-pub fn cargo_test(_attr: TokenStream, item: TokenStream) -> TokenStream {
+pub fn cargo_test(attr: TokenStream, item: TokenStream) -> TokenStream {
     let span = Span::call_site();
     let mut ret = TokenStream::new();
     ret.extend(Some(TokenTree::from(Punct::new('#', Spacing::Alone))));
@@ -13,6 +13,8 @@ pub fn cargo_test(_attr: TokenStream, item: TokenStream) -> TokenStream {
         test.into(),
     ))));
 
+    let build_std = contains_ident(&attr, "build_std");
+
     for token in item {
         let group = match token {
             TokenTree::Group(g) => {
@@ -29,25 +31,20 @@ pub fn cargo_test(_attr: TokenStream, item: TokenStream) -> TokenStream {
             }
         };
 
-        let mut new_body = vec![
-            TokenTree::from(Ident::new("let", span)),
-            TokenTree::from(Ident::new("_test_guard", span)),
-            TokenTree::from(Punct::new('=', Spacing::Alone)),
-            TokenTree::from(Ident::new("crate", span)),
-            TokenTree::from(Punct::new(':', Spacing::Joint)),
-            TokenTree::from(Punct::new(':', Spacing::Alone)),
-            TokenTree::from(Ident::new("support", span)),
-            TokenTree::from(Punct::new(':', Spacing::Joint)),
-            TokenTree::from(Punct::new(':', Spacing::Alone)),
-            TokenTree::from(Ident::new("paths", span)),
-            TokenTree::from(Punct::new(':', Spacing::Joint)),
-            TokenTree::from(Punct::new(':', Spacing::Alone)),
-            TokenTree::from(Ident::new("init_root", span)),
-            TokenTree::from(Group::new(Delimiter::Parenthesis, TokenStream::new())),
-            TokenTree::from(Punct::new(';', Spacing::Alone)),
-        ]
-        .into_iter()
-        .collect::<TokenStream>();
+        let mut new_body =
+            to_token_stream("let _test_guard = cargo_test_support::paths::init_root();");
+
+        // If this is a `build_std` test (aka `tests/build-std/*.rs`) then they
+        // only run on nightly and they only run when specifically instructed to
+        // on CI.
+        if build_std {
+            let ts = to_token_stream("if !cargo_test_support::is_nightly() { return }");
+            new_body.extend(ts);
+            let ts = to_token_stream(
+                "if std::env::var(\"CARGO_RUN_BUILD_STD_TESTS\").is_err() { return }",
+            );
+            new_body.extend(ts);
+        }
         new_body.extend(group.stream());
         ret.extend(Some(TokenTree::from(Group::new(
             group.delimiter(),
@@ -57,3 +54,14 @@ pub fn cargo_test(_attr: TokenStream, item: TokenStream) -> TokenStream {
 
     return ret;
 }
+
+fn contains_ident(t: &TokenStream, ident: &str) -> bool {
+    t.clone().into_iter().any(|t| match t {
+        TokenTree::Ident(i) => i.to_string() == ident,
+        _ => false,
+    })
+}
+
+fn to_token_stream(code: &str) -> TokenStream {
+    code.parse().unwrap()
+}

crates/cargo-test-support/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "cargo-test-support"
+version = "0.1.0"
+authors = ["Alex Crichton <[email protected]>"]
+edition = "2018"
+
+[lib]
+doctest = false
+
+[dependencies]
+cargo = { path = "../.." }
+cargo-test-macro = { path = "../cargo-test-macro" }
+filetime = "0.2"
+flate2 = "1.0"
+git2 = "0.10"
+glob = "0.3"
+lazy_static = "1.0"
+remove_dir_all = "0.5"
+serde_json = "1.0"
+tar = "0.4"
+url = "2.0"

tests/testsuite/support/cross_compile.rs → crates/cargo-test-support/src/cross_compile.rs

@@ -1,10 +1,9 @@
+use crate::{basic_bin_manifest, main_file, project};
 use std::env;
 use std::process::Command;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Once;
 
-use crate::support::{basic_bin_manifest, main_file, project};
-
 pub fn disabled() -> bool {
     // First, disable if `./configure` requested so.
     match env::var("CFG_DISABLE_CROSS_TESTS") {

tests/testsuite/support/git.rs → crates/cargo-test-support/src/git.rs

@@ -38,15 +38,13 @@ use some of the helper functions in this file to interact with the repository.
 
 */
 
+use crate::{path2url, project, Project, ProjectBuilder};
+use git2;
 use std::fs::{self, File};
 use std::io::prelude::*;
 use std::path::{Path, PathBuf};
-
-use git2;
 use url::Url;
 
-use crate::support::{path2url, project, Project, ProjectBuilder};
-
 #[must_use]
 pub struct RepoBuilder {
     repo: git2::Repository,

tests/testsuite/support/install.rs → crates/cargo-test-support/src/install.rs

@@ -1,8 +1,7 @@
+use crate::paths;
 use std::env::consts::EXE_SUFFIX;
 use std::path::{Path, PathBuf};
 
-use crate::support::paths;
-
 /// Used by `cargo install` tests to assert an executable binary
 /// has been installed. Example usage:
 ///

tests/testsuite/support/mod.rs → crates/cargo-test-support/src/lib.rs

@@ -125,6 +125,7 @@ use url::Url;
 
 use self::paths::CargoPathExt;
 
+#[macro_export]
 macro_rules! t {
     ($e:expr) => {
         match $e {
@@ -134,6 +135,8 @@ macro_rules! t {
     };
 }
 
+pub use cargo_test_macro::cargo_test;
+
 pub mod cross_compile;
 pub mod git;
 pub mod paths;
@@ -409,7 +412,7 @@ impl Project {
     ///             .with_stdout("bar\n")
     ///             .run();
     pub fn process<T: AsRef<OsStr>>(&self, program: T) -> Execs {
-        let mut p = crate::support::process(program);
+        let mut p = process(program);
         p.cwd(self.root());
         execs().with_process_builder(p)
     }
@@ -1425,7 +1428,7 @@ pub fn lines_match(expected: &str, mut actual: &str) -> bool {
     actual.is_empty() || expected.ends_with("[..]")
 }
 
-#[cargo_test]
+#[test]
 fn lines_match_works() {
     assert!(lines_match("a b", "a b"));
     assert!(lines_match("a[..]b", "a b"));

tests/testsuite/support/paths.rs → crates/cargo-test-support/src/paths.rs

@@ -1,3 +1,5 @@
+use filetime::{self, FileTime};
+use lazy_static::lazy_static;
 use std::cell::RefCell;
 use std::collections::HashMap;
 use std::env;
@@ -7,9 +9,6 @@ use std::path::{Path, PathBuf};
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::Mutex;
 
-use filetime::{self, FileTime};
-use lazy_static::lazy_static;
-
 static CARGO_INTEGRATION_TEST_DIR: &str = "cit";
 
 lazy_static! {

tests/testsuite/support/publish.rs → crates/cargo-test-support/src/publish.rs

@@ -1,12 +1,10 @@
+use crate::registry::{self, alt_api_path};
+use crate::{find_json_mismatch, lines_match};
+use flate2::read::GzDecoder;
 use std::collections::{HashMap, HashSet};
 use std::fs::File;
 use std::io::{self, prelude::*, SeekFrom};
 use std::path::{Path, PathBuf};
-
-use crate::support::registry::{self, alt_api_path};
-use crate::support::{find_json_mismatch, lines_match};
-
-use flate2::read::GzDecoder;
 use tar::Archive;
 
 fn read_le_u32<R>(mut reader: R) -> io::Result<u32>

tests/testsuite/support/registry.rs → crates/cargo-test-support/src/registry.rs

@@ -1,18 +1,16 @@
-use std::collections::HashMap;
-use std::fs::{self, File};
-use std::io::prelude::*;
-use std::path::{Path, PathBuf};
-
+use crate::git::repo;
+use crate::paths;
 use cargo::sources::CRATES_IO_INDEX;
 use cargo::util::Sha256;
 use flate2::write::GzEncoder;
 use flate2::Compression;
+use std::collections::HashMap;
+use std::fs::{self, File};
+use std::io::prelude::*;
+use std::path::{Path, PathBuf};
 use tar::{Builder, Header};
 use url::Url;
 
-use crate::support::git::repo;
-use crate::support::paths;
-
 /// Gets the path to the local index pretending to be crates.io. This is a Git repo
 /// initialized with a `config.json` file pointing to `dl_path` for downloads
 /// and `api_path` for uploads.

src/cargo/core/compiler/standard_lib.rs

@@ -7,6 +7,7 @@ use crate::core::{Dependency, PackageId, PackageSet, Resolve, SourceId, Workspac
 use crate::ops::{self, Packages};
 use crate::util::errors::CargoResult;
 use std::collections::{HashMap, HashSet};
+use std::env;
 use std::path::PathBuf;
 
 /// Parse the `-Zbuild-std` flag.
@@ -148,6 +149,10 @@ pub fn generate_std_roots<'a>(
 }
 
 fn detect_sysroot_src_path(ws: &Workspace<'_>) -> CargoResult<PathBuf> {
+    if let Some(s) = env::var_os("__CARGO_TESTS_ONLY_SRC_ROOT") {
+        return Ok(s.into());
+    }
+
     // NOTE: This is temporary until we figure out how to acquire the source.
     // If we decide to keep the sysroot probe, then BuildConfig will need to
     // be restructured so that the TargetInfo is created earlier and passed