Merge pull request #616 from RalfJung/cargo-miri

Fix cargo miri on unit tests, refactor it a bit, set rust flag instead of feature flag
2019-02-07 14:44:14 +01:00 · 2019-02-07 14:44:14 +01:00 · 1889b9fe5a
commit 1889b9fe5a
parent 2d4ebf017d 5766b32871
8 changed files with 417 additions and 177 deletions
--- a/Cargo.toml
+++ b/Cargo.toml
@ -55,3 +55,6 @@ rustc_tests = []
 [dev-dependencies]
 compiletest_rs = { version = "0.3.17", features = ["tmp"] }
 colored = "1.6"
+
+[profile.release]
+debug = true
--- a/src/bin/cargo-miri.rs
+++ b/src/bin/cargo-miri.rs
@ -7,10 +7,10 @@ use std::io::{self, Write, BufRead};
 use std::process::Command;
 use std::fs::{self, File};

-const CARGO_MIRI_HELP: &str = r#"Interprets bin crates
+const CARGO_MIRI_HELP: &str = r#"Interprets bin crates and tests in Miri

 Usage:
-    cargo miri [subcommand] [options] [--] [<opts>...]
+    cargo miri [subcommand] [options] [--] [<miri opts>...]

 Subcommands:
    run                      Run binaries (default)
@ -22,12 +22,13 @@ Common options:
    --features               Features to compile for the package
    -V, --version            Print version info and exit

-Other options are the same as `cargo rustc`.
+Other [options] are the same as `cargo rustc`.  Everything after the "--" is
+passed verbatim to Miri.

-The feature `cargo-miri` is automatically defined for convenience. You can use
+The config flag `miri` is automatically defined for convenience. You can use
 it to configure the resource limits

-    #![cfg_attr(feature = "cargo-miri", memory_size = 42)]
+    #![cfg_attr(miri, memory_size = 42)]

 available resource limits are `memory_size`, `step_limit`, `stack_limit`
 "#;
@ -53,23 +54,32 @@ fn show_error(msg: String) -> ! {
    std::process::exit(1)
 }

+// Determines whether a --flag is present
+fn has_arg_flag(name: &str) -> bool {
+    let mut args = std::env::args().take_while(|val| val != "--");
+    args.any(|val| val == name)
+}
+
+/// Gets the value of a --flag
 fn get_arg_flag_value(name: &str) -> Option<String> {
    // stop searching at `--`
-    let mut args = std::env::args().skip_while(|val| !(val.starts_with(name) || val == "--"));
-
-    match args.next() {
-        Some(ref p) if p == "--" => None,
-        Some(ref p) if p == name => args.next(),
-        Some(p) => {
-            // Make sure this really starts with `$name=`, we didn't test for the `=` yet.
-            let v = &p[name.len()..]; // strip leading `$name`
-            if v.starts_with('=') {
-                Some(v[1..].to_owned()) // strip leading `=`
-            } else {
-                None
-            }
-        },
-        None => None,
+    let mut args = std::env::args().take_while(|val| val != "--");
+    loop {
+        let arg = match args.next() {
+            Some(arg) => arg,
+            None => return None,
+        };
+        if !arg.starts_with(name) {
+            continue;
+        }
+        let suffix = &arg[name.len()..]; // strip leading `name`
+        if suffix.is_empty() {
+            // This argument is exactly `name`, the next one is the value
+            return args.next();
+        } else if suffix.starts_with('=') {
+            // This argument is `name=value`, get the value
+            return Some(suffix[1..].to_owned()); // strip leading `=`
+        }
    }
 }

@ -272,167 +282,163 @@ fn main() {
        // each applicable target, but with the RUSTC env var set to the `cargo-miri`
        // binary so that we come back in the other branch, and dispatch
        // the invocations to rustc and miri, respectively.
-
-        let (subcommand, skip) = match std::env::args().nth(2).deref() {
-            Some("test") => (MiriCommand::Test, 3),
-            Some("run") => (MiriCommand::Run, 3),
-            Some("setup") => (MiriCommand::Setup, 3),
-            // Default command, if there is an option or nothing
-            Some(s) if s.starts_with("-") => (MiriCommand::Run, 2),
-            None => (MiriCommand::Run, 2),
-            // Unvalid command
-            Some(s) => {
-                show_error(format!("Unknown command `{}`", s))
-            }
-        };
-
-        // We always setup
-        let ask = subcommand != MiriCommand::Setup;
-        setup(ask);
-        if subcommand == MiriCommand::Setup {
-            // Stop here.
-            return;
-        }
-
-        // Now run the command.
-        for target in list_targets() {
-            let args = std::env::args().skip(skip);
-            let kind = target.kind.get(0).expect(
-                "badly formatted cargo metadata: target::kind is an empty array",
-            );
-            match (subcommand, &kind[..]) {
-                (MiriCommand::Test, "test") => {
-                    // For test binaries we call `cargo rustc --test target -- <rustc args>`
-                    if let Err(code) = process(
-                        vec!["--test".to_string(), target.name].into_iter().chain(
-                            args,
-                        ),
-                    )
-                    {
-                        std::process::exit(code);
-                    }
-                }
-                (MiriCommand::Test, "lib") => {
-                    // For libraries we call `cargo rustc -- --test <rustc args>`
-                    // Notice now that `--test` is a rustc arg rather than a cargo arg. This tells
-                    // rustc to build a test harness which calls all #[test] functions.
-                    // We then execute that harness just like any other binary.
-                    if let Err(code) = process(
-                        vec!["--".to_string(), "--test".to_string()].into_iter().chain(
-                            args,
-                        ),
-                    )
-                    {
-                        std::process::exit(code);
-                    }
-                }
-                (MiriCommand::Run, "bin") => {
-                    // For ordinary binaries we call `cargo rustc --bin target -- <rustc args>`
-                    if let Err(code) = process(
-                        vec!["--bin".to_string(), target.name].into_iter().chain(
-                            args,
-                        ),
-                    )
-                    {
-                        std::process::exit(code);
-                    }
-                }
-                _ => {}
-            }
-        }
+        in_cargo_miri();
    } else if let Some("rustc") = std::env::args().nth(1).as_ref().map(AsRef::as_ref) {
        // This arm is executed when cargo-miri runs `cargo rustc` with the `RUSTC_WRAPPER` env var set to itself:
        // Dependencies get dispatched to rustc, the final test/binary to miri.
-
-        let home = option_env!("RUSTUP_HOME").or(option_env!("MULTIRUST_HOME"));
-        let toolchain = option_env!("RUSTUP_TOOLCHAIN").or(option_env!("MULTIRUST_TOOLCHAIN"));
-        let sys_root = if let Ok(sysroot) = ::std::env::var("MIRI_SYSROOT") {
-            sysroot
-        } else if let (Some(home), Some(toolchain)) = (home, toolchain) {
-            format!("{}/toolchains/{}", home, toolchain)
-        } else {
-            option_env!("RUST_SYSROOT")
-                .map(|s| s.to_owned())
-                .or_else(|| {
-                    Command::new("rustc")
-                        .arg("--print")
-                        .arg("sysroot")
-                        .output()
-                        .ok()
-                        .and_then(|out| String::from_utf8(out.stdout).ok())
-                        .map(|s| s.trim().to_owned())
-                })
-                .expect("need to specify RUST_SYSROOT env var during miri compilation, or use rustup or multirust")
-        };
-
-        // this conditional check for the --sysroot flag is there so users can call `cargo-miri` directly
-        // without having to pass --sysroot or anything
-        let rustc_args = std::env::args().skip(2);
-        let mut args: Vec<String> = if std::env::args().any(|s| s == "--sysroot") {
-            rustc_args.collect()
-        } else {
-            rustc_args
-                .chain(Some("--sysroot".to_owned()))
-                .chain(Some(sys_root))
-                .collect()
-        };
-        args.splice(0..0, miri::miri_default_args().iter().map(ToString::to_string));
-        args.extend_from_slice(&["--cfg".to_owned(), r#"feature="cargo-miri""#.to_owned()]);
-
-        // this check ensures that dependencies are built but not interpreted and the final crate is
-        // interpreted but not built
-        let miri_enabled = std::env::args().any(|s| s == "--emit=dep-info,metadata");
-        let mut command = if miri_enabled {
-            let mut path = std::env::current_exe().expect("current executable path invalid");
-            path.set_file_name("miri");
-            Command::new(path)
-        } else {
-            Command::new("rustc")
-        };
-        command.args(&args);
-
-        match command.status() {
-            Ok(exit) => {
-                if !exit.success() {
-                    std::process::exit(exit.code().unwrap_or(42));
-                }
-            }
-            Err(ref e) if miri_enabled => panic!("error during miri run: {:?}", e),
-            Err(ref e) => panic!("error during rustc call: {:?}", e),
-        }
+        inside_cargo_rustc();
    } else {
        show_error(format!("Must be called with either `miri` or `rustc` as first argument."))
    }
 }

-fn process<I>(old_args: I) -> Result<(), i32>
-where
-    I: Iterator<Item = String>,
-{
-    let mut args = vec!["rustc".to_owned()];
+fn in_cargo_miri() {
+    let (subcommand, skip) = match std::env::args().nth(2).deref() {
+        Some("test") => (MiriCommand::Test, 3),
+        Some("run") => (MiriCommand::Run, 3),
+        Some("setup") => (MiriCommand::Setup, 3),
+        // Default command, if there is an option or nothing
+        Some(s) if s.starts_with("-") => (MiriCommand::Run, 2),
+        None => (MiriCommand::Run, 2),
+        // Unvalid command
+        Some(s) => {
+            show_error(format!("Unknown command `{}`", s))
+        }
+    };
+    let verbose = has_arg_flag("-v");

-    let mut found_dashes = false;
-    for arg in old_args {
-        found_dashes |= arg == "--";
-        args.push(arg);
+    // We always setup
+    let ask = subcommand != MiriCommand::Setup;
+    setup(ask);
+    if subcommand == MiriCommand::Setup {
+        // Stop here.
+        return;
    }
-    if !found_dashes {
-        args.push("--".to_owned());
-    }
-    args.push("--emit=dep-info,metadata".to_owned());

-    let path = std::env::current_exe().expect("current executable path invalid");
-    let exit_status = Command::new("cargo")
-        .args(&args)
-        .env("RUSTC_WRAPPER", path)
-        .spawn()
-        .expect("could not run cargo")
-        .wait()
-        .expect("failed to wait for cargo?");
+    // Now run the command.
+    for target in list_targets() {
+        let mut args = std::env::args().skip(skip);
+        let kind = target.kind.get(0).expect(
+            "badly formatted cargo metadata: target::kind is an empty array",
+        );
+        // Now we run `cargo rustc $FLAGS $ARGS`, giving the user the
+        // change to add additional flags.  "FLAGS" is set to identify
+        // this target.  The user gets to control what gets actually passed to Miri.
+        // However, we need to add a flag to what gets passed to rustc for the finaly
+        // binary, so that we know to interpret that with Miri.
+        // So after the first "--", we add "-Zcargo-miri-marker".
+        let mut cmd = Command::new("cargo");
+        cmd.arg("rustc");
+        match (subcommand, &kind[..]) {
+            (MiriCommand::Run, "bin") => {
+                // FIXME: We just run all the binaries here.
+                // We should instead support `cargo miri --bin foo`.
+                cmd.arg("--bin").arg(target.name);
+            }
+            (MiriCommand::Test, "test") => {
+                cmd.arg("--test").arg(target.name);
+            }
+            (MiriCommand::Test, "lib") |
+            (MiriCommand::Test, "bin") => {
+                cmd.arg(format!("--{}", kind)).arg(target.name).arg("--profile").arg("test");
+            }
+            // The remaining targets we do not even want to build
+            _ => continue,
+        }
+        // add user-defined args until first "--"
+        while let Some(arg) = args.next() {
+            if arg == "--" {
+                break;
+            }
+            cmd.arg(arg);
+        }
+        // add "--" "-Zcargo-miri-marker" and the remaining user flags
+        cmd
+            .arg("--")
+            .arg("cargo-miri-marker")
+            .args(args);
+        let path = std::env::current_exe().expect("current executable path invalid");
+        cmd.env("RUSTC_WRAPPER", path);
+        if verbose {
+            eprintln!("+ {:?}", cmd);
+        }

-    if exit_status.success() {
-        Ok(())
-    } else {
-        Err(exit_status.code().unwrap_or(-1))
+        let exit_status = cmd
+            .spawn()
+            .expect("could not run cargo")
+            .wait()
+            .expect("failed to wait for cargo?");
+
+        if !exit_status.success() {
+            std::process::exit(exit_status.code().unwrap_or(-1))
+        }
+    }
+}
+
+fn inside_cargo_rustc() {
+    let home = option_env!("RUSTUP_HOME").or(option_env!("MULTIRUST_HOME"));
+    let toolchain = option_env!("RUSTUP_TOOLCHAIN").or(option_env!("MULTIRUST_TOOLCHAIN"));
+    let sys_root = if let Ok(sysroot) = ::std::env::var("MIRI_SYSROOT") {
+        sysroot
+    } else if let (Some(home), Some(toolchain)) = (home, toolchain) {
+        format!("{}/toolchains/{}", home, toolchain)
+    } else {
+        option_env!("RUST_SYSROOT")
+            .map(|s| s.to_owned())
+            .or_else(|| {
+                Command::new("rustc")
+                    .arg("--print")
+                    .arg("sysroot")
+                    .output()
+                    .ok()
+                    .and_then(|out| String::from_utf8(out.stdout).ok())
+                    .map(|s| s.trim().to_owned())
+            })
+            .expect("need to specify RUST_SYSROOT env var during miri compilation, or use rustup or multirust")
+    };
+
+    // this conditional check for the --sysroot flag is there so users can call `cargo-miri` directly
+    // without having to pass --sysroot or anything
+    let rustc_args = std::env::args().skip(2);
+    let mut args: Vec<String> = if std::env::args().any(|s| s == "--sysroot") {
+        rustc_args.collect()
+    } else {
+        rustc_args
+            .chain(Some("--sysroot".to_owned()))
+            .chain(Some(sys_root))
+            .collect()
+    };
+    args.splice(0..0, miri::miri_default_args().iter().map(ToString::to_string));
+
+    // see if we have cargo-miri-marker, which means we want to interpret this crate in Miri
+    // (and remove the marker).
+    let needs_miri = if let Some(pos) = args.iter().position(|arg| arg == "cargo-miri-marker") {
+        args.remove(pos);
+        true
+    } else {
+        false
+    };
+
+
+    let mut command = if needs_miri {
+        let mut path = std::env::current_exe().expect("current executable path invalid");
+        path.set_file_name("miri");
+        Command::new(path)
+    } else {
+        Command::new("rustc")
+    };
+    command.args(&args);
+    if has_arg_flag("-v") {
+        eprintln!("+ {:?}", command);
+    }
+
+    match command.status() {
+        Ok(exit) => {
+            if !exit.success() {
+                std::process::exit(exit.code().unwrap_or(42));
+            }
+        }
+        Err(ref e) if needs_miri => panic!("error during miri run: {:?}", e),
+        Err(ref e) => panic!("error during rustc call: {:?}", e),
    }
 }
--- a/src/lib.rs
+++ b/src/lib.rs
@ -54,7 +54,7 @@ pub use crate::stacked_borrows::{Borrow, Stack, Stacks, BorStackItem};
 pub fn miri_default_args() -> &'static [&'static str] {
    // The flags here should be kept in sync with what bootstrap adds when `test-miri` is
    // set, which happens in `bootstrap/bin/rustc.rs` in the rustc sources.
-    &["-Zalways-encode-mir", "-Zmir-emit-retag", "-Zmir-opt-level=0"]
+    &["-Zalways-encode-mir", "-Zmir-emit-retag", "-Zmir-opt-level=0", "--cfg=miri"]
 }

 // Used by priroda
--- a/test-cargo-miri/Cargo.lock
+++ b/test-cargo-miri/Cargo.lock
@ -1,3 +1,15 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "autocfg"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "bitflags"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "byteorder"
 version = "1.0.0"
@ -8,7 +20,192 @@ name = "cargo-miri-test"
 version = "0.1.0"
 dependencies = [
 "byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

+[[package]]
+name = "cloudabi"
+version = "0.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "fuchsia-cprng"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "libc"
+version = "0.2.48"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "rand"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_hc 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_isaac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_jitter 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_os 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_pcg 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "rand_hc"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_isaac"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_jitter"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_os"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_pcg"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_xorshift"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rdrand"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rustc_version"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "semver"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "semver-parser"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "winapi"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [metadata]
+"checksum autocfg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a6d640bee2da49f60a4068a7fae53acde8982514ab7bae8b8cea9e88cbcfd799"
+"checksum bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "228047a76f468627ca71776ecdebd732a3423081fcf5125585bcd7c49886ce12"
 "checksum byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c40977b0ee6b9885c9013cd41d9feffdd22deb3bb4dc3a71d901cc7a77de18c8"
+"checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
+"checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
+"checksum libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)" = "e962c7641008ac010fa60a7dfdc1712449f29c44ef2d4702394aea943ee75047"
+"checksum rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)" = "6d71dacdc3c88c1fde3885a3be3fbab9f35724e6ce99467f7d9c5026132184ca"
+"checksum rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "556d3a1ca6600bfcbab7c7c91ccb085ac7fbbcd70e008a98742e7847f4f7bcef"
+"checksum rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
+"checksum rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d0e7a549d590831370895ab7ba4ea0c1b6b011d106b5ff2da6eee112615e6dc0"
+"checksum rand_hc 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7b40677c7be09ae76218dc623efbf7b18e34bced3f38883af07bb75630a21bc4"
+"checksum rand_isaac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ded997c9d5f13925be2a6fd7e66bf1872597f759fd9dd93513dd7e92e5a5ee08"
+"checksum rand_jitter 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "080723c6145e37503a2224f801f252e14ac5531cb450f4502698542d188cb3c0"
+"checksum rand_os 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "b7c690732391ae0abafced5015ffb53656abfaec61b342290e5eb56b286a679d"
+"checksum rand_pcg 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "086bd09a33c7044e56bb44d5bdde5a60e7f119a9e95b0775f545de759a32fe05"
+"checksum rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cbf7e9e623549b0e21f6e97cf8ecf247c1a8fd2e8a992ae265314300b2455d5c"
+"checksum rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
+"checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
+"checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
+"checksum semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
+"checksum winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "92c1eb33641e276cfa214a0522acad57be5c56b10cb348b3c5117db75f3ac4b0"
+"checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+"checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
--- a/test-cargo-miri/Cargo.toml
+++ b/test-cargo-miri/Cargo.toml
@ -6,3 +6,6 @@ edition = "2018"

 [dependencies]
 byteorder = "1.0"
+
+[dev-dependencies]
+rand = "0.6.5"
--- a/test-cargo-miri/src/main.rs
+++ b/test-cargo-miri/src/main.rs
@ -1,3 +1,7 @@
+extern crate byteorder;
+#[cfg(test)]
+extern crate rand;
+
 use byteorder::{BigEndian, ByteOrder};

 fn main() {
@ -7,3 +11,17 @@ fn main() {
    println!("{:#010x}", n);
    eprintln!("standard error");
 }
+
+#[cfg(test)]
+mod test {
+    use rand::{Rng, SeedableRng};
+
+    // Make sure in-crate tests with dev-dependencies work
+    #[test]
+    fn rng() {
+        let mut rng = rand::rngs::StdRng::seed_from_u64(0xcafebeef);
+        let x: u32 = rng.gen();
+        let y: u32 = rng.gen();
+        assert_ne!(x, y);
+    }
+}
--- a/test-cargo-miri/test.stdout.ref
+++ b/test-cargo-miri/test.stdout.ref
@ -1,7 +1,13 @@

+running 1 test
+test test::rng ... ok
+
+test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
+
+
 running 2 tests
-test bar ... ok
-test baz ... ok
+test rng ... ok
+test simple ... ok

 test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

--- a/test-cargo-miri/tests/test.rs
+++ b/test-cargo-miri/tests/test.rs
@ -1,17 +1,24 @@
+extern crate rand;
+
+use rand::{Rng, SeedableRng};
+
 #[test]
-fn bar() {
+fn simple() {
    assert_eq!(4, 4);
 }

 // Having more than 1 test does seem to make a difference
 // (i.e., this calls ptr::swap which having just one test does not).
 #[test]
-fn baz() {
-    assert_eq!(5, 5);
+fn rng() {
+    let mut rng = rand::rngs::StdRng::seed_from_u64(0xdeadcafe);
+    let x: u32 = rng.gen();
+    let y: u32 = rng.gen();
+    assert_ne!(x, y);
 }

 // A test that won't work on miri
-#[cfg(not(feature = "cargo-miri"))]
+#[cfg(not(miri))]
 #[test]
 fn does_not_work_on_miri() {
    let x = 0u8;