Auto merge of #3554 - RalfJung:freebsd, r=RalfJung

document unofficially supported OSes

Also tweak the freeBSD testing a bit.

Author: bors

src/tools/miri/README.md

@@ -224,8 +224,11 @@ degree documented below):
 - `s390x-unknown-linux-gnu` is supported as our "big-endian target of choice".
 - For every other target with OS `linux`, `macos`, or `windows`, Miri should generally work, but we
   make no promises and we don't run tests for such targets.
-- For targets on other operating systems, even basic operations such as printing to the standard
-  output might not work, and Miri might fail before even reaching the `main` function.
+- We have unofficial support (not maintained by the Miri team itself) for some further operating systems.
+  - `freebsd`: **maintainer wanted**. Supports `std::env` and parts of `std::{thread, fs}`, but not `std::sync`.
+  - `android`: **maintainer wanted**. Support very incomplete, but a basic "hello world" works.
+  - `wasm`: **maintainer wanted**. Support very incomplete, not even standard output works, but an empty `main` function works.
+- For targets on other operating systems, Miri might fail before even reaching the `main` function.
 
 However, even for targets that we do support, the degree of support for accessing platform APIs
 (such as the file system) differs between targets: generally, Linux targets have the best support,

src/tools/miri/ci/ci.sh

@@ -141,11 +141,13 @@ case $HOST_TARGET in
     MIRI_TEST_TARGET=arm-unknown-linux-gnueabi run_tests
     MIRI_TEST_TARGET=s390x-unknown-linux-gnu run_tests # big-endian architecture of choice
     # Partially supported targets (tier 2)
-    MIRI_TEST_TARGET=x86_64-unknown-freebsd run_tests_minimal hello integer vec panic/panic concurrency/simple pthread-threadname libc-getentropy libc-getrandom libc-misc libc-fs atomic env align num_cpus
-    MIRI_TEST_TARGET=i686-unknown-freebsd run_tests_minimal hello integer vec panic/panic concurrency/simple pthread-threadname libc-getentropy libc-getrandom libc-misc libc-fs atomic env align num_cpus
-    MIRI_TEST_TARGET=aarch64-linux-android run_tests_minimal hello integer vec panic/panic
-    MIRI_TEST_TARGET=wasm32-wasi run_tests_minimal no_std integer strings wasm
-    MIRI_TEST_TARGET=wasm32-unknown-unknown run_tests_minimal no_std integer strings wasm
+    VERY_BASIC="integer vec string btreemap" # common things we test on all of them (if they have std), requires no target-specific shims
+    BASIC="$VERY_BASIC hello hashmap alloc align" # ensures we have the shims for stdout and basic data structures
+    MIRI_TEST_TARGET=x86_64-unknown-freebsd run_tests_minimal $BASIC panic/panic concurrency/simple atomic threadname libc-getentropy libc-getrandom libc-misc fs env num_cpus
+    MIRI_TEST_TARGET=i686-unknown-freebsd   run_tests_minimal $BASIC panic/panic concurrency/simple atomic threadname libc-getentropy libc-getrandom libc-misc fs env num_cpus
+    MIRI_TEST_TARGET=aarch64-linux-android  run_tests_minimal $VERY_BASIC hello panic/panic
+    MIRI_TEST_TARGET=wasm32-wasi run_tests_minimal $VERY_BASIC wasm
+    MIRI_TEST_TARGET=wasm32-unknown-unknown run_tests_minimal $VERY_BASIC wasm
     MIRI_TEST_TARGET=thumbv7em-none-eabihf run_tests_minimal no_std
     # Custom target JSON file
     MIRI_TEST_TARGET=tests/avr.json MIRI_NO_STD=1 run_tests_minimal no_std

src/tools/miri/src/shims/unix/freebsd/foreign_items.rs

@@ -47,21 +47,6 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     this.read_scalar(len)?,
                 )?;
             }
-            "getrandom" => {
-                let [ptr, len, flags] =
-                    this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
-                let ptr = this.read_pointer(ptr)?;
-                let len = this.read_target_usize(len)?;
-                let _flags = this.read_scalar(flags)?.to_i32()?;
-                // flags on freebsd does not really matter
-                // in practice, GRND_RANDOM does not particularly draw from /dev/random
-                // since it is the same as to /dev/urandom.
-                // GRND_INSECURE is only an alias of GRND_NONBLOCK, which
-                // does not affect the RNG.
-                // https://man.freebsd.org/cgi/man.cgi?query=getrandom&sektion=2&n=1
-                this.gen_random(ptr, len)?;
-                this.write_scalar(Scalar::from_target_usize(len, this), dest)?;
-            }
 
             // File related shims
             // For those, we both intercept `func` and `call@FBSD_1.0` symbols cases
@@ -90,7 +75,22 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 this.write_scalar(result, dest)?;
             }
 
-            // errno
+            // Miscellaneous
+            "getrandom" => {
+                let [ptr, len, flags] =
+                    this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
+                let ptr = this.read_pointer(ptr)?;
+                let len = this.read_target_usize(len)?;
+                let _flags = this.read_scalar(flags)?.to_i32()?;
+                // flags on freebsd does not really matter
+                // in practice, GRND_RANDOM does not particularly draw from /dev/random
+                // since it is the same as to /dev/urandom.
+                // GRND_INSECURE is only an alias of GRND_NONBLOCK, which
+                // does not affect the RNG.
+                // https://man.freebsd.org/cgi/man.cgi?query=getrandom&sektion=2&n=1
+                this.gen_random(ptr, len)?;
+                this.write_scalar(Scalar::from_target_usize(len, this), dest)?;
+            }
             "__error" => {
                 let [] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
                 let errno_place = this.last_error_place()?;

src/tools/miri/tests/pass/align_offset_symbolic.rs

@@ -62,7 +62,10 @@ fn test_from_utf8() {
     const N: usize = 10;
     let vec = vec![0x4141414141414141u64; N];
     let content = unsafe { std::slice::from_raw_parts(vec.as_ptr() as *const u8, 8 * N) };
-    println!("{:?}", std::str::from_utf8(content).unwrap());
+    assert_eq!(
+        std::str::from_utf8(content).unwrap(),
+        "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
+    );
 }
 
 fn test_u64_array() {

src/tools/miri/tests/pass/align_offset_symbolic.stdout

@@ -31,8 +31,8 @@ fn main() {
     }
 
     // Regression test for Debug impl's
-    println!("{:?} {:?}", dst, dst.iter());
-    println!("{:?}", VecDeque::<u32>::new().iter());
+    format!("{:?} {:?}", dst, dst.iter());
+    format!("{:?}", VecDeque::<u32>::new().iter());
 
     for a in dst {
         assert_eq!(*a, 2);