From 494cde2bbf222f4bce9e7fb89eda8e9c8d2559ec Mon Sep 17 00:00:00 2001
From: Lander Brandt <landerb@fb.com>
Date: Wed, 9 Mar 2022 13:28:50 -0800
Subject: [PATCH] cleanup detection of unix OS

---
 src/helpers.rs             | 13 ++++++++-----
 src/machine.rs             |  8 ++++----
 src/shims/dlsym.rs         |  3 ++-
 src/shims/foreign_items.rs |  3 ++-
 4 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/src/helpers.rs b/src/helpers.rs
index 0b37b78b6d..7386482339 100644
--- a/src/helpers.rs
+++ b/src/helpers.rs
@@ -438,14 +438,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
     }
 
     /// Helper function used inside the shims of foreign functions to assert that the target OS
-    /// is `target_os`. It panics showing a message with the `name` of the foreign function
+    /// is part of the UNIX family. It panics showing a message with the `name` of the foreign function
     /// if this is not the case.
     fn assert_target_os_is_unix(&self, name: &str) {
         assert!(
-            matches!(
-                self.eval_context_ref().tcx.sess.target.os.as_str(),
-                "linux" | "macos" | "android"
-            ),
+            target_os_is_unix(self.eval_context_ref().tcx.sess.target.os.as_str()),
             "`{}` is only available for supported UNIX family targets",
             name,
         );
@@ -788,3 +785,9 @@ pub fn simd_element_to_bool<'tcx>(elem: ImmTy<'tcx, Tag>) -> InterpResult<'tcx,
         _ => throw_ub_format!("each element of a SIMD mask must be all-0-bits or all-1-bits"),
     })
 }
+
+/// Helper function used inside the shims of foreign functions to check that the `target_os` is
+/// part of the UNIX family.
+pub fn target_os_is_unix(target_os: &str) -> bool {
+    matches!(target_os, "linux" | "macos" | "android")
+}
diff --git a/src/machine.rs b/src/machine.rs
index 5984aee984..5f878a5a66 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -263,12 +263,12 @@ impl MemoryExtra {
                                 symbol_name
                             )
                         });
-                    let (provenance, offset) =
-                        this.memory.create_fn_alloc(FnVal::Other(dlsym)).into_parts();
-                    let ptr = Pointer::new(Some(provenance), offset);
+                    let ptr = this.memory.create_fn_alloc(FnVal::Other(dlsym));
+
                     let place = this.allocate(layout, MiriMemoryKind::ExternStatic.into())?;
                     this.write_pointer(ptr, &place.into())?;
-                    Self::add_extern_static(this, symbol_name, place.ptr);
+
+                    Self::add_extern_static(this, symbol_name, place.ptr.into());
                 },
             _ => {} // No "extern statics" supported on this target
         }
diff --git a/src/shims/dlsym.rs b/src/shims/dlsym.rs
index 4befaf26aa..5d59450a08 100644
--- a/src/shims/dlsym.rs
+++ b/src/shims/dlsym.rs
@@ -1,6 +1,7 @@
 use rustc_middle::mir;
 use rustc_target::spec::abi::Abi;
 
+use crate::helpers::target_os_is_unix;
 use crate::*;
 use shims::posix::dlsym as posix;
 use shims::windows::dlsym as windows;
@@ -18,7 +19,7 @@ impl Dlsym {
     pub fn from_str(name: &[u8], target_os: &str) -> InterpResult<'static, Option<Dlsym>> {
         let name = &*String::from_utf8_lossy(name);
         Ok(match target_os {
-            "linux" | "macos" | "android" =>
+            target if target_os_is_unix(target) =>
                 posix::Dlsym::from_str(name, target_os)?.map(Dlsym::Posix),
             "windows" => windows::Dlsym::from_str(name)?.map(Dlsym::Windows),
             os => bug!("dlsym not implemented for target_os {}", os),
diff --git a/src/shims/foreign_items.rs b/src/shims/foreign_items.rs
index 64ec9dcf8c..46fa795c1c 100644
--- a/src/shims/foreign_items.rs
+++ b/src/shims/foreign_items.rs
@@ -26,6 +26,7 @@ use rustc_target::{
 };
 
 use super::backtrace::EvalContextExt as _;
+use crate::helpers::target_os_is_unix;
 use crate::*;
 
 /// Returned by `emulate_foreign_item_by_name`.
@@ -687,7 +688,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
 
             // Platform-specific shims
             _ => match this.tcx.sess.target.os.as_str() {
-                "linux" | "macos" | "android" => return shims::posix::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, abi, args, dest, ret),
+                target if target_os_is_unix(target) => return shims::posix::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, abi, args, dest, ret),
                 "windows" => return shims::windows::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, abi, args, dest, ret),
                 target => throw_unsup_format!("the target `{}` is not supported", target),
             }