implement Windows shim for 'GetEnvironmentStringsW'

Author: JOE1994

src/helpers.rs

@@ -493,17 +493,6 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
     /// Helper function to read an OsString from a 0x0000-terminated sequence of u16,
     /// which is what the Windows APIs usually handle.
     fn read_os_str_from_wide_str(&self, scalar: Scalar<Tag>) -> InterpResult<'tcx, OsString> {
-        #[cfg(target_os = "windows")]
-        fn u16vec_to_osstring<'tcx>(u16_vec: Vec<u16>) -> InterpResult<'tcx, OsString> {
-            Ok(std::os::windows::ffi::OsStringExt::from_wide(&u16_vec[..]))
-        }
-        #[cfg(not(target_os = "windows"))]
-        fn u16vec_to_osstring<'tcx>(u16_vec: Vec<u16>) -> InterpResult<'tcx, OsString> {
-            let s = String::from_utf16(&u16_vec[..])
-                .map_err(|_| err_unsup_format!("{:?} is not a valid utf-16 string", u16_vec))?;
-            Ok(s.into())
-        }
-
         let u16_vec = self.eval_context_ref().memory.read_wide_str(scalar)?;
         u16vec_to_osstring(u16_vec)
     }
@@ -637,6 +626,17 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
     }
 }
 
+#[cfg(target_os = "windows")]
+pub fn u16vec_to_osstring<'tcx>(u16_vec: Vec<u16>) -> InterpResult<'tcx, OsString> {
+    Ok(std::os::windows::ffi::OsStringExt::from_wide(&u16_vec[..]))
+}
+#[cfg(not(target_os = "windows"))]
+pub fn u16vec_to_osstring<'tcx>(u16_vec: Vec<u16>) -> InterpResult<'tcx, OsString> {
+    let s = String::from_utf16(&u16_vec[..])
+        .map_err(|_| err_unsup_format!("{:?} is not a valid utf-16 string", u16_vec))?;
+    Ok(s.into())
+}
+
 pub fn immty_from_int_checked<'tcx>(
     int: impl Into<i128>,
     layout: TyLayout<'tcx>,

src/lib.rs

@@ -49,7 +49,7 @@ pub use crate::diagnostics::{
     NonHaltingDiagnostic,
 };
 pub use crate::eval::{create_ecx, eval_main, MiriConfig, TerminationInfo};
-pub use crate::helpers::EvalContextExt as HelpersEvalContextExt;
+pub use crate::helpers::{EvalContextExt as HelpersEvalContextExt, u16vec_to_osstring};
 pub use crate::machine::{
     AllocExtra, Evaluator, FrameData, MemoryExtra, MiriEvalContext, MiriEvalContextExt,
     MiriMemoryKind, NUM_CPUS, PAGE_SIZE, STACK_ADDR, STACK_SIZE,

src/shims/foreign_items/windows.rs

@@ -1,5 +1,6 @@
 use crate::*;
 use crate::rustc_target::abi::LayoutOf;
+use crate::helpers::u16vec_to_osstring;
 use rustc::mir;
 use rustc::ty::layout::Size;
 use std::iter;
@@ -44,14 +45,14 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                 for &item in this.machine.env_vars.values()? {
                     let env_var = this.read_os_str_from_target_str(Scalar::from(item))?;
                     env_vars.push(env_var);
-                    env_vars.push(" ");
+                    env_vars.push(u16vec_to_osstring(vec![0x0000 as u16])?);
                 }
 
                 // Allocate environment block
                 let tcx = this.tcx;
                 let env_block_size = env_vars.len() + 1;
                 let env_block_type = tcx.mk_array(tcx.types.u16, u64::try_from(env_block_size).unwrap());
-                let env_block_place = this.allocate(this.layout_of(env_block_type)?, MiriMemoryKind::Machine.into());
+                let env_block_place = this.allocate(this.layout_of(env_block_type)?, MiriMemoryKind::WinHeap.into());
 
                 // Store environment variables to environment block
                 // Final null terminator(block terminator) is pushed by `write_os_str_to_wide_str`
@@ -62,8 +63,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             }
 
             "FreeEnvironmentStringsW" => {
-                // let old_vars_ptr = this.read_scalar(args[0])?.not_undef()?;
-                // this.memory.deallocate(this.force_ptr(old_vars_ptr)?, None, MiriMemoryKind::Machine.into())?;
+                let old_vars_ptr = this.read_scalar(args[0])?.not_undef()?;
+                this.memory.deallocate(this.force_ptr(old_vars_ptr)?, None, MiriMemoryKind::WinHeap.into())?;
             }
 
             // File related shims