From a4bd68a45f50a9e77efde073e047beff8593e3ad Mon Sep 17 00:00:00 2001 From: JOE1994 Date: Fri, 27 Dec 2019 20:32:20 -0500 Subject: [PATCH] Add helper 'alloc_os_str_as_c_str' and use it in env_var emulation --- src/helpers.rs | 14 +++++++++++++ src/shims/env.rs | 43 +++++++++++++++++++------------------- src/shims/foreign_items.rs | 12 +++++++++++ 3 files changed, 47 insertions(+), 22 deletions(-) diff --git a/src/helpers.rs b/src/helpers.rs index 242e2b1d4a13..18b433a0e4a5 100644 --- a/src/helpers.rs +++ b/src/helpers.rs @@ -497,6 +497,20 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx .write_bytes(scalar, bytes.iter().copied().chain(iter::once(0u8)))?; Ok(true) } + + fn alloc_os_str_as_c_str( + &mut self, + os_str: &OsStr, + memkind: MemoryKind + ) -> Pointer { + let size = os_str.len() as u64 + 1; // Make space for `0` terminator. + let this = self.eval_context_mut(); + + let arg_type = this.tcx.mk_array(this.tcx.types.u8, size); + let arg_place = this.allocate(this.layout_of(arg_type).unwrap(), memkind); + self.write_os_str_to_c_str(os_str, arg_place.ptr, size).unwrap(); + arg_place.ptr.assert_ptr() + } } pub fn immty_from_int_checked<'tcx>( diff --git a/src/shims/env.rs b/src/shims/env.rs index 1e655ca821d8..1151561553f9 100644 --- a/src/shims/env.rs +++ b/src/shims/env.rs @@ -1,18 +1,18 @@ use std::collections::HashMap; -use std::ffi::OsString; +use std::ffi::{OsString, OsStr}; use std::env; use crate::stacked_borrows::Tag; use crate::*; use rustc::ty::layout::Size; -use rustc_mir::interpret::{Memory, Pointer}; +use rustc_mir::interpret::Pointer; #[derive(Default)] pub struct EnvVars { /// Stores pointers to the environment variables. These variables must be stored as /// null-terminated C strings with the `"{name}={value}"` format. - map: HashMap, Pointer>, + map: HashMap>, } impl EnvVars { @@ -30,24 +30,23 @@ impl EnvVars { for (name, value) in env::vars() { if !excluded_env_vars.contains(&name) { let var_ptr = - alloc_env_var(name.as_bytes(), value.as_bytes(), &mut ecx.memory); - ecx.machine.env_vars.map.insert(name.into_bytes(), var_ptr); + alloc_env_var_as_c_str(name.as_ref(), value.as_ref(), ecx); + ecx.machine.env_vars.map.insert(OsString::from(name), var_ptr); } } } } } -fn alloc_env_var<'mir, 'tcx>( - name: &[u8], - value: &[u8], - memory: &mut Memory<'mir, 'tcx, Evaluator<'tcx>>, +fn alloc_env_var_as_c_str<'mir, 'tcx>( + name: &OsStr, + value: &OsStr, + ecx: &mut InterpCx<'mir, 'tcx, Evaluator<'tcx>>, ) -> Pointer { - let mut bytes = name.to_vec(); - bytes.push(b'='); - bytes.extend_from_slice(value); - bytes.push(0); - memory.allocate_static_bytes(bytes.as_slice(), MiriMemoryKind::Env.into()) + let mut name_osstring = name.to_os_string(); + name_osstring.push("="); + name_osstring.push(value); + ecx.alloc_os_str_as_c_str(name_osstring.as_os_str(), MiriMemoryKind::Env.into()) } impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {} @@ -56,7 +55,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx let this = self.eval_context_mut(); let name_ptr = this.read_scalar(name_op)?.not_undef()?; - let name = this.memory.read_c_str(name_ptr)?; + let name = this.read_os_str_from_c_str(name_ptr)?; Ok(match this.machine.env_vars.map.get(name) { // The offset is used to strip the "{name}=" part of the string. Some(var_ptr) => { @@ -71,20 +70,20 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx name_op: OpTy<'tcx, Tag>, value_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i32> { - let this = self.eval_context_mut(); + let mut this = self.eval_context_mut(); let name_ptr = this.read_scalar(name_op)?.not_undef()?; let value_ptr = this.read_scalar(value_op)?.not_undef()?; - let value = this.memory.read_c_str(value_ptr)?; + let value = this.read_os_str_from_c_str(value_ptr)?; let mut new = None; if !this.is_null(name_ptr)? { - let name = this.memory.read_c_str(name_ptr)?; - if !name.is_empty() && !name.contains(&b'=') { + let name = this.read_os_str_from_c_str(name_ptr)?; + if !name.is_empty() && !name.to_string_lossy().contains('=') { new = Some((name.to_owned(), value.to_owned())); } } if let Some((name, value)) = new { - let var_ptr = alloc_env_var(&name, &value, &mut this.memory); + let var_ptr = alloc_env_var_as_c_str(&name, &value, &mut this); if let Some(var) = this.machine.env_vars.map.insert(name.to_owned(), var_ptr) { this.memory .deallocate(var, None, MiriMemoryKind::Env.into())?; @@ -101,8 +100,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx let name_ptr = this.read_scalar(name_op)?.not_undef()?; let mut success = None; if !this.is_null(name_ptr)? { - let name = this.memory.read_c_str(name_ptr)?.to_owned(); - if !name.is_empty() && !name.contains(&b'=') { + let name = this.read_os_str_from_c_str(name_ptr)?.to_owned(); + if !name.is_empty() && !name.to_string_lossy().contains('=') { success = Some(this.machine.env_vars.map.remove(&name)); } } diff --git a/src/shims/foreign_items.rs b/src/shims/foreign_items.rs index 5bdd12b4eb1d..07e3b7d75826 100644 --- a/src/shims/foreign_items.rs +++ b/src/shims/foreign_items.rs @@ -956,10 +956,22 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx this.write_null(dest)?; } "GetEnvironmentVariableW" => { + // args[0] : LPCWSTR lpName (32-bit ptr to a const string of 16-bit Unicode chars) + // args[1] : LPWSTR lpBuffer (32-bit pointer to a string of 16-bit Unicode chars) + // lpBuffer : ptr to buffer that receives contents of the env_var as a null-terminated string. + // Return `# of chars` stored in the buffer pointed to by lpBuffer, excluding null-terminator. + // Return 0 upon failure. + // This is not the env var you are looking for. this.set_last_error(Scalar::from_u32(203))?; // ERROR_ENVVAR_NOT_FOUND this.write_null(dest)?; } + "SetEnvironmentVariableW" => { + // args[0] : LPCWSTR lpName (32-bit ptr to a const string of 16-bit Unicode chars) + // args[1] : LPCWSTR lpValue (32-bit ptr to a const string of 16-bit Unicode chars) + // Return nonzero if success, else return 0. + throw_unsup_format!("can't set environment variable on Windows"); + } "GetCommandLineW" => { this.write_scalar( this.machine.cmd_line.expect("machine must be initialized"),