Auto merge of #907 - christianpoveda:env-vars-shim, r=RalfJung

Move env shims to its own module

r? @RalfJung

src/eval.rs

@@ -39,7 +39,6 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
  Evaluator::new(config.communicate),
  MemoryExtra::new(StdRng::seed_from_u64(config.seed.unwrap_or(0)), config.validate),
  );
-
  // Complete initialization.
  EnvVars::init(&mut ecx, config.communicate);
 

src/lib.rs

@@ -33,7 +33,7 @@ pub use crate::shims::foreign_items::EvalContextExt as ForeignItemsEvalContextEx
 pub use crate::shims::intrinsics::EvalContextExt as IntrinsicsEvalContextExt;
 pub use crate::shims::tls::{EvalContextExt as TlsEvalContextExt, TlsData};
 pub use crate::shims::dlsym::{Dlsym, EvalContextExt as DlsymEvalContextExt};
-pub use crate::shims::env::EnvVars;
+pub use crate::shims::env::{EnvVars, EvalContextExt as EnvEvalContextExt};
 pub use crate::operator::EvalContextExt as OperatorEvalContextExt;
 pub use crate::range_map::RangeMap;
 pub use crate::helpers::{EvalContextExt as HelpersEvalContextExt};

src/shims/env.rs

@@ -22,21 +22,9 @@ impl EnvVars {
  }
  }
  }
-
- pub(crate) fn get(&self, name: &[u8]) -> Option<&Pointer<Tag>> {
- self.map.get(name)
- }
-
- pub(crate) fn unset(&mut self, name: &[u8]) -> Option<Pointer<Tag>> {
- self.map.remove(name)
- }
-
- pub(crate) fn set(&mut self, name: Vec<u8>, ptr: Pointer<Tag>) -> Option<Pointer<Tag>>{
- self.map.insert(name, ptr)
- }
 }
 
-pub(crate) fn alloc_env_value<'mir, 'tcx>(
+fn alloc_env_value<'mir, 'tcx>(
  bytes: &[u8],
  memory: &mut Memory<'mir, 'tcx, Evaluator<'tcx>>,
 ) -> Pointer<Tag> {
@@ -58,3 +46,72 @@ pub(crate) fn alloc_env_value<'mir, 'tcx>(
  alloc.write_bytes(&tcx, trailing_zero_ptr, &[0]).unwrap();
  ptr
 }
+
+impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
+pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
+ fn getenv(
+ &mut self,
+ name_op: OpTy<'tcx, Tag>,
+ ) -> InterpResult<'tcx, Scalar<Tag>> {
+ 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)?;
+ Ok(match this.machine.env_vars.map.get(name) {
+ Some(&var) => Scalar::Ptr(var),
+ None => Scalar::ptr_null(&*this.tcx),
+ })
+ }
+
+ fn setenv(
+ &mut self,
+ name_op: OpTy<'tcx, Tag>,
+ value_op: OpTy<'tcx, Tag>,
+ ) -> InterpResult<'tcx, i32> {
+ let 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 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'=') {
+ new = Some((name.to_owned(), value.to_owned()));
+ }
+ }
+ if let Some((name, value)) = new {
+ let value_copy = alloc_env_value(&value, this.memory_mut());
+ if let Some(var) = this.machine.env_vars.map.insert(name.to_owned(), value_copy) {
+ this.memory_mut().deallocate(var, None, MiriMemoryKind::Env.into())?;
+ }
+ Ok(0)
+ } else {
+ Ok(-1)
+ }
+ }
+
+ fn unsetenv(
+ &mut self,
+ name_op: OpTy<'tcx, Tag>,
+ ) -> InterpResult<'tcx, i32> {
+ let this = self.eval_context_mut();
+
+ 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'=') {
+ success = Some(this.machine.env_vars.map.remove(&name));
+ }
+ }
+ if let Some(old) = success {
+ if let Some(var) = old {
+ this.memory_mut().deallocate(var, None, MiriMemoryKind::Env.into())?;
+ }
+ Ok(0)
+ } else {
+ Ok(-1)
+ }
+ }
+}

src/shims/foreign_items.rs

@@ -8,7 +8,6 @@ use syntax::attr;
 use syntax::symbol::sym;
 
 use crate::*;
-use crate::shims::env::alloc_env_value;
 
 impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
@@ -423,60 +422,18 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  }
 
  "getenv" => {
- let result = {
- let name_ptr = this.read_scalar(args[0])?.not_undef()?;
- let name = this.memory().read_c_str(name_ptr)?;
- match this.machine.env_vars.get(name) {
- Some(&var) => Scalar::Ptr(var),
- None => Scalar::ptr_null(&*this.tcx),
- }
- };
+ let result = this.getenv(args[0])?;
  this.write_scalar(result, dest)?;
  }
 
  "unsetenv" => {
- let mut success = None;
- {
- let name_ptr = this.read_scalar(args[0])?.not_undef()?;
- if !this.is_null(name_ptr)? {
- let name = this.memory().read_c_str(name_ptr)?.to_owned();
- if !name.is_empty() && !name.contains(&b'=') {
- success = Some(this.machine.env_vars.unset(&name));
- }
- }
- }
- if let Some(old) = success {
- if let Some(var) = old {
- this.memory_mut().deallocate(var, None, MiriMemoryKind::Env.into())?;
- }
- this.write_null(dest)?;
- } else {
- this.write_scalar(Scalar::from_int(-1, dest.layout.size), dest)?;
- }
+ let result = this.unsetenv(args[0])?;
+ this.write_scalar(Scalar::from_int(result, dest.layout.size), dest)?;
  }
 
  "setenv" => {
- let mut new = None;
- {
- let name_ptr = this.read_scalar(args[0])?.not_undef()?;
- let value_ptr = this.read_scalar(args[1])?.not_undef()?;
- let value = this.memory().read_c_str(value_ptr)?;
- if !this.is_null(name_ptr)? {
- let name = this.memory().read_c_str(name_ptr)?;
- if !name.is_empty() && !name.contains(&b'=') {
- new = Some((name.to_owned(), value.to_owned()));
- }
- }
- }
- if let Some((name, value)) = new {
- let value_copy = alloc_env_value(&value, this.memory_mut());
- if let Some(var) = this.machine.env_vars.set(name.to_owned(), value_copy) {
- this.memory_mut().deallocate(var, None, MiriMemoryKind::Env.into())?;
- }
- this.write_null(dest)?;
- } else {
- this.write_scalar(Scalar::from_int(-1, dest.layout.size), dest)?;
- }
+ let result = this.setenv(args[0], args[1])?;
+ this.write_scalar(Scalar::from_int(result, dest.layout.size), dest)?;
  }
 
  "write" => {