Merge pull request #34 from oli-obk/alignment

use ty::layout::Size and ty::layout::TargetDataLayout

Author: solson

src/interpreter/mod.rs

@@ -35,7 +35,7 @@ pub struct EvalContext<'a, 'tcx: 'a> {
     mir_cache: RefCell<DefIdMap<Rc<mir::Mir<'tcx>>>>,
 
     /// The virtual memory system.
-    memory: Memory<'tcx>,
+    memory: Memory<'a, 'tcx>,
 
     /// Precomputed statics, constants and promoteds.
     statics: HashMap<ConstantId<'tcx>, Pointer>,
@@ -138,11 +138,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
             tcx: tcx,
             mir_map: mir_map,
             mir_cache: RefCell::new(DefIdMap()),
-            memory: Memory::new(tcx.sess
-                                   .target
-                                   .uint_type
-                                   .bit_width()
-                                   .expect("Session::target::uint_type was usize")/8),
+            memory: Memory::new(&tcx.data_layout),
             statics: HashMap::new(),
             stack: Vec::new(),
         }
@@ -162,7 +158,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
         &self.memory
     }
 
-    pub fn memory_mut(&mut self) -> &mut Memory<'tcx> {
+    pub fn memory_mut(&mut self) -> &mut Memory<'a, 'tcx> {
         &mut self.memory
     }
 
@@ -182,7 +178,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
                 Ok(ptr)
             }
             Str(ref s) => {
-                let psize = self.memory.pointer_size;
+                let psize = self.memory.pointer_size();
                 let static_ptr = self.memory.allocate(s.len());
                 let ptr = self.memory.allocate(psize * 2);
                 self.memory.write_bytes(static_ptr, s.as_bytes())?;
@@ -191,7 +187,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
                 Ok(ptr)
             }
             ByteStr(ref bs) => {
-                let psize = self.memory.pointer_size;
+                let psize = self.memory.pointer_size();
                 let static_ptr = self.memory.allocate(bs.len());
                 let ptr = self.memory.allocate(psize);
                 self.memory.write_bytes(static_ptr, bs)?;
@@ -515,7 +511,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
                 match lv.extra {
                     LvalueExtra::None => {},
                     LvalueExtra::Length(len) => {
-                        let len_ptr = dest.offset(self.memory.pointer_size as isize);
+                        let len_ptr = dest.offset(self.memory.pointer_size() as isize);
                         self.memory.write_usize(len_ptr, len)?;
                     }
                     LvalueExtra::DowncastVariant(..) =>
@@ -541,7 +537,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
 
                         match (&src_pointee_ty.sty, &dest_pointee_ty.sty) {
                             (&ty::TyArray(_, length), &ty::TySlice(_)) => {
-                                let len_ptr = dest.offset(self.memory.pointer_size as isize);
+                                let len_ptr = dest.offset(self.memory.pointer_size() as isize);
                                 self.memory.write_usize(len_ptr, length as u64)?;
                             }
 
@@ -655,7 +651,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
                 Ok(Size::from_bytes(0))
             }
             FatPointer { .. } => {
-                let bytes = layout::FAT_PTR_ADDR * self.memory.pointer_size;
+                let bytes = layout::FAT_PTR_ADDR * self.memory.pointer_size();
                 Ok(Size::from_bytes(bytes as u64))
             }
             _ => Err(EvalError::Unimplemented(format!("can't handle type: {:?}, with layout: {:?}", ty, layout))),
@@ -766,7 +762,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
                         let ptr = self.memory.read_ptr(base.ptr)?;
                         let extra = match pointee_ty.sty {
                             ty::TySlice(_) | ty::TyStr => {
-                                let len_ptr = base.ptr.offset(self.memory.pointer_size as isize);
+                                let len_ptr = base.ptr.offset(self.memory.pointer_size() as isize);
                                 let len = self.memory.read_usize(len_ptr)?;
                                 LvalueExtra::Length(len)
                             }
@@ -815,7 +811,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
 
     pub fn read_primval(&mut self, ptr: Pointer, ty: Ty<'tcx>) -> EvalResult<'tcx, PrimVal> {
         use syntax::ast::{IntTy, UintTy};
-        let val = match (self.memory.pointer_size, &ty.sty) {
+        let val = match (self.memory.pointer_size(), &ty.sty) {
             (_, &ty::TyBool)              => PrimVal::Bool(self.memory.read_bool(ptr)?),
             (_, &ty::TyChar)              => {
                 let c = self.memory.read_uint(ptr, 4)? as u32;
@@ -923,7 +919,7 @@ pub fn eval_main<'a, 'tcx: 'a>(
 
     if mir.arg_decls.len() == 2 {
         // start function
-        let ptr_size = ecx.memory().pointer_size;
+        let ptr_size = ecx.memory().pointer_size();
         let nargs = ecx.memory_mut().allocate(ptr_size);
         ecx.memory_mut().write_usize(nargs, 0).unwrap();
         let args = ecx.memory_mut().allocate(ptr_size);

src/interpreter/terminator.rs

@@ -277,7 +277,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
             .collect();
         let args_ptrs = args_res?;
 
-        let pointer_size = self.memory.pointer_size;
+        let pointer_size = self.memory.pointer_size();
 
         match name {
             "add_with_overflow" => self.intrinsic_with_overflow(mir::BinOp::Add, &args[0], &args[1], dest, dest_layout)?,
@@ -368,7 +368,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
                         ty::TySlice(_) | ty::TyStr => {
                             let elem_ty = ty.sequence_element_type(self.tcx);
                             let elem_size = self.type_size(elem_ty) as u64;
-                            let ptr_size = self.memory.pointer_size as isize;
+                            let ptr_size = self.memory.pointer_size() as isize;
                             let n = self.memory.read_usize(args_ptrs[0].offset(ptr_size))?;
                             self.memory.write_uint(dest, n * elem_size, pointer_size)?;
                         }
@@ -557,7 +557,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
                         self.memory.deallocate(contents_ptr)?;
                     }
                     Err(EvalError::ReadBytesAsPointer) => {
-                        let size = self.memory.pointer_size;
+                        let size = self.memory.pointer_size();
                         let possible_drop_fill = self.memory.read_bytes(ptr, size)?;
                         if possible_drop_fill.iter().all(|&b| b == mem::POST_DROP_U8) {
                             return Ok(());

src/memory.rs

@@ -6,6 +6,7 @@ use std::{fmt, iter, mem, ptr};
 use rustc::hir::def_id::DefId;
 use rustc::ty::BareFnTy;
 use rustc::ty::subst::Substs;
+use rustc::ty::layout::TargetDataLayout;
 
 use error::{EvalError, EvalResult};
 use primval::PrimVal;
@@ -53,7 +54,7 @@ pub struct FunctionDefinition<'tcx> {
 // Top-level interpreter memory
 ////////////////////////////////////////////////////////////////////////////////
 
-pub struct Memory<'tcx> {
+pub struct Memory<'a, 'tcx> {
     /// Actual memory allocations (arbitrary bytes, may contain pointers into other allocations)
     alloc_map: HashMap<AllocId, Allocation>,
     /// Function "allocations". They exist solely so pointers have something to point to, and
@@ -62,18 +63,17 @@ pub struct Memory<'tcx> {
     /// Inverse map of `functions` so we don't allocate a new pointer every time we need one
     function_alloc_cache: HashMap<FunctionDefinition<'tcx>, AllocId>,
     next_id: AllocId,
-    pub pointer_size: usize,
+    pub layout: &'a TargetDataLayout,
 }
 
-impl<'tcx> Memory<'tcx> {
-    // FIXME: pass tcx.data_layout (This would also allow it to use primitive type alignments to diagnose unaligned memory accesses.)
-    pub fn new(pointer_size: usize) -> Self {
+impl<'a, 'tcx> Memory<'a, 'tcx> {
+    pub fn new(layout: &'a TargetDataLayout) -> Self {
         Memory {
             alloc_map: HashMap::new(),
             functions: HashMap::new(),
             function_alloc_cache: HashMap::new(),
             next_id: AllocId(0),
-            pointer_size: pointer_size,
+            layout: layout,
         }
     }
 
@@ -156,10 +156,13 @@ impl<'tcx> Memory<'tcx> {
         Ok(())
     }
 
-    ////////////////////////////////////////////////////////////////////////////////
-    // Allocation accessors
-    ////////////////////////////////////////////////////////////////////////////////
+    pub fn pointer_size(&self) -> usize {
+        self.layout.pointer_size.bytes() as usize
+    }
+}
 
+/// Allocation accessors
+impl<'a, 'tcx> Memory<'a, 'tcx> {
     pub fn get(&self, id: AllocId) -> EvalResult<'tcx, &Allocation> {
         match self.alloc_map.get(&id) {
             Some(alloc) => Ok(alloc),
@@ -235,21 +238,20 @@ impl<'tcx> Memory<'tcx> {
             if !relocations.is_empty() {
                 print!("{:1$}", "", prefix.len()); // Print spaces.
                 let mut pos = 0;
-                let relocation_width = (self.pointer_size - 1) * 3;
+                let relocation_width = (self.pointer_size() - 1) * 3;
                 for (i, target_id) in relocations {
                     print!("{:1$}", "", (i - pos) * 3);
                     print!("└{0:─^1$}┘ ", format!("({})", target_id), relocation_width);
-                    pos = i + self.pointer_size;
+                    pos = i + self.pointer_size();
                 }
                 println!("");
             }
         }
     }
+}
 
-    ////////////////////////////////////////////////////////////////////////////////
-    // Byte accessors
-    ////////////////////////////////////////////////////////////////////////////////
-
+/// Byte accessors
+impl<'a, 'tcx> Memory<'a, 'tcx> {
     fn get_bytes_unchecked(&self, ptr: Pointer, size: usize) -> EvalResult<'tcx, &[u8]> {
         let alloc = self.get(ptr.alloc_id)?;
         if ptr.offset + size > alloc.bytes.len() {
@@ -287,11 +289,10 @@ impl<'tcx> Memory<'tcx> {
         self.mark_definedness(ptr, size, true)?;
         self.get_bytes_unchecked_mut(ptr, size)
     }
+}
 
-    ////////////////////////////////////////////////////////////////////////////////
-    // Reading and writing
-    ////////////////////////////////////////////////////////////////////////////////
-
+/// Reading and writing
+impl<'a, 'tcx> Memory<'a, 'tcx> {
     pub fn copy(&mut self, src: Pointer, dest: Pointer, size: usize) -> EvalResult<'tcx, ()> {
         self.check_relocation_edges(src, size)?;
 
@@ -336,7 +337,7 @@ impl<'tcx> Memory<'tcx> {
     }
 
     pub fn read_ptr(&self, ptr: Pointer) -> EvalResult<'tcx, Pointer> {
-        let size = self.pointer_size;
+        let size = self.pointer_size();
         self.check_defined(ptr, size)?;
         let offset = self.get_bytes_unchecked(ptr, size)?
             .read_uint::<NativeEndian>(size).unwrap() as usize;
@@ -349,7 +350,7 @@ impl<'tcx> Memory<'tcx> {
 
     pub fn write_ptr(&mut self, dest: Pointer, ptr: Pointer) -> EvalResult<'tcx, ()> {
         {
-            let size = self.pointer_size;
+            let size = self.pointer_size();
             let mut bytes = self.get_bytes_mut(dest, size)?;
             bytes.write_uint::<NativeEndian>(ptr.offset as u64, size).unwrap();
         }
@@ -358,7 +359,7 @@ impl<'tcx> Memory<'tcx> {
     }
 
     pub fn write_primval(&mut self, ptr: Pointer, val: PrimVal) -> EvalResult<'tcx, ()> {
-        let pointer_size = self.pointer_size;
+        let pointer_size = self.pointer_size();
         match val {
             PrimVal::Bool(b) => self.write_bool(ptr, b),
             PrimVal::I8(n)   => self.write_int(ptr, n as i64, 1),
@@ -406,31 +407,30 @@ impl<'tcx> Memory<'tcx> {
     }
 
     pub fn read_isize(&self, ptr: Pointer) -> EvalResult<'tcx, i64> {
-        self.read_int(ptr, self.pointer_size)
+        self.read_int(ptr, self.pointer_size())
     }
 
     pub fn write_isize(&mut self, ptr: Pointer, n: i64) -> EvalResult<'tcx, ()> {
-        let size = self.pointer_size;
+        let size = self.pointer_size();
         self.write_int(ptr, n, size)
     }
 
     pub fn read_usize(&self, ptr: Pointer) -> EvalResult<'tcx, u64> {
-        self.read_uint(ptr, self.pointer_size)
+        self.read_uint(ptr, self.pointer_size())
     }
 
     pub fn write_usize(&mut self, ptr: Pointer, n: u64) -> EvalResult<'tcx, ()> {
-        let size = self.pointer_size;
+        let size = self.pointer_size();
         self.write_uint(ptr, n, size)
     }
+}
 
-    ////////////////////////////////////////////////////////////////////////////////
-    // Relocations
-    ////////////////////////////////////////////////////////////////////////////////
-
+/// Relocations
+impl<'a, 'tcx> Memory<'a, 'tcx> {
     fn relocations(&self, ptr: Pointer, size: usize)
         -> EvalResult<'tcx, btree_map::Range<usize, AllocId>>
     {
-        let start = ptr.offset.saturating_sub(self.pointer_size - 1);
+        let start = ptr.offset.saturating_sub(self.pointer_size() - 1);
         let end = ptr.offset + size;
         Ok(self.get(ptr.alloc_id)?.relocations.range(Included(&start), Excluded(&end)))
     }
@@ -444,7 +444,7 @@ impl<'tcx> Memory<'tcx> {
         let start = ptr.offset;
         let end = start + size;
         let first = *keys.first().unwrap();
-        let last = *keys.last().unwrap() + self.pointer_size;
+        let last = *keys.last().unwrap() + self.pointer_size();
 
         let alloc = self.get_mut(ptr.alloc_id)?;
 
@@ -478,11 +478,10 @@ impl<'tcx> Memory<'tcx> {
         self.get_mut(dest.alloc_id)?.relocations.extend(relocations);
         Ok(())
     }
+}
 
-    ////////////////////////////////////////////////////////////////////////////////
-    // Undefined bytes
-    ////////////////////////////////////////////////////////////////////////////////
-
+/// Undefined bytes
+impl<'a, 'tcx> Memory<'a, 'tcx> {
     // FIXME(solson): This is a very naive, slow version.
     fn copy_undef_mask(&mut self, src: Pointer, dest: Pointer, size: usize) -> EvalResult<'tcx, ()> {
         // The bits have to be saved locally before writing to dest in case src and dest overlap.

tests/compile-fail/invalid_enum_discriminant.rs

@@ -0,0 +1,14 @@
+#[repr(C)]
+pub enum Foo {
+    A, B, C, D
+}
+
+fn main() {
+    let f = unsafe { std::mem::transmute::<i32, Foo>(42) };
+    match f {
+        Foo::A => {}, //~ ERROR invalid enum discriminant value read
+        Foo::B => {},
+        Foo::C => {},
+        Foo::D => {},
+    }
+}

tests/compile-fail/match_char.rs

@@ -0,0 +1,8 @@
+fn main() {
+    assert!(std::char::from_u32(-1_i32 as u32).is_none());
+    match unsafe { std::mem::transmute::<i32, char>(-1) } {
+        'a' => {}, //~ERROR tried to interpret an invalid 32-bit value as a char: 4294967295
+        'b' => {},
+        _ => {},
+    }
+}

tests/compiletest.rs

@@ -77,7 +77,7 @@ fn compile_test() {
             match cmd.output() {
                 Ok(ref output) if output.status.success() => writeln!(stderr.lock(), "ok").unwrap(),
                 Ok(output) => {
-                    writeln!(stderr.lock(), "FAILED with exit code {}", output.status.code().unwrap_or(0)).unwrap();
+                    writeln!(stderr.lock(), "FAILED with exit code {:?}", output.status.code()).unwrap();
                     writeln!(stderr.lock(), "stdout: \n {}", std::str::from_utf8(&output.stdout).unwrap()).unwrap();
                     writeln!(stderr.lock(), "stderr: \n {}", std::str::from_utf8(&output.stderr).unwrap()).unwrap();
                     panic!("some tests failed");