Remove pointers from the Sway IR. (FuelLabs#3663)

Remove pointers from IR.
    
The pointers in the IR are not really pointers, but are local variables.
We want to add proper pointers to the IR though and naming the local
variables as pointers adds ambiguity.
    
This change renames `get_ptr` to `get_local` and removes `ptr` and `mut`
from the serialised output.  `get_local` no longer performs casts so
`cast_ptr` has been added as a stopgap until we add a better solution.

sway-core/src/asm_generation/asm_builder/functions.rs

@@ -310,7 +310,10 @@ impl<'ir> AsmBuilder<'ir> {
                         }
 
                         // The base is an offset.  Dereference it.
-                        if val.get_type(self.context).unwrap().is_copy_type() {
+                        if val
+                            .get_type(self.context)
+                            .map_or(false, |t| self.is_copy_type(&t))
+                        {
                             self.cur_bytecode.push(Op {
                                 opcode: either::Either::Left(VirtualOp::LW(
                                     single_arg_reg.clone(),
@@ -344,7 +347,7 @@ impl<'ir> AsmBuilder<'ir> {
                     let current_arg_reg = self.value_to_register(val);
                     let arg_type = val.get_type(self.context).unwrap();
                     let arg_type_size_bytes = ir_type_size_in_bytes(self.context, &arg_type);
-                    if arg_type.is_copy_type() {
+                    if self.is_copy_type(&arg_type) {
                         if arg_word_offset > compiler_constants::TWELVE_BITS {
                             let offs_reg = self.reg_seqr.next();
                             self.cur_bytecode.push(Op {
@@ -589,15 +592,14 @@ impl<'ir> AsmBuilder<'ir> {
         // Stack offsets are in words to both enforce alignment and simplify use with LW/SW.
         let mut stack_base = 0_u64;
         for (_name, ptr) in function.locals_iter(self.context) {
-            if !ptr.is_mutable(self.context) && ptr.get_initializer(self.context).is_some() {
-                let constant = ptr.get_initializer(self.context).unwrap();
+            if let Some(constant) = ptr.get_initializer(self.context) {
                 let data_id = self
                     .data_section
                     .insert_data_value(Entry::from_constant(self.context, constant));
                 self.ptr_map.insert(*ptr, Storage::Data(data_id));
             } else {
                 match ptr.get_type(self.context) {
-                    Type::Unit | Type::Bool | Type::Uint(_) | Type::Pointer(_) => {
+                    Type::Unit | Type::Bool | Type::Uint(_) => {
                         self.ptr_map.insert(*ptr, Storage::Stack(stack_base));
                         stack_base += 1;
                     }

sway-core/src/asm_generation/from_ir.rs

@@ -173,7 +173,7 @@ pub enum StateAccessType {
 
 pub(crate) fn ir_type_size_in_bytes(context: &Context, ty: &Type) -> u64 {
     match ty {
-        Type::Unit | Type::Bool | Type::Uint(_) | Type::Pointer(_) => 8,
+        Type::Unit | Type::Bool | Type::Uint(_) => 8,
         Type::Slice => 16,
         Type::B256 => 32,
         Type::String(n) => size_bytes_round_up_to_word_alignment!(n),

sway-core/src/ir_generation/compile.rs

@@ -313,7 +313,7 @@ pub(super) fn compile_function(
             .parameters
             .iter()
             .map(|param| convert_fn_param(type_engine, context, param))
-            .collect::<Result<Vec<(String, Type, Span)>, CompileError>>()?;
+            .collect::<Result<Vec<(String, Type, bool, Span)>, CompileError>>()?;
 
         compile_fn_with_args(
             engines,
@@ -388,17 +388,11 @@ fn convert_fn_param(
     type_engine: &TypeEngine,
     context: &mut Context,
     param: &ty::TyFunctionParameter,
-) -> Result<(String, Type, Span), CompileError> {
+) -> Result<(String, Type, bool, Span), CompileError> {
     convert_resolved_typeid(type_engine, context, &param.type_id, &param.type_span).map(|ty| {
-        (
-            param.name.as_str().into(),
-            if param.is_reference && type_engine.look_up_type_id(param.type_id).is_copy_type() {
-                Type::Pointer(Pointer::new(context, ty, param.is_mutable, None))
-            } else {
-                ty
-            },
-            param.name.span(),
-        )
+        let by_ref =
+            param.is_reference && type_engine.look_up_type_id(param.type_id).is_copy_type();
+        (param.name.as_str().into(), ty, by_ref, param.name.span())
     })
 }
 
@@ -410,7 +404,7 @@ fn compile_fn_with_args(
     module: Module,
     ast_fn_decl: &ty::TyFunctionDeclaration,
     is_entry: bool,
-    args: Vec<(String, Type, Span)>,
+    args: Vec<(String, Type, bool, Span)>,
     selector: Option<[u8; 4]>,
     logged_types_map: &HashMap<TypeId, LogId>,
     messages_types_map: &HashMap<TypeId, MessageId>,
@@ -432,17 +426,18 @@ fn compile_fn_with_args(
 
     let mut args = args
         .into_iter()
-        .map(|(name, ty, span)| (name, ty, md_mgr.span_to_md(context, &span)))
+        .map(|(name, ty, by_ref, span)| (name, ty, by_ref, md_mgr.span_to_md(context, &span)))
         .collect::<Vec<_>>();
 
     let ret_type = convert_resolved_typeid(type_engine, context, return_type, return_type_span)?;
 
-    let returns_by_ref = !is_entry && !ret_type.is_copy_type();
+    let returns_by_ref = !is_entry && !type_engine.look_up_type_id(*return_type).is_copy_type();
     if returns_by_ref {
         // Instead of 'returning' a by-ref value we make the last argument an 'out' parameter.
         args.push((
             "__ret_value".to_owned(),
-            Type::Pointer(Pointer::new(context, ret_type, true, None)),
+            ret_type,
+            true,
             md_mgr.span_to_md(context, return_type_span),
         ));
     }
@@ -488,9 +483,7 @@ fn compile_fn_with_args(
     // together and is invalid.  This can happen with diverging control flow or with implicit
     // returns.  We can double check here and make sure the return value type is correct.
     ret_val = match ret_val.get_type(context) {
-        Some(ret_val_type) if ret_type.eq(context, &ret_val_type.strip_ptr_type(context)) => {
-            ret_val
-        }
+        Some(ret_val_type) if ret_type.eq(context, &ret_val_type) => ret_val,
 
         // Mismatched or unavailable type.  Set ret_val to a correctly typed Undef.
         _otherwise => Value::new_constant(context, Constant::get_undef(ret_type)),
@@ -593,9 +586,9 @@ fn compile_abi_method(
         .iter()
         .map(|param| {
             convert_resolved_typeid(type_engine, context, &param.type_id, &param.type_span)
-                .map(|ty| (param.name.as_str().into(), ty, param.name.span()))
+                .map(|ty| (param.name.as_str().into(), ty, false, param.name.span()))
         })
-        .collect::<Result<Vec<(String, Type, Span)>, CompileError>>()?;
+        .collect::<Result<Vec<(String, Type, bool, Span)>, CompileError>>()?;
 
     compile_fn_with_args(
         engines,

sway-core/src/ir_generation/const_eval.rs

@@ -34,28 +34,24 @@ pub(crate) fn compile_const_decl(
     // Check if it's a processed local constant.
     if let Some(fn_compiler) = env.function_compiler {
         let mut found_local = false;
-        if let Some(ptr) = fn_compiler.get_function_ptr(env.context, name.as_str()) {
+        if let Some(local_var) = fn_compiler.get_function_var(env.context, name.as_str()) {
             found_local = true;
-            if !ptr.is_mutable(env.context) {
-                if let Some(constant) = ptr.get_initializer(env.context) {
-                    return Ok(Some(Value::new_constant(env.context, constant.clone())));
-                }
+            if let Some(constant) = local_var.get_initializer(env.context) {
+                return Ok(Some(Value::new_constant(env.context, constant.clone())));
             }
 
-            // Check if a constant was stored to the pointer in the current block
+            // Check if a constant was stored to a local variable in the current block.
             let mut stored_const_opt: Option<&Constant> = None;
             for ins in fn_compiler.current_block.instruction_iter(env.context) {
                 if let Some(Instruction::Store {
                     dst_val,
                     stored_val,
                 }) = ins.get_instruction(env.context)
                 {
-                    if let Some(Instruction::GetPointer {
-                        base_ptr: base_ptr_2,
-                        ..
-                    }) = dst_val.get_instruction(env.context)
+                    if let Some(Instruction::GetLocal(store_dst_var)) =
+                        dst_val.get_instruction(env.context)
                     {
-                        if &ptr == base_ptr_2 {
+                        if &local_var == store_dst_var {
                             stored_const_opt = stored_val.get_constant(env.context);
                         }
                     }