From bc90fae43364bba600319f6ffd2a48f53baf6067 Mon Sep 17 00:00:00 2001
From: Jean Privat <jean@pryen.org>
Date: Tue, 20 Jan 2009 14:59:50 -0500
Subject: [PATCH] Make 'self' a standard parameter (ParamVariable) This
 simplify the implementation and allows isa to work on self.
 A new test, base_isa_cast_self, is also added to check cast
 on self.

---
 src/compiling/compiling_global.nit    |    6 ++-
 src/compiling/compiling_methods.nit   |   24 ++++++++----
 src/syntax/syntax_base.nit            |   12 +++++-
 src/syntax/typing.nit                 |   34 +++++++++--------
 tests/base_isa_cast_self.nit          |   65 +++++++++++++++++++++++++++++++++
 tests/sav/base_isa_cast_self.sav      |    5 +++
 tests/sav/base_isa_cast_self_alt1.sav |    1 +
 tests/sav/base_isa_cast_self_alt2.sav |    1 +
 tests/sav/base_isa_cast_self_alt3.sav |    1 +
 tests/sav/base_isa_cast_self_alt4.sav |    1 +
 tests/sav/base_isa_cast_self_alt5.sav |    4 ++
 tests/sav/base_isa_cast_self_alt6.sav |    5 +++
 12 files changed, 133 insertions(+), 26 deletions(-)
 create mode 100644 tests/base_isa_cast_self.nit
 create mode 100644 tests/sav/base_isa_cast_self.sav
 create mode 100644 tests/sav/base_isa_cast_self_alt1.sav
 create mode 100644 tests/sav/base_isa_cast_self_alt2.sav
 create mode 100644 tests/sav/base_isa_cast_self_alt3.sav
 create mode 100644 tests/sav/base_isa_cast_self_alt4.sav
 create mode 100644 tests/sav/base_isa_cast_self_alt5.sav
 create mode 100644 tests/sav/base_isa_cast_self_alt6.sav

diff --git a/src/compiling/compiling_global.nit b/src/compiling/compiling_global.nit
index 15f8376..519878e 100644
--- a/src/compiling/compiling_global.nit
+++ b/src/compiling/compiling_global.nit
@@ -845,11 +845,15 @@ redef class MMLocalClass
 			var ctx_old = v.ctx
 			v.ctx = new CContext
 
-			v.nmc.method_params = ["OBJ2VAL(obj)"]
+			var self_var = new ParamVariable(null, null)
+			var self_var_cname = v.cfc.register_variable(self_var)
+			v.nmc.method_params = [self_var]
 
 			v.add_instr("obj_t obj;")
 			v.add_instr("obj = alloc(sizeof(val_t) * {itab.length});")
 			v.add_instr("obj->vft = (classtable_elt_t*)VFT_{name};")
+			v.add_assignment(self_var_cname, "OBJ2VAL(obj)")
+
 			for g in global_properties do
 				var p = self[g]
 				var t = p.signature.return_type
diff --git a/src/compiling/compiling_methods.nit b/src/compiling/compiling_methods.nit
index af1e848..2729ea1 100644
--- a/src/compiling/compiling_methods.nit
+++ b/src/compiling/compiling_methods.nit
@@ -114,9 +114,13 @@ redef class CompilerVisitor
 		while i < l do
 			var p = n.super_init_calls[i]
 			if p == stop_prop then break
-			var cargs = nmc.method_params
+			var cargs = new Array[String]
 			if p.signature.arity == 0 then
-				cargs = [nmc.method_params[0]]
+				cargs.add(cfc.varname(nmc.method_params[0]))
+			else
+				for va in nmc.method_params do
+					cargs.add(cfc.varname(va))
+				end
 			end
 			#s.append(" {p}")
 			p.compile_call(self, cargs)
@@ -205,8 +209,8 @@ class NitMethodContext
 	# Is a "return" found in the method body
 	readable writable attr _has_return: Bool = false
 
-	# Association between parameters and the corresponding c variables
-	readable writable attr _method_params: Array[String] 
+	# Association between parameters and the corresponding variables
+	readable writable attr _method_params: Array[ParamVariable] 
 
 	# Where a nit return must branch
 	readable writable attr _return_label: String 
@@ -463,6 +467,10 @@ redef class AConcreteMethPropdef
 		var old_nmc = v.nmc
 		v.nmc = new NitMethodContext(method)
 
+		var cname = v.cfc.register_variable(self_var)
+		v.add_assignment(cname, params[0])
+		v.nmc.method_params = [self_var]
+
 		var orig_meth: MMLocalProperty = method.global.intro
 		var orig_sig = orig_meth.signature_for(method.signature.recv)
 		if n_signature != null then
@@ -470,6 +478,7 @@ redef class AConcreteMethPropdef
 			assert sig isa ASignature
 			for ap in sig.n_params do
 				var cname = v.cfc.register_variable(ap.variable)
+				v.nmc.method_params.add(ap.variable)
 				var orig_type = orig_sig[ap.position]
 				if not orig_type < ap.variable.stype then
 					# FIXME: do not test always
@@ -488,7 +497,6 @@ redef class AConcreteMethPropdef
 			v.add_instr("if (init_table[{itpos}]) return;")
 		end
 
-		v.nmc.method_params = params
 		v.nmc.return_label = "return_label{v.new_number}"
 		if method.signature.return_type != null then
 			v.nmc.return_value = v.cfc.get_var
@@ -993,7 +1001,7 @@ end
 redef class ASelfExpr
 	redef meth compile_expr(v)
 	do
-		return v.nmc.method_params[0]
+		return v.cfc.varname(v.nmc.method_params[0])
 	end
 end
 
@@ -1227,10 +1235,10 @@ redef class ASuperExpr
 			arity = init_in_superclass.signature.arity
 		end
 		var args = new Array[String].with_capacity(arity + 1)
-		args.add(v.nmc.method_params[0])
+		args.add(v.cfc.varname(v.nmc.method_params[0]))
 		if n_args.length != arity then
 			for i in [0..arity[ do
-				args.add(v.nmc.method_params[i + 1])
+				args.add(v.cfc.varname(v.nmc.method_params[i + 1]))
 			end
 		else
 			for na in n_args do
diff --git a/src/syntax/syntax_base.nit b/src/syntax/syntax_base.nit
index ecbeffa..4703700 100644
--- a/src/syntax/syntax_base.nit
+++ b/src/syntax/syntax_base.nit
@@ -207,8 +207,8 @@ abstract class Variable
 
 	init(n: Symbol, d: PNode)
 	do
-		assert n != null
-		assert d != null
+		#assert n != null
+		#assert d != null
 		_name = n
 		_decl = d
 	end
@@ -415,6 +415,9 @@ end
 redef class AMethPropdef
 	# Associated method (MM entity)
 	meth method: MMMethSrcMethod is abstract
+
+	# Associated 'self' variable
+	meth self_var: ParamVariable is abstract
 end
 
 redef class ATypePropdef
@@ -578,6 +581,11 @@ redef class AForVardeclExpr
 	readable writable attr _variable: AutoVariable
 end
 
+redef class ASelfExpr
+	# Associated local variable
+	readable writable attr _variable: ParamVariable 
+end
+
 redef class AVarFormExpr
 	# Associated local variable
 	readable writable attr _variable: Variable 
diff --git a/src/syntax/typing.nit b/src/syntax/typing.nit
index 7da9d4e..5d01a75 100644
--- a/src/syntax/typing.nit
+++ b/src/syntax/typing.nit
@@ -44,8 +44,8 @@ special AbsSyntaxVisitor
 	# Current knowledge about variables names and types
 	readable writable attr _variable_ctx: VariableContext
 
-	# Type of the receiver
-	readable writable attr _self_type: MMType
+	# The current reciever
+	readable writable attr _self_var: ParamVariable
 
 	# Block of the current method
 	readable writable attr _top_block: PExpr
@@ -196,7 +196,8 @@ end
 redef class PClassdef
 	redef meth accept_typing(v)
 	do
-		v.self_type = local_class.get_type
+		v.self_var = new ParamVariable("self".to_symbol, self)
+		v.self_var.stype = local_class.get_type
 		super
 	end
 end
@@ -212,9 +213,11 @@ redef class AAttrPropdef
 end
 
 redef class AMethPropdef
+	redef readable attr _self_var: ParamVariable
 	redef meth accept_typing(v)
 	do
 		v.variable_ctx = new VariableContext
+		_self_var = v.self_var
 		super
 	end
 end
@@ -293,8 +296,8 @@ redef class PExpr
 	# Is the expression the current receiver (implicit or explicit)
 	meth is_self: Bool do return false
 
-	# Is the expression a variable access
-	meth is_variable: Bool do return false
+	# The variable accessed is any
+	meth its_variable: Variable do return null
 
 	# The variable type information if current boolean expression is true
 	readable private attr _if_true_variable_ctx: VariableContext
@@ -422,7 +425,7 @@ redef class AAssertExpr
 end
 
 redef class AVarExpr
-	redef meth is_variable do return true
+	redef meth its_variable do return variable
 
 	redef meth after_typing(v)
 	do
@@ -481,10 +484,12 @@ redef class AMinusAssignOp
 end
 
 redef class ASelfExpr
+	redef meth its_variable do return variable
+
 	redef meth after_typing(v)
 	do
-		assert v.self_type != null
-		_stype = v.self_type
+		variable = v.self_var
+		_stype = v.variable_ctx.stype(variable)
 	end
 
         redef meth is_self do return true
@@ -682,7 +687,7 @@ special ASuperInitCall
 			_init_in_superclass = p
 			register_super_init_call(v, p)
 			if n_args.length > 0 then
-				var signature = get_signature(v, v.self_type, p, true)
+				var signature = get_signature(v, v.self_var.stype, p, true)
 				_arguments = process_signature(v, signature, p, n_args.to_a)
 			end
 		else
@@ -690,12 +695,12 @@ special ASuperInitCall
 			return
 		end
 
-		if precs.first.signature_for(v.self_type).return_type != null then
+		if precs.first.signature_for(v.self_var.stype).return_type != null then
 			var stypes = new Array[MMType]
 			var stype: MMType = null
 			for prop in precs do
 				assert prop isa MMMethod
-				var t = prop.signature_for(v.self_type).return_type.for_module(v.module).adapt_to(v.local_property.signature.recv)
+				var t = prop.signature_for(v.self_var.stype).return_type.for_module(v.module).adapt_to(v.local_property.signature.recv)
 				stypes.add(t)
 				if stype == null or stype < t then
 					stype = t
@@ -1138,10 +1143,9 @@ end
 redef class AIsaExpr
 	redef meth after_typing(v)
 	do
-		if n_expr.is_variable then
-			var n = n_expr
-			assert n isa AVarExpr
-			_if_true_variable_ctx = v.variable_ctx.sub_with(n.variable, n_type.stype)
+		var variable = n_expr.its_variable
+		if variable != null then
+			_if_true_variable_ctx = v.variable_ctx.sub_with(variable, n_type.stype)
 		end
 		_stype = v.type_bool
 	end
diff --git a/tests/base_isa_cast_self.nit b/tests/base_isa_cast_self.nit
new file mode 100644
index 0000000..1bb78f4
--- /dev/null
+++ b/tests/base_isa_cast_self.nit
@@ -0,0 +1,65 @@
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Copyright 2009 Jean Privat <jean@pryen.org>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import kernel
+
+class A
+	init do end
+
+	meth work
+	do
+		if self isa B then
+			foo
+			if self isa C then
+				bar
+			end
+#alt1#			bar
+			foo
+		else
+#alt2#			foo
+		end
+#alt3#		foo
+
+		if self isa B and self == self then
+			foo
+		end
+
+		if self isa B or self == self then
+#alt4#			foo
+		end
+
+		assert self isa B
+		foo
+	end
+end
+
+class B
+special A
+	meth foo do 0.output
+	init do end
+end
+
+class C
+special B
+	meth bar do 1.output
+	init do end
+end
+
+var a: A
+a = new C
+#alt5#a = new B
+#alt6#a = new A
+a.work
diff --git a/tests/sav/base_isa_cast_self.sav b/tests/sav/base_isa_cast_self.sav
new file mode 100644
index 0000000..6473747
--- /dev/null
+++ b/tests/sav/base_isa_cast_self.sav
@@ -0,0 +1,5 @@
+0
+1
+0
+0
+0
diff --git a/tests/sav/base_isa_cast_self_alt1.sav b/tests/sav/base_isa_cast_self_alt1.sav
new file mode 100644
index 0000000..cc26292
--- /dev/null
+++ b/tests/sav/base_isa_cast_self_alt1.sav
@@ -0,0 +1 @@
+alt/base_isa_cast_self_alt1.nit:29,4--6: Error: Method or variable 'bar' unknown in B.
diff --git a/tests/sav/base_isa_cast_self_alt2.sav b/tests/sav/base_isa_cast_self_alt2.sav
new file mode 100644
index 0000000..d757bd5
--- /dev/null
+++ b/tests/sav/base_isa_cast_self_alt2.sav
@@ -0,0 +1 @@
+alt/base_isa_cast_self_alt2.nit:32,4--6: Error: Method or variable 'foo' unknown in A.
diff --git a/tests/sav/base_isa_cast_self_alt3.sav b/tests/sav/base_isa_cast_self_alt3.sav
new file mode 100644
index 0000000..730fb76
--- /dev/null
+++ b/tests/sav/base_isa_cast_self_alt3.sav
@@ -0,0 +1 @@
+alt/base_isa_cast_self_alt3.nit:34,3--5: Error: Method or variable 'foo' unknown in A.
diff --git a/tests/sav/base_isa_cast_self_alt4.sav b/tests/sav/base_isa_cast_self_alt4.sav
new file mode 100644
index 0000000..f41b3c1
--- /dev/null
+++ b/tests/sav/base_isa_cast_self_alt4.sav
@@ -0,0 +1 @@
+alt/base_isa_cast_self_alt4.nit:41,4--6: Error: Method or variable 'foo' unknown in A.
diff --git a/tests/sav/base_isa_cast_self_alt5.sav b/tests/sav/base_isa_cast_self_alt5.sav
new file mode 100644
index 0000000..44e0be8
--- /dev/null
+++ b/tests/sav/base_isa_cast_self_alt5.sav
@@ -0,0 +1,4 @@
+0
+0
+0
+0
diff --git a/tests/sav/base_isa_cast_self_alt6.sav b/tests/sav/base_isa_cast_self_alt6.sav
new file mode 100644
index 0000000..7951723
--- /dev/null
+++ b/tests/sav/base_isa_cast_self_alt6.sav
@@ -0,0 +1,5 @@
+Assert failed in base_isa_cast_self_alt6::A::work (alt/base_isa_cast_self_alt6.nit:44)
+,---- Stack trace -- - -  -
+| base_isa_cast_self_alt6::A::work (alt/base_isa_cast_self_alt6.nit:22)
+| base_isa_cast_self_alt6::Sys::(kernel::Sys::main) (alt/base_isa_cast_self_alt6.nit:61)
+`------------------- - -  -
-- 
1.7.9.5