Finished assignment expression

9 files changed, 88 insertions, 24 deletions

diff --git a/Notes.org b/Notes.org
index 8e6fbe4..c41d0ad 100644
--- a/Notes.org
+++ b/Notes.org
@@ -117,6 +117,10 @@
      Have to be careful because of the way the expressions are parsed.
      Constant expressions will just output li    $2, 6 for example
 
+***** Assignment
+
+      I'm assuming that the right hand side of an assigment is always a variable.
+
 **** TODO Function class
 
 **** TODO Statement class
diff --git a/c_compiler/GRTAGS b/c_compiler/GRTAGS
index 13d7d20..4a1db03 100644
--- a/c_compiler/GRTAGS
+++ b/c_compiler/GRTAGS
diff --git a/c_compiler/GTAGS b/c_compiler/GTAGS
index 5418332..b730179 100644
--- a/c_compiler/GTAGS
+++ b/c_compiler/GTAGS
diff --git a/c_compiler/include/expression.hpp b/c_compiler/include/expression.hpp
index d446972..d77d9d5 100644
--- a/c_compiler/include/expression.hpp
+++ b/c_compiler/include/expression.hpp
@@ -4,25 +4,55 @@
 #include "node.hpp"
 
 
-class Expression : public Node {
+class Expression : public Node
+{
 public:
+    virtual ~Expression();
+    
+    virtual VariableStackBindings printasm(VariableStackBindings bindings) const = 0;
+    
     virtual void print() const;
     virtual void printxml() const;
+    virtual int32_t getPostfixStackPosition(VariableStackBindings bindings) const;
+};
+
+
+class OperationExpression : public Expression
+{
+protected:
+    Expression* lhs;
+    Expression* rhs;
+public:
+    OperationExpression(Expression* _lhs, Expression* _rhs);
+    virtual ~OperationExpression();
+
     virtual VariableStackBindings printasm(VariableStackBindings bindings) const = 0;
 };
 
 
-class Identifier : public Expression {
+class AssignmentExpression : public OperationExpression
+{
+public:
+    AssignmentExpression(Expression* _lhs, Expression* _rhs);
+
+    virtual VariableStackBindings printasm(VariableStackBindings bindings) const;
+};
+
+
+class Identifier : public Expression
+{
 private:
     std::string m_id;
 public:
     Identifier(const std::string& id);
 
     virtual VariableStackBindings printasm(VariableStackBindings bindings) const;
+    virtual int32_t getPostfixStackPosition(VariableStackBindings bindings) const;
 };
 
 
-class Constant : public Expression {
+class Constant : public Expression
+{
 private:
     int32_t m_constant;
 public:
diff --git a/c_compiler/src/c_parser.y b/c_compiler/src/c_parser.y
index b3430ee..c762151 100644
--- a/c_compiler/src/c_parser.y
+++ b/c_compiler/src/c_parser.y
@@ -202,7 +202,7 @@ SelectionStatement:
 
 ExpressionStatement:
 		T_SC { $$ = new ExpressionStatement(); }
-|	Expression T_SC { $$ = new ExpressionStatement(); }
+|	Expression T_SC { $$ = new ExpressionStatement($1); }
 		;
 
 JumpStatement:
@@ -223,7 +223,7 @@ Expression:
 
 AssignmentExpression:
 		ConditionalExpression { $$ = $1; }
-	|	UnaryExpression ASSIGN_OPER AssignmentExpression { $$ = $1; }
+|	UnaryExpression ASSIGN_OPER AssignmentExpression { $$ = new AssignmentExpression($1, $3); }
 		;
 
 ASSIGN_OPER:
diff --git a/c_compiler/src/expression.cpp b/c_compiler/src/expression.cpp
index d9a366b..29bfe0d 100644
--- a/c_compiler/src/expression.cpp
+++ b/c_compiler/src/expression.cpp
@@ -5,12 +5,50 @@
 
 // Expression definition
 
+Expression::~Expression()
+{}
+
 void Expression::print() const
 {}
 
 void Expression::printxml() const
 {}
 
+int32_t Expression::getPostfixStackPosition(VariableStackBindings bindings) const
+{
+    return -1;
+}
+
+
+// OperationExpression definition
+
+OperationExpression::OperationExpression(Expression* _lhs, Expression* _rhs)
+    : lhs(_lhs), rhs(_rhs)
+{}
+
+OperationExpression::~OperationExpression()
+{
+    delete lhs;
+    delete rhs;
+}
+
+
+// Assignment Expression definition
+
+AssignmentExpression::AssignmentExpression(Expression* _lhs, Expression* _rhs)
+    : OperationExpression(_lhs, _rhs)
+{}
+
+VariableStackBindings AssignmentExpression::printasm(VariableStackBindings bindings) const
+{
+    int32_t store_stack_position = lhs->getPostfixStackPosition(bindings);
+    rhs->printasm(bindings);
+
+    std::cout << "\tsw\t$2," << store_stack_position << "($fp)" << std::endl;
+								   
+    return bindings;
+}
+
 
 // Identifier definition
 
@@ -30,6 +68,15 @@ VariableStackBindings Identifier::printasm(VariableStackBindings bindings) const
     return bindings;
 }
 
+int32_t Identifier::getPostfixStackPosition(VariableStackBindings bindings) const
+{
+    if(bindings.bindingExists(m_id)) {
+	return bindings.getStackPosition(m_id);
+    }
+
+    return -1;
+}
+
 
 // Constant definition
 
diff --git a/c_compiler/src/statement.cpp b/c_compiler/src/statement.cpp
index af382dc..50217fb 100644
--- a/c_compiler/src/statement.cpp
+++ b/c_compiler/src/statement.cpp
@@ -150,11 +150,9 @@ VariableStackBindings ExpressionStatement::printasm(VariableStackBindings bindin
 {
     if(next_statement != nullptr)
 	next_statement->printasm(bindings);
-    
-    if(m_expr != nullptr) {
-	std::cout << "SHould print" << std::endl;
+
+    if(m_expr != nullptr)
 	m_expr->printasm(bindings);
-    }
     
     return bindings;
 }
diff --git a/c_compiler/test/in/04.c b/c_compiler/test/in/04.c
deleted file mode 100644
index 57cf697..0000000
--- a/c_compiler/test/in/04.c
+++ /dev/null
@@ -1,9 +0,0 @@
-int main() {
-	int a = 3;
-	int b = 5;
-	return a + b;
-}
-
-int f(int a, int v) {
-	return a + v;
-}
diff --git a/c_compiler/test/in/05.c b/c_compiler/test/in/05.c
deleted file mode 100644
index 546012c..0000000
--- a/c_compiler/test/in/05.c
+++ /dev/null
@@ -1,6 +0,0 @@
-char *glob;
-
-int main() {
-	glob = "Yann";
-	return 0;
-}