1 files changed, 86 insertions, 22 deletions

diff --git a/include/ast.h b/include/ast.h
index d89d099..1198a98 100644
--- a/include/ast.h
+++ b/include/ast.h
@@ -19,6 +19,7 @@
 #define AST_ERR_DEF_DUP -20
 
 typedef struct Ast Ast;
+typedef struct FunctionParameter FunctionParameter;
 typedef struct FunctionSignature FunctionSignature;
 typedef struct FunctionCall FunctionCall;
 typedef struct StructDecl StructDecl;
@@ -33,6 +34,7 @@ typedef struct Binop Binop;
 typedef struct IfStatement IfStatement;
 typedef struct ElseIfStatement ElseIfStatement;
 typedef struct WhileStatement WhileStatement;
+typedef struct ReturnExpr ReturnExpr;
 
 /* TODO: Instead of using pointers, use the data directly */
 typedef union {
@@ -50,6 +52,7 @@ typedef union {
     Binop *binop;
     IfStatement *if_stmt;
     WhileStatement *while_stmt;
+    ReturnExpr *return_expr;
 } AstValue;
 
 typedef enum {
@@ -65,7 +68,8 @@ typedef enum {
     AST_VARIABLE,
     AST_BINOP,
     AST_IF_STATEMENT,
-    AST_WHILE_STATEMENT
+    AST_WHILE_STATEMENT,
+    AST_RETURN
 } AstType;
 
 typedef enum {
@@ -75,17 +79,50 @@ typedef enum {
     AST_SSA_RESOLVED
 } AstResolveStatus;
 
+typedef enum {
+    RESOLVED_TYPE_NONE,
+    RESOLVED_TYPE_LHS_EXPR,
+    RESOLVED_TYPE_FUNC_SIG
+} AstResolvedTypeEnum;
+
 typedef struct {
-    LhsExpr *type;
+    union {
+        LhsExpr *lhs_expr;
+        FunctionSignature *func_sig;
+    } value;
+    AstResolvedTypeEnum type;
+} AstResolvedType;
+
+typedef struct {
+    AstResolvedType type;
     AstResolveStatus status;
-    Parser *parser; /* Borrowed. This is the parser that is currently parsing the expression */
+    SsaRegister ssa_reg;
 } AstResolveData;
 
+typedef enum {
+    NAMED_OBJECT_NONE,
+    NAMED_OBJECT_LHS_EXPR,
+    NAMED_OBJECT_FUNC_PARAM
+} ScopeNamedObjectType;
+
+typedef struct {
+    union {
+        LhsExpr *lhs_expr;
+        FunctionParameter *func_param;
+    } value;
+    ScopeNamedObjectType type;
+    AstResolveData *resolve_data; /* Borrowed from @value.func_param or from the Ast @value.lhs_expr belongs to */
+} ScopeNamedObject;
+
 struct Ast {
     AstValue value;
     AstType type;
     AstResolveData resolve_data;
-    SsaRegister ssa_reg;
+    /*
+        Borrowed. This is the parser (thread) that is currently parsing the expression.
+        TODO: Move this to LhsExpr
+    */
+    Parser *parser;
 };
 
 struct Scope {
@@ -94,8 +131,22 @@ struct Scope {
     Scope *parent;
     /* Is null unless the scope is a file scope, in which case this is the parser that owns the scope */
     Parser *parser;
+    FunctionSignature *function_signature; /* Borrowed from FunctionDecl. Only used if the scope belongs to FunctionDecl */
 };
 
+typedef struct {
+    enum {
+        VARIABLE_TYPE_NONE,
+        VARIABLE_TYPE_VARIABLE,
+        VARIABLE_TYPE_SIGNATURE
+    } type;
+
+    union {
+        Variable *variable;
+        FunctionSignature *signature;
+    } value;
+} VariableType;
+
 struct FileScopeReference {
     Parser *parser;
     Buffer canonical_path;
@@ -103,15 +154,30 @@ struct FileScopeReference {
 
 struct Variable {
     BufferView name;
-    Ast *resolved_var; /* resolved_var will always be a LhsExpr after resolved */
+    ScopeNamedObject resolved_var;
+};
+
+struct FunctionParameter {
+    BufferView name;
+    VariableType type;
+    AstResolveData resolve_data;
 };
 
+typedef struct {
+    VariableType type;
+    AstResolvedType resolved_type;
+} FunctionReturnType;
+
 struct FunctionSignature {
-    int params; /* TODO: Implement signatures */
+    Buffer/*FunctionParameter*/ parameters;
+    Buffer/*FunctionReturnType*/ return_types;
+    /* Borrowed from the FunctionDecl the function signature belongs to. This is used to access the scope the function signature belongs to */
+    FunctionDecl *func_decl;
     bool resolved;
 };
 
 struct FunctionDecl {
+    LhsExpr *lhs_expr; /* Borrowed from the LhsExpr that owns this FunctionDecl if it exists, otherwise NULL */
     FunctionSignature *signature;
     Scope body;
     SsaFuncIndex ssa_func_index;
@@ -128,22 +194,9 @@ struct StructDecl {
 
 struct StructField {
     BufferView name;
-    Variable type;
+    VariableType type;
 };
 
-typedef struct {
-    enum {
-        VARIABLE_TYPE_NONE,
-        VARIABLE_TYPE_VARIABLE,
-        VARIABLE_TYPE_SIGNATURE
-    } type;
-
-    union {
-        Variable *variable;
-        FunctionSignature *signature;
-    } value;
-} VariableType;
-
 typedef enum {
     DECL_FLAG_NONE        = 0,
     DECL_FLAG_EXTERN      = 1 << 0,
@@ -221,6 +274,10 @@ struct WhileStatement {
     Scope body;
 };
 
+struct ReturnExpr {
+    Ast *rhs_expr;
+};
+
 typedef struct {
     jmp_buf env;
     amal_compiler *compiler; /* Borrowed */
@@ -235,12 +292,18 @@ typedef struct {
 CHECK_RESULT int ast_create(ArenaAllocator *allocator, void *value, AstType type, Ast **result);
 BufferView ast_get_name(Ast *self);
 
-void function_signature_init(FunctionSignature *self);
+CHECK_RESULT int function_signature_init(FunctionSignature *self, ArenaAllocator *allocator);
+/* Adds a copy of @param to the function signature parameter list */
+CHECK_RESULT int function_signature_add_parameter(FunctionSignature *self, const FunctionParameter *param);
+/* Adds a copy of @return_type to the function signature return type list */
+CHECK_RESULT int function_signature_add_return_type(FunctionSignature *self, const VariableType *return_type);
+void function_parameter_init(FunctionParameter *self);
 CHECK_RESULT int funcdecl_init(FunctionDecl *self, FunctionSignature *signature, Scope *parent, ArenaAllocator *allocator);
 CHECK_RESULT int funccall_init(FunctionCall *self, BufferView name, ArenaAllocator *allocator);
 CHECK_RESULT int structdecl_init(StructDecl *self, Scope *parent, ArenaAllocator *allocator);
 LhsExpr* structdecl_get_field_by_name(StructDecl *self, BufferView field_name);
-void structfield_init(StructField *self, BufferView name, BufferView type_name);
+/* Copies @type */
+void structfield_init(StructField *self, BufferView name, VariableType *type);
 void lhsexpr_init(LhsExpr *self, DeclFlag decl_flag, BufferView var_name);
 void assignmentexpr_init(AssignmentExpr *self, Ast *lhs_expr, Ast *rhs_expr);
 void import_init(Import *self, BufferView path);
@@ -251,6 +314,7 @@ void binop_init(Binop *self);
 CHECK_RESULT int if_statement_init(IfStatement *self, Scope *parent, ArenaAllocator *allocator);
 CHECK_RESULT int else_if_statement_init(ElseIfStatement *self, Scope *parent, ArenaAllocator *allocator);
 CHECK_RESULT int while_statement_init(WhileStatement *self, Scope *parent, ArenaAllocator *allocator);
+void return_expr_init(ReturnExpr *self, Ast *rhs_expr);
 
 CHECK_RESULT int scope_init(Scope *self, Scope *parent, ArenaAllocator *allocator);
 CHECK_RESULT int file_scope_reference_init(FileScopeReference *self, BufferView canonical_path, ArenaAllocator *allocator);