Add nullable, add bytecode documentation

3 files changed, 41 insertions, 4 deletions

diff --git a/include/ast.h b/include/ast.h
index 4c54766..6a40980 100644
--- a/include/ast.h
+++ b/include/ast.h
@@ -2,6 +2,7 @@
 #define AMALGAM_AST_H
 
 #include "defs.h"
+#include "nullable.h"
 #include "std/defs.h"
 #include "std/buffer_view.h"
 #include "std/buffer.h"
@@ -17,6 +18,7 @@
 #define AST_ERR -1
 #define AST_ERR_DEF_DUP -20
 
+typedef struct Ast Ast;
 typedef struct FunctionSignature FunctionSignature;
 typedef struct FunctionCall FunctionCall;
 typedef struct StructDecl StructDecl;
@@ -79,12 +81,14 @@ typedef struct {
     Parser *parser; /* Borrowed. This is the parser that is currently parsing the expression */
 } AstResolveData;
 
-typedef struct {
+struct Ast {
     AstValue value;
     AstType type;
     AstResolveData resolve_data;
     SsaRegister ssa_reg;
-} Ast;
+};
+
+DefineNullablePtrType(Ast);
 
 struct Scope {
     Buffer/*<Ast*>*/ ast_objects;
@@ -156,7 +160,7 @@ struct LhsExpr {
     bool is_const;
     BufferView var_name;
     VariableType type;
-    Ast *rhs_expr;
+    NullablePtr(Ast) rhs_expr;
 };
 
 struct AssignmentExpr {
@@ -244,4 +248,8 @@ CHECK_RESULT int scope_add_child(Scope *self, Ast *child);
 /* longjump to compiler env on failure */
 void scope_resolve(Scope *self, AstCompilerContext *context);
 
+
+
+CHECK_RESULT bool resolved_type_is_func_decl(Ast *self);
+
 #endif
diff --git a/include/bytecode/bytecode.h b/include/bytecode/bytecode.h
index 32488cc..4c54fbd 100644
--- a/include/bytecode/bytecode.h
+++ b/include/bytecode/bytecode.h
@@ -11,7 +11,7 @@
 /*doc(Opcode)
     Variable length opcodes. Sizes range from 1 to 4 bytes.
     # Instruction formats
-    Instructions can be in 6 different formats:
+    Instructions can be in 7 different formats:
     1. 1 byte: Opcode(u8)
     2. 2 bytes: Opcode(u8) + register(u8)
     3. 3 bytes: Opcode(u8) + register(u8) + register(u8)
diff --git a/include/nullable.h b/include/nullable.h
new file mode 100644
index 0000000..6c4d3a7
--- /dev/null
+++ b/include/nullable.h
@@ -0,0 +1,29 @@
+#ifndef AMAL_NULLABLE_H
+#define AMAL_NULLABLE_H
+
+struct __nullable_type_dummy{ int _; };
+
+int assert_not_null(void *val);
+
+#ifdef DEBUG
+#define DefineNullablePtrType(type)                 \
+    typedef struct type##_nullable type##_nullable; \
+    struct type##_nullable {                        \
+        type *value;                                \
+    }
+#define NullablePtr(type) type##_nullable
+#define nullable_unwrap(nullable_type) \
+    (assert_not_null((nullable_type).value) ? ((nullable_type).value) : NULL)
+#define nullable_assign(nullable_type, new_value) ((nullable_type).value = (new_value))
+#define is_not_null(nullable_type) ((nullable_type).value != NULL)
+#define nullable_raw(nullable_type) ((nullable_type).value)
+#else
+#define DefineNullablePtrType(type)
+#define NullablePtr(type) type*
+#define nullable_unwrap(value) value
+#define nullable_assign(nullable_type, new_value) ((nullable_type) = (new_value))
+#define is_not_null(nullable_type) ((nullable_type) != NULL)
+#define nullable_raw(nullable_type) (nullable_type)
+#endif
+
+#endif