[PATCH olang 2/5] scope: make scope a bi-directional tree

[Carlos Maniero <carlos@maniero.me>]

In x86 architecture it is needed to reserve the stack space for local
variables. The code generators needs to compute this value from diving into
the tree from the function scope to the deepest level. So a
bi-directional scope are required.

Signed-off-by: Carlos Maniero <carlos@maniero.me>
Co-authored-by: Johnny Richard <johnny@johnnyrichard.com>
---
 src/scope.c | 14 ++++++++++++++
 src/scope.h |  2 ++
 2 files changed, 16 insertions(+)

diff --git a/src/scope.c b/src/scope.c
index 3271856..b23e865 100644
--- a/src/scope.c
+++ b/src/scope.c
@@ -33,6 +33,18 @@ scope_new(arena_t *arena)
     }
     scope->arena = arena;
     scope->symbols = map_new(arena);
+
+    // FIXME: create a list_new function to avoid spreading this.
+    list_t *children = (list_t *)arena_alloc(arena, sizeof(list_t));
+
+    if (children == NULL) {
+        fprintf(stderr, "[FATAL] Out of memory: scope_new: %s\n", strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+
+    list_init(children, arena);
+
+    scope->children = children;
     return scope;
 }
 
@@ -89,6 +101,8 @@ scope_push(scope_t *scope)
     scope_t *child = scope_new(scope->arena);
     child->parent = scope;
 
+    list_append(scope->children, child);
+
     return child;
 }
 
diff --git a/src/scope.h b/src/scope.h
index ddb0cd0..7f7eaae 100644
--- a/src/scope.h
+++ b/src/scope.h
@@ -18,6 +18,7 @@
 #define SCOPE_H
 
 #include "arena.h"
+#include "list.h"
 #include "map.h"
 #include "string_view.h"
 
@@ -29,6 +30,7 @@ typedef struct symbol
 typedef struct scope
 {
     struct scope *parent;
+    list_t *children;
     arena_t *arena;
     map_t *symbols;
 } scope_t;
-- 
2.34.1