feat: allow global variable initializer to reference another global variable addresses

2 files changed, 45 insertions, 4 deletions

diff --git a/src/codegen.c b/src/codegen.c
index 91f8cc6..36f854d 100644
--- a/src/codegen.c
+++ b/src/codegen.c
@@ -736,14 +736,32 @@ void codegen(Program* prog, FILE* out) {
     for (int i = 0; i < prog->vars->node_len; ++i) {
         AstNode* var = prog->vars->node_items + i;
         if (var->node_expr) {
-            if (type_sizeof(var->ty) == 1)
+            if (type_sizeof(var->ty) == 1) {
+                if (var->node_expr->kind != AstNodeKind_int_expr)
+                    unimplemented();
                 fprintf(g->out, "  %s: .byte %d\n", var->name, var->node_expr->node_int_value);
-            else if (type_sizeof(var->ty) == 2)
+            } else if (type_sizeof(var->ty) == 2) {
+                if (var->node_expr->kind != AstNodeKind_int_expr)
+                    unimplemented();
                 fprintf(g->out, "  %s: .word %d\n", var->name, var->node_expr->node_int_value);
-            else if (type_sizeof(var->ty) == 4)
+            } else if (type_sizeof(var->ty) == 4) {
+                if (var->node_expr->kind != AstNodeKind_int_expr)
+                    unimplemented();
                 fprintf(g->out, "  %s: .int %d\n", var->name, var->node_expr->node_int_value);
-            else
+            } else if (var->ty->kind == TypeKind_ptr) {
+                if (var->node_expr->kind == AstNodeKind_ref_expr) {
+                    if (var->node_expr->node_operand->kind != AstNodeKind_gvar) {
+                        unimplemented();
+                    }
+                    fprintf(g->out, "  %s: .quad %s\n", var->name, var->node_expr->node_operand->name);
+                } else if (var->node_expr->kind == AstNodeKind_gvar) {
+                    fprintf(g->out, "  %s: .quad %s\n", var->name, var->node_expr->name);
+                } else {
+                    unimplemented();
+                }
+            } else {
                 unimplemented();
+            }
         } else {
             fprintf(g->out, "  %s: .zero %d\n", var->name, type_sizeof(var->ty));
         }
diff --git a/tests/test_global_variables.sh b/tests/test_global_variables.sh
index b4eef09..8de1483 100644
--- a/tests/test_global_variables.sh
+++ b/tests/test_global_variables.sh
@@ -14,3 +14,26 @@ int main() {
 }
 EOF
 
+test_exit_code 0 <<'EOF'
+#include "../../helpers.h"
+
+int a;
+int* b = &a;
+int c[10];
+int* d = c;
+int e, *f = e, g[10], *h = g;
+
+int main() {
+    *b = 123;
+    ASSERT_EQ(123, a);
+
+    d[2] = 42;
+    ASSERT_EQ(42, c[2]);
+
+    *f = 456;
+    ASSERT_EQ(456, e);
+
+    h[5] = 789;
+    ASSERT_EQ(789, g[5]);
+}
+EOF