From ec2ff09eff11104ba0d5d4fea0bb04bd2f017f4c Mon Sep 17 00:00:00 2001
From: "Wolfgang (Blub) Bumiller" <blub@speed.at>
Date: Mon, 26 Nov 2012 00:15:07 +0100
Subject: [PATCH] operator &~= must not cause the generated binstore to free
 the destination twice

---
 ast.c    | 5 ++++-
 ast.h    | 2 ++
 parser.c | 5 ++++-
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/ast.c b/ast.c
index fb58547..a622db6 100644
--- a/ast.c
+++ b/ast.c
@@ -435,6 +435,8 @@ ast_binstore* ast_binstore_new(lex_ctx ctx, int storop, int op,
     self->dest    = left;
     self->source  = right;
 
+    self->keep_dest = false;
+
     self->expression.vtype = left->expression.vtype;
     if (left->expression.next) {
         self->expression.next = ast_type_copy(ctx, left);
@@ -451,7 +453,8 @@ ast_binstore* ast_binstore_new(lex_ctx ctx, int storop, int op,
 
 void ast_binstore_delete(ast_binstore *self)
 {
-    ast_unref(self->dest);
+    if (!self->keep_dest)
+        ast_unref(self->dest);
     ast_unref(self->source);
     ast_expression_delete((ast_expression*)self);
     mem_d(self);
diff --git a/ast.h b/ast.h
index 29c3192..f1ca3c8 100644
--- a/ast.h
+++ b/ast.h
@@ -234,6 +234,8 @@ struct ast_binstore_s
     int             opbin;
     ast_expression *dest;
     ast_expression *source;
+    /* for &~= which uses the destination in a binary in source we can use this */
+    bool            keep_dest;
 };
 ast_binstore* ast_binstore_new(lex_ctx    ctx,
                                int        storeop,
diff --git a/parser.c b/parser.c
index 1268d03..ea84205 100644
--- a/parser.c
+++ b/parser.c
@@ -485,6 +485,7 @@ static bool parser_sy_pop(parser_t *parser, shunt *sy)
     ast_expression *exprs[3];
     ast_block      *blocks[3];
     ast_value      *asvalue[3];
+    ast_binstore   *asbinstore;
     size_t i, assignop, addop, subop;
     qcint  generated_op = 0;
 
@@ -1141,7 +1142,9 @@ static bool parser_sy_pop(parser_t *parser, shunt *sy)
             if (ast_istype(exprs[0], ast_value) && asvalue[0]->constant) {
                 parseerror(parser, "assignment to constant `%s`", asvalue[0]->name);
             }
-            out = (ast_expression*)ast_binstore_new(ctx, assignop, INSTR_SUB_F, exprs[0], out);
+            asbinstore = ast_binstore_new(ctx, assignop, INSTR_SUB_F, exprs[0], out);
+            asbinstore->keep_dest = true;
+            out = (ast_expression*)asbinstore;
             break;
     }
 #undef NotSameType
-- 
2.39.2