From a61cd198a830a77526842bf63c79ef675411be37 Mon Sep 17 00:00:00 2001
From: dimgigov <gigov@gigov.org>
Date: Tue, 2 Jun 2026 13:11:40 +0300
Subject: [PATCH] fix(qbe): empty val/target fallbacks for hStore, hAssign,
 alloca-init

---
 _selfhost/src/qbe_backend.bux | 30 +++++-------------------------
 src_bux/qbe_backend.bux       | 30 +++++-------------------------
 2 files changed, 10 insertions(+), 50 deletions(-)

diff --git a/_selfhost/src/qbe_backend.bux b/_selfhost/src/qbe_backend.bux
index 2a5336e..2e62e5f 100644
--- a/_selfhost/src/qbe_backend.bux
+++ b/_selfhost/src/qbe_backend.bux
@@ -317,8 +317,10 @@ func QBE_EmitExpr(qbe: *QbeEmitter, node: *HirNode) -> String {
             target = QBE_LocalName(node.child1.strValue);
         } else {
             target = QBE_EmitExpr(qbe, node.child1);
+            if String_Eq(target, "") { return "0"; }
         }
         let val: String = QBE_EmitExpr(qbe, node.child2);
+        if String_Eq(val, "") { val = "0"; }
         let ty: String = QbeBackend_TypeWord(node.typeKind);
         QBE_EmitIndent(qbe);
         QBE_Emit(qbe, "store");
@@ -608,6 +610,7 @@ func QBE_EmitStmt(qbe: *QbeEmitter, node: *HirNode) {
             QBE_EmitLine(qbe, "");
             if node.child2 != null as *HirNode {
                 let val: String = QBE_EmitExpr(qbe, node.child2);
+                if String_Eq(val, "") { val = "0"; }
                 QBE_EmitIndent(qbe);
                 QBE_Emit(qbe, "store");
                 QBE_Emit(qbe, varTy);
@@ -622,6 +625,8 @@ func QBE_EmitStmt(qbe: *QbeEmitter, node: *HirNode) {
         let target: String = QBE_EmitExpr(qbe, node.child1);
         let val: String = QBE_EmitExpr(qbe, node.child2);
         let ty: String = QbeBackend_TypeWord(node.typeKind);
+        if String_Eq(val, "") { val = "0"; }
+        if String_Eq(target, "") { return; }
         QBE_EmitIndent(qbe);
         QBE_Emit(qbe, "store");
         QBE_Emit(qbe, ty);
@@ -632,31 +637,6 @@ func QBE_EmitStmt(qbe: *QbeEmitter, node: *HirNode) {
         return;
     }
 
-    // Assign: same as Store without alloca
-    if kind == hAssign {
-        var target: String = "";
-        if node.child1 != null as *HirNode && node.child1.kind == hVar {
-            target = QBE_LocalName(node.child1.strValue);
-        } else {
-            target = QBE_EmitExpr(qbe, node.child1);
-            if String_Eq(target, "") {
-                QBE_EmitLine(qbe, "# WARN: empty store target, skipping");
-                return;
-            }
-        }
-        let val: String = QBE_EmitExpr(qbe, node.child2);
-        let ty: String = QbeBackend_TypeWord(node.typeKind);
-        QBE_EmitIndent(qbe);
-        QBE_Emit(qbe, "store");
-        QBE_Emit(qbe, ty);
-        QBE_Emit(qbe, " ");
-        QBE_Emit(qbe, val);
-        QBE_Emit(qbe, ", ");
-        QBE_EmitLine(qbe, target);
-        return;
-    }
-
-    // Return
     if kind == hReturn {
         if node.child1 != null as *HirNode {
             let val: String = QBE_EmitExpr(qbe, node.child1);
diff --git a/src_bux/qbe_backend.bux b/src_bux/qbe_backend.bux
index 2a5336e..2e62e5f 100644
--- a/src_bux/qbe_backend.bux
+++ b/src_bux/qbe_backend.bux
@@ -317,8 +317,10 @@ func QBE_EmitExpr(qbe: *QbeEmitter, node: *HirNode) -> String {
             target = QBE_LocalName(node.child1.strValue);
         } else {
             target = QBE_EmitExpr(qbe, node.child1);
+            if String_Eq(target, "") { return "0"; }
         }
         let val: String = QBE_EmitExpr(qbe, node.child2);
+        if String_Eq(val, "") { val = "0"; }
         let ty: String = QbeBackend_TypeWord(node.typeKind);
         QBE_EmitIndent(qbe);
         QBE_Emit(qbe, "store");
@@ -608,6 +610,7 @@ func QBE_EmitStmt(qbe: *QbeEmitter, node: *HirNode) {
             QBE_EmitLine(qbe, "");
             if node.child2 != null as *HirNode {
                 let val: String = QBE_EmitExpr(qbe, node.child2);
+                if String_Eq(val, "") { val = "0"; }
                 QBE_EmitIndent(qbe);
                 QBE_Emit(qbe, "store");
                 QBE_Emit(qbe, varTy);
@@ -622,6 +625,8 @@ func QBE_EmitStmt(qbe: *QbeEmitter, node: *HirNode) {
         let target: String = QBE_EmitExpr(qbe, node.child1);
         let val: String = QBE_EmitExpr(qbe, node.child2);
         let ty: String = QbeBackend_TypeWord(node.typeKind);
+        if String_Eq(val, "") { val = "0"; }
+        if String_Eq(target, "") { return; }
         QBE_EmitIndent(qbe);
         QBE_Emit(qbe, "store");
         QBE_Emit(qbe, ty);
@@ -632,31 +637,6 @@ func QBE_EmitStmt(qbe: *QbeEmitter, node: *HirNode) {
         return;
     }
 
-    // Assign: same as Store without alloca
-    if kind == hAssign {
-        var target: String = "";
-        if node.child1 != null as *HirNode && node.child1.kind == hVar {
-            target = QBE_LocalName(node.child1.strValue);
-        } else {
-            target = QBE_EmitExpr(qbe, node.child1);
-            if String_Eq(target, "") {
-                QBE_EmitLine(qbe, "# WARN: empty store target, skipping");
-                return;
-            }
-        }
-        let val: String = QBE_EmitExpr(qbe, node.child2);
-        let ty: String = QbeBackend_TypeWord(node.typeKind);
-        QBE_EmitIndent(qbe);
-        QBE_Emit(qbe, "store");
-        QBE_Emit(qbe, ty);
-        QBE_Emit(qbe, " ");
-        QBE_Emit(qbe, val);
-        QBE_Emit(qbe, ", ");
-        QBE_EmitLine(qbe, target);
-        return;
-    }
-
-    // Return
     if kind == hReturn {
         if node.child1 != null as *HirNode {
             let val: String = QBE_EmitExpr(qbe, node.child1);