fix: error reporting for global variables

src/AstGen.zig

@@ -491,6 +491,7 @@ fn setDeclaration(
         name: Ir.NullTerminatedString,
         value: Ir.Inst.Index,
         gi: *GenIr,
+        node: *const Ast.Node,
     },
 ) !void {
     const astgen = args.gi.astgen;
@@ -498,17 +499,19 @@ fn setDeclaration(
     try astgen.extra.ensureUnusedCapacity(astgen.gpa, extra_len);
 
     const inst_data = &astgen.instructions.items[@intFromEnum(decl_index)].data;
-    inst_data.payload.extra_index = astgen.addExtraAssumeCapacity(
-        Ir.Inst.Declaration{
+    inst_data.payload = .{
+        .src_offset = @intCast(args.node.loc.start),
+        .extra_index = astgen.addExtraAssumeCapacity(Ir.Inst.Declaration{
             .name = args.name,
             .value = args.value,
-        },
-    );
+        }),
+    };
 }
 
 fn setDeclVarPayload(
     decl_index: Ir.Inst.Index,
     body_block: *GenIr,
+    node: *const Ast.Node,
 ) !void {
     defer body_block.unstack();
 
@@ -518,11 +521,12 @@ fn setDeclVarPayload(
     try astgen.extra.ensureUnusedCapacity(astgen.gpa, extra_len);
 
     const inst_data = &astgen.instructions.items[@intFromEnum(decl_index)].data;
-    inst_data.payload.extra_index = astgen.addExtraAssumeCapacity(
-        Ir.Inst.Var{
+    inst_data.payload = .{
+        .src_offset = @intCast(node.loc.start),
+        .extra_index = astgen.addExtraAssumeCapacity(Ir.Inst.Var{
             .body_len = @intCast(body.len),
-        },
-    );
+        }),
+    };
     astgen.appendBlockBody(body);
 }
 
@@ -1266,11 +1270,12 @@ fn varDecl(gi: *GenIr, scope: *Scope, decl_node: *const Ast.Node) !void {
     _ = try expr(&decl_block, scope, expr_node);
     const name_str = try astgen.strFromNode(identifier_node);
 
-    try setDeclVarPayload(var_inst, &decl_block);
+    try setDeclVarPayload(var_inst, &decl_block, identifier_node);
     try setDeclaration(decl_inst, .{
         .name = name_str.index,
         .value = var_inst,
         .gi = gi,
+        .node = decl_node,
     });
     try astgen.globals.append(gpa, decl_inst);
 }
@@ -1328,13 +1333,14 @@ fn defaultBlock(
         .name = decl_str.index,
         .value = knot_inst,
         .gi = gi,
+        .node = body_node,
     });
 }
 
 fn stitchDeclInner(
     gi: *GenIr,
     scope: *Scope,
-    _: *const Ast.Node,
+    node: *const Ast.Node,
     prototype_node: *const Ast.Node,
     body_node: ?*const Ast.Node,
 ) InnerError!void {
@@ -1377,6 +1383,7 @@ fn stitchDeclInner(
         .name = decl_str.index,
         .value = stitch_inst,
         .gi = gi,
+        .node = node,
     });
 }
 
@@ -1450,6 +1457,7 @@ fn knotDecl(gi: *GenIr, parent_scope: *Scope, decl_node: *const Ast.Node) InnerE
         .name = name_str.index,
         .value = knot_inst,
         .gi = gi,
+        .node = decl_node,
     });
 }
 
@@ -1461,7 +1469,6 @@ fn file(gi: *GenIr, scope: *Scope, file_node: *const Ast.Node) InnerError!void {
         },
     });
 
-    var start_index: usize = 0;
     var file_scope = gi.makeSubBlock();
     defer file_scope.unstack();
 
@@ -1472,12 +1479,8 @@ fn file(gi: *GenIr, scope: *Scope, file_node: *const Ast.Node) InnerError!void {
     const first_child = nested_decls_list[0];
     if (first_child.tag == .block_stmt) {
         try defaultBlock(&file_scope, scope, first_child);
-        if (nested_decls_list.len > 1)
-            start_index += 1
-        else
-            return file_scope.setBlockBody(file_inst);
     }
-    for (nested_decls_list[start_index..]) |child_node| {
+    for (nested_decls_list[1..]) |child_node| {
         switch (child_node.tag) {
             .knot_decl => try knotDecl(gi, scope, child_node),
             .stitch_decl => try stitchDecl(gi, scope, child_node),