From 9b832e7f530833de93857444a86e34c8d99e4755 Mon Sep 17 00:00:00 2001
From: Veikka Tuominen <git@vexu.eu>
Date: Wed, 9 Nov 2022 18:01:34 +0200
Subject: [PATCH] Sema: make check for namespace lookup of private declarations
 more strict

Previously sema only checked that the private declaration was in the same
file as the lookup but now it also checks that the namespace where
the decl was included from was also in the same file.

Closes #13077
---
 src/Sema.zig                             | 8 ++++----
 test/behavior/usingnamespace.zig         | 4 ++++
 test/behavior/usingnamespace/file_0.zig  | 1 +
 test/behavior/usingnamespace/file_1.zig  | 9 +++++++++
 test/behavior/usingnamespace/imports.zig | 5 +++++
 5 files changed, 23 insertions(+), 4 deletions(-)
 create mode 100644 test/behavior/usingnamespace/file_0.zig
 create mode 100644 test/behavior/usingnamespace/file_1.zig
 create mode 100644 test/behavior/usingnamespace/imports.zig

diff --git a/src/Sema.zig b/src/Sema.zig
index 0ca92fb649..b93a892dcc 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -5658,14 +5658,14 @@ fn lookupInNamespace(
         const src_file = block.namespace.file_scope;
 
         const gpa = sema.gpa;
-        var checked_namespaces: std.AutoArrayHashMapUnmanaged(*Namespace, void) = .{};
+        var checked_namespaces: std.AutoArrayHashMapUnmanaged(*Namespace, bool) = .{};
         defer checked_namespaces.deinit(gpa);
 
         // Keep track of name conflicts for error notes.
         var candidates: std.ArrayListUnmanaged(Decl.Index) = .{};
         defer candidates.deinit(gpa);
 
-        try checked_namespaces.put(gpa, namespace, {});
+        try checked_namespaces.put(gpa, namespace, namespace.file_scope == src_file);
         var check_i: usize = 0;
 
         while (check_i < checked_namespaces.count()) : (check_i += 1) {
@@ -5674,7 +5674,7 @@ fn lookupInNamespace(
                 // Skip decls which are not marked pub, which are in a different
                 // file than the `a.b`/`@hasDecl` syntax.
                 const decl = mod.declPtr(decl_index);
-                if (decl.is_pub or src_file == decl.getFileScope()) {
+                if (decl.is_pub or (src_file == decl.getFileScope() and checked_namespaces.values()[check_i])) {
                     try candidates.append(gpa, decl_index);
                 }
             }
@@ -5693,7 +5693,7 @@ fn lookupInNamespace(
                 try sema.ensureDeclAnalyzed(sub_usingnamespace_decl_index);
                 const ns_ty = sub_usingnamespace_decl.val.castTag(.ty).?.data;
                 const sub_ns = ns_ty.getNamespace().?;
-                try checked_namespaces.put(gpa, sub_ns, {});
+                try checked_namespaces.put(gpa, sub_ns, src_file == sub_usingnamespace_decl.getFileScope());
             }
         }
 
diff --git a/test/behavior/usingnamespace.zig b/test/behavior/usingnamespace.zig
index 83f720ff85..97ab86b172 100644
--- a/test/behavior/usingnamespace.zig
+++ b/test/behavior/usingnamespace.zig
@@ -75,3 +75,7 @@ test {
     const a = AA.b(42);
     try expect(a.x == AA.c().expected);
 }
+
+comptime {
+    _ = @import("usingnamespace/file_1.zig");
+}
diff --git a/test/behavior/usingnamespace/file_0.zig b/test/behavior/usingnamespace/file_0.zig
new file mode 100644
index 0000000000..584f583c56
--- /dev/null
+++ b/test/behavior/usingnamespace/file_0.zig
@@ -0,0 +1 @@
+pub const A = 123;
diff --git a/test/behavior/usingnamespace/file_1.zig b/test/behavior/usingnamespace/file_1.zig
new file mode 100644
index 0000000000..971fb8958d
--- /dev/null
+++ b/test/behavior/usingnamespace/file_1.zig
@@ -0,0 +1,9 @@
+const std = @import("std");
+const expect = std.testing.expect;
+const imports = @import("imports.zig");
+
+const A = 456;
+
+test {
+    try expect(imports.A == 123);
+}
diff --git a/test/behavior/usingnamespace/imports.zig b/test/behavior/usingnamespace/imports.zig
new file mode 100644
index 0000000000..bbbc7dd8ca
--- /dev/null
+++ b/test/behavior/usingnamespace/imports.zig
@@ -0,0 +1,5 @@
+const file_0 = @import("file_0.zig");
+const file_1 = @import("file_1.zig");
+
+pub usingnamespace file_0;
+pub usingnamespace file_1;