Handling for cross-package imports of "export name". (#3967)

Starts warning on duplicate "export name" because I'm updating name
lookup to make it work.

Need to think harder about how to handle cross-package "export import".
But adding some failing tests to sketch out what *should* work.

toolchain/check/handle_export.cpp

@@ -38,6 +38,20 @@ auto HandleExportDecl(Context& context, Parse::ExportDeclId node_id) -> bool {
     return true;
   }
 
+  auto inst = context.insts().Get(inst_id);
+
+  if (inst.Is<SemIR::ExportDecl>()) {
+    CARBON_DIAGNOSTIC(ExportRedundant, Warning,
+                      "`export` matches previous `export`.");
+    CARBON_DIAGNOSTIC(ExportPrevious, Note, "Previous `export` here.");
+    context.emitter()
+        .Build(node_id, ExportRedundant)
+        // Use the location of the export itself, not the exported instruction.
+        .Note(context.insts().GetLocId(inst_id), ExportPrevious)
+        .Emit();
+    return true;
+  }
+
   auto import_ref = context.insts().TryGetAs<SemIR::ImportRefLoaded>(inst_id);
   if (!import_ref) {
     CARBON_DIAGNOSTIC(ExportNotImportedEntity, Error,
@@ -57,6 +71,14 @@ auto HandleExportDecl(Context& context, Parse::ExportDeclId node_id) -> bool {
                                   .value_id = inst_id}});
   context.AddExport(export_id);
 
+  // Replace the ImportRef in name lookup, both for the above duplicate
+  // diagnostic and so that cross-package imports can find it easily.
+  auto bind_name = context.bind_names().Get(import_ref->bind_name_id);
+  auto& names = context.name_scopes().Get(bind_name.enclosing_scope_id).names;
+  auto it = names.find(bind_name.name_id);
+  CARBON_CHECK(it->second == inst_id);
+  it->second = export_id;
+
   return true;
 }
 

toolchain/check/testdata/alias/no_prelude/export_name.carbon

@@ -96,7 +96,7 @@ var d: D* = &c;
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [template] {
 // CHECK:STDOUT:     .C = %import_ref.1
-// CHECK:STDOUT:     .D = %import_ref.2
+// CHECK:STDOUT:     .D = %D
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref.1 = import_ref ir1, inst+1, unloaded
 // CHECK:STDOUT:   %import_ref.2: type = import_ref ir1, inst+5, loaded [template = constants.%C]
@@ -118,8 +118,8 @@ var d: D* = &c;
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [template] {
-// CHECK:STDOUT:     .C = %import_ref.1
 // CHECK:STDOUT:     .D = %import_ref.2
+// CHECK:STDOUT:     .C = %C
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref.1: type = import_ref ir1, inst+1, loaded [template = constants.%C]
 // CHECK:STDOUT:   %import_ref.2 = import_ref ir1, inst+5, unloaded

toolchain/check/testdata/class/no_prelude/export_name.carbon

@@ -62,7 +62,7 @@ var c: C = {};
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [template] {
-// CHECK:STDOUT:     .C = %import_ref.1
+// CHECK:STDOUT:     .C = %C
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref.1: type = import_ref ir1, inst+1, loaded [template = constants.%C]
 // CHECK:STDOUT:   %import_ref.2 = import_ref ir1, inst+2, unloaded

toolchain/check/testdata/function/declaration/no_prelude/export_name.carbon

@@ -61,7 +61,7 @@ var f: () = F();
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [template] {
-// CHECK:STDOUT:     .F = %import_ref
+// CHECK:STDOUT:     .F = %F
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref: F = import_ref ir1, inst+1, loaded [template = constants.%struct]
 // CHECK:STDOUT:   %F: F = export F, %import_ref [template = constants.%struct]

toolchain/check/testdata/interface/no_prelude/export_name.carbon

@@ -65,7 +65,7 @@ fn UseEmpty(i: I) {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [template] {
-// CHECK:STDOUT:     .I = %import_ref.1
+// CHECK:STDOUT:     .I = %I
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref.1: type = import_ref ir1, inst+1, loaded [template = constants.%.1]
 // CHECK:STDOUT:   %import_ref.2 = import_ref ir1, inst+3, unloaded

toolchain/check/testdata/packages/no_prelude/cross_package_export.carbon

@@ -0,0 +1,429 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+
+// ============================================================================
+// Setup files
+// ============================================================================
+
+// --- base.carbon
+
+package Other library "base";
+
+class C {
+  var x: ();
+};
+
+// --- export_import.carbon
+
+package Other library "export_import";
+
+export import library "base";
+
+// --- export_import_copy.carbon
+
+package Other library "export_import_copy";
+
+export import library "base";
+
+// --- export_name.carbon
+
+package Other library "export_name";
+
+import library "base";
+
+export C;
+
+// --- export_name_copy.carbon
+
+package Other library "export_name_copy";
+
+import library "base";
+
+export C;
+
+// ============================================================================
+// Test files
+// ============================================================================
+
+// --- fail_todo_use_export_import.carbon
+
+library "use_export_import";
+
+import Other library "export_import";
+
+// CHECK:STDERR: fail_todo_use_export_import.carbon:[[@LINE+4]]:8: ERROR: Name `C` not found.
+// CHECK:STDERR: var c: Other.C = {.x = ()};
+// CHECK:STDERR:        ^~~~~~~
+// CHECK:STDERR:
+var c: Other.C = {.x = ()};
+
+// --- fail_todo_use_export_import_both.carbon
+
+library "use_export_import_both";
+
+import Other library "export_import";
+import Other library "export_import_copy";
+
+// CHECK:STDERR: fail_todo_use_export_import_both.carbon:[[@LINE+4]]:8: ERROR: Name `C` not found.
+// CHECK:STDERR: var c: Other.C = {.x = ()};
+// CHECK:STDERR:        ^~~~~~~
+// CHECK:STDERR:
+var c: Other.C = {.x = ()};
+
+// --- use_export_name.carbon
+
+library "use_export_name";
+
+import Other library "export_name";
+
+var c: Other.C = {.x = ()};
+
+// --- fail_todo_use_export_name_both.carbon
+
+library "use_export_name_both";
+
+import Other library "export_name";
+// CHECK:STDERR: fail_todo_use_export_name_both.carbon:[[@LINE+18]]:1: In import.
+// CHECK:STDERR: import Other library "export_name_copy";
+// CHECK:STDERR: ^~~~~~
+// CHECK:STDERR: export_name_copy.carbon:4:1: In import.
+// CHECK:STDERR: import library "base";
+// CHECK:STDERR: ^~~~~~
+// CHECK:STDERR: base.carbon:4:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: class C {
+// CHECK:STDERR: ^~~~~~~~~
+// CHECK:STDERR: fail_todo_use_export_name_both.carbon:[[@LINE-10]]:1: In import.
+// CHECK:STDERR: import Other library "export_name";
+// CHECK:STDERR: ^~~~~~
+// CHECK:STDERR: export_name.carbon:4:1: In import.
+// CHECK:STDERR: import library "base";
+// CHECK:STDERR: ^~~~~~
+// CHECK:STDERR: base.carbon:4:1: Name is previously declared here.
+// CHECK:STDERR: class C {
+// CHECK:STDERR: ^~~~~~~~~
+import Other library "export_name_copy";
+
+// CHECK:STDERR: fail_todo_use_export_name_both.carbon:[[@LINE+4]]:8: In name lookup for `C`.
+// CHECK:STDERR: var c: Other.C = {.x = ()};
+// CHECK:STDERR:        ^~~~~~~
+// CHECK:STDERR:
+var c: Other.C = {.x = ()};
+
+// --- fail_todo_use_export_all.carbon
+
+library "use_export_all";
+
+import Other library "export_import";
+import Other library "export_name";
+import Other library "export_import_copy";
+// CHECK:STDERR: fail_todo_use_export_all.carbon:[[@LINE+18]]:1: In import.
+// CHECK:STDERR: import Other library "export_name_copy";
+// CHECK:STDERR: ^~~~~~
+// CHECK:STDERR: export_name_copy.carbon:4:1: In import.
+// CHECK:STDERR: import library "base";
+// CHECK:STDERR: ^~~~~~
+// CHECK:STDERR: base.carbon:4:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: class C {
+// CHECK:STDERR: ^~~~~~~~~
+// CHECK:STDERR: fail_todo_use_export_all.carbon:[[@LINE-11]]:1: In import.
+// CHECK:STDERR: import Other library "export_name";
+// CHECK:STDERR: ^~~~~~
+// CHECK:STDERR: export_name.carbon:4:1: In import.
+// CHECK:STDERR: import library "base";
+// CHECK:STDERR: ^~~~~~
+// CHECK:STDERR: base.carbon:4:1: Name is previously declared here.
+// CHECK:STDERR: class C {
+// CHECK:STDERR: ^~~~~~~~~
+import Other library "export_name_copy";
+
+// CHECK:STDERR: fail_todo_use_export_all.carbon:[[@LINE+3]]:8: In name lookup for `C`.
+// CHECK:STDERR: var c: Other.C = {.x = ()};
+// CHECK:STDERR:        ^~~~~~~
+var c: Other.C = {.x = ()};
+
+// CHECK:STDOUT: --- base.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %C: type = class_type @C [template]
+// CHECK:STDOUT:   %.1: type = tuple_type () [template]
+// CHECK:STDOUT:   %.2: type = unbound_element_type C, () [template]
+// CHECK:STDOUT:   %.3: type = struct_type {.x: ()} [template]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .C = %C.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %C.decl: type = class_decl @C [template = constants.%C] {}
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @C {
+// CHECK:STDOUT:   %.loc5_11.1: () = tuple_literal ()
+// CHECK:STDOUT:   %.loc5_11.2: type = converted %.loc5_11.1, constants.%.1 [template = constants.%.1]
+// CHECK:STDOUT:   %.loc5_8: <unbound element of class C> = field_decl x, element0 [template]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%C
+// CHECK:STDOUT:   .x = %.loc5_8
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- export_import.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .C = %import_ref
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %import_ref = import_ref ir1, inst+1, unloaded
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- export_import_copy.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .C = %import_ref
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %import_ref = import_ref ir1, inst+1, unloaded
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- export_name.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %C: type = class_type @C [template]
+// CHECK:STDOUT:   %.1: type = tuple_type () [template]
+// CHECK:STDOUT:   %.2: type = struct_type {.x: ()} [template]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .C = %C
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %import_ref.1: type = import_ref ir1, inst+1, loaded [template = constants.%C]
+// CHECK:STDOUT:   %import_ref.2 = import_ref ir1, inst+2, unloaded
+// CHECK:STDOUT:   %import_ref.3 = import_ref ir1, inst+7, unloaded
+// CHECK:STDOUT:   %C: type = export C, %import_ref.1 [template = constants.%C]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @C {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = file.%import_ref.2
+// CHECK:STDOUT:   .x = file.%import_ref.3
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- export_name_copy.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %C: type = class_type @C [template]
+// CHECK:STDOUT:   %.1: type = tuple_type () [template]
+// CHECK:STDOUT:   %.2: type = struct_type {.x: ()} [template]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .C = %C
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %import_ref.1: type = import_ref ir1, inst+1, loaded [template = constants.%C]
+// CHECK:STDOUT:   %import_ref.2 = import_ref ir1, inst+2, unloaded
+// CHECK:STDOUT:   %import_ref.3 = import_ref ir1, inst+7, unloaded
+// CHECK:STDOUT:   %C: type = export C, %import_ref.1 [template = constants.%C]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @C {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = file.%import_ref.2
+// CHECK:STDOUT:   .x = file.%import_ref.3
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_todo_use_export_import.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %.1: type = tuple_type () [template]
+// CHECK:STDOUT:   %.2: type = struct_type {.x: ()} [template]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .Other = %Other
+// CHECK:STDOUT:     .c = %c
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Other: <namespace> = namespace [template] {}
+// CHECK:STDOUT:   %Other.ref: <namespace> = name_ref Other, %Other [template = %Other]
+// CHECK:STDOUT:   %C.ref: <error> = name_ref C, <error> [template = <error>]
+// CHECK:STDOUT:   %c.var: ref <error> = var c
+// CHECK:STDOUT:   %c: ref <error> = bind_name c, %c.var
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @__global_init() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %.loc10_25: () = tuple_literal ()
+// CHECK:STDOUT:   %.loc10_26: {.x: ()} = struct_literal (%.loc10_25)
+// CHECK:STDOUT:   assign file.%c.var, <error>
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_todo_use_export_import_both.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %.1: type = tuple_type () [template]
+// CHECK:STDOUT:   %.2: type = struct_type {.x: ()} [template]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .Other = %Other
+// CHECK:STDOUT:     .c = %c
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Other: <namespace> = namespace [template] {}
+// CHECK:STDOUT:   %Other.ref: <namespace> = name_ref Other, %Other [template = %Other]
+// CHECK:STDOUT:   %C.ref: <error> = name_ref C, <error> [template = <error>]
+// CHECK:STDOUT:   %c.var: ref <error> = var c
+// CHECK:STDOUT:   %c: ref <error> = bind_name c, %c.var
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @__global_init() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %.loc11_25: () = tuple_literal ()
+// CHECK:STDOUT:   %.loc11_26: {.x: ()} = struct_literal (%.loc11_25)
+// CHECK:STDOUT:   assign file.%c.var, <error>
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- use_export_name.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %C: type = class_type @C [template]
+// CHECK:STDOUT:   %.1: type = tuple_type () [template]
+// CHECK:STDOUT:   %.2: type = struct_type {.x: ()} [template]
+// CHECK:STDOUT:   %.3: type = ptr_type {.x: ()} [template]
+// CHECK:STDOUT:   %tuple: () = tuple_value () [template]
+// CHECK:STDOUT:   %struct: C = struct_value (%tuple) [template]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .Other = %Other
+// CHECK:STDOUT:     .c = %c
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Other: <namespace> = namespace [template] {}
+// CHECK:STDOUT:   %Other.ref: <namespace> = name_ref Other, %Other [template = %Other]
+// CHECK:STDOUT:   %import_ref.1: type = import_ref ir1, inst+10, loaded [template = constants.%C]
+// CHECK:STDOUT:   %import_ref.2 = import_ref ir1, inst+8, unloaded
+// CHECK:STDOUT:   %import_ref.3 = import_ref ir1, inst+9, unloaded
+// CHECK:STDOUT:   %C.ref: type = name_ref C, %import_ref.1 [template = constants.%C]
+// CHECK:STDOUT:   %c.var: ref C = var c
+// CHECK:STDOUT:   %c: ref C = bind_name c, %c.var
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @C {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = file.%import_ref.2
+// CHECK:STDOUT:   .x = file.%import_ref.3
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @__global_init() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %.loc6_25.1: () = tuple_literal ()
+// CHECK:STDOUT:   %.loc6_26.1: {.x: ()} = struct_literal (%.loc6_25.1)
+// CHECK:STDOUT:   %.loc6_26.2: ref () = class_element_access file.%c.var, element0
+// CHECK:STDOUT:   %.loc6_25.2: init () = tuple_init () to %.loc6_26.2 [template = constants.%tuple]
+// CHECK:STDOUT:   %.loc6_26.3: init () = converted %.loc6_25.1, %.loc6_25.2 [template = constants.%tuple]
+// CHECK:STDOUT:   %.loc6_26.4: init C = class_init (%.loc6_26.3), file.%c.var [template = constants.%struct]
+// CHECK:STDOUT:   %.loc6_27: init C = converted %.loc6_26.1, %.loc6_26.4 [template = constants.%struct]
+// CHECK:STDOUT:   assign file.%c.var, %.loc6_27
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_todo_use_export_name_both.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %C: type = class_type @C [template]
+// CHECK:STDOUT:   %.1: type = tuple_type () [template]
+// CHECK:STDOUT:   %.2: type = struct_type {.x: ()} [template]
+// CHECK:STDOUT:   %.3: type = ptr_type {.x: ()} [template]
+// CHECK:STDOUT:   %tuple: () = tuple_value () [template]
+// CHECK:STDOUT:   %struct: C = struct_value (%tuple) [template]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .Other = %Other
+// CHECK:STDOUT:     .c = %c
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Other: <namespace> = namespace [template] {}
+// CHECK:STDOUT:   %Other.ref: <namespace> = name_ref Other, %Other [template = %Other]
+// CHECK:STDOUT:   %import_ref.1: type = import_ref ir1, inst+10, loaded [template = constants.%C]
+// CHECK:STDOUT:   %import_ref.2 = import_ref ir1, inst+8, unloaded
+// CHECK:STDOUT:   %import_ref.3 = import_ref ir1, inst+9, unloaded
+// CHECK:STDOUT:   %import_ref.4 = import_ref ir2, inst+10, unloaded
+// CHECK:STDOUT:   %C.ref: type = name_ref C, %import_ref.1 [template = constants.%C]
+// CHECK:STDOUT:   %c.var: ref C = var c
+// CHECK:STDOUT:   %c: ref C = bind_name c, %c.var
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @C {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = file.%import_ref.2
+// CHECK:STDOUT:   .x = file.%import_ref.3
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @__global_init() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %.loc29_25.1: () = tuple_literal ()
+// CHECK:STDOUT:   %.loc29_26.1: {.x: ()} = struct_literal (%.loc29_25.1)
+// CHECK:STDOUT:   %.loc29_26.2: ref () = class_element_access file.%c.var, element0
+// CHECK:STDOUT:   %.loc29_25.2: init () = tuple_init () to %.loc29_26.2 [template = constants.%tuple]
+// CHECK:STDOUT:   %.loc29_26.3: init () = converted %.loc29_25.1, %.loc29_25.2 [template = constants.%tuple]
+// CHECK:STDOUT:   %.loc29_26.4: init C = class_init (%.loc29_26.3), file.%c.var [template = constants.%struct]
+// CHECK:STDOUT:   %.loc29_27: init C = converted %.loc29_26.1, %.loc29_26.4 [template = constants.%struct]
+// CHECK:STDOUT:   assign file.%c.var, %.loc29_27
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_todo_use_export_all.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %C: type = class_type @C [template]
+// CHECK:STDOUT:   %.1: type = tuple_type () [template]
+// CHECK:STDOUT:   %.2: type = struct_type {.x: ()} [template]
+// CHECK:STDOUT:   %.3: type = ptr_type {.x: ()} [template]
+// CHECK:STDOUT:   %tuple: () = tuple_value () [template]
+// CHECK:STDOUT:   %struct: C = struct_value (%tuple) [template]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .Other = %Other
+// CHECK:STDOUT:     .c = %c
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Other: <namespace> = namespace [template] {}
+// CHECK:STDOUT:   %Other.ref: <namespace> = name_ref Other, %Other [template = %Other]
+// CHECK:STDOUT:   %import_ref.1: type = import_ref ir2, inst+10, loaded [template = constants.%C]
+// CHECK:STDOUT:   %import_ref.2 = import_ref ir2, inst+8, unloaded
+// CHECK:STDOUT:   %import_ref.3 = import_ref ir2, inst+9, unloaded
+// CHECK:STDOUT:   %import_ref.4 = import_ref ir4, inst+10, unloaded
+// CHECK:STDOUT:   %C.ref: type = name_ref C, %import_ref.1 [template = constants.%C]
+// CHECK:STDOUT:   %c.var: ref C = var c
+// CHECK:STDOUT:   %c: ref C = bind_name c, %c.var
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @C {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = file.%import_ref.2
+// CHECK:STDOUT:   .x = file.%import_ref.3
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @__global_init() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %.loc30_25.1: () = tuple_literal ()
+// CHECK:STDOUT:   %.loc30_26.1: {.x: ()} = struct_literal (%.loc30_25.1)
+// CHECK:STDOUT:   %.loc30_26.2: ref () = class_element_access file.%c.var, element0
+// CHECK:STDOUT:   %.loc30_25.2: init () = tuple_init () to %.loc30_26.2 [template = constants.%tuple]
+// CHECK:STDOUT:   %.loc30_26.3: init () = converted %.loc30_25.1, %.loc30_25.2 [template = constants.%tuple]
+// CHECK:STDOUT:   %.loc30_26.4: init C = class_init (%.loc30_26.3), file.%c.var [template = constants.%struct]
+// CHECK:STDOUT:   %.loc30_27: init C = converted %.loc30_26.1, %.loc30_26.4 [template = constants.%struct]
+// CHECK:STDOUT:   assign file.%c.var, %.loc30_27
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:

toolchain/check/testdata/packages/no_prelude/export_mixed.carbon

@@ -171,8 +171,8 @@ var d: D = {.y = ()};
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [template] {
-// CHECK:STDOUT:     .C = %import_ref.1
 // CHECK:STDOUT:     .D = %import_ref.2
+// CHECK:STDOUT:     .C = %C
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref.1: type = import_ref ir2, inst+1, loaded [template = constants.%C]
 // CHECK:STDOUT:   %import_ref.2 = import_ref ir2, inst+11, unloaded
@@ -197,8 +197,8 @@ var d: D = {.y = ()};
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [template] {
-// CHECK:STDOUT:     .C = %import_ref.1
 // CHECK:STDOUT:     .D = %import_ref.2
+// CHECK:STDOUT:     .C = %C
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref.1: type = import_ref ir1, inst+1, loaded [template = constants.%C]
 // CHECK:STDOUT:   %import_ref.2 = import_ref ir1, inst+11, unloaded

toolchain/check/testdata/packages/no_prelude/export_name.carbon

@@ -169,6 +169,13 @@ library "repeat_export";
 import library "base";
 
 export C;
+// CHECK:STDERR: repeat_export.carbon:[[@LINE+7]]:1: WARNING: `export` matches previous `export`.
+// CHECK:STDERR: export C;
+// CHECK:STDERR: ^~~~~~~~~
+// CHECK:STDERR: repeat_export.carbon:[[@LINE-4]]:1: Previous `export` here.
+// CHECK:STDERR: export C;
+// CHECK:STDERR: ^~~~~~~~~
+// CHECK:STDERR:
 export C;
 
 // --- use_repeat_export.carbon
@@ -246,13 +253,13 @@ private export C;
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [template] {
-// CHECK:STDOUT:     .C = %import_ref.1
 // CHECK:STDOUT:     .NS = %NS
+// CHECK:STDOUT:     .C = %C
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref.1: type = import_ref ir1, inst+1, loaded [template = constants.%C]
 // CHECK:STDOUT:   %import_ref.2: <namespace> = import_ref ir1, inst+11, loaded
 // CHECK:STDOUT:   %NS: <namespace> = namespace %import_ref.2, [template] {
-// CHECK:STDOUT:     .NSC = %import_ref.3
+// CHECK:STDOUT:     .NSC = %NSC
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref.3: type = import_ref ir1, inst+12, loaded [template = constants.%NSC]
 // CHECK:STDOUT:   %import_ref.4 = import_ref ir1, inst+7, unloaded
@@ -302,13 +309,13 @@ private export C;
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [template] {
-// CHECK:STDOUT:     .C = %import_ref.1
 // CHECK:STDOUT:     .NS = %NS
+// CHECK:STDOUT:     .C = %C
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref.1: type = import_ref ir1, inst+13, loaded [template = constants.%C]
 // CHECK:STDOUT:   %import_ref.2: <namespace> = import_ref ir1, inst+3, loaded
 // CHECK:STDOUT:   %NS: <namespace> = namespace %import_ref.2, [template] {
-// CHECK:STDOUT:     .NSC = %import_ref.3
+// CHECK:STDOUT:     .NSC = %NSC
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref.3: type = import_ref ir1, inst+21, loaded [template = constants.%NSC]
 // CHECK:STDOUT:   %import_ref.4 = import_ref ir1, inst+12, unloaded
@@ -793,8 +800,8 @@ private export C;
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [template] {
-// CHECK:STDOUT:     .C = %import_ref.1
 // CHECK:STDOUT:     .NS = %NS
+// CHECK:STDOUT:     .C = %C
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref.1: type = import_ref ir1, inst+1, loaded [template = constants.%C]
 // CHECK:STDOUT:   %import_ref.2: <namespace> = import_ref ir1, inst+11, loaded
@@ -804,8 +811,7 @@ private export C;
 // CHECK:STDOUT:   %import_ref.3 = import_ref ir1, inst+12, unloaded
 // CHECK:STDOUT:   %import_ref.4 = import_ref ir1, inst+7, unloaded
 // CHECK:STDOUT:   %import_ref.5 = import_ref ir1, inst+2, unloaded
-// CHECK:STDOUT:   %C.loc6: type = export C, %import_ref.1 [template = constants.%C]
-// CHECK:STDOUT:   %C.loc7: type = export C, %import_ref.1 [template = constants.%C]
+// CHECK:STDOUT:   %C: type = export C, %import_ref.1 [template = constants.%C]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: class @C {
@@ -867,8 +873,8 @@ private export C;
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [template] {
-// CHECK:STDOUT:     .C = %import_ref.1
 // CHECK:STDOUT:     .NS = %NS
+// CHECK:STDOUT:     .C = %C
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref.1: type = import_ref ir1, inst+1, loaded [template = constants.%C]
 // CHECK:STDOUT:   %import_ref.2: <namespace> = import_ref ir1, inst+11, loaded

toolchain/check/testdata/var/no_prelude/export_name.carbon

@@ -67,7 +67,7 @@ var w: () = v;
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [template] {
-// CHECK:STDOUT:     .v = %import_ref
+// CHECK:STDOUT:     .v = %v
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %import_ref: ref () = import_ref ir1, inst+5, loaded
 // CHECK:STDOUT:   %v: ref () = export v, %import_ref

toolchain/diagnostics/diagnostic_kind.def

@@ -203,6 +203,8 @@ CARBON_DIAGNOSTIC_KIND(ConstructionOfAbstractClass)
 // Export checking.
 CARBON_DIAGNOSTIC_KIND(ExportNotImportedEntity)
 CARBON_DIAGNOSTIC_KIND(ExportNotImportedEntitySource)
+CARBON_DIAGNOSTIC_KIND(ExportRedundant)
+CARBON_DIAGNOSTIC_KIND(ExportPrevious)
 
 // Interface checking.
 CARBON_DIAGNOSTIC_KIND(InterfacePreviousDefinition)