[modules] When diagnosing a missing module import, suggest adding a #include if

the current language doesn't have an import syntax and we can figure out a
suitable file to include.

llvm-svn: 267802

1 files changed, 33 insertions, 0 deletions

diff --git a/clang/test/Modules/suggest-include.cpp b/clang/test/Modules/suggest-include.cpp
new file mode 100644
index 00000000000..e10c3f38aba
--- /dev/null
+++ b/clang/test/Modules/suggest-include.cpp
@@ -0,0 +1,33 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t -fimplicit-module-maps -I%S/Inputs/suggest-include %s -verify
+
+#include "empty.h" // import the module file
+
+// expected-note@usetextual1.h:2 {{previous}}
+// expected-note@textual2.h:1 {{previous}}
+// expected-note@textual3.h:1 {{previous}}
+// expected-note@textual4.h:1 {{previous}}
+// expected-note@textual5.h:1 {{previous}}
+// expected-note@private1.h:1 {{previous}}
+// expected-note@private2.h:1 {{previous}}
+// expected-note@private3.h:1 {{previous}}
+
+void f() {
+  (void)::usetextual1; // expected-error {{missing '#include "usetextual1.h"'}}
+  (void)::usetextual2; // expected-error {{missing '#include "usetextual2.h"'}}
+  (void)::textual3; // expected-error-re {{{{^}}missing '#include "usetextual3.h"'}}
+  // Don't suggest a #include that includes the entity via a path that leaves
+  // the module. In that case we can't be sure that we've picked the right header.
+  (void)::textual4; // expected-error-re {{{{^}}declaration of 'textual4'}}
+  (void)::textual5; // expected-error-re {{{{^}}declaration of 'textual5'}}
+
+  // Don't suggest #including a private header.
+  // FIXME: We could suggest including "useprivate1.h" here, as it's the only
+  // public way to get at this declaration.
+  (void)::private1; // expected-error-re {{{{^}}declaration of 'private1'}}
+  // FIXME: Should we be suggesting an import at all here? Should declarations
+  // in private headers be visible when the surrounding module is imported?
+  (void)::private2; // expected-error-re {{{{^}}declaration of 'private2'}}
+  // Even if we suggest an include for private1, we should not do so here.
+  (void)::private3; // expected-error-re {{{{^}}declaration of 'private3'}}
+}