[clang][deps] Test "Fix __has_include behavior with umbrella headers" with include-tree (#7672)

Author: jansvoboda11

clang/test/ClangScanDeps/modules-include-tree-has-include-umbrella-header.c

@@ -0,0 +1,59 @@
+// This test checks that __has_include(<FW/PrivateHeader.h>) in a module does
+// not clobber #include <FW/PrivateHeader.h> in importers of said module.
+
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+
+//--- cdb.json.template
+[{
+  "file": "DIR/tu.c",
+  "directory": "DIR",
+  "command": "clang DIR/tu.c -fmodules -fmodules-cache-path=DIR/cache -I DIR/modules -F DIR/frameworks -o DIR/tu.o"
+}]
+
+//--- frameworks/FW.framework/Modules/module.private.modulemap
+framework module FW_Private {
+  umbrella header "A.h"
+  module * { export * }
+}
+//--- frameworks/FW.framework/PrivateHeaders/A.h
+#include <FW/B.h>
+//--- frameworks/FW.framework/PrivateHeaders/B.h
+#include "dependency.h"
+
+//--- modules/module.modulemap
+module Poison { header "poison.h" }
+module Import { header "import.h" }
+module Dependency { header "dependency.h" }
+//--- modules/poison.h
+#if __has_include(<FW/B.h>)
+#define HAS_B 1
+#else
+#define HAS_B 0
+#endif
+//--- modules/import.h
+#include <FW/B.h>
+//--- modules/dependency.h
+
+//--- tu.c
+#include "poison.h"
+
+#if __has_include(<FW/B.h>)
+#endif
+
+#include "import.h"
+
+#include <FW/B.h>
+
+// RUN: sed -e "s|DIR|%/t|g" %t/cdb.json.template > %t/cdb.json
+// RUN: clang-scan-deps -compilation-database %t/cdb.json -format experimental-include-tree-full -cas-path %t/cas > %t/deps.json
+// RUN: %deps-to-rsp %t/deps.json --tu-index 0 > %t/tu.rsp
+// RUN: cat %t/tu.rsp | sed -E 's|.*"-fcas-include-tree" "(llvmcas://[[:xdigit:]]+)".*|\1|' > %t/tu.casid
+// RUN: clang-cas-test -cas %t/cas -print-include-tree @%t/tu.casid | FileCheck %s -DPREFIX=%/t
+
+// Let's check that the TU actually imports FW_Private.B instead of treating FW/B.h as textual.
+// CHECK:      [[PREFIX]]/tu.c llvmcas://
+// CHECK-NEXT: 1:1 <built-in> llvmcas://
+// CHECK-NEXT: 2:1 (Module) Poison
+// CHECK-NEXT: 7:1 (Module) Import
+// CHECK-NEXT: 9:1 (Module) FW_Private.B