[clang] [clang][modules][deps] Implicit modules are out of date when their explicit imports are (PR #138920)

[Cyndy Ishida via cfe-commits]

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@@ -0,0 +1,178 @@
+// Test that modifications to a common header (imported from both a PCH and a TU)
+// cause rebuilds of dependent modules imported from the TU on incremental build.
+
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+
+//--- module.modulemap
+module mod_common { header "mod_common.h" }
+module mod_tu { header "mod_tu.h" }
+module mod_tu_extra { header "mod_tu_extra.h" }
+
+//--- mod_common.h
+#define MOD_COMMON_MACRO 0
+//--- mod_tu.h
+#include "mod_common.h"
+#if MOD_COMMON_MACRO
+#include "mod_tu_extra.h"
+#endif
+
+//--- mod_tu_extra.h
+
+//--- prefix.h
+#include "mod_common.h"
+
+//--- tu.c
+#include "mod_tu.h"
+
+// Clean: scan the PCH.
+// RUN: clang-scan-deps -format experimental-full -o %t/deps_pch_clean.json -- \
+// RUN:     %clang -x c-header %t/prefix.h -o %t/prefix.h.pch -F %t \
+// RUN:     -fmodules -fimplicit-module-maps -fmodules-cache-path=%t/cache
+
+// Clean: build the PCH.
+// RUN: %deps-to-rsp %t/deps_pch_clean.json --module-name mod_common > %t/mod_common.rsp
+// RUN: %deps-to-rsp %t/deps_pch_clean.json --tu-index 0 > %t/pch.rsp
+// RUN: %clang @%t/mod_common.rsp
+// RUN: %clang @%t/pch.rsp
+
+// Clean: scan the TU.
+// RUN: clang-scan-deps -format experimental-full -o %t/deps_tu_clean.json -- \
+// RUN:     %clang -c %t/tu.c -o %t/tu.o -include %t/prefix.h -F %t \
+// RUN:     -fmodules -fimplicit-module-maps -fmodules-cache-path=%t/cache
+// RUN: cat %t/deps_tu_clean.json | sed 's:\\\\\?:/:g' | FileCheck %s --check-prefix=CHECK-TU-CLEAN -DPREFIX=%/t
+// CHECK-TU-CLEAN:      {
+// CHECK-TU-CLEAN-NEXT:   "modules": [
+// CHECK-TU-CLEAN-NEXT:     {
+// CHECK-TU-CLEAN-NEXT:       "clang-module-deps": [],
+// CHECK-TU-CLEAN-NEXT:       "clang-modulemap-file": "[[PREFIX]]/module.modulemap",
+// CHECK-TU-CLEAN-NEXT:       "command-line": [
+// CHECK-TU-CLEAN:            ],
+// CHECK-TU-CLEAN-NEXT:       "context-hash": "{{.*}}",
+// CHECK-TU-CLEAN-NEXT:       "file-deps": [
+// CHECK-TU-CLEAN-NEXT:         "[[PREFIX]]/module.modulemap",
+// CHECK-TU-CLEAN-NEXT:         "[[PREFIX]]/mod_tu.h"
+// CHECK-TU-CLEAN-NEXT:       ],
+// CHECK-TU-CLEAN-NEXT:       "link-libraries": [],
+// CHECK-TU-CLEAN-NEXT:       "name": "mod_tu"
+// CHECK-TU-CLEAN-NEXT:     }
+// CHECK-TU-CLEAN-NEXT:   ],
+// CHECK-TU-CLEAN-NEXT:   "translation-units": [
+// CHECK-TU-CLEAN-NEXT:     {
+// CHECK-TU-CLEAN-NEXT:       "commands": [
+// CHECK-TU-CLEAN-NEXT:         {
+// CHECK-TU-CLEAN-NEXT:           "clang-context-hash": "{{.*}}",
+// CHECK-TU-CLEAN-NEXT:           "clang-module-deps": [
+// CHECK-TU-CLEAN-NEXT:             {
+// CHECK-TU-CLEAN-NEXT:               "context-hash": "{{.*}}",
+// CHECK-TU-CLEAN-NEXT:               "module-name": "mod_tu"
+// CHECK-TU-CLEAN-NEXT:             }
+// CHECK-TU-CLEAN-NEXT:           ],
+// CHECK-TU-CLEAN-NEXT:           "command-line": [
+// CHECK-TU-CLEAN:                ],
+// CHECK-TU-CLEAN-NEXT:           "executable": "{{.*}}",
+// CHECK-TU-CLEAN-NEXT:           "file-deps": [
+// CHECK-TU-CLEAN-NEXT:             "[[PREFIX]]/tu.c",
+// CHECK-TU-CLEAN-NEXT:             "[[PREFIX]]/prefix.h.pch"
+// CHECK-TU-CLEAN-NEXT:           ],
+// CHECK-TU-CLEAN-NEXT:           "input-file": "[[PREFIX]]/tu.c"
+// CHECK-TU-CLEAN-NEXT:         }
+// CHECK-TU-CLEAN-NEXT:       ]
+// CHECK-TU-CLEAN-NEXT:     }
+// CHECK-TU-CLEAN:        ]
+// CHECK-TU-CLEAN:      }
+
+// Clean: build the TU.
+// RUN: %deps-to-rsp %t/deps_tu_clean.json --module-name mod_tu > %t/mod_tu.rsp
+// RUN: %deps-to-rsp %t/deps_tu_clean.json --tu-index 0 > %t/tu.rsp
+// RUN: %clang @%t/mod_tu.rsp
+// RUN: %clang @%t/tu.rsp
+
+// Incremental: modify the common module.
+// RUN: sleep 1
----------------
cyndyishida wrote:

ah I see, you're modifying the header in a way that file size would stay the same. 

https://github.com/llvm/llvm-project/pull/138920