1 files changed, 110 insertions, 0 deletions
diff --git a/clang/test/Modules/no-transitive-identifier-change.cppm b/clang/test/Modules/no-transitive-identifier-change.cppm
new file mode 100644
index 0000000..97e8ac4
--- /dev/null
+++ b/clang/test/Modules/no-transitive-identifier-change.cppm
@@ -0,0 +1,110 @@
+// Testing that adding an new identifier in an unused module file won't change 
+// the BMI of the current module file.
+//
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+//
+// RUN: %clang_cc1 -std=c++20 %t/m-partA.cppm -emit-reduced-module-interface -o %t/m-partA.pcm
+// RUN: %clang_cc1 -std=c++20 %t/m-partA.v1.cppm -emit-reduced-module-interface -o \
+// RUN:     %t/m-partA.v1.pcm
+// RUN: %clang_cc1 -std=c++20 %t/m-partB.cppm -emit-reduced-module-interface -o %t/m-partB.pcm
+// RUN: %clang_cc1 -std=c++20 %t/m.cppm -emit-reduced-module-interface -o %t/m.pcm \
+// RUN:     -fmodule-file=m:partA=%t/m-partA.pcm -fmodule-file=m:partB=%t/m-partB.pcm
+// RUN: %clang_cc1 -std=c++20 %t/m.cppm -emit-reduced-module-interface -o %t/m.v1.pcm \
+// RUN:     -fmodule-file=m:partA=%t/m-partA.v1.pcm -fmodule-file=m:partB=%t/m-partB.pcm
+//
+// RUN: %clang_cc1 -std=c++20 %t/useBOnly.cppm -emit-reduced-module-interface -o %t/useBOnly.pcm \
+// RUN:     -fmodule-file=m=%t/m.pcm -fmodule-file=m:partA=%t/m-partA.pcm \
+// RUN:     -fmodule-file=m:partB=%t/m-partB.pcm
+// RUN: %clang_cc1 -std=c++20 %t/useBOnly.cppm -emit-reduced-module-interface -o %t/useBOnly.v1.pcm \
+// RUN:     -fmodule-file=m=%t/m.v1.pcm -fmodule-file=m:partA=%t/m-partA.v1.pcm \
+// RUN:     -fmodule-file=m:partB=%t/m-partB.pcm
+// Since useBOnly only uses partB from module M, the change in partA shouldn't affect
+// useBOnly.
+// RUN: diff %t/useBOnly.pcm %t/useBOnly.v1.pcm &> /dev/null
+//
+// RUN: %clang_cc1 -std=c++20 %t/useAOnly.cppm -emit-reduced-module-interface -o %t/useAOnly.pcm \
+// RUN:     -fmodule-file=m=%t/m.pcm -fmodule-file=m:partA=%t/m-partA.pcm \
+// RUN:     -fmodule-file=m:partB=%t/m-partB.pcm
+// RUN: %clang_cc1 -std=c++20 %t/useAOnly.cppm -emit-reduced-module-interface -o %t/useAOnly.v1.pcm \
+// RUN:     -fmodule-file=m=%t/m.v1.pcm -fmodule-file=m:partA=%t/m-partA.v1.pcm \
+// RUN:     -fmodule-file=m:partB=%t/m-partB.pcm
+// useAOnly should differ
+// RUN: not diff %t/useAOnly.pcm %t/useAOnly.v1.pcm &> /dev/null
+
+//--- m-partA.cppm
+export module m:partA;
+
+export inline int getA() {
+    return 43;
+}
+
+export class A {
+public:
+    int getMem();
+};
+
+export template <typename T>
+class ATempl {
+public:
+    T getT();
+};
+
+//--- m-partA.v1.cppm
+export module m:partA;
+
+export inline int getA() {
+    return 43;
+}
+
+// Now we add a new declaration without introducing a new type.
+// The consuming module which didn't use m:partA completely is expected to be
+// not changed.
+export inline int getA2() {
+    return 88;
+}
+
+export class A {
+public:
+    int getMem();
+    // Now we add a new declaration without introducing a new type.
+    // The consuming module which didn't use m:partA completely is expected to be
+    // not changed.
+    int getMem2();
+};
+
+export template <typename T>
+class ATempl {
+public:
+    T getT();
+    // Add a new declaration without introducing a new type.
+    T getT2();
+};
+
+//--- m-partB.cppm
+export module m:partB;
+
+export inline int getB() {
+    return 430;
+}
+
+//--- m.cppm
+export module m;
+export import :partA;
+export import :partB;
+
+//--- useBOnly.cppm
+export module useBOnly;
+import m;
+
+export inline int get() {
+    return getB();
+}
+
+//--- useAOnly.cppm
+export module useAOnly;
+import m;
+
+export inline int get() {
+    return getA();
+}