[llvm][ReadTAPI] Add & fix rpath comparison checks

* Check and emit out differences in rpath inputs
* Prevent rpaths from being overwritten
* Capture file path for tbd-v5

(cherry picked from commit 1a0d699)

Author: cyndyishida

llvm/lib/TextAPI/InterfaceFile.cpp

@@ -48,16 +48,16 @@ void InterfaceFile::addParentUmbrella(const Target &Target_, StringRef Parent) {
 }
 
 void InterfaceFile::addRPath(const Target &InputTarget, StringRef RPath) {
-  auto Iter = lower_bound(RPaths, InputTarget,
-                          [](const std::pair<Target, std::string> &LHS,
-                             Target RHS) { return LHS.first < RHS; });
+  using RPathEntryT = const std::pair<Target, std::string>;
+  RPathEntryT Entry(InputTarget, RPath);
+  auto Iter =
+      lower_bound(RPaths, Entry,
+                  [](RPathEntryT &LHS, RPathEntryT &RHS) { return LHS < RHS; });
 
-  if ((Iter != RPaths.end()) && !(InputTarget < Iter->first)) {
-    Iter->second = std::string(RPath);
+  if ((Iter != RPaths.end()) && (*Iter == Entry))
     return;
-  }
 
-  RPaths.emplace(Iter, InputTarget, std::string(RPath));
+  RPaths.emplace(Iter, Entry);
 }
 
 void InterfaceFile::addTarget(const Target &Target) {

llvm/lib/TextAPI/TextStub.cpp

@@ -1119,6 +1119,8 @@ TextAPIReader::get(MemoryBufferRef InputBuffer) {
     auto FileOrErr = getInterfaceFileFromJSON(InputBuffer.getBuffer());
     if (!FileOrErr)
       return FileOrErr.takeError();
+
+    (*FileOrErr)->setPath(Ctx.Path);
     return std::move(*FileOrErr);
   }
   yaml::Input YAMLIn(InputBuffer.getBuffer(), &Ctx, DiagHandler, &Ctx);

llvm/test/tools/llvm-readtapi/compare-rpaths.test

@@ -0,0 +1,20 @@
+; RUN: rm -rf %t
+; RUN: split-file %s %t  
+; RUN: not llvm-readtapi --compare %t/missing_rpath.tbd  %t/rpaths.tbd 2>&1 | FileCheck %s 
+
+; CHECK: < {{.*}}missing_rpath.tbd
+; CHECK: > {{.*}}rpaths.tbd
+
+; CHECK: Run Path Search Paths
+; CHECK-NEXT:         x86_64-apple-macos13
+; CHECK-NEXT:                 > /usr/lib/swift
+; CHECK-NEXT:                 > @loader_path/../../../
+; CHECK-NEXT:         arm64-apple-macos13
+; CHECK-NEXT:                 > /usr/lib/swift
+; CHECK-NEXT:                 > @loader_path/../../../
+
+//--- missing_rpath.tbd
+{"main_library":{"exported_symbols":[{"text":{"global":["_foo"]}}],"flags":[{"attributes":["not_app_extension_safe"]}],"install_names":[{"name":"@rpath/libFake.dylib"}],"target_info":[{"min_deployment":"13","target":"x86_64-macos"},{"min_deployment":"13","target":"arm64-macos"}]},"tapi_tbd_version":5}
+
+//--- rpaths.tbd
+{"main_library":{"exported_symbols":[{"text":{"global":["_foo"]}}],"rpaths": [{"paths": [ "@loader_path/../../../", "/usr/lib/swift"]}], "flags":[{"attributes":["not_app_extension_safe"]}],"install_names":[{"name":"@rpath/libFake.dylib"}],"target_info":[{"min_deployment":"13","target":"x86_64-macos"},{"min_deployment":"13","target":"arm64-macos"}]},"tapi_tbd_version":5}

llvm/tools/llvm-readtapi/DiffEngine.cpp

@@ -374,6 +374,10 @@ DiffEngine::findDifferences(const InterfaceFile *IFLHS,
                                        IFRHS->reexportedLibraries(),
                                        "Reexported Libraries"));
 
+  if (IFLHS->rpaths() != IFRHS->rpaths())
+    Output.push_back(recordDifferences(IFLHS->rpaths(), IFRHS->rpaths(),
+                                       "Run Path Search Paths"));
+
   if (IFLHS->allowableClients() != IFRHS->allowableClients())
     Output.push_back(recordDifferences(IFLHS->allowableClients(),
                                        IFRHS->allowableClients(),