[Reproducers] Have clang make use of lldb's VFS.

[JDevlieghere]

Summary

In r353906 we hooked up clang and lldb's reproducer infrastructure to
capture files used by clang. This patch adds the necessary logic to have
clang reuse the files from lldb's reproducer during replay.

[aprantl]

lldb/lit/Reproducer/Modules/Inputs/main.cpp

6

This is not very robust, since there is no code on this line. Personally I'd use:

void stop() {}

int main(int argc, char **argv) {
  Foo foo;
  stop(); // break here
  return 0;
}

lldb/lit/Reproducer/Modules/TestModuleCXX.test

10

does %clang set a -fmodule-cache-path ?
Please make sure that one is set otherwise this will cause chaos on incremental bots where upstream clang changes the PCM file format without bumping the version number,.

[JDevlieghere]

• Code review feedback Adrian

[aprantl]

lldb/lit/Reproducer/Modules/TestModuleCXX.test

17

Does %lldb source the config file that sets the module cache path?
I think it does...

lldb/lit/Reproducer/Modules/TestModuleCocoa.test

8

Does this have to be the real Cocoa? It's both really expensive to compile it and will vary based on the SDK.

[JDevlieghere]

• Have lldb use a custom module cache and remove it before replaying the reproducer.
• Remove the cocoa test now that we have a capture and replay test.

[aprantl]

LGTM as long as we always set a custom module cache path.

lldb/include/lldb/Host/FileSystem.h

   llvm::ErrorOr<std::string> GetExternalPath(const llvm::Twine &path);
   llvm::ErrorOr<std::string> GetExternalPath(const FileSpec &file_spec);
 
+  llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> GetVirtualFileSystem() {
+    return m_fs;
+  }
+
 private:
   static llvm::Optional<FileSystem> &InstanceImpl();
   llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> m_fs;

lldb/include/lldb/Symbol/ClangASTImporter.h

 #include "clang/Basic/FileManager.h"
 #include "clang/Basic/FileSystemOptions.h"
 
+#include "lldb/Host/FileSystem.h"
 #include "lldb/Symbol/CompilerDeclContext.h"
 #include "lldb/lldb-types.h"
 

         vbase_offsets;
   };
 
-  ClangASTImporter() : m_file_manager(clang::FileSystemOptions()) {}
+  ClangASTImporter()
+      : m_file_manager(clang::FileSystemOptions(),
+                       FileSystem::Instance().GetVirtualFileSystem()) {}
 
   clang::QualType CopyType(clang::ASTContext *dst_ctx,
                            clang::ASTContext *src_ctx, clang::QualType type);

lldb/lit/Reproducer/Modules/Inputs/Bar.h

+struct Bar {
+  int success;
+};

lldb/lit/Reproducer/Modules/Inputs/Foo.h

+struct Foo {};

lldb/lit/Reproducer/Modules/Inputs/ModuleCXX.in

+breakpoint set -f main.cpp -l 5
+run
+expr -l Objective-C++ -- @import Foo
+expr -l Objective-C++ -- @import Bar
+expr -- Bar()
+reproducer generate

lldb/lit/Reproducer/Modules/Inputs/main.cpp

+#include "Foo.h"
+
+void stop() {}
+
+int main(int argc, char **argv) {
+  Foo foo;
+  stop(); // break here.
+  return 0;
+}

lldb/lit/Reproducer/Modules/Inputs/module.modulemap

+module Foo {
+  header "Foo.h"
+}
+
+module Bar {
+  header "Bar.h"
+}

lldb/lit/Reproducer/Modules/TestModuleCXX.test

+# Start fresh.
+# RUN: rm -rf %t.root
+# RUN: rm -rf %t.cache
+
+# Create a temporary root we can remove later.
+# RUN: mkdir -p %t.root
+# RUN: mkdir -p %t.cache
+# RUN: cp %S/Inputs/main.cpp %t.root
+# RUN: cp %S/Inputs/Foo.h %t.root
+# RUN: cp %S/Inputs/Bar.h %t.root
+# RUN: cp %S/Inputs/module.modulemap %t.root
+
+# Compile the test case form the temporary root.
+# RUN: %clang %t.root/main.cpp -g -fmodules -fmodules -fcxx-modules -fmodules-cache-path=%t.cache -o %t.root/a.out
+
+# Capture the debug session.
+# RUN: %lldb -x -b -s %S/Inputs/ModuleCXX.in --capture %t.repro %t.root/a.out | FileCheck %s --check-prefix CAPTURE
+# CAPTURE: (success = 0)
+
+# RUN: cat %t.repro/files.yaml | FileCheck %s --check-prefix YAML
+# YAML-DAG: Foo.h
+# YAML-DAG: Bar.h
+# YAML-DAG: module.modulemap
+
+# Remove the temporary root.
+# RUN: rm -rf %t.root
+# RUN: rm -rf %t.cache
+
+# Replay the debug session.
+# RUN: %lldb -x -b -s %S/Inputs/ModuleCXX.in --replay %t.repro %t.root/a.out | FileCheck %s --check-prefix REPLAY
+# REPLAY: (success = 0)

lldb/lit/Reproducer/Modules/TestModuleCocoa.test

+# REQUIRES: system-darwin
+#
+# This tests that modules files from clang end up in the reproducer.
+#
+# RUN: %lldb -x -b -s %S/Inputs/ModuleCocoa.in --capture %t.repro
+# cat %t.repro/files.yaml | FileCheck %s --check-prefix YAML
+#
+# CHECK: Cocoa.h

lldb/lit/Reproducer/TestClangFileRepro.test

-# REQUIRES: system-darwin
-#
-# This tests that modules files from clang end up in the reproducer.
-#
-# RUN: %lldb -x -b -s %S/Inputs/ModuleCapture.in --capture %t.repro
-# cat %t.repro/files.yaml | FileCheck %s
-#
-# CHECK: Cocoa.h

lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp

     opts.IncludeModuleFiles = true;
   }
 
+  // Make sure clang uses the same VFS as LLDB.
+  m_compiler->setVirtualFileSystem(
+      FileSystem::Instance().GetVirtualFileSystem());
+
   lldb::LanguageType frame_lang =
       expr.Language(); // defaults to lldb::eLanguageTypeUnknown
   bool overridden_target_opts = false;

lldb/source/Plugins/ExpressionParser/Clang/ClangModulesDeclVendor.cpp

     opts.IncludeModuleFiles = true;
   }
 
+  // Make sure clang uses the same VFS as LLDB.
+  instance->setVirtualFileSystem(FileSystem::Instance().GetVirtualFileSystem());
   instance->setDiagnostics(diagnostics_engine.get());
   instance->setInvocation(invocation);
 

lldb/source/Plugins/Language/ClangCommon/ClangHighlighter.cpp

 
 #include "ClangHighlighter.h"
 
+#include "lldb/Host/FileSystem.h"
 #include "lldb/Target/Language.h"
 #include "lldb/Utility/AnsiTerminal.h"
 #include "lldb/Utility/StreamString.h"

   using namespace clang;
 
   FileSystemOptions file_opts;
-  FileManager file_mgr(file_opts);
+  FileManager file_mgr(file_opts,
+                       FileSystem::Instance().GetVirtualFileSystem());
 
   unsigned line_number = previous_lines.count('\n') + 1U;
 

lldb/source/Symbol/ClangASTContext.cpp

 clang::FileManager *ClangASTContext::getFileManager() {
   if (m_file_manager_up == nullptr) {
     clang::FileSystemOptions file_system_options;
-    m_file_manager_up.reset(new clang::FileManager(file_system_options));
+    m_file_manager_up.reset(new clang::FileManager(
+        file_system_options, FileSystem::Instance().GetVirtualFileSystem()));
   }
   return m_file_manager_up.get();
 }