Collect module import remarks in the types log.

This patch enables the module import remarks in the Swift LangOpts,
and sends them straight to the types log. Over the existing log entry
in LoadOneModule, this has the advantage that these remarks are
generated also for modules that are dependencies of other modules, not
just the top level imports. It works for Swift and Clang modules
imported by Swift modules.

Author: adrian-prantl

lldb/source/Plugins/TypeSystem/Swift/StoringDiagnosticConsumer.h

@@ -15,6 +15,7 @@
 
 #include "Plugins/ExpressionParser/Swift/SwiftDiagnostic.h"
 
+#include "lldb/Utility/LLDBLog.h"
 #include "lldb/Utility/StreamString.h"
 
 #include "swift/AST/DiagnosticEngine.h"
@@ -198,6 +199,13 @@ class StoringDiagnosticConsumer : public swift::DiagnosticConsumer {
       std::string &s = os.str();
       formatted_text = !s.empty() ? std::move(s) : std::string(text);
     }
+    if (info.Kind == swift::DiagnosticKind::Remark &&
+        info.ID == swift::diag::module_loaded.ID) {
+      // Divert module import remarks into the logs.
+      LLDB_LOG(GetLog(LLDBLog::Types), "{0} Module import remark: {1}",
+               m_ast_context.GetDescription(), formatted_text);
+      return;
+    }
     RawDiagnostic diagnostic(
         formatted_text, info.Kind, bufferName.str(), bufferID, line_col.first,
         line_col.second,

lldb/source/Plugins/TypeSystem/Swift/SwiftASTContext.cpp

@@ -999,6 +999,7 @@ void SwiftASTContext::SetCompilerInvocationLLDBOverrides() {
   // for the protocol conforming types.
   lang_opts.AllowModuleWithCompilerErrors = true;
   lang_opts.EnableTargetOSChecking = false;
+  lang_opts.EnableModuleLoadingRemarks = true;
 
   // Bypass deserialization safety to allow deserializing internal details from
   // swiftmodule files.

lldb/test/API/lang/swift/module_import/Makefile

@@ -0,0 +1,2 @@
+SWIFT_SOURCES := main.swift
+include Makefile.rules

lldb/test/API/lang/swift/module_import/TestSwiftModuleImport.py

@@ -0,0 +1,22 @@
+import lldb
+from lldbsuite.test.decorators import *
+import lldbsuite.test.lldbtest as lldbtest
+import lldbsuite.test.lldbutil as lldbutil
+import unittest2
+
+class TestSwiftModuleImport(lldbtest.TestBase):
+
+    mydir = lldbtest.TestBase.compute_mydir(__file__)
+    NO_DEBUG_INFO_TESTCASE = True
+
+    @swiftTest
+    def test(self):
+        self.build()
+        target, process, thread, bkpt = lldbutil.run_to_source_breakpoint(
+            self, 'break here', lldb.SBFileSpec('main.swift'))
+
+        log = self.getBuildArtifact("types.log")
+        self.runCmd('log enable lldb types -f "%s"' % log)
+        self.expect("expression -- 0")
+        self.filecheck('platform shell cat "%s"' % log, __file__)
+#       CHECK: SwiftASTContextForExpressions{{.*}}Module import remark: loaded module 'a'

lldb/test/API/lang/swift/module_import/main.swift

@@ -0,0 +1 @@
+print("break here")