Remove some ProcFileReader occurences

Summary:
ProcFileReader is the cause of the dependency from Host to ProcessLinux
module. Since it's interface is also obsolete (ReadIntoDataBuffer is
trivially replaceable by llvm::MemoryBuffer functions and
ProcessLineByLine is trivially implementable with StringRefs), instead
of moving it around I'm planning to obliterate it. This is the first
step, where I remove a couple of occurences in linux/Host.cpp, and
modernize some code around that.

I have introduced linux/Support.h, which holds two utility functions
now, whose resposibility is to construct the appropriate proc file names
-- the only useful feature of ProcFileReader.

I add a couple of tests for these functions, and for
Host::GetProcessInfo. It's worth noting that these are the first
host-specific unit tests in lldb.

Reviewers: zturner, eugene

Subscribers: srhines, lldb-commits, mgorny

Differential Revision: https://reviews.llvm.org/D30942

llvm-svn: 297843

1 files changed, 34 insertions, 0 deletions

diff --git a/lldb/source/Host/linux/Support.cpp b/lldb/source/Host/linux/Support.cpp
new file mode 100644
index 00000000000..8fbb60052e3
--- /dev/null
+++ b/lldb/source/Host/linux/Support.cpp
@@ -0,0 +1,34 @@
+//===-- Support.cpp ---------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Host/linux/Support.h"
+#include "lldb/Utility/Log.h"
+#include "llvm/Support/MemoryBuffer.h"
+
+llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
+lldb_private::getProcFile(::pid_t pid, ::pid_t tid, const llvm::Twine &file) {
+  Log *log = GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
+  std::string File =
+      ("/proc/" + llvm::Twine(pid) + "/task/" + llvm::Twine(tid) + "/" + file)
+          .str();
+  auto Ret = llvm::MemoryBuffer::getFileAsStream(File);
+  if (!Ret)
+    LLDB_LOG(log, "Failed to open {0}: {1}", File, Ret.getError().message());
+  return Ret;
+}
+
+llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
+lldb_private::getProcFile(::pid_t pid, const llvm::Twine &file) {
+  Log *log = GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
+  std::string File = ("/proc/" + llvm::Twine(pid) + "/" + file).str();
+  auto Ret = llvm::MemoryBuffer::getFileAsStream(File);
+  if (!Ret)
+    LLDB_LOG(log, "Failed to open {0}: {1}", File, Ret.getError().message());
+  return Ret;
+}