Implement GetSharedLibraryInfoAddress

Summary:
This is the third patch to improve module loading in a series that started here (where I explain the motivation and solution): D62499

Add functions to read the r_debug location to know where the linked list of loaded libraries are so I can generate the `xfer:libraries-svr4` packet.
I'm also using this function to implement `GetSharedLibraryInfoAddress` that was "not implemented" for linux.
Most of this code was inspired by the current ds2 implementation here: https://github.com/facebook/ds2/blob/master/Sources/Target/POSIX/ELFProcess.cpp.

Reviewers: clayborg, xiaobai, labath

Reviewed By: clayborg, labath

Subscribers: emaste, krytarowski, mgorny, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D62501

llvm-svn: 363458

2 files changed, 3 insertions, 29 deletions

diff --git a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
index 81d257e95e18..7637237aa16b 100644
--- a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
+++ b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
@@ -288,7 +288,7 @@ NativeProcessLinux::NativeProcessLinux(::pid_t pid, int terminal_fd,
                                        NativeDelegate &delegate,
                                        const ArchSpec &arch, MainLoop &mainloop,
                                        llvm::ArrayRef<::pid_t> tids)
-    : NativeProcessProtocol(pid, terminal_fd, delegate), m_arch(arch) {
+    : NativeProcessELF(pid, terminal_fd, delegate), m_arch(arch) {
   if (m_terminal_fd != -1) {
     Status status = EnsureFDFlags(m_terminal_fd, O_NONBLOCK);
     assert(status.Success());
@@ -1389,11 +1389,6 @@ Status NativeProcessLinux::DeallocateMemory(lldb::addr_t addr) {
   return Status("not implemented");
 }
 
-lldb::addr_t NativeProcessLinux::GetSharedLibraryInfoAddress() {
-  // punt on this for now
-  return LLDB_INVALID_ADDRESS;
-}
-
 size_t NativeProcessLinux::UpdateThreads() {
   // The NativeProcessLinux monitoring threads are always up to date with
   // respect to thread state and they keep the thread list populated properly.
@@ -2082,18 +2077,3 @@ Status NativeProcessLinux::StopProcessorTracingOnThread(lldb::user_id_t traceid,
 
   return error;
 }
-
-llvm::Optional<uint64_t>
-NativeProcessLinux::GetAuxValue(enum AuxVector::EntryType type) {
-  if (m_aux_vector == nullptr) {
-    auto buffer_or_error = GetAuxvData();
-    if (!buffer_or_error)
-      return llvm::None;
-    DataExtractor auxv_data(buffer_or_error.get()->getBufferStart(),
-                            buffer_or_error.get()->getBufferSize(),
-                            GetByteOrder(), GetAddressByteSize());
-    m_aux_vector = llvm::make_unique<AuxVector>(auxv_data);
-  }
-
-  return m_aux_vector->GetAuxValue(type);
-}
diff --git a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.h b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.h
index 0a67af0a0a46..1366f0b1fe3c 100644
--- a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.h
+++ b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.h
@@ -12,7 +12,6 @@
 #include <csignal>
 #include <unordered_set>
 
-#include "Plugins/Process/Utility/AuxVector.h"
 #include "lldb/Host/Debug.h"
 #include "lldb/Host/HostThread.h"
 #include "lldb/Host/linux/Support.h"
@@ -22,8 +21,8 @@
 #include "lldb/lldb-types.h"
 
 #include "NativeThreadLinux.h"
+#include "Plugins/Process/POSIX/NativeProcessELF.h"
 #include "ProcessorTrace.h"
-#include "lldb/Host/common/NativeProcessProtocol.h"
 
 namespace lldb_private {
 class Status;
@@ -37,7 +36,7 @@ namespace process_linux {
 /// for debugging.
 ///
 /// Changes in the inferior process state are broadcasted.
-class NativeProcessLinux : public NativeProcessProtocol {
+class NativeProcessLinux : public NativeProcessELF {
 public:
   class Factory : public NativeProcessProtocol::Factory {
   public:
@@ -77,8 +76,6 @@ public:
 
   Status DeallocateMemory(lldb::addr_t addr) override;
 
-  lldb::addr_t GetSharedLibraryInfoAddress() override;
-
   size_t UpdateThreads() override;
 
   const ArchSpec &GetArchitecture() const override { return m_arch; }
@@ -103,8 +100,6 @@ public:
     return getProcFile(GetID(), "auxv");
   }
 
-  llvm::Optional<uint64_t> GetAuxValue(enum AuxVector::EntryType type);
-
   lldb::user_id_t StartTrace(const TraceOptions &config,
                              Status &error) override;
 
@@ -135,7 +130,6 @@ protected:
 private:
   MainLoop::SignalHandleUP m_sigchld_handle;
   ArchSpec m_arch;
-  std::unique_ptr<AuxVector> m_aux_vector;
 
   LazyBool m_supports_mem_region = eLazyBoolCalculate;
   std::vector<std::pair<MemoryRegionInfo, FileSpec>> m_mem_region_cache;