1 files changed, 176 insertions, 94 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index 9648f1f..fb67151 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -24,6 +24,7 @@
 #include <sys/types.h>
 
 #include "lldb/Breakpoint/Watchpoint.h"
+#include "lldb/Breakpoint/WatchpointResource.h"
 #include "lldb/Core/Debugger.h"
 #include "lldb/Core/Module.h"
 #include "lldb/Core/ModuleSpec.h"
@@ -1798,24 +1799,29 @@ ThreadSP ProcessGDBRemote::SetThreadStopInfo(
           addr_t wp_hit_addr = desc_extractor.GetU64(LLDB_INVALID_ADDRESS);
           watch_id_t watch_id = LLDB_INVALID_WATCH_ID;
           bool silently_continue = false;
-          WatchpointSP wp_sp;
+          WatchpointResourceSP wp_resource_sp;
           if (wp_hit_addr != LLDB_INVALID_ADDRESS) {
-            wp_sp = GetTarget().GetWatchpointList().FindByAddress(wp_hit_addr);
+            wp_resource_sp =
+                m_watchpoint_resource_list.FindByAddress(wp_hit_addr);
             // On MIPS, \a wp_hit_addr outside the range of a watched
             // region means we should silently continue, it is a false hit.
             ArchSpec::Core core = GetTarget().GetArchitecture().GetCore();
-            if (!wp_sp && core >= ArchSpec::kCore_mips_first &&
+            if (!wp_resource_sp && core >= ArchSpec::kCore_mips_first &&
                 core <= ArchSpec::kCore_mips_last)
               silently_continue = true;
           }
-          if (!wp_sp && wp_addr != LLDB_INVALID_ADDRESS)
-            wp_sp = GetTarget().GetWatchpointList().FindByAddress(wp_addr);
-          if (wp_sp) {
-            watch_id = wp_sp->GetID();
-          }
-          if (watch_id == LLDB_INVALID_WATCH_ID) {
+          if (!wp_resource_sp && wp_addr != LLDB_INVALID_ADDRESS)
+            wp_resource_sp = m_watchpoint_resource_list.FindByAddress(wp_addr);
+          if (!wp_resource_sp) {
             Log *log(GetLog(GDBRLog::Watchpoints));
             LLDB_LOGF(log, "failed to find watchpoint");
+            watch_id = LLDB_INVALID_SITE_ID;
+          } else {
+            // LWP_TODO: This is hardcoding a single Watchpoint in a
+            // Resource, need to add
+            // StopInfo::CreateStopReasonWithWatchpointResource which
+            // represents all watchpoints that were tripped at this stop.
+            watch_id = wp_resource_sp->GetConstituentAtIndex(0)->GetID();
           }
           thread_sp->SetStopInfo(StopInfo::CreateStopReasonWithWatchpointID(
               *thread_sp, watch_id, silently_continue));
@@ -2239,8 +2245,8 @@ StateType ProcessGDBRemote::SetThreadStopInfo(StringExtractor &stop_packet) {
         lldb::addr_t wp_addr = LLDB_INVALID_ADDRESS;
         value.getAsInteger(16, wp_addr);
 
-        WatchpointSP wp_sp =
-            GetTarget().GetWatchpointList().FindByAddress(wp_addr);
+        WatchpointResourceSP wp_resource_sp =
+            m_watchpoint_resource_list.FindByAddress(wp_addr);
 
         // Rewrite gdb standard watch/rwatch/awatch to
         // "reason:watchpoint" + "description:ADDR",
@@ -3109,102 +3115,182 @@ Status ProcessGDBRemote::DisableBreakpointSite(BreakpointSite *bp_site) {
 }
 
 // Pre-requisite: wp != NULL.
-static GDBStoppointType GetGDBStoppointType(Watchpoint *wp) {
-  assert(wp);
-  bool watch_read = wp->WatchpointRead();
-  bool watch_write = wp->WatchpointWrite();
-  bool watch_modify = wp->WatchpointModify();
-
-  // watch_read, watch_write, watch_modify cannot all be false.
-  assert((watch_read || watch_write || watch_modify) &&
-         "watch_read, watch_write, watch_modify cannot all be false.");
-  if (watch_read && (watch_write || watch_modify))
+static GDBStoppointType
+GetGDBStoppointType(const WatchpointResourceSP &wp_res_sp) {
+  assert(wp_res_sp);
+  bool read = wp_res_sp->WatchpointResourceRead();
+  bool write = wp_res_sp->WatchpointResourceWrite();
+
+  assert((read || write) &&
+         "WatchpointResource type is neither read nor write");
+  if (read && write)
     return eWatchpointReadWrite;
-  else if (watch_read)
+  else if (read)
     return eWatchpointRead;
-  else // Must be watch_write or watch_modify, then.
+  else
     return eWatchpointWrite;
 }
 
-Status ProcessGDBRemote::EnableWatchpoint(Watchpoint *wp, bool notify) {
+Status ProcessGDBRemote::EnableWatchpoint(WatchpointSP wp_sp, bool notify) {
   Status error;
-  if (wp) {
-    user_id_t watchID = wp->GetID();
-    addr_t addr = wp->GetLoadAddress();
-    Log *log(GetLog(GDBRLog::Watchpoints));
-    LLDB_LOGF(log, "ProcessGDBRemote::EnableWatchpoint(watchID = %" PRIu64 ")",
-              watchID);
-    if (wp->IsEnabled()) {
-      LLDB_LOGF(log,
-                "ProcessGDBRemote::EnableWatchpoint(watchID = %" PRIu64
-                ") addr = 0x%8.8" PRIx64 ": watchpoint already enabled.",
-                watchID, (uint64_t)addr);
-      return error;
-    }
+  if (!wp_sp) {
+    error.SetErrorString("No watchpoint specified");
+    return error;
+  }
+  user_id_t watchID = wp_sp->GetID();
+  addr_t addr = wp_sp->GetLoadAddress();
+  Log *log(GetLog(GDBRLog::Watchpoints));
+  LLDB_LOGF(log, "ProcessGDBRemote::EnableWatchpoint(watchID = %" PRIu64 ")",
+            watchID);
+  if (wp_sp->IsEnabled()) {
+    LLDB_LOGF(log,
+              "ProcessGDBRemote::EnableWatchpoint(watchID = %" PRIu64
+              ") addr = 0x%8.8" PRIx64 ": watchpoint already enabled.",
+              watchID, (uint64_t)addr);
+    return error;
+  }
 
-    GDBStoppointType type = GetGDBStoppointType(wp);
-    // Pass down an appropriate z/Z packet...
-    if (m_gdb_comm.SupportsGDBStoppointPacket(type)) {
-      if (m_gdb_comm.SendGDBStoppointTypePacket(type, true, addr,
-                                                wp->GetByteSize(),
-                                                GetInterruptTimeout()) == 0) {
-        wp->SetEnabled(true, notify);
-        return error;
-      } else
-        error.SetErrorString("sending gdb watchpoint packet failed");
-    } else
-      error.SetErrorString("watchpoints not supported");
+  bool read = wp_sp->WatchpointRead();
+  bool write = wp_sp->WatchpointWrite() || wp_sp->WatchpointModify();
+  size_t size = wp_sp->GetByteSize();
+
+  // New WatchpointResources needed to implement this Watchpoint.
+  std::vector<WatchpointResourceSP> resources;
+
+  // LWP_TODO: Break up the user's request into pieces that can be watched
+  // given the capabilities of the target cpu / stub software.
+  // As a default, breaking the watched region up into target-pointer-sized,
+  // aligned, groups.
+  //
+  // Beyond the default, a stub can / should inform us of its capabilities,
+  // e.g. a stub that can do AArch64 power-of-2 MASK watchpoints.
+  //
+  // And the cpu may have unique capabilities. AArch64 BAS watchpoints
+  // can watch any sequential bytes in a doubleword, but Intel watchpoints
+  // can only watch 1, 2, 4, 8 bytes within a doubleword.
+  WatchpointResourceSP wp_res_sp =
+      std::make_shared<WatchpointResource>(addr, size, read, write);
+  resources.push_back(wp_res_sp);
+
+  // LWP_TODO: Now that we know the WP Resources needed to implement this
+  // Watchpoint, we need to look at currently allocated Resources in the
+  // Process and if they match, or are within the same memory granule, or
+  // overlapping memory ranges, then we need to combine them.  e.g. one
+  // Watchpoint watching 1 byte at 0x1002 and a second watchpoint watching 1
+  // byte at 0x1003, they must use the same hardware watchpoint register
+  // (Resource) to watch them.
+
+  // This may mean that an existing resource changes its type (read to
+  // read+write) or address range it is watching, in which case the old
+  // watchpoint needs to be disabled and the new Resource addr/size/type
+  // watchpoint enabled.
+
+  // If we modify a shared Resource to accomodate this newly added Watchpoint,
+  // and we are unable to set all of the Resources for it in the inferior, we
+  // will return an error for this Watchpoint and the shared Resource should
+  // be restored.  e.g. this Watchpoint requires three Resources, one which
+  // is shared with another Watchpoint.  We extend the shared Resouce to
+  // handle both Watchpoints and we try to set two new ones.  But if we don't
+  // have sufficient watchpoint register for all 3, we need to show an error
+  // for creating this Watchpoint and we should reset the shared Resource to
+  // its original configuration because it is no longer shared.
+
+  bool set_all_resources = true;
+  std::vector<WatchpointResourceSP> succesfully_set_resources;
+  for (const auto &wp_res_sp : resources) {
+    addr_t addr = wp_res_sp->GetLoadAddress();
+    size_t size = wp_res_sp->GetByteSize();
+    GDBStoppointType type = GetGDBStoppointType(wp_res_sp);
+    if (!m_gdb_comm.SupportsGDBStoppointPacket(type) ||
+        m_gdb_comm.SendGDBStoppointTypePacket(type, true, addr, size,
+                                              GetInterruptTimeout())) {
+      set_all_resources = false;
+      break;
+    } else {
+      succesfully_set_resources.push_back(wp_res_sp);
+    }
+  }
+  if (set_all_resources) {
+    wp_sp->SetEnabled(true, notify);
+    for (const auto &wp_res_sp : resources) {
+      // LWP_TODO: If we expanded/reused an existing Resource,
+      // it's already in the WatchpointResourceList.
+      wp_res_sp->AddConstituent(wp_sp);
+      m_watchpoint_resource_list.Add(wp_res_sp);
+    }
+    return error;
   } else {
-    error.SetErrorString("Watchpoint argument was NULL.");
+    // We failed to allocate one of the resources.  Unset all
+    // of the new resources we did successfully set in the
+    // process.
+    for (const auto &wp_res_sp : succesfully_set_resources) {
+      addr_t addr = wp_res_sp->GetLoadAddress();
+      size_t size = wp_res_sp->GetByteSize();
+      GDBStoppointType type = GetGDBStoppointType(wp_res_sp);
+      m_gdb_comm.SendGDBStoppointTypePacket(type, false, addr, size,
+                                            GetInterruptTimeout());
+    }
+    error.SetErrorString("Setting one of the watchpoint resources failed");
   }
-  if (error.Success())
-    error.SetErrorToGenericError();
   return error;
 }
 
-Status ProcessGDBRemote::DisableWatchpoint(Watchpoint *wp, bool notify) {
+Status ProcessGDBRemote::DisableWatchpoint(WatchpointSP wp_sp, bool notify) {
   Status error;
-  if (wp) {
-    user_id_t watchID = wp->GetID();
+  if (!wp_sp) {
+    error.SetErrorString("Watchpoint argument was NULL.");
+    return error;
+  }
+
+  user_id_t watchID = wp_sp->GetID();
 
-    Log *log(GetLog(GDBRLog::Watchpoints));
+  Log *log(GetLog(GDBRLog::Watchpoints));
 
-    addr_t addr = wp->GetLoadAddress();
+  addr_t addr = wp_sp->GetLoadAddress();
+
+  LLDB_LOGF(log,
+            "ProcessGDBRemote::DisableWatchpoint (watchID = %" PRIu64
+            ") addr = 0x%8.8" PRIx64,
+            watchID, (uint64_t)addr);
 
+  if (!wp_sp->IsEnabled()) {
     LLDB_LOGF(log,
               "ProcessGDBRemote::DisableWatchpoint (watchID = %" PRIu64
-              ") addr = 0x%8.8" PRIx64,
+              ") addr = 0x%8.8" PRIx64 " -- SUCCESS (already disabled)",
               watchID, (uint64_t)addr);
+    // See also 'class WatchpointSentry' within StopInfo.cpp. This disabling
+    // attempt might come from the user-supplied actions, we'll route it in
+    // order for the watchpoint object to intelligently process this action.
+    wp_sp->SetEnabled(false, notify);
+    return error;
+  }
 
-    if (!wp->IsEnabled()) {
-      LLDB_LOGF(log,
-                "ProcessGDBRemote::DisableWatchpoint (watchID = %" PRIu64
-                ") addr = 0x%8.8" PRIx64 " -- SUCCESS (already disabled)",
-                watchID, (uint64_t)addr);
-      // See also 'class WatchpointSentry' within StopInfo.cpp. This disabling
-      // attempt might come from the user-supplied actions, we'll route it in
-      // order for the watchpoint object to intelligently process this action.
-      wp->SetEnabled(false, notify);
-      return error;
-    }
+  if (wp_sp->IsHardware()) {
+    bool disabled_all = true;
 
-    if (wp->IsHardware()) {
-      GDBStoppointType type = GetGDBStoppointType(wp);
-      // Pass down an appropriate z/Z packet...
-      if (m_gdb_comm.SendGDBStoppointTypePacket(type, false, addr,
-                                                wp->GetByteSize(),
-                                                GetInterruptTimeout()) == 0) {
-        wp->SetEnabled(false, notify);
-        return error;
-      } else
-        error.SetErrorString("sending gdb watchpoint packet failed");
+    std::vector<WatchpointResourceSP> unused_resources;
+    for (const auto &wp_res_sp : m_watchpoint_resource_list.Sites()) {
+      if (wp_res_sp->ConstituentsContains(wp_sp)) {
+        GDBStoppointType type = GetGDBStoppointType(wp_res_sp);
+        addr_t addr = wp_res_sp->GetLoadAddress();
+        size_t size = wp_res_sp->GetByteSize();
+        if (m_gdb_comm.SendGDBStoppointTypePacket(type, false, addr, size,
+                                                  GetInterruptTimeout())) {
+          disabled_all = false;
+        } else {
+          wp_res_sp->RemoveConstituent(wp_sp);
+          if (wp_res_sp->GetNumberOfConstituents() == 0)
+            unused_resources.push_back(wp_res_sp);
+        }
+      }
     }
-    // TODO: clear software watchpoints if we implement them
-  } else {
-    error.SetErrorString("Watchpoint argument was NULL.");
+    for (auto &wp_res_sp : unused_resources)
+      m_watchpoint_resource_list.Remove(wp_res_sp->GetID());
+
+    wp_sp->SetEnabled(false, notify);
+    if (!disabled_all)
+      error.SetErrorString("Failure disabling one of the watchpoint locations");
   }
-  if (error.Success())
-    error.SetErrorToGenericError();
   return error;
 }
 
@@ -5456,16 +5542,12 @@ void ProcessGDBRemote::DidForkSwitchHardwareTraps(bool enable) {
     });
   }
 
-  WatchpointList &wps = GetTarget().GetWatchpointList();
-  size_t wp_count = wps.GetSize();
-  for (size_t i = 0; i < wp_count; ++i) {
-    WatchpointSP wp = wps.GetByIndex(i);
-    if (wp->IsEnabled()) {
-      GDBStoppointType type = GetGDBStoppointType(wp.get());
-      m_gdb_comm.SendGDBStoppointTypePacket(type, enable, wp->GetLoadAddress(),
-                                            wp->GetByteSize(),
-                                            GetInterruptTimeout());
-    }
+  for (const auto &wp_res_sp : m_watchpoint_resource_list.Sites()) {
+    addr_t addr = wp_res_sp->GetLoadAddress();
+    size_t size = wp_res_sp->GetByteSize();
+    GDBStoppointType type = GetGDBStoppointType(wp_res_sp);
+    m_gdb_comm.SendGDBStoppointTypePacket(type, true, addr, size,
+                                          GetInterruptTimeout());
   }
 }