Thread hardening part 3. Now lldb_private::Thread objects have std::weak_ptr

objects for the backlink to the lldb_private::Process. The issues we were
running into before was someone was holding onto a shared pointer to a 
lldb_private::Thread for too long, and the lldb_private::Process parent object
would get destroyed and the lldb_private::Thread had a "Process &m_process"
member which would just treat whatever memory that used to be a Process as a
valid Process. This was mostly happening for lldb_private::StackFrame objects
that had a member like "Thread &m_thread". So this completes the internal
strong/weak changes.

Documented the ExecutionContext and ExecutionContextRef classes so that our
LLDB developers can understand when and where to use ExecutionContext and 
ExecutionContextRef objects.

llvm-svn: 151009

1 files changed, 11 insertions, 8 deletions

diff --git a/lldb/source/Commands/CommandObjectRegister.cpp b/lldb/source/Commands/CommandObjectRegister.cpp
index 7b0e0c38c99..c34e6eee2e4 100644
--- a/lldb/source/Commands/CommandObjectRegister.cpp
+++ b/lldb/source/Commands/CommandObjectRegister.cpp
@@ -96,17 +96,20 @@ public:
                 bool prefix_with_altname = m_command_options.alternate_name;
                 bool prefix_with_name = !prefix_with_altname;
                 reg_value.Dump(&strm, reg_info, prefix_with_name, prefix_with_altname, m_format_options.GetFormat());
-                if (((reg_info->encoding == eEncodingUint) || (reg_info->encoding == eEncodingSint)) && 
-                    (reg_info->byte_size == reg_ctx->GetThread().GetProcess().GetAddressByteSize()))
+                if ((reg_info->encoding == eEncodingUint) || (reg_info->encoding == eEncodingSint))
                 {
-                    addr_t reg_addr = reg_value.GetAsUInt64(LLDB_INVALID_ADDRESS);
-                    if (reg_addr != LLDB_INVALID_ADDRESS)
+                    Process *process = exe_ctx.GetProcessPtr();
+                    if (process && reg_info->byte_size == process->GetAddressByteSize())
                     {
-                        Address so_reg_addr;
-                        if (exe_ctx.GetTargetRef().GetSectionLoadList().ResolveLoadAddress(reg_addr, so_reg_addr))
+                        addr_t reg_addr = reg_value.GetAsUInt64(LLDB_INVALID_ADDRESS);
+                        if (reg_addr != LLDB_INVALID_ADDRESS)
                         {
-                            strm.PutCString ("  ");
-                            so_reg_addr.Dump(&strm, exe_ctx.GetBestExecutionContextScope(), Address::DumpStyleResolvedDescription);
+                            Address so_reg_addr;
+                            if (exe_ctx.GetTargetRef().GetSectionLoadList().ResolveLoadAddress(reg_addr, so_reg_addr))
+                            {
+                                strm.PutCString ("  ");
+                                so_reg_addr.Dump(&strm, exe_ctx.GetBestExecutionContextScope(), Address::DumpStyleResolvedDescription);
+                            }
                         }
                     }
                 }