Re-land: [lldb] Use vFlash commands when writing to target's flash memory regions

The difference between this and the previous patch is that now we use
ELF physical addresses only for loading objects into the target (and the
rest of the module load address logic still uses virtual addresses).

Summary:
When writing an object file over gdb-remote, use the vFlashErase, vFlashWrite, and vFlashDone commands if the write address is in a flash memory region.  A bare metal target may have this kind of setup.

- Update ObjectFileELF to set load addresses using physical addresses.  A typical case may be a data section with a physical address in ROM and a virtual address in RAM, which should be loaded to the ROM address.
- Add support for querying the target's qXfer:memory-map, which contains information about flash memory regions, leveraging MemoryRegionInfo data structures with minor modifications
- Update ProcessGDBRemote to use vFlash commands in DoWriteMemory when the target address is in a flash region

Original discussion at http://lists.llvm.org/pipermail/lldb-dev/2018-January/013093.html

Reviewers: clayborg, labath

Reviewed By: labath

Subscribers: llvm-commits, arichardson, emaste, mgorny, lldb-commits

Differential Revision: https://reviews.llvm.org/D42145
Patch by Owen Shaw <llvm@owenpshaw.net>.

llvm-svn: 327970

1 files changed, 12 insertions, 0 deletions

diff --git a/lldb/source/Host/common/XML.cpp b/lldb/source/Host/common/XML.cpp
index c3169bd6e08..42e3d4b6e92 100644
--- a/lldb/source/Host/common/XML.cpp
+++ b/lldb/source/Host/common/XML.cpp
@@ -151,6 +151,18 @@ llvm::StringRef XMLNode::GetAttributeValue(const char *name,
     return llvm::StringRef();
 }
 
+bool XMLNode::GetAttributeValueAsUnsigned(const char *name, uint64_t &value,
+                                          uint64_t fail_value, int base) const {
+#if defined(LIBXML2_DEFINED)
+  llvm::StringRef str_value = GetAttributeValue(name, "");
+#else
+  llvm::StringRef str_value;
+#endif
+  bool success = false;
+  value = StringConvert::ToUInt64(str_value.data(), fail_value, base, &success);
+  return success;
+}
+
 void XMLNode::ForEachChildNode(NodeCallback const &callback) const {
 #if defined(LIBXML2_DEFINED)
   if (IsValid())