Get function start line number from DWARF info

DWARF info contains info about the line number at which a function starts (DW_AT_decl_line).

This patch creates a function to look up the start line number for a function, and returns it in
DILineInfo when looking up debug info for a particular address.

Patch by Simon Que!

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D27962

llvm-svn: 294231

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
index 9a05ae8d38a..6949366323b 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
@@ -291,6 +291,10 @@ DWARFDie::getName(DINameKind Kind) const {
   return nullptr;
 }
 
+uint64_t DWARFDie::getDeclLine() const {
+  return toUnsigned(findRecursively(DW_AT_decl_line), 0);
+}
+
 void DWARFDie::getCallerFrame(uint32_t &CallFile, uint32_t &CallLine,
                               uint32_t &CallColumn) const {
   CallFile = toUnsigned(find(DW_AT_call_file), 0);