DebugInfo: Implement debug_line.dwo for file names used in type units during -gsplit-dwarf
This removes an attribute (and more importantly, a relocation) from
skeleton type units and removes some unnecessary file names from the
debug_line section that remains in the .o (and linked executable) file.
There's still a few places we could shave off some more space here:
* use compilation dir of the underlying compilation unit (since all the
type units share that compilation dir - though this would be more
complicated in LTO cases where they don't (keep a map of compilation
dir->line table header?))
* Remove some of the unnecessary header fields from the line table since
they're not needed in this situation (about 12 bytes per table).
llvm-svn: 204099
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 71ff75d..4756509 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -27,6 +27,7 @@
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/MC/MachineLocation.h"
+#include "llvm/MC/MCDwarf.h"
#include "llvm/Support/Allocator.h"
namespace llvm {
@@ -486,6 +487,10 @@
// Holder for the skeleton information.
DwarfFile SkeletonHolder;
+ // Store file names for type units under fission in a line table header that
+ // will be emitted into debug_line.dwo.
+ MCDwarfLineTableHeader SplitTypeUnitFileTable;
+
void addScopeVariable(LexicalScope *LS, DbgVariable *Var);
const SmallVectorImpl<DwarfUnit *> &getUnits() {
@@ -621,6 +626,9 @@
/// \brief Emit the debug abbrev dwo section.
void emitDebugAbbrevDWO();
+ /// \brief Emit the debug line dwo section.
+ void emitDebugLineDWO();
+
/// \brief Emit the debug str dwo section.
void emitDebugStrDWO();