[MC] Add support for encoding CodeView variable definition ranges

CodeView, like most other debug formats, represents the live range of a
variable so that debuggers might print them out.

They use a variety of records to represent how a particular variable
might be available (in a register, in a frame pointer, etc.) along with
a set of ranges where this debug information is relevant.

However, the format only allows us to use ranges which are limited to a
maximum of 0xF000 in size.  This means that we need to split our debug
information into chunks of 0xF000.

Because the layout of code is not known until *very* late, we must use a
new fragment to record the information we need until we can know
*exactly* what the range is.

llvm-svn: 259868

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCObjectStreamer.cpp b/llvm/lib/MC/MCObjectStreamer.cpp
index 40c2e8dab9f..b90f0a80cfe 100644
--- a/llvm/lib/MC/MCObjectStreamer.cpp
+++ b/llvm/lib/MC/MCObjectStreamer.cpp
@@ -396,6 +396,13 @@ void MCObjectStreamer::EmitCVInlineLinetableDirective(
       SecondaryFunctionIds);
 }
 
+void MCObjectStreamer::EmitCVDefRangeDirective(
+    ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
+    StringRef FixedSizePortion) {
+  getContext().getCVContext().emitDefRange(*this, Ranges, FixedSizePortion);
+  this->MCStreamer::EmitCVDefRangeDirective(Ranges, FixedSizePortion);
+}
+
 void MCObjectStreamer::EmitCVStringTableDirective() {
   getContext().getCVContext().emitStringTable(*this);
 }