Refactor DebugLocDWARFExpression so it doesn't require access to the

TargetRegisterInfo. DebugLocEntry now holds a buffer with the raw bytes
of the pre-calculated DWARF expression.

Ought to be NFC, but it does slightly alter the output format of the
textual assembly.

This reapplies 230930 without the assertion in DebugLocEntry::finalize()
because not all Machine registers can be lowered into DWARF register
numbers and floating point constants cannot be expressed.

llvm-svn: 231023

1 files changed, 29 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/ByteStreamer.h b/llvm/lib/CodeGen/AsmPrinter/ByteStreamer.h
index 42be1149e97..179a4d49582 100644
--- a/llvm/lib/CodeGen/AsmPrinter/ByteStreamer.h
+++ b/llvm/lib/CodeGen/AsmPrinter/ByteStreamer.h
@@ -19,6 +19,8 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/MC/MCStreamer.h"
+#include "llvm/Support/LEB128.h"
+#include <string>
 
 namespace llvm {
 class ByteStreamer {
@@ -66,6 +68,33 @@ class HashingByteStreamer : public ByteStreamer {
     Hash.addULEB128(DWord);
   }
 };
+
+class BufferByteStreamer : public ByteStreamer {
+private:
+  SmallVectorImpl<char> &Buffer;
+  // FIXME: This is actually only needed for textual asm output.
+  SmallVectorImpl<std::string> &Comments;
+
+public:
+  BufferByteStreamer(SmallVectorImpl<char> &Buffer,
+                     SmallVectorImpl<std::string> &Comments)
+  : Buffer(Buffer), Comments(Comments) {}
+  void EmitInt8(uint8_t Byte, const Twine &Comment) override {
+    Buffer.push_back(Byte);
+    Comments.push_back(Comment.str());
+  }
+  void EmitSLEB128(uint64_t DWord, const Twine &Comment) override {
+    raw_svector_ostream OSE(Buffer);
+    encodeSLEB128(DWord, OSE);
+    Comments.push_back(Comment.str());
+  }
+  void EmitULEB128(uint64_t DWord, const Twine &Comment) override {
+    raw_svector_ostream OSE(Buffer);
+    encodeULEB128(DWord, OSE);
+    Comments.push_back(Comment.str());
+  }
+};
+
 }
 
 #endif