DWARF: Unify form size handling code

Summary:
This patch replaces the two switches which are deducing the size of
various forms with a single implementation. I have put the new
implementation into BinaryFormat, to avoid introducing dependencies
between the two independent libraries (DebugInfo and CodeGen) that need
this functionality.

Reviewers: aprantl, JDevlieghere, dblaikie

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D44418

llvm-svn: 327486

1 files changed, 8 insertions, 46 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
index 0832544c0d6..d935c05dcc6 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
@@ -425,51 +425,15 @@ void DIEInteger::EmitValue(const AsmPrinter *Asm, dwarf::Form Form) const {
 /// SizeOf - Determine size of integer value in bytes.
 ///
 unsigned DIEInteger::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
+  dwarf::FormParams Params;
+  if (AP)
+    Params = {AP->getDwarfVersion(), uint8_t(AP->getPointerSize()),
+              AP->OutStreamer->getContext().getDwarfFormat()};
+
+  if (Optional<uint8_t> FixedSize = dwarf::getFixedFormByteSize(Form, Params))
+    return *FixedSize;
+
   switch (Form) {
-  case dwarf::DW_FORM_implicit_const:
-  case dwarf::DW_FORM_flag_present:
-    return 0;
-  case dwarf::DW_FORM_flag:
-  case dwarf::DW_FORM_ref1:
-  case dwarf::DW_FORM_data1:
-  case dwarf::DW_FORM_strx1:
-  case dwarf::DW_FORM_addrx1:
-    return sizeof(int8_t);
-  case dwarf::DW_FORM_ref2:
-  case dwarf::DW_FORM_data2:
-  case dwarf::DW_FORM_strx2:
-  case dwarf::DW_FORM_addrx2:
-    return sizeof(int16_t);
-  case dwarf::DW_FORM_strx3:
-    return 3;
-  case dwarf::DW_FORM_ref4:
-  case dwarf::DW_FORM_data4:
-  case dwarf::DW_FORM_ref_sup4:
-  case dwarf::DW_FORM_strx4:
-  case dwarf::DW_FORM_addrx4:
-    return sizeof(int32_t);
-  case dwarf::DW_FORM_ref8:
-  case dwarf::DW_FORM_ref_sig8:
-  case dwarf::DW_FORM_data8:
-  case dwarf::DW_FORM_ref_sup8:
-    return sizeof(int64_t);
-  case dwarf::DW_FORM_ref_addr:
-    if (AP->getDwarfVersion() == 2)
-      return AP->getPointerSize();
-    LLVM_FALLTHROUGH;
-  case dwarf::DW_FORM_strp:
-  case dwarf::DW_FORM_GNU_ref_alt:
-  case dwarf::DW_FORM_GNU_strp_alt:
-  case dwarf::DW_FORM_line_strp:
-  case dwarf::DW_FORM_sec_offset:
-  case dwarf::DW_FORM_strp_sup:
-    switch (AP->OutStreamer->getContext().getDwarfFormat()) {
-    case dwarf::DWARF32:
-      return 4;
-    case dwarf::DWARF64:
-      return 8;
-    }
-    llvm_unreachable("Invalid DWARF format");
   case dwarf::DW_FORM_GNU_str_index:
   case dwarf::DW_FORM_GNU_addr_index:
   case dwarf::DW_FORM_ref_udata:
@@ -478,8 +442,6 @@ unsigned DIEInteger::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
     return getULEB128Size(Integer);
   case dwarf::DW_FORM_sdata:
     return getSLEB128Size(Integer);
-  case dwarf::DW_FORM_addr:
-    return AP->getPointerSize();
   default: llvm_unreachable("DIE Value form not supported yet");
   }
 }