[DebugInfo] Use a common method to determine a suitable form for section offsts (6/19).

[ikudrin]

Summary

This is mostly an NFC patch because the involved methods are used when emitting DWO files, which is incompatible with DWARFv3, or for platforms where DWARF64 is not supported yet.

[dblaikie]

Sounds good - testing dependent on review of prior patches. As mentioned in prior patches, I'd lean towards more feature/end-to-end testing, rather than unit testing, and if that change is made in those earlier patches this one would be updated to be consistent with that choice.

[ikudrin]

• Update to reflect changes in the parent commits.

llvm/lib/CodeGen/AsmPrinter/DIE.cpp

 }
 
 /// SizeOf - Determine size of delta value in bytes.
 ///
 unsigned DIEDelta::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
   switch (Form) {
   case dwarf::DW_FORM_data4:
     return 4;
+  case dwarf::DW_FORM_data8:
+    return 8;
   case dwarf::DW_FORM_sec_offset:
     return AP->getDwarfOffsetByteSize();
   default:
     llvm_unreachable("DIE Value form not supported yet");
   }
 }
 
 LLVM_DUMP_METHOD

llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp

 }
 
 void DwarfUnit::addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label) {
   addLabel(Die, (dwarf::Attribute)0, Form, Label);
 }
 
 void DwarfUnit::addSectionOffset(DIE &Die, dwarf::Attribute Attribute,
                                  uint64_t Integer) {
-  if (DD->getDwarfVersion() >= 4)
-    addUInt(Die, Attribute, dwarf::DW_FORM_sec_offset, Integer);
-  else
-    addUInt(Die, Attribute, dwarf::DW_FORM_data4, Integer);
+  addUInt(Die, Attribute, DD->getDwarfSectionOffsetForm(), Integer);
 }
 
 unsigned DwarfTypeUnit::getOrCreateSourceID(const DIFile *File) {
   if (!SplitLineTable)
     return getCU().getOrCreateSourceID(File);
   if (!UsedLineTable) {
     UsedLineTable = true;
     // This is a split type unit that needs a line table.
void DwarfTypeUnit::emitHeader(bool UseOffsets) {
   Asm->OutStreamer->emitIntValue(Ty ? Ty->getOffset() : 0,
                                  sizeof(Ty->getOffset()));
 }
 
 DIE::value_iterator
 DwarfUnit::addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
                            const MCSymbol *Hi, const MCSymbol *Lo) {
   return Die.addValue(DIEValueAllocator, Attribute,
-                      DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
-                                                 : dwarf::DW_FORM_data4,
+                      DD->getDwarfSectionOffsetForm(),
                       new (DIEValueAllocator) DIEDelta(Hi, Lo));
 }
 
 DIE::value_iterator
 DwarfUnit::addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
                            const MCSymbol *Label, const MCSymbol *Sec) {
   if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
     return addLabel(Die, Attribute, DD->getDwarfSectionOffsetForm(), Label);

llvm/unittests/CodeGen/DIETest.cpp

TEST_P(DIEDeltaFixture, EmitValue) {
   EXPECT_CALL(TestPrinter->getMS(), emitAbsoluteSymbolDiff(Hi, Lo, Size));
   Tst.emitValue(TestPrinter->getAP(), Form);
 }
 
 INSTANTIATE_TEST_CASE_P(
     DIETestParams, DIEDeltaFixture,
     testing::Values(
         DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_data4, 4u},
+        DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_data8, 8u},
         DIETestParams{4, dwarf::DWARF32, dwarf::DW_FORM_sec_offset, 4u},
         DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_data4, 4u},
+        DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_data8, 8u},
         DIETestParams{4, dwarf::DWARF64, dwarf::DW_FORM_sec_offset, 8u}), );
 
 struct DIELocListFixture : public DIEFixtureBase {
   void SetUp() override { DIEFixtureBase::SetUp(); }
 };
 
 TEST_P(DIELocListFixture, SizeOf) {
   if (!TestPrinter)