[DWARFv5] Emit split type units in .debug_info.dwo

[probinson]

Summary

I laugh and say "nothing's that simple."

Ideas for test cases that would get split CUs and TUs to step on each others toes?
I really thought having them in the same section would be a problem.

[dblaikie]

Looks good to me! Seems to come out naturally/unsurprisingly/unlikely to be weird by DwarfFile::emitUnit - whether it's TUs, CUs, in different sections, the same section, interleaved or separate.

Go engineering! always nice to see it come together so well :)

llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
 
   NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
                 CU.getLanguage());
 
   uint64_t Signature = makeTypeSignature(Identifier);
   NewTU.setTypeSignature(Signature);
   Ins.first->second = Signature;
 
-  if (useSplitDwarf())
-    // FIXME: v5 split type units belong in .debug_info.dwo.
-    NewTU.setSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
-  else {
+  if (useSplitDwarf()) {
+    MCSection *Section =
+        getDwarfVersion() <= 4
+            ? Asm->getObjFileLowering().getDwarfTypesDWOSection()
+            : Asm->getObjFileLowering().getDwarfInfoDWOSection();
+    NewTU.setSection(Section);
+  } else {
     MCSection *Section =
         getDwarfVersion() <= 4
             ? Asm->getObjFileLowering().getDwarfTypesSection(Signature)
             : Asm->getObjFileLowering().getDwarfInfoSection(Signature);
     NewTU.setSection(Section);
     // Non-split type units reuse the compile unit's line table.
     CU.applyStmtList(UnitDie);
   }

llvm/trunk/test/CodeGen/X86/dwarf-headers.ll

 ; Verify the v5 split headers.
 ;
 ; O-5: .debug_info contents:
 ; O-5: 0x00000000: Compile Unit: {{.*}} version = 0x0005 unit_type = DW_UT_skeleton abbr_offset
 ; O-5-SAME:        DWO_id = 0xccd7e58ef8bf4aa6
 ; O-5: 0x00000014: DW_TAG_compile_unit
 ;
 ; DWO-5: .debug_info.dwo contents:
-; DWO-5: 0x00000000: Compile Unit: {{.*}} version = 0x0005 unit_type = DW_UT_split_compile abbr_offset
-; DWO-5-SAME:        DWO_id = 0xccd7e58ef8bf4aa6
-; DWO-5: 0x00000014: DW_TAG_compile_unit
-;
-; FIXME: V5 wants type units in .debug_info.dwo not .debug_types.dwo.
-; DWO-5: .debug_types.dwo contents:
 ; DWO-5: 0x00000000: Type Unit: {{.*}} version = 0x0005 unit_type = DW_UT_split_type abbr_offset
 ; DWO-5: 0x00000018: DW_TAG_type_unit
+; DWO-5: 0x00000033: Compile Unit: {{.*}} version = 0x0005 unit_type = DW_UT_split_compile abbr_offset
+; DWO-5-SAME:        DWO_id = 0xccd7e58ef8bf4aa6
+; DWO-5: 0x00000047: DW_TAG_compile_unit
 
 
 ; ModuleID = 't.cpp'
 source_filename = "t.cpp"
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 %struct.S = type { i32 }

llvm/trunk/test/CodeGen/X86/dwarf-split-line-1.ll

 ; Verify that split type units with no source locations don't have a
 ; DW_AT_stmt_list attribute, and the .debug_line.dwo section is suppressed.
 
 ; RUN: llc -split-dwarf-file=foo.dwo -split-dwarf-output=%t.dwo \
 ; RUN:     -dwarf-version=5 -generate-type-units \
 ; RUN:     -filetype=obj -O0 -mtriple=x86_64-unknown-linux-gnu < %s
 ; RUN: llvm-dwarfdump -v %t.dwo | FileCheck %s
 
-; FIXME: V5 wants type units in .debug_info.dwo not .debug_types.dwo.
 ; CHECK-NOT: .debug_line.dwo
-; CHECK: .debug_types.dwo contents:
+; CHECK: .debug_info.dwo contents:
 ; CHECK: 0x00000000: Type Unit: {{.*}} version = 0x0005 unit_type = DW_UT_split_type abbr_offset
 ; CHECK: 0x00000018: DW_TAG_type_unit
 ; CHECK-NOT: DW_AT_stmt_list
 ; CHECK-NOT: DW_AT_decl_file
+; CHECK: Compile Unit:
 ; CHECK-NOT: .debug_line.dwo
 
 ; ModuleID = 't.cpp'
 source_filename = "t.cpp"
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 %struct.S = type { i32 }

llvm/trunk/test/CodeGen/X86/dwarf-split-line-2.ll

 ; Verify that if we have two split type units, one with source locations and
 ; one without, the one without locations doesn't have a DW_AT_stmt_list
 ; attribute, but the other one does and the .debug_line.dwo section is present.
 
 ; RUN: llc -split-dwarf-file=foo.dwo -split-dwarf-output=%t.dwo \
 ; RUN:     -dwarf-version=5 -generate-type-units \
 ; RUN:     -filetype=obj -O0 -mtriple=x86_64-unknown-linux-gnu < %s
 ; RUN: llvm-dwarfdump -v %t.dwo | FileCheck %s
 
 ; Currently the no-source-location type comes out first.
-; FIXME: V5 wants type units in .debug_info.dwo not .debug_types.dwo.
-; CHECK: .debug_types.dwo contents:
+; CHECK: .debug_info.dwo contents:
 ; CHECK: 0x00000000: Type Unit: {{.*}} name = 'S'
 ; CHECK-SAME: (next unit at [[TU2:0x[0-9a-f]+]])
 ; CHECK: DW_TAG_type_unit
 ; CHECK-NOT: DW_AT_stmt_list
 ; CHECK-NOT: DW_AT_decl_file
 ; CHECK: [[TU2]]: Type Unit: {{.*}} name = 'T'
 ; CHECK: DW_TAG_type_unit
 ; CHECK: DW_AT_stmt_list