Remove DwarfUnit::LabelEnd in favor of computing the length of the section directly

This was a compile-unit specific label (unused in type units) and seems
unnecessary anyway when we can more easily directly compute the size of
the compile unit.

llvm-svn: 221067

llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h

@@ -173,6 +173,10 @@ public:
     this->SectionSym = SectionSym;
   }
 
+  unsigned getLength() {
+    return sizeof(uint32_t) + // Length field
+        getHeaderSize() + UnitDie.getSize();
+  }
 };
 
 } // end llvm namespace

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -1598,7 +1598,7 @@ void DwarfDebug::emitDebugPubSection(
     Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
 
     Asm->OutStreamer.AddComment("Compilation Unit Length");
-    Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
+    Asm->EmitInt32(TheU->getLength());
 
     // Emit the pubnames for this compilation unit.
     for (const auto &GI : Globals) {

llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp

@@ -65,7 +65,6 @@ void DwarfFile::emitUnits(const MCSymbol *ASectionSym) {
     TheU->emitHeader(ASectionSym);
 
     DD.emitDIE(Die);
-    Asm->OutStreamer.EmitLabel(TheU->getLabelEnd());
   }
 }
 

llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp

@@ -1750,8 +1750,6 @@ void DwarfUnit::initSection(const MCSection *Section) {
   this->Section = Section;
   this->LabelBegin =
       Asm->GetTempSymbol(Section->getLabelBeginName(), getUniqueID());
-  this->LabelEnd =
-      Asm->GetTempSymbol(Section->getLabelEndName(), getUniqueID());
 }
 
 void DwarfTypeUnit::emitHeader(const MCSymbol *ASectionSym) const {

llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h

@@ -132,9 +132,6 @@ protected:
   /// The start of the unit within its section.
   MCSymbol *LabelBegin;
 
-  /// The end of the unit within its section.
-  MCSymbol *LabelEnd;
-
   DwarfUnit(unsigned UID, dwarf::Tag, DICompileUnit CU, AsmPrinter *A,
             DwarfDebug *DW, DwarfFile *DWU);
 
@@ -152,11 +149,6 @@ public:
     return LabelBegin;
   }
 
-  MCSymbol *getLabelEnd() const {
-    assert(Section);
-    return LabelEnd;
-  }
-
   // Accessors.
   unsigned getUniqueID() const { return UniqueID; }
   uint16_t getLanguage() const { return CUNode.getLanguage(); }

llvm/test/DebugInfo/X86/ref_addr_relocation.ll

@@ -23,7 +23,7 @@
 ; CHECK: DW_TAG_variable
 ; CHECK: .long [[TYPE:.*]] # DW_AT_type
 ; CHECK: DW_TAG_structure_type
-; CHECK: debug_info_end0
+; CHECK: debug_info_begin1
 ; CHECK: DW_TAG_compile_unit
 ; CHECK-NOT: DW_TAG_structure_type
 ; This variable's type is in the 1st CU.
@@ -31,7 +31,7 @@
 ; Make sure this is relocatable.
 ; CHECK: .quad .Lsection_info+[[TYPE]] # DW_AT_type
 ; CHECK-NOT: DW_TAG_structure_type
-; CHECK: debug_info_end1
+; CHECK: .section
 
 ; CHECK-DWARF: DW_TAG_compile_unit
 ; CHECK-DWARF: 0x[[ADDR:.*]]: DW_TAG_structure_type

llvm/test/DebugInfo/dwarf-public-names.ll

@@ -37,7 +37,7 @@
 
 ; Skip the output to the header of the pubnames section.
 ; CHECK: debug_pubnames
-; CHECK: version = 0x0002
+; CHECK: version = 0x0002 {{.*}} unit_size = 0x00000128
 
 ; Check for each name in the output.
 ; CHECK-DAG: "ns"