Move alignment from MCSectionData to MCSection.

This starts merging MCSection and MCSectionData.

There are a few issues with the current split between MCSection and
MCSectionData.

* It optimizes the the not as important case. We want the production
of .o files to be really fast, but the split puts the information used
for .o emission in a separate data structure.

* The ELF/COFF/MachO hierarchy is not represented in MCSectionData,
leading to some ad-hoc ways to represent the various flags.

* It makes it harder to remember where each item is.

The attached patch starts merging the two by moving the alignment from
MCSectionData to MCSection.

Most of the patch is actually just dropping 'const', since
MCSectionData is mutable, but MCSection was not.

llvm-svn: 237936

1 files changed, 12 insertions, 13 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 7b7c8be372a..bc2917d42b3 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1285,7 +1285,7 @@ void DwarfDebug::emitAbbreviations() {
   Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
 }
 
-void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
+void DwarfDebug::emitAccel(DwarfAccelTable &Accel, MCSection *Section,
                            StringRef TableName) {
   Accel.FinalizeTable(Asm, TableName);
   Asm->OutStreamer->SwitchSection(Section);
@@ -1379,16 +1379,16 @@ static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
 ///
 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
-  const MCSection *PSec =
-      GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
-               : Asm->getObjFileLowering().getDwarfPubNamesSection();
+  MCSection *PSec = GnuStyle
+                        ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
+                        : Asm->getObjFileLowering().getDwarfPubNamesSection();
 
   emitDebugPubSection(GnuStyle, PSec, "Names",
                       &DwarfCompileUnit::getGlobalNames);
 }
 
 void DwarfDebug::emitDebugPubSection(
-    bool GnuStyle, const MCSection *PSec, StringRef Name,
+    bool GnuStyle, MCSection *PSec, StringRef Name,
     const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
   for (const auto &NU : CUMap) {
     DwarfCompileUnit *TheU = NU.second;
@@ -1448,9 +1448,9 @@ void DwarfDebug::emitDebugPubSection(
 }
 
 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
-  const MCSection *PSec =
-      GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
-               : Asm->getObjFileLowering().getDwarfPubTypesSection();
+  MCSection *PSec = GnuStyle
+                        ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
+                        : Asm->getObjFileLowering().getDwarfPubTypesSection();
 
   emitDebugPubSection(GnuStyle, PSec, "Types",
                       &DwarfCompileUnit::getGlobalTypes);
@@ -1611,13 +1611,13 @@ struct ArangeSpan {
 // address we can tie back to a CU.
 void DwarfDebug::emitDebugARanges() {
   // Provides a unique id per text section.
-  MapVector<const MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
+  MapVector<MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
 
   // Filter labels by section.
   for (const SymbolCU &SCU : ArangeLabels) {
     if (SCU.Sym->isInSection()) {
       // Make a note of this symbol and it's section.
-      const MCSection *Section = &SCU.Sym->getSection();
+      MCSection *Section = &SCU.Sym->getSection();
       if (!Section->getKind().isMetadata())
         SectionMap[Section].push_back(SCU);
     } else {
@@ -1630,7 +1630,7 @@ void DwarfDebug::emitDebugARanges() {
 
   // Add terminating symbols for each section.
   for (const auto &I : SectionMap) {
-    const MCSection *Section = I.first;
+    MCSection *Section = I.first;
     MCSymbol *Sym = nullptr;
 
     if (Section)
@@ -1873,8 +1873,7 @@ void DwarfDebug::emitDebugLineDWO() {
 // sections.
 void DwarfDebug::emitDebugStrDWO() {
   assert(useSplitDwarf() && "No split dwarf?");
-  const MCSection *OffSec =
-      Asm->getObjFileLowering().getDwarfStrOffDWOSection();
+  MCSection *OffSec = Asm->getObjFileLowering().getDwarfStrOffDWOSection();
   InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
                          OffSec);
 }