[MC] Untangle MCContext and MCObjectFileInfo

This untangles the MCContext and the MCObjectFileInfo. There is a circular
dependency between MCContext and MCObjectFileInfo. Currently this dependency
also exists during construction: You can't contruct a MOFI without a MCContext
without constructing the MCContext with a dummy version of that MOFI first.
This removes this dependency during construction. In a perfect world,
MCObjectFileInfo wouldn't depend on MCContext at all, but only be stored in the
MCContext, like other MC information. This is future work.

This also shifts/adds more information to the MCContext making it more
available to the different targets. Namely:

- TargetTriple
- ObjectFileType
- SubtargetInfo

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D101462

1 files changed, 11 insertions, 9 deletions

diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 7388ffb..5315ec9 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -1645,7 +1645,7 @@ MCSection *TargetLoweringObjectFileCOFF::SelectSectionForGlobal(
       // Append "$symbol" to the section name *before* IR-level mangling is
       // applied when targetting mingw. This is what GCC does, and the ld.bfd
       // COFF linker will not properly handle comdats otherwise.
-      if (getTargetTriple().isWindowsGNUEnvironment())
+      if (getContext().getTargetTriple().isWindowsGNUEnvironment())
         raw_svector_ostream(Name) << '$' << ComdatGV->getName();
 
       return getContext().getCOFFSection(Name, Characteristics, Kind,
@@ -1762,7 +1762,8 @@ void TargetLoweringObjectFileCOFF::emitLinkerDirectives(
   std::string Flags;
   for (const GlobalValue &GV : M.global_values()) {
     raw_string_ostream OS(Flags);
-    emitLinkerFlagsForGlobalCOFF(OS, &GV, getTargetTriple(), getMangler());
+    emitLinkerFlagsForGlobalCOFF(OS, &GV, getContext().getTargetTriple(),
+                                 getMangler());
     OS.flush();
     if (!Flags.empty()) {
       Streamer.SwitchSection(getDrectveSection());
@@ -1786,7 +1787,8 @@ void TargetLoweringObjectFileCOFF::emitLinkerDirectives(
           continue;
 
         raw_string_ostream OS(Flags);
-        emitLinkerFlagsForUsedCOFF(OS, GV, getTargetTriple(), getMangler());
+        emitLinkerFlagsForUsedCOFF(OS, GV, getContext().getTargetTriple(),
+                                   getMangler());
         OS.flush();
 
         if (!Flags.empty()) {
@@ -1865,16 +1867,16 @@ static MCSectionCOFF *getCOFFStaticStructorSection(MCContext &Ctx,
 
 MCSection *TargetLoweringObjectFileCOFF::getStaticCtorSection(
     unsigned Priority, const MCSymbol *KeySym) const {
-  return getCOFFStaticStructorSection(getContext(), getTargetTriple(), true,
-                                      Priority, KeySym,
-                                      cast<MCSectionCOFF>(StaticCtorSection));
+  return getCOFFStaticStructorSection(
+      getContext(), getContext().getTargetTriple(), true, Priority, KeySym,
+      cast<MCSectionCOFF>(StaticCtorSection));
 }
 
 MCSection *TargetLoweringObjectFileCOFF::getStaticDtorSection(
     unsigned Priority, const MCSymbol *KeySym) const {
-  return getCOFFStaticStructorSection(getContext(), getTargetTriple(), false,
-                                      Priority, KeySym,
-                                      cast<MCSectionCOFF>(StaticDtorSection));
+  return getCOFFStaticStructorSection(
+      getContext(), getContext().getTargetTriple(), false, Priority, KeySym,
+      cast<MCSectionCOFF>(StaticDtorSection));
 }
 
 const MCExpr *TargetLoweringObjectFileCOFF::lowerRelativeReference(