switch MCSectionCOFF from a syntactic to semantic representation,

patch by Peter Housel!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103267 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 69 insertions, 28 deletions

diff --git a/lib/MC/MCContext.cpp b/lib/MC/MCContext.cpp
index dc757bb0bf..93388c00f8 100644
--- a/lib/MC/MCContext.cpp
+++ b/lib/MC/MCContext.cpp
@@ -11,6 +11,7 @@
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCSectionMachO.h"
 #include "llvm/MC/MCSectionELF.h"
+#include "llvm/MC/MCSectionCOFF.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/Twine.h"
@@ -18,11 +19,13 @@ using namespace llvm;
 
 typedef StringMap<const MCSectionMachO*> MachOUniqueMapTy;
 typedef StringMap<const MCSectionELF*> ELFUniqueMapTy;
+typedef StringMap<const MCSectionCOFF*> COFFUniqueMapTy;
 
 
 MCContext::MCContext(const MCAsmInfo &mai) : MAI(mai), NextUniqueID(0) {
   MachOUniquingMap = 0;
   ELFUniquingMap = 0;
+  COFFUniquingMap = 0;
 }
 
 MCContext::~MCContext() {
@@ -32,6 +35,7 @@ MCContext::~MCContext() {
   // If we have the MachO uniquing map, free it.
   delete (MachOUniqueMapTy*)MachOUniquingMap;
   delete (ELFUniqueMapTy*)ELFUniquingMap;
+  delete (COFFUniqueMapTy*)COFFUniquingMap;
 }
 
 //===----------------------------------------------------------------------===//
@@ -122,4 +126,19 @@ getELFSection(StringRef Section, unsigned Type, unsigned Flags,
   return Result;
 }
 
-
+const MCSection *MCContext::
+getCOFFSection(StringRef Section, unsigned Flags, SectionKind Kind) {
+  if (COFFUniquingMap == 0)
+    COFFUniquingMap = new COFFUniqueMapTy();
+  COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)COFFUniquingMap;
+  
+  // Do the lookup, if we have a hit, return it.
+  StringMapEntry<const MCSectionCOFF*> &Entry = Map.GetOrCreateValue(Section);
+  if (Entry.getValue()) return Entry.getValue();
+  
+  MCSectionCOFF *Result = new (*this) MCSectionCOFF(Entry.getKey(), Flags,
+                                                    Kind);
+  
+  Entry.setValue(Result);
+  return Result;
+}
diff --git a/lib/MC/MCSection.cpp b/lib/MC/MCSection.cpp
index f6e96368eb..a792d56317 100644
--- a/lib/MC/MCSection.cpp
+++ b/lib/MC/MCSection.cpp
@@ -20,30 +20,3 @@ using namespace llvm;
 MCSection::~MCSection() {
 }
 
-//===----------------------------------------------------------------------===//
-// MCSectionCOFF
-//===----------------------------------------------------------------------===//
-
-MCSectionCOFF *MCSectionCOFF::
-Create(StringRef Name, bool IsDirective, SectionKind K, MCContext &Ctx) {
-  char *NameCopy = static_cast<char*>(
-    Ctx.Allocate(Name.size(), /*Alignment=*/1));
-  memcpy(NameCopy, Name.data(), Name.size());
-  return new (Ctx) MCSectionCOFF(StringRef(NameCopy, Name.size()),
-                                 IsDirective, K);
-}
-
-void MCSectionCOFF::PrintSwitchToSection(const MCAsmInfo &MAI,
-                                         raw_ostream &OS) const {
-  
-  if (isDirective()) {
-    OS << getName() << '\n';
-    return;
-  }
-  OS << "\t.section\t" << getName() << ",\"";
-  if (getKind().isText())
-    OS << 'x';
-  if (getKind().isWriteable())
-    OS << 'w';
-  OS << "\"\n";
-}
diff --git a/lib/MC/MCSectionCOFF.cpp b/lib/MC/MCSectionCOFF.cpp
new file mode 100644
index 0000000000..f26768a764
--- /dev/null
+++ b/lib/MC/MCSectionCOFF.cpp
@@ -0,0 +1,49 @@
+//===- lib/MC/MCSectionCOFF.cpp - COFF Code Section Representation --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/MC/MCSectionCOFF.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+MCSectionCOFF::~MCSectionCOFF() {} // anchor.
+
+// ShouldOmitSectionDirective - Decides whether a '.section' directive
+// should be printed before the section name
+bool MCSectionCOFF::ShouldOmitSectionDirective(StringRef Name,
+                                               const MCAsmInfo &MAI) const {
+  
+  // FIXME: Does .section .bss/.data/.text work everywhere??
+  if (Name == ".text" || Name == ".data" || Name == ".bss")
+    return true;
+
+  return false;
+}
+
+void MCSectionCOFF::PrintSwitchToSection(const MCAsmInfo &MAI,
+                                         raw_ostream &OS) const {
+  
+  if (ShouldOmitSectionDirective(SectionName, MAI)) {
+    OS << '\t' << getSectionName() << '\n';
+    return;
+  }
+
+  OS << "\t.section\t" << getSectionName() << ",\"";
+  if (getKind().isText())
+    OS << 'x';
+  if (getKind().isWriteable())
+    OS << 'w';
+  else
+    OS << 'r';
+  if (getFlags() & MCSectionCOFF::IMAGE_SCN_MEM_DISCARDABLE)
+    OS << 'n';
+  OS << "\"\n";
+}