Change MCSectionELF to represent a section semantically instead of

syntactically as a string, very similiar to what Chris did with MachO.
The parsing support and validation is not introduced yet.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78890 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 123 insertions, 0 deletions

diff --git a/lib/MC/MCSectionELF.cpp b/lib/MC/MCSectionELF.cpp
new file mode 100644
index 0000000000..d172a9c923
--- /dev/null
+++ b/lib/MC/MCSectionELF.cpp
@@ -0,0 +1,123 @@
+//===- lib/MC/MCSectionELF.cpp - ELF 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/MCSectionELF.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetAsmInfo.h"
+
+using namespace llvm;
+
+MCSectionELF *MCSectionELF::
+Create(const StringRef &Section, unsigned Type, unsigned Flags,
+       SectionKind K, bool hasCrazyBSS, bool isExplicit, MCContext &Ctx) {
+  return new 
+    (Ctx) MCSectionELF(Section, Type, Flags, K, hasCrazyBSS, isExplicit);
+}
+
+// ShouldOmitSectionDirective - Decides whether a '.section' directive
+// should be printed before the section name
+bool MCSectionELF::ShouldOmitSectionDirective(const char *Name) const {
+  
+  // PPC/Linux doesn't support the .bss directive, it needs .section .bss.
+  // FIXME: Does .section .bss/.data/.text work everywhere??
+  if ((!HasCrazyBSS && strncmp(Name, ".bss", 4) == 0) || 
+      strncmp(Name, ".text", 5) == 0 || 
+      strncmp(Name, ".data", 5) == 0)
+    return true;
+
+  return false;
+}
+
+// ShouldPrintSectionType - Only prints the section type if supported
+bool MCSectionELF::ShouldPrintSectionType(unsigned Ty) const {
+  
+  if (IsExplicit && !(Ty == SHT_NOBITS || Ty == SHT_PROGBITS))
+    return false;
+
+  return true;
+}
+
+void MCSectionELF::PrintSwitchToSection(const TargetAsmInfo &TAI,
+                                        raw_ostream &OS) const {
+  
+  if (ShouldOmitSectionDirective(SectionName.c_str())) {
+    OS << '\t' << getSectionName() << '\n';
+    return;
+  }
+
+  OS << "\t.section\t" << getSectionName();
+  
+  // Handle the weird solaris syntax if desired.
+  if (TAI.usesSunStyleELFSectionSwitchSyntax() && 
+      !(Flags & MCSectionELF::SHF_MERGE)) {
+    if (Flags & MCSectionELF::SHF_ALLOC)
+      OS << ",#alloc";
+    if (Flags & MCSectionELF::SHF_EXECINSTR)
+      OS << ",#execinstr";
+    if (Flags & MCSectionELF::SHF_WRITE)
+      OS << ",#write";
+    if (Flags & MCSectionELF::SHF_TLS)
+      OS << ",#tls";
+  } else {
+    OS << ",\"";
+  
+    if (Flags & MCSectionELF::SHF_ALLOC)
+      OS << 'a';
+    if (Flags & MCSectionELF::SHF_EXECINSTR)
+      OS << 'x';
+    if (Flags & MCSectionELF::SHF_WRITE)
+      OS << 'w';
+    if (Flags & MCSectionELF::SHF_MERGE)
+      OS << 'M';
+    if (Flags & MCSectionELF::SHF_STRINGS)
+      OS << 'S';
+    if (Flags & MCSectionELF::SHF_TLS)
+      OS << 'T';
+   
+    OS << '"';
+
+    if (ShouldPrintSectionType(Type)) {
+      OS << ',';
+   
+      // If comment string is '@', e.g. as on ARM - use '%' instead
+      if (TAI.getCommentString()[0] == '@')
+        OS << '%';
+      else
+        OS << '@';
+    
+      if (Type == MCSectionELF::SHT_INIT_ARRAY)
+        OS << "init_array";
+      else if (Type == MCSectionELF::SHT_FINI_ARRAY)
+        OS << "fini_array";
+      else if (Type == MCSectionELF::SHT_PREINIT_ARRAY)
+        OS << "preinit_array";
+      else if (Type == MCSectionELF::SHT_NOBITS)
+        OS << "nobits";
+      else if (Type == MCSectionELF::SHT_PROGBITS)
+        OS << "progbits";
+    
+      if (getKind().isMergeable1ByteCString()) {
+        OS << ",1";
+      } else if (getKind().isMergeable2ByteCString()) {
+        OS << ",2";
+      } else if (getKind().isMergeable4ByteCString() || 
+                 getKind().isMergeableConst4()) {
+        OS << ",4";
+      } else if (getKind().isMergeableConst8()) {
+        OS << ",8";
+      } else if (getKind().isMergeableConst16()) {
+        OS << ",16";
+      }
+    }
+  }
+  
+  OS << '\n';
+}
+