Add a InitSections method to the streamer interface.

The ELF implementation now creates text, data and bss to match the gnu as
behavior.

The text streamer still has the old MachO specific behavior since
the testsuite checks that it will error when a directive is given
before a setting the current section for example.

A nice benefit is that -n is not required anymore when producing
ELF files.

llvm-svn: 114027

1 files changed, 33 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCELFStreamer.cpp b/llvm/lib/MC/MCELFStreamer.cpp
index 6490cc7a82e..deb1a0de208 100644
--- a/llvm/lib/MC/MCELFStreamer.cpp
+++ b/llvm/lib/MC/MCELFStreamer.cpp
@@ -46,6 +46,7 @@ public:
   /// @name MCStreamer Interface
   /// @{
 
+  virtual void InitSections();
   virtual void EmitLabel(MCSymbol *Symbol);
   virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
   virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
@@ -109,10 +110,42 @@ public:
   virtual void Finish();
 
   /// @}
+  void SetSection(StringRef Section, unsigned Type, unsigned Flags,
+                  SectionKind Kind) {
+    SwitchSection(getContext().getELFSection(Section, Type, Flags, Kind));
+  }
+
+  void SetSectionData() {
+    SetSection(".data", MCSectionELF::SHT_PROGBITS,
+               MCSectionELF::SHF_WRITE |MCSectionELF::SHF_ALLOC,
+               SectionKind::getDataRel());
+    EmitCodeAlignment(4, 0);
+  }
+  void SetSectionText() {
+    SetSection(".text", MCSectionELF::SHT_PROGBITS,
+               MCSectionELF::SHF_EXECINSTR |
+               MCSectionELF::SHF_ALLOC, SectionKind::getText());
+    EmitCodeAlignment(4, 0);
+  }
+  void SetSectionBss() {
+    SetSection(".bss", MCSectionELF::SHT_NOBITS,
+               MCSectionELF::SHF_WRITE |
+               MCSectionELF::SHF_ALLOC, SectionKind::getBSS());
+    EmitCodeAlignment(4, 0);
+  }
 };
 
 } // end anonymous namespace.
 
+void MCELFStreamer::InitSections() {
+  // This emulates the same behavior of GNU as. This makes it easier
+  // to compare the output as the major sections are in the same order.
+  SetSectionText();
+  SetSectionData();
+  SetSectionBss();
+  SetSectionText();
+}
+
 void MCELFStreamer::EmitLabel(MCSymbol *Symbol) {
   assert(Symbol->isUndefined() && "Cannot define a symbol twice!");