Expose an InitToTextSection through MCStreamer.

The aim of this patch is to fix the following piece of code in the
platform-independent AsmParser:

void AsmParser::CheckForValidSection() {
  if (!ParsingInlineAsm && !getStreamer().getCurrentSection()) {
    TokError("expected section directive before assembly directive");
    Out.SwitchSection(Ctx.getMachOSection(
                        "__TEXT", "__text",
                        MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
                        0, SectionKind::getText()));
  }
}

This was added for the "-n" option of llvm-mc.

The proposed fix adds another virtual method to MCStreamer, called
InitToTextSection. Conceptually, it's similar to the existing
InitSections which initializes all common sections and switches to
text. The new method is implemented by each platform streamer in a way
that it sees fit. So AsmParser can now do this:

void AsmParser::CheckForValidSection() {
  if (!ParsingInlineAsm && !getStreamer().getCurrentSection()) {
    TokError("expected section directive before assembly directive");
    Out.InitToTextSection();
  }
}

Which is much more reasonable.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172450 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 34 insertions, 11 deletions

diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index e234dfe..dd5112c 100644
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -127,11 +127,16 @@ public:
   virtual void ChangeSection(const MCSection *Section);
 
   virtual void InitSections() {
+    InitToTextSection();
+  }
+
+  virtual void InitToTextSection() {
     // FIXME, this is MachO specific, but the testsuite
     // expects this.
-    SwitchSection(getContext().getMachOSection("__TEXT", "__text",
-                         MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
-                         0, SectionKind::getText()));
+    SwitchSection(getContext().getMachOSection(
+                                      "__TEXT", "__text",
+                                      MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
+                                      0, SectionKind::getText()));
   }
 
   virtual void EmitLabel(MCSymbol *Symbol);
diff --git a/lib/MC/MCELFStreamer.cpp b/lib/MC/MCELFStreamer.cpp
index d05fcca..cae73be 100644
--- a/lib/MC/MCELFStreamer.cpp
+++ b/lib/MC/MCELFStreamer.cpp
@@ -65,6 +65,10 @@ inline void MCELFStreamer::SetSectionBss() {
 MCELFStreamer::~MCELFStreamer() {
 }
 
+void MCELFStreamer::InitToTextSection() {
+  SetSectionText();
+}
+
 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.
diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp
index 82ccdd4..f947dda 100644
--- a/lib/MC/MCMachOStreamer.cpp
+++ b/lib/MC/MCMachOStreamer.cpp
@@ -42,6 +42,7 @@ public:
   /// @{
 
   virtual void InitSections();
+  virtual void InitToTextSection();
   virtual void EmitLabel(MCSymbol *Symbol);
   virtual void EmitDebugLabel(MCSymbol *Symbol);
   virtual void EmitEHSymAttributes(const MCSymbol *Symbol,
@@ -90,10 +91,14 @@ public:
 } // end anonymous namespace.
 
 void MCMachOStreamer::InitSections() {
-  SwitchSection(getContext().getMachOSection("__TEXT", "__text",
-                                    MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
-                                    0, SectionKind::getText()));
+  InitToTextSection();
+}
 
+void MCMachOStreamer::InitToTextSection() {
+  SwitchSection(getContext().getMachOSection(
+                                    "__TEXT", "__text",
+                                    MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS, 0,
+                                    SectionKind::getText()));
 }
 
 void MCMachOStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
diff --git a/lib/MC/MCNullStreamer.cpp b/lib/MC/MCNullStreamer.cpp
index 364c324..3eee5ca 100644
--- a/lib/MC/MCNullStreamer.cpp
+++ b/lib/MC/MCNullStreamer.cpp
@@ -24,6 +24,9 @@ namespace {
     /// @name MCStreamer Interface
     /// @{
 
+    virtual void InitToTextSection() {
+    }
+
     virtual void InitSections() {
     }
 
diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 752cc19..262cb2c 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -708,10 +708,7 @@ bool AsmParser::Run(bool NoInitialTextSection, bool NoFinalize) {
 void AsmParser::CheckForValidSection() {
   if (!ParsingInlineAsm && !getStreamer().getCurrentSection()) {
     TokError("expected section directive before assembly directive");
-    Out.SwitchSection(Ctx.getMachOSection(
-                        "__TEXT", "__text",
-                        MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
-                        0, SectionKind::getText()));
+    Out.InitToTextSection();
   }
 }
 
diff --git a/lib/MC/MCPureStreamer.cpp b/lib/MC/MCPureStreamer.cpp
index 97e5a69..6ce7ae8 100644
--- a/lib/MC/MCPureStreamer.cpp
+++ b/lib/MC/MCPureStreamer.cpp
@@ -36,6 +36,7 @@ public:
   /// @{
 
   virtual void InitSections();
+  virtual void InitToTextSection();
   virtual void EmitLabel(MCSymbol *Symbol);
   virtual void EmitDebugLabel(MCSymbol *Symbol);
   virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
@@ -104,11 +105,14 @@ public:
 } // end anonymous namespace.
 
 void MCPureStreamer::InitSections() {
+  InitToTextSection();
+}
+
+void MCPureStreamer::InitToTextSection() {
   // FIMXE: To what!?
   SwitchSection(getContext().getMachOSection("__TEXT", "__text",
                                     MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
                                     0, SectionKind::getText()));
-
 }
 
 void MCPureStreamer::EmitLabel(MCSymbol *Symbol) {
diff --git a/lib/MC/WinCOFFStreamer.cpp b/lib/MC/WinCOFFStreamer.cpp
index 5489ef8..cc2c272 100644
--- a/lib/MC/WinCOFFStreamer.cpp
+++ b/lib/MC/WinCOFFStreamer.cpp
@@ -50,6 +50,7 @@ public:
   // MCStreamer interface
 
   virtual void InitSections();
+  virtual void InitToTextSection();
   virtual void EmitLabel(MCSymbol *Symbol);
   virtual void EmitDebugLabel(MCSymbol *Symbol);
   virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
@@ -173,6 +174,10 @@ void WinCOFFStreamer::AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
 
 // MCStreamer interface
 
+void WinCOFFStreamer::InitToTextSection() {
+  SetSectionText();
+}
+
 void WinCOFFStreamer::InitSections() {
   SetSectionText();
   SetSectionData();