llvm-mc: Support -n, useful for comparing -integrated-as output since the
compiler may not lead with the text section.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98418 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/MC/MCParser/AsmParser.h b/include/llvm/MC/MCParser/AsmParser.h
index 66b6dac..06e0920 100644
--- a/include/llvm/MC/MCParser/AsmParser.h
+++ b/include/llvm/MC/MCParser/AsmParser.h
@@ -64,7 +64,7 @@
             const MCAsmInfo &MAI);
   ~AsmParser();
 
-  bool Run();
+  bool Run(bool NoInitialTextSection);
 
   
   void AddDirectiveHandler(StringRef Directive,
diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 50964ae..a241106 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -138,15 +138,14 @@
   return *tok;
 }
 
-bool AsmParser::Run() {
-  // Create the initial section.
+bool AsmParser::Run(bool NoInitialTextSection) {
+  // Create the initial section, if requested.
   //
-  // FIXME: Support -n.
   // FIXME: Target hook & command line option for initial section.
-  Out.SwitchSection(getMachOSection("__TEXT", "__text",
-                                    MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
-                                    0, SectionKind::getText()));
-
+  if (!NoInitialTextSection)
+    Out.SwitchSection(getMachOSection("__TEXT", "__text",
+                                      MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
+                                      0, SectionKind::getText()));
 
   // Prime the lexer.
   Lex();
diff --git a/tools/llvm-mc/llvm-mc.cpp b/tools/llvm-mc/llvm-mc.cpp
index 48e0d3d..666f0ba 100644
--- a/tools/llvm-mc/llvm-mc.cpp
+++ b/tools/llvm-mc/llvm-mc.cpp
@@ -84,6 +84,10 @@
 TripleName("triple", cl::desc("Target triple to assemble for, "
                               "see -version for available targets"));
 
+static cl::opt<bool>
+NoInitialTextSection("n", cl::desc(
+                   "Don't assume assembly file starts in the text section"));
+
 enum ActionType {
   AC_AsLex,
   AC_Assemble,
@@ -303,7 +307,7 @@
 
   Parser.setTargetParser(*TAP.get());
 
-  int Res = Parser.Run();
+  int Res = Parser.Run(NoInitialTextSection);
   if (Out != &fouts())
     delete Out;