Add support for naked functions

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76198 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 11 insertions, 3 deletions

diff --git a/lib/AsmParser/LLLexer.cpp b/lib/AsmParser/LLLexer.cpp
index 97e8e6ad18..1dc463110b 100644
--- a/lib/AsmParser/LLLexer.cpp
+++ b/lib/AsmParser/LLLexer.cpp
@@ -541,6 +541,7 @@ lltok::Kind LLLexer::LexIdentifier() {
   KEYWORD(sspreq);
   KEYWORD(noredzone);
   KEYWORD(noimplicitfloat);
+  KEYWORD(naked);
 
   KEYWORD(type);
   KEYWORD(opaque);
diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 080575df84..6a6478f37b 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -775,6 +775,7 @@ bool LLParser::ParseOptionalAttrs(unsigned &Attrs, unsigned AttrKind) {
     case lltok::kw_sspreq:          Attrs |= Attribute::StackProtectReq; break;
     case lltok::kw_noredzone:       Attrs |= Attribute::NoRedZone; break;
     case lltok::kw_noimplicitfloat: Attrs |= Attribute::NoImplicitFloat; break;
+    case lltok::kw_naked:           Attrs |= Attribute::Naked; break;
         
     case lltok::kw_align: {
       unsigned Alignment;
diff --git a/lib/AsmParser/LLToken.h b/lib/AsmParser/LLToken.h
index b5194ad83f..8f813f39b6 100644
--- a/lib/AsmParser/LLToken.h
+++ b/lib/AsmParser/LLToken.h
@@ -84,6 +84,7 @@ namespace lltok {
     kw_sspreq,
     kw_noredzone,
     kw_noimplicitfloat,
+    kw_naked,
 
     kw_type,
     kw_opaque,
diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp
index 546a84ec87..5aa37c9044 100644
--- a/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/lib/CodeGen/PrologEpilogInserter.cpp
@@ -51,6 +51,7 @@ FunctionPass *llvm::createPrologEpilogCodeInserter() { return new PEI(); }
 /// frame indexes with appropriate references.
 ///
 bool PEI::runOnMachineFunction(MachineFunction &Fn) {
+  const Function* F = Fn.getFunction();
   const TargetRegisterInfo *TRI = Fn.getTarget().getRegisterInfo();
   RS = TRI->requiresRegisterScavenging(Fn) ? new RegScavenger() : NULL;
 
@@ -80,7 +81,8 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) {
   placeCSRSpillsAndRestores(Fn);
 
   // Add the code to save and restore the callee saved registers
-  insertCSRSpillsAndRestores(Fn);
+  if (!F->hasFnAttr(Attribute::Naked))
+    insertCSRSpillsAndRestores(Fn);
 
   // Allow the target machine to make final modifications to the function
   // before the frame layout is finalized.
@@ -94,7 +96,8 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) {
   // called functions.  Because of this, calculateCalleeSavedRegisters
   // must be called before this function in order to set the HasCalls
   // and MaxCallFrameSize variables.
-  insertPrologEpilogCode(Fn);
+  if (!F->hasFnAttr(Attribute::Naked))
+    insertPrologEpilogCode(Fn);
 
   // Replace all MO_FrameIndex operands with physical register references
   // and actual offsets.
diff --git a/lib/VMCore/Attributes.cpp b/lib/VMCore/Attributes.cpp
index 8dfbd1d502..5d763c34fe 100644
--- a/lib/VMCore/Attributes.cpp
+++ b/lib/VMCore/Attributes.cpp
@@ -40,7 +40,7 @@ std::string Attribute::getAsString(Attributes Attrs) {
   if (Attrs & Attribute::NoCapture)
     Result += "nocapture ";
   if (Attrs & Attribute::StructRet)
-    Result += "sret ";  
+    Result += "sret ";
   if (Attrs & Attribute::ByVal)
     Result += "byval ";
   if (Attrs & Attribute::Nest)
@@ -63,6 +63,8 @@ std::string Attribute::getAsString(Attributes Attrs) {
     Result += "noredzone ";
   if (Attrs & Attribute::NoImplicitFloat)
     Result += "noimplicitfloat ";
+  if (Attrs & Attribute::Naked)
+    Result += "naked ";
   if (Attrs & Attribute::Alignment) {
     Result += "align ";
     Result += utostr(Attribute::getAlignmentFromAttrs(Attrs));