Add support for naked functions
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76198 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/LangRef.html b/docs/LangRef.html
index 15f95e2..4885a84 100644
--- a/docs/LangRef.html
+++ b/docs/LangRef.html
@@ -1109,6 +1109,9 @@
<dt><tt>noimplicitfloat</tt></dt>
<dd>This attributes disables implicit floating point instructions.</dd>
+<dt><tt>naked</tt></dt>
+<dd>This attribute disables prologue / epilogue emission for the function</dd>
+
</dl>
</div>
diff --git a/include/llvm-c/Core.h b/include/llvm-c/Core.h
index d723d11..ee8058e 100644
--- a/include/llvm-c/Core.h
+++ b/include/llvm-c/Core.h
@@ -98,7 +98,8 @@
LLVMByValAttribute = 1<<7,
LLVMNestAttribute = 1<<8,
LLVMReadNoneAttribute = 1<<9,
- LLVMReadOnlyAttribute = 1<<10
+ LLVMReadOnlyAttribute = 1<<10,
+ LLVMNakedAttribute = 1<<24
} LLVMAttribute;
typedef enum {
diff --git a/include/llvm/Attributes.h b/include/llvm/Attributes.h
index 134e350..49f6057 100644
--- a/include/llvm/Attributes.h
+++ b/include/llvm/Attributes.h
@@ -57,6 +57,7 @@
const Attributes NoRedZone = 1<<22; /// disable redzone
const Attributes NoImplicitFloat = 1<<23; /// disable implicit floating point
/// instructions.
+const Attributes Naked = 1<<24; ///< Naked function
/// @brief Attributes that only apply to function parameters.
const Attributes ParameterOnly = ByVal | Nest | StructRet | NoCapture;
@@ -65,7 +66,7 @@
/// be used on return values or function parameters.
const Attributes FunctionOnly = NoReturn | NoUnwind | ReadNone | ReadOnly |
NoInline | AlwaysInline | OptimizeForSize | StackProtect | StackProtectReq |
- NoRedZone | NoImplicitFloat;
+ NoRedZone | NoImplicitFloat | Naked;
/// @brief Parameter attributes that do not apply to vararg call arguments.
const Attributes VarArgsIncompatible = StructRet;
diff --git a/lib/AsmParser/LLLexer.cpp b/lib/AsmParser/LLLexer.cpp
index 97e8e6a..1dc4631 100644
--- a/lib/AsmParser/LLLexer.cpp
+++ b/lib/AsmParser/LLLexer.cpp
@@ -541,6 +541,7 @@
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 080575d..6a6478f 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -775,6 +775,7 @@
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 b5194ad..8f813f3 100644
--- a/lib/AsmParser/LLToken.h
+++ b/lib/AsmParser/LLToken.h
@@ -84,6 +84,7 @@
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 546a84e..5aa37c9 100644
--- a/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/lib/CodeGen/PrologEpilogInserter.cpp
@@ -51,6 +51,7 @@
/// 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 @@
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 @@
// 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 8dfbd1d..5d763c3 100644
--- a/lib/VMCore/Attributes.cpp
+++ b/lib/VMCore/Attributes.cpp
@@ -40,7 +40,7 @@
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 @@
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));