//===- Target/TargetJITInfo.h - Target Information for JIT ------*- C++ -*-===//
-//
+//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+//
//===----------------------------------------------------------------------===//
//
// This file exposes an abstract interface used by the Just-In-Time code
#ifndef LLVM_TARGET_TARGETJITINFO_H
#define LLVM_TARGET_TARGETJITINFO_H
+#include <cassert>
+
namespace llvm {
class Function;
class FunctionPassManager;
class MachineCodeEmitter;
+ class MachineRelocation;
/// TargetJITInfo - Target specific information required by the Just-In-Time
/// code generator.
- struct TargetJITInfo {
+ class TargetJITInfo {
+ public:
virtual ~TargetJITInfo() {}
-
+
/// addPassesToJITCompile - Add passes to the specified pass manager to
/// implement a fast code generator for this target.
///
virtual void addPassesToJITCompile(FunctionPassManager &PM) = 0;
-
+
/// replaceMachineCodeForFunction - Make it so that calling the function
/// whose machine code is at OLD turns into a call to NEW, perhaps by
/// overwriting OLD with a branch to NEW. This is used for self-modifying
/// code.
///
- virtual void replaceMachineCodeForFunction (void *Old, void *New) = 0;
-
- /// getJITStubForFunction - Create or return a stub for the specified
- /// function. This stub acts just like the specified function, except that
- /// it allows the "address" of the function to be taken without having to
- /// generate code for it. Targets do not need to implement this method, but
- /// doing so will allow for faster startup of the JIT.
- ///
- virtual void *getJITStubForFunction(Function *F, MachineCodeEmitter &MCE) {
+ virtual void replaceMachineCodeForFunction(void *Old, void *New) = 0;
+
+ /// emitFunctionStub - Use the specified MachineCodeEmitter object to emit a
+ /// small native function that simply calls the function at the specified
+ /// address. Return the address of the resultant function.
+ virtual void *emitFunctionStub(void *Fn, MachineCodeEmitter &MCE) {
+ assert(0 && "This target doesn't implement emitFunctionStub!");
return 0;
}
+
+ /// LazyResolverFn - This typedef is used to represent the function that
+ /// unresolved call points should invoke. This is a target specific
+ /// function that knows how to walk the stack and find out which stub the
+ /// call is coming from.
+ typedef void (*LazyResolverFn)();
+
+ /// JITCompilerFn - This typedef is used to represent the JIT function that
+ /// lazily compiles the function corresponding to a stub. The JIT keeps
+ /// track of the mapping between stubs and LLVM Functions, the target
+ /// provides the ability to figure out the address of a stub that is called
+ /// by the LazyResolverFn.
+ typedef void* (*JITCompilerFn)(void *);
+
+ /// getLazyResolverFunction - This method is used to initialize the JIT,
+ /// giving the target the function that should be used to compile a
+ /// function, and giving the JIT the target function used to do the lazy
+ /// resolving.
+ virtual LazyResolverFn getLazyResolverFunction(JITCompilerFn) {
+ assert(0 && "Not implemented for this target!");
+ return 0;
+ }
+
+ /// relocate - Before the JIT can run a block of code that has been emitted,
+ /// it must rewrite the code to contain the actual addresses of any
+ /// referenced global symbols.
+ virtual void relocate(void *Function, MachineRelocation *MR,
+ unsigned NumRelocs, unsigned char* GOTBase) {
+ assert(NumRelocs == 0 && "This target does not have relocations!");
+ }
+
+ /// needsGOT - Allows a target to specify that it would like the
+ // JIT to manage a GOT for it.
+ bool needsGOT() const { return useGOT; }
+
+ protected:
+ bool useGOT;
+
};
} // End llvm namespace