llvm/lib/Analysis/JumpInstrTableInfo.cpp
Tom Roeder 5d0f7af3dc Add a new attribute called 'jumptable' that creates jump-instruction tables for functions marked with this attribute.
It includes a pass that rewrites all indirect calls to jumptable functions to pass through these tables.

This also adds backend support for generating the jump-instruction tables on ARM and X86.
Note that since the jumptable attribute creates a second function pointer for a
function, any function marked with jumptable must also be marked with unnamed_addr.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210280 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-05 19:29:43 +00:00

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1.3 KiB
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//===-- JumpInstrTableInfo.cpp: Info for Jump-Instruction Tables ----------===//
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief Information about jump-instruction tables that have been created by
/// JumpInstrTables pass.
///
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "jiti"
#include "llvm/Analysis/JumpInstrTableInfo.h"
#include "llvm/Analysis/Passes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Type.h"
using namespace llvm;
INITIALIZE_PASS(JumpInstrTableInfo, "jump-instr-table-info",
"Jump-Instruction Table Info", true, true)
char JumpInstrTableInfo::ID = 0;
ImmutablePass *llvm::createJumpInstrTableInfoPass() {
return new JumpInstrTableInfo();
}
JumpInstrTableInfo::JumpInstrTableInfo() : ImmutablePass(ID), Tables() {
initializeJumpInstrTableInfoPass(*PassRegistry::getPassRegistry());
}
JumpInstrTableInfo::~JumpInstrTableInfo() {}
void JumpInstrTableInfo::insertEntry(FunctionType *TableFunTy, Function *Target,
Function *Jump) {
Tables[TableFunTy].push_back(JumpPair(Target, Jump));
}