diff options
author | Yonghong Song <yhs@fb.com> | 2017-11-16 00:52:30 +0000 |
---|---|---|
committer | Yonghong Song <yhs@fb.com> | 2017-11-16 00:52:30 +0000 |
commit | 0df1955fdb388964e250c6f3af89fa0e8b3104a6 (patch) | |
tree | 0bb09f10e4a84f046fd86dee143e3c1da3902f72 /lib/Target/BPF | |
parent | 64b77007a6d25d832d1ff55939d7eace23e15c6f (diff) |
bpf: enable llvm-objdump to print out symbolized jmp target
Add hook in BPF backend so that llvm-objdump can print out
the jmp target with label names, e.g.,
...
if r1 != 2 goto 6 <LBB0_2>
...
goto 7 <LBB0_4>
...
LBB0_2:
...
LBB0_4:
...
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318358 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/BPF')
-rw-r--r-- | lib/Target/BPF/MCTargetDesc/BPFMCTargetDesc.cpp | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/lib/Target/BPF/MCTargetDesc/BPFMCTargetDesc.cpp b/lib/Target/BPF/MCTargetDesc/BPFMCTargetDesc.cpp index c8fbc0c2207..5c3bba6e669 100644 --- a/lib/Target/BPF/MCTargetDesc/BPFMCTargetDesc.cpp +++ b/lib/Target/BPF/MCTargetDesc/BPFMCTargetDesc.cpp @@ -15,6 +15,7 @@ #include "BPF.h" #include "InstPrinter/BPFInstPrinter.h" #include "MCTargetDesc/BPFMCAsmInfo.h" +#include "llvm/MC/MCInstrAnalysis.h" #include "llvm/MC/MCInstrInfo.h" #include "llvm/MC/MCRegisterInfo.h" #include "llvm/MC/MCSubtargetInfo.h" @@ -68,6 +69,35 @@ static MCInstPrinter *createBPFMCInstPrinter(const Triple &T, return nullptr; } +namespace { + +class BPFMCInstrAnalysis : public MCInstrAnalysis { +public: + explicit BPFMCInstrAnalysis(const MCInstrInfo *Info) + : MCInstrAnalysis(Info) {} + + bool evaluateBranch(const MCInst &Inst, uint64_t Addr, uint64_t Size, + uint64_t &Target) const override { + // The target is the 3rd operand of cond inst and the 1st of uncond inst. + int64_t Imm; + if (isConditionalBranch(Inst)) { + Imm = Inst.getOperand(2).getImm(); + } else if (isUnconditionalBranch(Inst)) + Imm = Inst.getOperand(0).getImm(); + else + return false; + + Target = Addr + Size + Imm * Size; + return true; + } +}; + +} // end anonymous namespace + +static MCInstrAnalysis *createBPFInstrAnalysis(const MCInstrInfo *Info) { + return new BPFMCInstrAnalysis(Info); +} + extern "C" void LLVMInitializeBPFTargetMC() { for (Target *T : {&getTheBPFleTarget(), &getTheBPFbeTarget(), &getTheBPFTarget()}) { @@ -89,6 +119,9 @@ extern "C" void LLVMInitializeBPFTargetMC() { // Register the MCInstPrinter. TargetRegistry::RegisterMCInstPrinter(*T, createBPFMCInstPrinter); + + // Register the MC instruction analyzer. + TargetRegistry::RegisterMCInstrAnalysis(*T, createBPFInstrAnalysis); } // Register the MC code emitter @@ -114,4 +147,5 @@ extern "C" void LLVMInitializeBPFTargetMC() { TargetRegistry::RegisterMCAsmBackend(getTheBPFTarget(), createBPFbeAsmBackend); } + } |