codegen: Move remaining BPF function calls into IRBuilderBPF

src/codegen_llvm.cpp

@@ -20,53 +20,30 @@ void CodegenLLVM::visit(Builtin &builtin)
 {
   if (builtin.ident == "nsecs")
   {
-    // u64 ktime_get_ns()
-    FunctionType *gettime_func_type = FunctionType::get(b_.getInt64Ty(), false);
-    PointerType *gettime_func_ptr_type = PointerType::get(gettime_func_type, 0);
-    Constant *gettime_func = ConstantExpr::getCast(
-        Instruction::IntToPtr,
-        b_.getInt64(BPF_FUNC_ktime_get_ns),
-        gettime_func_ptr_type);
-    expr_ = b_.CreateCall(gettime_func);
+    expr_ = b_.CreateGetNs();
   }
   else if (builtin.ident == "pid" || builtin.ident == "tid")
   {
-    // u64 bpf_get_current_pid_tgid(void)
-    // Return: current->tgid << 32 | current->pid
-    FunctionType *getpidtgid_func_type = FunctionType::get(b_.getInt64Ty(), false);
-    PointerType *getpidtgid_func_ptr_type = PointerType::get(getpidtgid_func_type, 0);
-    Constant *getpidtgid_func = ConstantExpr::getCast(
-        Instruction::IntToPtr,
-        b_.getInt64(BPF_FUNC_get_current_pid_tgid),
-        getpidtgid_func_ptr_type);
-    CallInst *call = b_.CreateCall(getpidtgid_func);
+    Value *pidtgid = b_.CreateGetPidTgid();
     if (builtin.ident == "pid")
     {
-      expr_ = b_.CreateLShr(call, 32);
+      expr_ = b_.CreateLShr(pidtgid, 32);
     }
     else if (builtin.ident == "tid")
     {
-      expr_ = b_.CreateAnd(call, 0xffffffff);
+      expr_ = b_.CreateAnd(pidtgid, 0xffffffff);
     }
   }
   else if (builtin.ident == "uid" || builtin.ident == "gid")
   {
-    // u64 bpf_get_current_uid_gid(void)
-    // Return: current_gid << 32 | current_uid
-    FunctionType *getuidgid_func_type = FunctionType::get(b_.getInt64Ty(), false);
-    PointerType *getuidgid_func_ptr_type = PointerType::get(getuidgid_func_type, 0);
-    Constant *getuidgid_func = ConstantExpr::getCast(
-        Instruction::IntToPtr,
-        b_.getInt64(BPF_FUNC_get_current_uid_gid),
-        getuidgid_func_ptr_type);
-    CallInst *call = b_.CreateCall(getuidgid_func);
+    Value *uidgid = b_.CreateGetUidGid();
     if (builtin.ident == "uid")
     {
-      expr_ = b_.CreateAnd(call, 0xffffffff);
+      expr_ = b_.CreateAnd(uidgid, 0xffffffff);
     }
     else if (builtin.ident == "gid")
     {
-      expr_ = b_.CreateLShr(call, 32);
+      expr_ = b_.CreateLShr(uidgid, 32);
     }
   }
   else

src/irbuilderbpf.cpp

@@ -106,6 +106,46 @@ void IRBuilderBPF::CreateMapUpdateElem(Map &map, Value *key, Value *val)
   CallInst *call = CreateCall(update_func, {map_ptr, key, val, flags});
 }
 
+Value *IRBuilderBPF::CreateGetNs()
+{
+  // u64 ktime_get_ns()
+  // Return: current ktime
+  FunctionType *gettime_func_type = FunctionType::get(getInt64Ty(), false);
+  PointerType *gettime_func_ptr_type = PointerType::get(gettime_func_type, 0);
+  Constant *gettime_func = ConstantExpr::getCast(
+      Instruction::IntToPtr,
+      getInt64(BPF_FUNC_ktime_get_ns),
+      gettime_func_ptr_type);
+  return CreateCall(gettime_func);
+}
+
+Value *IRBuilderBPF::CreateGetPidTgid()
+{
+  // u64 bpf_get_current_pid_tgid(void)
+  // Return: current->tgid << 32 | current->pid
+  FunctionType *getpidtgid_func_type = FunctionType::get(getInt64Ty(), false);
+  PointerType *getpidtgid_func_ptr_type = PointerType::get(getpidtgid_func_type, 0);
+  Constant *getpidtgid_func = ConstantExpr::getCast(
+      Instruction::IntToPtr,
+      getInt64(BPF_FUNC_get_current_pid_tgid),
+      getpidtgid_func_ptr_type);
+  return CreateCall(getpidtgid_func);
+}
+
+Value *IRBuilderBPF::CreateGetUidGid()
+{
+  // u64 bpf_get_current_uid_gid(void)
+  // Return: current_gid << 32 | current_uid
+  FunctionType *getuidgid_func_type = FunctionType::get(getInt64Ty(), false);
+  PointerType *getuidgid_func_ptr_type = PointerType::get(getuidgid_func_type, 0);
+  Constant *getuidgid_func = ConstantExpr::getCast(
+      Instruction::IntToPtr,
+      getInt64(BPF_FUNC_get_current_uid_gid),
+      getuidgid_func_ptr_type);
+  return CreateCall(getuidgid_func);
+}
+
+
 } // namespace ast
 } // namespace bpftrace
 } // namespace ebpf

src/irbuilderbpf.h

@@ -21,7 +21,10 @@ public:
   AllocaInst *CreateAllocaBPF(llvm::Type *ty, const std::string &name="") const;
   Value *CreateBpfPseudoCall(Map &map);
   Value *CreateMapLookupElem(Map &map, Value *key);
-  void CreateMapUpdateElem(Map &map, Value *key, Value *val);
+  void   CreateMapUpdateElem(Map &map, Value *key, Value *val);
+  Value *CreateGetNs();
+  Value *CreateGetPidTgid();
+  Value *CreateGetUidGid();
 
 private:
   Module &module_;