| // Copyright 2014 Cloudera, Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #ifndef KUDU_CODEGEN_CODE_GENERATOR_H |
| #define KUDU_CODEGEN_CODE_GENERATOR_H |
| |
| #include "kudu/codegen/row_projector.h" |
| #include "kudu/gutil/gscoped_ptr.h" |
| #include "kudu/gutil/macros.h" |
| #include "kudu/gutil/ref_counted.h" |
| #include "kudu/util/status.h" |
| |
| namespace llvm { |
| class LLVMContext; |
| } // namespace llvm |
| |
| namespace kudu { |
| |
| class Schema; |
| |
| namespace codegen { |
| |
| class RowProjectorFunctions; |
| |
| // CodeGenerator is a top-level class that manages a per-module |
| // LLVM context, ExecutionEngine initialization, native target loading, |
| // and memory management. |
| // |
| // This generator is intended for JIT compilation of functions that |
| // are generated at runtime. These functions can make calls to pre-compiled |
| // C++ functions, which must be loaded from their *.ll files. |
| // |
| // Since the CodeGenerator is the owner of most of the LLVM compilation |
| // mechanisms (which in turn own most of the LLVM generated code), it also |
| // functions as a factory for the classes that use LLVM constructs dependent |
| // on the CodeGenerator's information. |
| // |
| // This class is thread-safe. |
| // |
| // The execution engine has a global lock for compilations. When a function |
| // is compiling, other threads will be blocked on their own compilations or |
| // runs. Because of this, a CodeGenerator should be assigned to a single |
| // compilation thread (See CompilationManager class). Threads may run |
| // codegen'd functions concurrently. |
| // |
| // Code generation may be disabled globally at compile time by defining |
| // the preprocessor macro KUDU_DISABLE_CODEGEN. |
| class CodeGenerator { |
| public: |
| // The constructor makes all the appropriate static LLVM initialization |
| // calls exactly once. |
| CodeGenerator(); |
| ~CodeGenerator(); |
| |
| // Attempts to initialize row projector functions by compiling code |
| // for the parameter schemas. Writes to 'out' upon success. |
| Status CompileRowProjector(const Schema& base, const Schema& proj, |
| scoped_refptr<RowProjectorFunctions>* out); |
| |
| private: |
| static void GlobalInit(); |
| |
| // TODO static ObjectCache shared b/w engines |
| |
| DISALLOW_COPY_AND_ASSIGN(CodeGenerator); |
| }; |
| |
| } // namespace codegen |
| } // namespace kudu |
| |
| #endif |