Home | History | Annotate | Download | only in slang
      1 /*
      2  * Copyright 2010, The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *     http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef _FRAMEWORKS_COMPILE_SLANG_SLANG_RS_METADATA_SPEC_H_  // NOLINT
     18 #define _FRAMEWORKS_COMPILE_SLANG_SLANG_RS_METADATA_SPEC_H_
     19 
     20 // Design Philosophy:
     21 //  Expensive encoding but cheap decoding process.
     22 //
     23 // 1. A string table concatenates ALL strings (including '\0' in t)
     24 // 2. A string index table which is an integer array containg the offset
     25 //    to access each string in the string table.
     26 // 3. All ->name field in RSType/RSVar/RSFunction now refer to an index in the
     27 //    string index table for offset lookup.
     28 // 4. RSType information is encoded as a byte stream like:
     29 //
     30 //                    [RSType #1][RSType #2] ... [RSType #N]
     31 //
     32 //    All ->type or ->base_type in RS*Type now becomes an index to RSType array.
     33 //
     34 // 5. RSVar => an string table index plus RSType array index
     35 // 6. RSFunction => an string table index
     36 
     37 namespace llvm {
     38   class Module;
     39 }
     40 
     41 // Forward declaration
     42 union RSType;
     43 
     44 struct RSVar {
     45   const char *name;  // variable name
     46   const union RSType *type;
     47 };
     48 
     49 struct RSFunction {
     50   const char *name;  // function name
     51 };
     52 
     53 // Opaque pointer
     54 typedef int RSMetadataEncoder;
     55 
     56 // Create a context associated with M for encoding metadata.
     57 RSMetadataEncoder *CreateRSMetadataEncoder(llvm::Module *M);
     58 
     59 // Encode V as a metadata in M. Return 0 if every thing goes well.
     60 int RSEncodeVarMetadata(RSMetadataEncoder *E, const RSVar *V);
     61 // Encode F as a metadata in M. Return 0 if every thing goes well.
     62 int RSEncodeFunctionMetadata(RSMetadataEncoder *E, const RSFunction *F);
     63 
     64 // Release the memory allocation of Encoder without flushing things.
     65 void DestroyRSMetadataEncoder(RSMetadataEncoder *E);
     66 
     67 // Flush metadata in E to its associated module and Destroy it. Return 0 if
     68 // every thing goes well. This will also call the DestroyRSMetadataEncoder().
     69 int FinalizeRSMetadataEncoder(RSMetadataEncoder *E);
     70 
     71 // TODO(slang): Decoder
     72 struct RSMetadata {
     73   unsigned num_vars;
     74   unsigned num_funcs;
     75 
     76   RSVar *vars;
     77   RSFunction *funcs;
     78 
     79   void *context;
     80 };
     81 
     82 // struct RSMetadata *RSDecodeMetadata(llvm::Module *M);
     83 // void RSReleaseMetadata(struct RSMetadata *MD);
     84 
     85 #endif  // _FRAMEWORKS_COMPILE_SLANG_SLANG_RS_METADATA_SPEC_H_  NOLINT
     86