slang_rs_backend.cpp revision a67e4451d0d03b4ab7866b64807d95a8399c73a0 
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#include "slang_rs_backend.h"
18
19#include <string>
20#include <vector>
21
22#include "llvm/ADT/Twine.h"
23#include "llvm/ADT/StringExtras.h"
24
25#include "llvm/Constant.h"
26#include "llvm/Constants.h"
27#include "llvm/DerivedTypes.h"
28#include "llvm/Function.h"
29#include "llvm/Metadata.h"
30#include "llvm/Module.h"
31
32#include "llvm/Support/IRBuilder.h"
33
34#include "slang_assert.h"
35#include "slang_rs.h"
36#include "slang_rs_context.h"
37#include "slang_rs_export_func.h"
38#include "slang_rs_export_type.h"
39#include "slang_rs_export_var.h"
40#include "slang_rs_metadata.h"
41
42namespace slang {
43
44RSBackend::RSBackend(RSContext *Context,
45                     clang::Diagnostic *Diags,
46                     const clang::CodeGenOptions &CodeGenOpts,
47                     const clang::TargetOptions &TargetOpts,
48                     PragmaList *Pragmas,
49                     llvm::raw_ostream *OS,
50                     Slang::OutputType OT,
51                     clang::SourceManager &SourceMgr,
52                     bool AllowRSPrefix)
53    : Backend(Diags,
54              CodeGenOpts,
55              TargetOpts,
56              Pragmas,
57              OS,
58              OT),
59      mContext(Context),
60      mSourceMgr(SourceMgr),
61      mAllowRSPrefix(AllowRSPrefix),
62      mExportVarMetadata(NULL),
63      mExportFuncMetadata(NULL),
64      mExportTypeMetadata(NULL),
65      mRSObjectSlotsMetadata(NULL),
66      mRefCount(mContext->getASTContext()) {
67  return;
68}
69
70// 1) Add zero initialization of local RS object types
71void RSBackend::AnnotateFunction(clang::FunctionDecl *FD) {
72  if (FD &&
73      FD->hasBody() &&
74      !SlangRS::IsFunctionInRSHeaderFile(FD, mSourceMgr)) {
75    mRefCount.Init();
76    mRefCount.Visit(FD->getBody());
77  }
78  return;
79}
80
81void RSBackend::HandleTopLevelDecl(clang::DeclGroupRef D) {
82  // Disallow user-defined functions with prefix "rs"
83  if (!mAllowRSPrefix) {
84    // Iterate all function declarations in the program.
85    for (clang::DeclGroupRef::iterator I = D.begin(), E = D.end();
86         I != E; I++) {
87      clang::FunctionDecl *FD = dyn_cast<clang::FunctionDecl>(*I);
88      if (FD == NULL)
89        continue;
90      if (!FD->getName().startswith("rs"))  // Check prefix
91        continue;
92      if (!SlangRS::IsFunctionInRSHeaderFile(FD, mSourceMgr))
93        mDiags.Report(clang::FullSourceLoc(FD->getLocation(), mSourceMgr),
94                      mDiags.getCustomDiagID(clang::Diagnostic::Error,
95                                             "invalid function name prefix, "
96                                             "\"rs\" is reserved: '%0'"))
97            << FD->getName();
98    }
99  }
100
101  // Process any non-static function declarations
102  for (clang::DeclGroupRef::iterator I = D.begin(), E = D.end(); I != E; I++) {
103    clang::FunctionDecl *FD = dyn_cast<clang::FunctionDecl>(*I);
104    if (FD && FD->isGlobal()) {
105      AnnotateFunction(FD);
106    }
107  }
108
109  Backend::HandleTopLevelDecl(D);
110  return;
111}
112
113namespace {
114
115static bool ValidateVarDecl(clang::VarDecl *VD) {
116  if (!VD) {
117    return true;
118  }
119
120  clang::ASTContext &C = VD->getASTContext();
121  const clang::Type *T = VD->getType().getTypePtr();
122  bool valid = true;
123
124  if (VD->getLinkage() == clang::ExternalLinkage) {
125    llvm::StringRef TypeName;
126    if (!RSExportType::NormalizeType(T, TypeName, &C.getDiagnostics(), VD)) {
127      valid = false;
128    }
129  }
130  valid &= RSExportType::ValidateVarDecl(VD);
131
132  return valid;
133}
134
135static bool ValidateASTContext(clang::ASTContext &C) {
136  bool valid = true;
137  clang::TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
138  for (clang::DeclContext::decl_iterator DI = TUDecl->decls_begin(),
139          DE = TUDecl->decls_end();
140       DI != DE;
141       DI++) {
142    clang::VarDecl *VD = dyn_cast<clang::VarDecl>(*DI);
143    if (VD && !ValidateVarDecl(VD)) {
144      valid = false;
145    }
146  }
147
148  return valid;
149}
150
151}  // namespace
152
153void RSBackend::HandleTranslationUnitPre(clang::ASTContext &C) {
154  clang::TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
155
156  if (!ValidateASTContext(C)) {
157    return;
158  }
159
160  int version = mContext->getVersion();
161  if (version == 0) {
162    // Not setting a version is an error
163    mDiags.Report(mDiags.getCustomDiagID(clang::Diagnostic::Error,
164                      "Missing pragma for version in source file"));
165  } else if (version > 1) {
166    mDiags.Report(mDiags.getCustomDiagID(clang::Diagnostic::Error,
167                      "Pragma for version in source file must be set to 1"));
168  }
169
170  // Process any static function declarations
171  for (clang::DeclContext::decl_iterator I = TUDecl->decls_begin(),
172          E = TUDecl->decls_end(); I != E; I++) {
173    if ((I->getKind() >= clang::Decl::firstFunction) &&
174        (I->getKind() <= clang::Decl::lastFunction)) {
175      clang::FunctionDecl *FD = dyn_cast<clang::FunctionDecl>(*I);
176      if (FD && !FD->isGlobal()) {
177        AnnotateFunction(FD);
178      }
179    }
180  }
181
182  return;
183}
184
185///////////////////////////////////////////////////////////////////////////////
186void RSBackend::HandleTranslationUnitPost(llvm::Module *M) {
187  if (!mContext->processExport()) {
188    return;
189  }
190
191  // Dump export variable info
192  if (mContext->hasExportVar()) {
193    int slotCount = 0;
194    if (mExportVarMetadata == NULL)
195      mExportVarMetadata = M->getOrInsertNamedMetadata(RS_EXPORT_VAR_MN);
196
197    llvm::SmallVector<llvm::Value*, 2> ExportVarInfo;
198
199    // We emit slot information (#rs_object_slots) for any reference counted
200    // RS type or pointer (which can also be bound).
201
202    for (RSContext::const_export_var_iterator I = mContext->export_vars_begin(),
203            E = mContext->export_vars_end();
204         I != E;
205         I++) {
206      const RSExportVar *EV = *I;
207      const RSExportType *ET = EV->getType();
208      bool countsAsRSObject = false;
209
210      // Variable name
211      ExportVarInfo.push_back(
212          llvm::MDString::get(mLLVMContext, EV->getName().c_str()));
213
214      // Type name
215      switch (ET->getClass()) {
216        case RSExportType::ExportClassPrimitive: {
217          const RSExportPrimitiveType *PT =
218              static_cast<const RSExportPrimitiveType*>(ET);
219          ExportVarInfo.push_back(
220              llvm::MDString::get(
221                mLLVMContext, llvm::utostr_32(PT->getType())));
222          if (PT->isRSObjectType()) {
223            countsAsRSObject = true;
224          }
225          break;
226        }
227        case RSExportType::ExportClassPointer: {
228          ExportVarInfo.push_back(
229              llvm::MDString::get(
230                mLLVMContext, ("*" + static_cast<const RSExportPointerType*>(ET)
231                  ->getPointeeType()->getName()).c_str()));
232          break;
233        }
234        case RSExportType::ExportClassMatrix: {
235          ExportVarInfo.push_back(
236              llvm::MDString::get(
237                mLLVMContext, llvm::utostr_32(
238                  RSExportPrimitiveType::DataTypeRSMatrix2x2 +
239                  static_cast<const RSExportMatrixType*>(ET)->getDim() - 2)));
240          break;
241        }
242        case RSExportType::ExportClassVector:
243        case RSExportType::ExportClassConstantArray:
244        case RSExportType::ExportClassRecord: {
245          ExportVarInfo.push_back(
246              llvm::MDString::get(mLLVMContext,
247                EV->getType()->getName().c_str()));
248          break;
249        }
250      }
251
252      mExportVarMetadata->addOperand(
253          llvm::MDNode::get(mLLVMContext, ExportVarInfo));
254      ExportVarInfo.clear();
255
256      if (mRSObjectSlotsMetadata == NULL) {
257        mRSObjectSlotsMetadata =
258            M->getOrInsertNamedMetadata(RS_OBJECT_SLOTS_MN);
259      }
260
261      if (countsAsRSObject) {
262        mRSObjectSlotsMetadata->addOperand(llvm::MDNode::get(mLLVMContext,
263            llvm::MDString::get(mLLVMContext, llvm::utostr_32(slotCount))));
264      }
265
266      slotCount++;
267    }
268  }
269
270  // Dump export function info
271  if (mContext->hasExportFunc()) {
272    if (mExportFuncMetadata == NULL)
273      mExportFuncMetadata =
274          M->getOrInsertNamedMetadata(RS_EXPORT_FUNC_MN);
275
276    llvm::SmallVector<llvm::Value*, 1> ExportFuncInfo;
277
278    for (RSContext::const_export_func_iterator
279            I = mContext->export_funcs_begin(),
280            E = mContext->export_funcs_end();
281         I != E;
282         I++) {
283      const RSExportFunc *EF = *I;
284
285      // Function name
286      if (!EF->hasParam()) {
287        ExportFuncInfo.push_back(llvm::MDString::get(mLLVMContext,
288                                                     EF->getName().c_str()));
289      } else {
290        llvm::Function *F = M->getFunction(EF->getName());
291        llvm::Function *HelperFunction;
292        const std::string HelperFunctionName(".helper_" + EF->getName());
293
294        slangAssert(F && "Function marked as exported disappeared in Bitcode");
295
296        // Create helper function
297        {
298          llvm::StructType *HelperFunctionParameterTy = NULL;
299
300          if (!F->getArgumentList().empty()) {
301            std::vector<llvm::Type*> HelperFunctionParameterTys;
302            for (llvm::Function::arg_iterator AI = F->arg_begin(),
303                 AE = F->arg_end(); AI != AE; AI++)
304              HelperFunctionParameterTys.push_back(AI->getType());
305
306            HelperFunctionParameterTy =
307                llvm::StructType::get(mLLVMContext, HelperFunctionParameterTys);
308          }
309
310          if (!EF->checkParameterPacketType(HelperFunctionParameterTy)) {
311            fprintf(stderr, "Failed to export function %s: parameter type "
312                            "mismatch during creation of helper function.\n",
313                    EF->getName().c_str());
314
315            const RSExportRecordType *Expected = EF->getParamPacketType();
316            if (Expected) {
317              fprintf(stderr, "Expected:\n");
318              Expected->getLLVMType()->dump();
319            }
320            if (HelperFunctionParameterTy) {
321              fprintf(stderr, "Got:\n");
322              HelperFunctionParameterTy->dump();
323            }
324          }
325
326          std::vector<llvm::Type*> Params;
327          if (HelperFunctionParameterTy) {
328            llvm::PointerType *HelperFunctionParameterTyP =
329                llvm::PointerType::getUnqual(HelperFunctionParameterTy);
330            Params.push_back(HelperFunctionParameterTyP);
331          }
332
333          llvm::FunctionType * HelperFunctionType =
334              llvm::FunctionType::get(F->getReturnType(),
335                                      Params,
336                                      /* IsVarArgs = */false);
337
338          HelperFunction =
339              llvm::Function::Create(HelperFunctionType,
340                                     llvm::GlobalValue::ExternalLinkage,
341                                     HelperFunctionName,
342                                     M);
343
344          HelperFunction->addFnAttr(llvm::Attribute::NoInline);
345          HelperFunction->setCallingConv(F->getCallingConv());
346
347          // Create helper function body
348          {
349            llvm::Argument *HelperFunctionParameter =
350                &(*HelperFunction->arg_begin());
351            llvm::BasicBlock *BB =
352                llvm::BasicBlock::Create(mLLVMContext, "entry", HelperFunction);
353            llvm::IRBuilder<> *IB = new llvm::IRBuilder<>(BB);
354            llvm::SmallVector<llvm::Value*, 6> Params;
355            llvm::Value *Idx[2];
356
357            Idx[0] =
358                llvm::ConstantInt::get(llvm::Type::getInt32Ty(mLLVMContext), 0);
359
360            // getelementptr and load instruction for all elements in
361            // parameter .p
362            for (size_t i = 0; i < EF->getNumParameters(); i++) {
363              // getelementptr
364              Idx[1] =
365                  llvm::ConstantInt::get(
366                      llvm::Type::getInt32Ty(mLLVMContext), i);
367              llvm::Value *Ptr = IB->CreateInBoundsGEP(HelperFunctionParameter,
368                                                       Idx,
369                                                       Idx + 2);
370
371              // load
372              llvm::Value *V = IB->CreateLoad(Ptr);
373              Params.push_back(V);
374            }
375
376            // Call and pass the all elements as parameter to F
377            llvm::CallInst *CI = IB->CreateCall(F, Params);
378
379            CI->setCallingConv(F->getCallingConv());
380
381            if (F->getReturnType() == llvm::Type::getVoidTy(mLLVMContext))
382              IB->CreateRetVoid();
383            else
384              IB->CreateRet(CI);
385
386            delete IB;
387          }
388        }
389
390        ExportFuncInfo.push_back(
391            llvm::MDString::get(mLLVMContext, HelperFunctionName.c_str()));
392      }
393
394      mExportFuncMetadata->addOperand(
395          llvm::MDNode::get(mLLVMContext, ExportFuncInfo));
396      ExportFuncInfo.clear();
397    }
398  }
399
400  // Dump export type info
401  if (mContext->hasExportType()) {
402    llvm::SmallVector<llvm::Value*, 1> ExportTypeInfo;
403
404    for (RSContext::const_export_type_iterator
405            I = mContext->export_types_begin(),
406            E = mContext->export_types_end();
407         I != E;
408         I++) {
409      // First, dump type name list to export
410      const RSExportType *ET = I->getValue();
411
412      ExportTypeInfo.clear();
413      // Type name
414      ExportTypeInfo.push_back(
415          llvm::MDString::get(mLLVMContext, ET->getName().c_str()));
416
417      if (ET->getClass() == RSExportType::ExportClassRecord) {
418        const RSExportRecordType *ERT =
419            static_cast<const RSExportRecordType*>(ET);
420
421        if (mExportTypeMetadata == NULL)
422          mExportTypeMetadata =
423              M->getOrInsertNamedMetadata(RS_EXPORT_TYPE_MN);
424
425        mExportTypeMetadata->addOperand(
426            llvm::MDNode::get(mLLVMContext, ExportTypeInfo));
427
428        // Now, export struct field information to %[struct name]
429        std::string StructInfoMetadataName("%");
430        StructInfoMetadataName.append(ET->getName());
431        llvm::NamedMDNode *StructInfoMetadata =
432            M->getOrInsertNamedMetadata(StructInfoMetadataName);
433        llvm::SmallVector<llvm::Value*, 3> FieldInfo;
434
435        slangAssert(StructInfoMetadata->getNumOperands() == 0 &&
436                    "Metadata with same name was created before");
437        for (RSExportRecordType::const_field_iterator FI = ERT->fields_begin(),
438                FE = ERT->fields_end();
439             FI != FE;
440             FI++) {
441          const RSExportRecordType::Field *F = *FI;
442
443          // 1. field name
444          FieldInfo.push_back(llvm::MDString::get(mLLVMContext,
445                                                  F->getName().c_str()));
446
447          // 2. field type name
448          FieldInfo.push_back(
449              llvm::MDString::get(mLLVMContext,
450                                  F->getType()->getName().c_str()));
451
452          // 3. field kind
453          switch (F->getType()->getClass()) {
454            case RSExportType::ExportClassPrimitive:
455            case RSExportType::ExportClassVector: {
456              const RSExportPrimitiveType *EPT =
457                  static_cast<const RSExportPrimitiveType*>(F->getType());
458              FieldInfo.push_back(
459                  llvm::MDString::get(mLLVMContext,
460                                      llvm::itostr(EPT->getKind())));
461              break;
462            }
463
464            default: {
465              FieldInfo.push_back(
466                  llvm::MDString::get(mLLVMContext,
467                                      llvm::itostr(
468                                        RSExportPrimitiveType::DataKindUser)));
469              break;
470            }
471          }
472
473          StructInfoMetadata->addOperand(
474              llvm::MDNode::get(mLLVMContext, FieldInfo));
475          FieldInfo.clear();
476        }
477      }   // ET->getClass() == RSExportType::ExportClassRecord
478    }
479  }
480
481  return;
482}
483
484RSBackend::~RSBackend() {
485  return;
486}
487
488}  // namespace slang
489