slang_rs_export_func.cpp revision c95381a2c3b6e9117901eef0687e861e4d533bfe 
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_export_func.h"
18
19#include <string>
20
21#include "clang/AST/ASTContext.h"
22#include "clang/AST/Decl.h"
23
24#include "llvm/IR/DataLayout.h"
25#include "llvm/IR/DerivedTypes.h"
26
27#include "slang_assert.h"
28#include "slang_rs_context.h"
29
30namespace slang {
31
32namespace {
33
34// Ensure that the exported function is actually valid
35static bool ValidateFuncDecl(slang::RSContext *Context,
36                             const clang::FunctionDecl *FD) {
37  slangAssert(Context && FD);
38  const clang::ASTContext &C = FD->getASTContext();
39  if (FD->getReturnType().getCanonicalType() != C.VoidTy) {
40    Context->ReportError(
41        FD->getLocation(),
42        "invokable non-static functions are required to return void");
43    return false;
44  }
45  return true;
46}
47
48}  // namespace
49
50RSExportFunc *RSExportFunc::Create(RSContext *Context,
51                                   const clang::FunctionDecl *FD) {
52  llvm::StringRef Name = FD->getName();
53  RSExportFunc *F;
54
55  slangAssert(!Name.empty() && "Function must have a name");
56
57  if (!ValidateFuncDecl(Context, FD)) {
58    return NULL;
59  }
60
61  F = new RSExportFunc(Context, Name, FD);
62
63  // Initialize mParamPacketType
64  if (FD->getNumParams() <= 0) {
65    F->mParamPacketType = NULL;
66  } else {
67    clang::ASTContext &Ctx = Context->getASTContext();
68
69    std::string Id(DUMMY_RS_TYPE_NAME_PREFIX"helper_func_param:");
70    Id.append(F->getName()).append(DUMMY_RS_TYPE_NAME_POSTFIX);
71
72    clang::RecordDecl *RD =
73        clang::RecordDecl::Create(Ctx, clang::TTK_Struct,
74                                  Ctx.getTranslationUnitDecl(),
75                                  clang::SourceLocation(),
76                                  clang::SourceLocation(),
77                                  &Ctx.Idents.get(Id));
78
79    for (unsigned i = 0; i < FD->getNumParams(); i++) {
80      const clang::ParmVarDecl *PVD = FD->getParamDecl(i);
81      llvm::StringRef ParamName = PVD->getName();
82
83      if (PVD->hasDefaultArg())
84        fprintf(stderr, "Note: parameter '%s' in function '%s' has default "
85                        "value which is not supported\n",
86                        ParamName.str().c_str(),
87                        F->getName().c_str());
88
89      clang::FieldDecl *FD =
90          clang::FieldDecl::Create(Ctx,
91                                   RD,
92                                   clang::SourceLocation(),
93                                   clang::SourceLocation(),
94                                   PVD->getIdentifier(),
95                                   PVD->getOriginalType(),
96                                   NULL,
97                                   /* BitWidth = */ NULL,
98                                   /* Mutable = */ false,
99                                   /* HasInit = */ clang::ICIS_NoInit);
100      RD->addDecl(FD);
101    }
102
103    RD->completeDefinition();
104
105    clang::QualType T = Ctx.getTagDeclType(RD);
106    slangAssert(!T.isNull());
107
108    RSExportType *ET =
109      RSExportType::Create(Context, T.getTypePtr());
110
111    if (ET == NULL) {
112      fprintf(stderr, "Failed to export the function %s. There's at least one "
113                      "parameter whose type is not supported by the "
114                      "reflection\n", F->getName().c_str());
115      return NULL;
116    }
117
118    slangAssert((ET->getClass() == RSExportType::ExportClassRecord) &&
119           "Parameter packet must be a record");
120
121    F->mParamPacketType = static_cast<RSExportRecordType *>(ET);
122  }
123
124  return F;
125}
126
127bool
128RSExportFunc::checkParameterPacketType(llvm::StructType *ParamTy) const {
129  if (ParamTy == NULL)
130    return !hasParam();
131  else if (!hasParam())
132    return false;
133
134  slangAssert(mParamPacketType != NULL);
135
136  const RSExportRecordType *ERT = mParamPacketType;
137  // must have same number of elements
138  if (ERT->getFields().size() != ParamTy->getNumElements())
139    return false;
140
141  const llvm::StructLayout *ParamTySL =
142      getRSContext()->getDataLayout()->getStructLayout(ParamTy);
143
144  unsigned Index = 0;
145  for (RSExportRecordType::const_field_iterator FI = ERT->fields_begin(),
146       FE = ERT->fields_end(); FI != FE; FI++, Index++) {
147    const RSExportRecordType::Field *F = *FI;
148
149    llvm::Type *T1 = F->getType()->getLLVMType();
150    llvm::Type *T2 = ParamTy->getTypeAtIndex(Index);
151
152    // Fast check
153    if (T1 == T2)
154      continue;
155
156    // Check offset
157    size_t T1Offset = F->getOffsetInParent();
158    size_t T2Offset = ParamTySL->getElementOffset(Index);
159
160    if (T1Offset != T2Offset)
161      return false;
162
163    // Check size
164    size_t T1Size = F->getType()->getAllocSize();
165    size_t T2Size = getRSContext()->getDataLayout()->getTypeAllocSize(T2);
166
167    if (T1Size != T2Size)
168      return false;
169  }
170
171  return true;
172}
173
174}  // namespace slang
175