slang_rs_check_ast.cpp revision ab94bccca64c9b126cbd1b732aa5e681d8639b99 
1/*
2 * Copyright 2012, 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_check_ast.h"
18
19#include "slang_assert.h"
20#include "slang.h"
21#include "slang_rs_export_foreach.h"
22#include "slang_rs_export_type.h"
23
24namespace slang {
25
26void RSCheckAST::VisitStmt(clang::Stmt *S) {
27  // This function does the actual iteration through all sub-Stmt's within
28  // a given Stmt. Note that this function is skipped by all of the other
29  // Visit* functions if we have already found a higher-level match.
30  for (clang::Stmt::child_iterator I = S->child_begin(), E = S->child_end();
31       I != E;
32       I++) {
33    if (clang::Stmt *Child = *I) {
34      Visit(Child);
35    }
36  }
37}
38
39void RSCheckAST::WarnOnSetElementAt(clang::CallExpr *E) {
40  clang::FunctionDecl *Decl;
41  Decl = clang::dyn_cast_or_null<clang::FunctionDecl>(E->getCalleeDecl());
42
43  if (!Decl || Decl->getNameAsString() != std::string("rsSetElementAt")) {
44    return;
45  }
46
47  clang::Expr *Expr;
48  clang::ImplicitCastExpr *ImplCast;
49  Expr = E->getArg(1);
50  ImplCast = clang::dyn_cast_or_null<clang::ImplicitCastExpr>(Expr);
51
52  if (!ImplCast) {
53    return;
54  }
55
56  const clang::Type *Ty;
57  const clang::VectorType *VectorTy;
58  const clang::BuiltinType *ElementTy;
59  Ty = ImplCast->getSubExpr()->getType()->getPointeeType()
60    ->getUnqualifiedDesugaredType();
61  VectorTy = clang::dyn_cast_or_null<clang::VectorType>(Ty);
62
63  if (VectorTy) {
64    ElementTy = clang::dyn_cast_or_null<clang::BuiltinType>(
65      VectorTy->getElementType()->getUnqualifiedDesugaredType());
66  } else {
67    ElementTy = clang::dyn_cast_or_null<clang::BuiltinType>(
68      Ty->getUnqualifiedDesugaredType());
69  }
70
71  if (!ElementTy) {
72    return;
73  }
74
75  // We only support vectors with 2, 3 or 4 elements.
76  if (VectorTy) {
77    switch (VectorTy->getNumElements()) {
78    default:
79      return;
80    case 2:
81    case 3:
82    case 4:
83      break;
84    }
85  }
86
87  const char *Name;
88
89  switch (ElementTy->getKind()) {
90    case clang::BuiltinType::Float:
91      Name = "float";
92      break;
93    case clang::BuiltinType::Double:
94      Name = "double";
95      break;
96    case clang::BuiltinType::Char_S:
97      Name = "char";
98      break;
99    case clang::BuiltinType::Short:
100      Name = "short";
101      break;
102    case clang::BuiltinType::Int:
103      Name = "int";
104      break;
105    case clang::BuiltinType::Long:
106      Name = "long";
107      break;
108    case clang::BuiltinType::UChar:
109      Name = "uchar";
110      break;
111    case clang::BuiltinType::UShort:
112      Name = "ushort";
113      break;
114    case clang::BuiltinType::UInt:
115      Name = "uint";
116      break;
117    case clang::BuiltinType::ULong:
118      Name = "ulong";
119      break;
120    default:
121      return;
122  }
123
124  clang::DiagnosticBuilder DiagBuilder =
125      Context->ReportWarning(E->getLocStart(),
126                             "untyped rsSetElementAt() can reduce performance. "
127                             "Use rsSetElementAt_%0%1() instead.");
128  DiagBuilder << Name;
129
130  if (VectorTy) {
131    DiagBuilder << VectorTy->getNumElements();
132  } else {
133    DiagBuilder << "";
134  }
135}
136
137void RSCheckAST::VisitCallExpr(clang::CallExpr *E) {
138  WarnOnSetElementAt(E);
139
140  for (clang::CallExpr::arg_iterator AI = E->arg_begin(), AE = E->arg_end();
141       AI != AE; ++AI) {
142    Visit(*AI);
143  }
144}
145
146void RSCheckAST::ValidateFunctionDecl(clang::FunctionDecl *FD) {
147  if (!FD) {
148    return;
149  }
150
151  clang::QualType resultType = FD->getReturnType().getCanonicalType();
152  bool isExtern = (FD->getFormalLinkage() == clang::ExternalLinkage);
153
154  // We use FD as our NamedDecl in the case of a bad return type.
155  if (!RSExportType::ValidateType(Context, C, resultType, FD,
156                                  FD->getLocStart(), mTargetAPI,
157                                  mIsFilterscript, isExtern)) {
158    mValid = false;
159  }
160
161  size_t numParams = FD->getNumParams();
162  for (size_t i = 0; i < numParams; i++) {
163    clang::ParmVarDecl *PVD = FD->getParamDecl(i);
164    clang::QualType QT = PVD->getType().getCanonicalType();
165    if (!RSExportType::ValidateType(Context, C, QT, PVD, PVD->getLocStart(),
166                                    mTargetAPI, mIsFilterscript, isExtern)) {
167      mValid = false;
168    }
169  }
170
171  bool saveKernel = mInKernel;
172  mInKernel = RSExportForEach::isRSForEachFunc(mTargetAPI, Context, FD);
173
174  if (clang::Stmt *Body = FD->getBody()) {
175    Visit(Body);
176  }
177
178  mInKernel = saveKernel;
179}
180
181
182void RSCheckAST::ValidateVarDecl(clang::VarDecl *VD) {
183  if (!VD) {
184    return;
185  }
186
187  clang::QualType QT = VD->getType();
188
189  if (VD->getFormalLinkage() == clang::ExternalLinkage) {
190    llvm::StringRef TypeName;
191    const clang::Type *T = QT.getTypePtr();
192    if (!RSExportType::NormalizeType(T, TypeName, Context, VD)) {
193      mValid = false;
194    }
195  }
196
197  // We don't allow static (non-const) variables within kernels.
198  if (mInKernel && VD->isStaticLocal()) {
199    if (!QT.isConstQualified()) {
200      Context->ReportError(
201          VD->getLocation(),
202          "Non-const static variables are not allowed in kernels: '%0'")
203          << VD->getName();
204      mValid = false;
205    }
206  }
207
208  if (!RSExportType::ValidateVarDecl(Context, VD, mTargetAPI, mIsFilterscript)) {
209    mValid = false;
210  } else if (clang::Expr *Init = VD->getInit()) {
211    // Only check the initializer if the decl is already ok.
212    Visit(Init);
213  }
214}
215
216
217void RSCheckAST::VisitDeclStmt(clang::DeclStmt *DS) {
218  if (!Slang::IsLocInRSHeaderFile(DS->getLocStart(), mSM)) {
219    for (clang::DeclStmt::decl_iterator I = DS->decl_begin(),
220                                        E = DS->decl_end();
221         I != E;
222         ++I) {
223      if (clang::VarDecl *VD = llvm::dyn_cast<clang::VarDecl>(*I)) {
224        ValidateVarDecl(VD);
225      } else if (clang::FunctionDecl *FD =
226            llvm::dyn_cast<clang::FunctionDecl>(*I)) {
227        ValidateFunctionDecl(FD);
228      }
229    }
230  }
231}
232
233
234void RSCheckAST::VisitCastExpr(clang::CastExpr *CE) {
235  if (CE->getCastKind() == clang::CK_BitCast) {
236    clang::QualType QT = CE->getType();
237    const clang::Type *T = QT.getTypePtr();
238    if (T->isVectorType()) {
239      if (llvm::isa<clang::ImplicitCastExpr>(CE)) {
240        Context->ReportError(CE->getExprLoc(), "invalid implicit vector cast");
241      } else {
242        Context->ReportError(CE->getExprLoc(), "invalid vector cast");
243      }
244      mValid = false;
245    }
246  }
247  Visit(CE->getSubExpr());
248}
249
250
251void RSCheckAST::VisitExpr(clang::Expr *E) {
252  // This is where FS checks for code using pointer and/or 64-bit expressions
253  // (i.e. things like casts).
254
255  // First we skip implicit casts (things like function calls and explicit
256  // array accesses rely heavily on them and they are valid.
257  E = E->IgnoreImpCasts();
258
259  // Expressions at this point in the checker are not externally visible.
260  static const bool kIsExtern = false;
261
262  if (mIsFilterscript &&
263      !Slang::IsLocInRSHeaderFile(E->getExprLoc(), mSM) &&
264      !RSExportType::ValidateType(Context, C, E->getType(), nullptr, E->getExprLoc(),
265                                  mTargetAPI, mIsFilterscript, kIsExtern)) {
266    mValid = false;
267  } else {
268    // Only visit sub-expressions if we haven't already seen a violation.
269    VisitStmt(E);
270  }
271}
272
273
274bool RSCheckAST::Validate() {
275  clang::TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
276  for (clang::DeclContext::decl_iterator DI = TUDecl->decls_begin(),
277          DE = TUDecl->decls_end();
278       DI != DE;
279       DI++) {
280    if (!Slang::IsLocInRSHeaderFile(DI->getLocStart(), mSM)) {
281      if (clang::VarDecl *VD = llvm::dyn_cast<clang::VarDecl>(*DI)) {
282        ValidateVarDecl(VD);
283      } else if (clang::FunctionDecl *FD =
284            llvm::dyn_cast<clang::FunctionDecl>(*DI)) {
285        ValidateFunctionDecl(FD);
286      } else if (clang::Stmt *Body = (*DI)->getBody()) {
287        Visit(Body);
288      }
289    }
290  }
291
292  return mValid;
293}
294
295}  // namespace slang
296