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1 //===-- TargetAttributesSema.cpp - Encapsulate target attributes-*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains semantic analysis implementation for target-specific
11 // attributes.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "TargetAttributesSema.h"
16 #include "clang/Sema/SemaInternal.h"
17 #include "clang/Basic/TargetInfo.h"
18 #include "clang/AST/DeclCXX.h"
19 #include "llvm/ADT/Triple.h"
20 
21 using namespace clang;
22 
~TargetAttributesSema()23 TargetAttributesSema::~TargetAttributesSema() {}
ProcessDeclAttribute(Scope * scope,Decl * D,const AttributeList & Attr,Sema & S) const24 bool TargetAttributesSema::ProcessDeclAttribute(Scope *scope, Decl *D,
25                                     const AttributeList &Attr, Sema &S) const {
26   return false;
27 }
28 
HandleMSP430InterruptAttr(Decl * d,const AttributeList & Attr,Sema & S)29 static void HandleMSP430InterruptAttr(Decl *d,
30                                       const AttributeList &Attr, Sema &S) {
31     // Check the attribute arguments.
32     if (Attr.getNumArgs() != 1) {
33       S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 1;
34       return;
35     }
36 
37     // FIXME: Check for decl - it should be void ()(void).
38 
39     Expr *NumParamsExpr = static_cast<Expr *>(Attr.getArg(0));
40     llvm::APSInt NumParams(32);
41     if (!NumParamsExpr->isIntegerConstantExpr(NumParams, S.Context)) {
42       S.Diag(Attr.getLoc(), diag::err_attribute_argument_not_int)
43         << "interrupt" << NumParamsExpr->getSourceRange();
44       return;
45     }
46 
47     unsigned Num = NumParams.getLimitedValue(255);
48     if ((Num & 1) || Num > 30) {
49       S.Diag(Attr.getLoc(), diag::err_attribute_argument_out_of_bounds)
50         << "interrupt" << (int)NumParams.getSExtValue()
51         << NumParamsExpr->getSourceRange();
52       return;
53     }
54 
55     d->addAttr(::new (S.Context) MSP430InterruptAttr(Attr.getLoc(), S.Context, Num));
56     d->addAttr(::new (S.Context) UsedAttr(Attr.getLoc(), S.Context));
57   }
58 
59 namespace {
60   class MSP430AttributesSema : public TargetAttributesSema {
61   public:
MSP430AttributesSema()62     MSP430AttributesSema() { }
ProcessDeclAttribute(Scope * scope,Decl * D,const AttributeList & Attr,Sema & S) const63     bool ProcessDeclAttribute(Scope *scope, Decl *D,
64                               const AttributeList &Attr, Sema &S) const {
65       if (Attr.getName()->getName() == "interrupt") {
66         HandleMSP430InterruptAttr(D, Attr, S);
67         return true;
68       }
69       return false;
70     }
71   };
72 }
73 
HandleMBlazeInterruptHandlerAttr(Decl * d,const AttributeList & Attr,Sema & S)74 static void HandleMBlazeInterruptHandlerAttr(Decl *d, const AttributeList &Attr,
75                                              Sema &S) {
76   // Check the attribute arguments.
77   if (Attr.getNumArgs() != 0) {
78     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 1;
79     return;
80   }
81 
82   // FIXME: Check for decl - it should be void ()(void).
83 
84   d->addAttr(::new (S.Context) MBlazeInterruptHandlerAttr(Attr.getLoc(),
85                                                           S.Context));
86   d->addAttr(::new (S.Context) UsedAttr(Attr.getLoc(), S.Context));
87 }
88 
HandleMBlazeSaveVolatilesAttr(Decl * d,const AttributeList & Attr,Sema & S)89 static void HandleMBlazeSaveVolatilesAttr(Decl *d, const AttributeList &Attr,
90                                           Sema &S) {
91   // Check the attribute arguments.
92   if (Attr.getNumArgs() != 0) {
93     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 1;
94     return;
95   }
96 
97   // FIXME: Check for decl - it should be void ()(void).
98 
99   d->addAttr(::new (S.Context) MBlazeSaveVolatilesAttr(Attr.getLoc(),
100                                                        S.Context));
101   d->addAttr(::new (S.Context) UsedAttr(Attr.getLoc(), S.Context));
102 }
103 
104 
105 namespace {
106   class MBlazeAttributesSema : public TargetAttributesSema {
107   public:
MBlazeAttributesSema()108     MBlazeAttributesSema() { }
ProcessDeclAttribute(Scope * scope,Decl * D,const AttributeList & Attr,Sema & S) const109     bool ProcessDeclAttribute(Scope *scope, Decl *D, const AttributeList &Attr,
110                               Sema &S) const {
111       if (Attr.getName()->getName() == "interrupt_handler") {
112         HandleMBlazeInterruptHandlerAttr(D, Attr, S);
113         return true;
114       } else if (Attr.getName()->getName() == "save_volatiles") {
115         HandleMBlazeSaveVolatilesAttr(D, Attr, S);
116         return true;
117       }
118       return false;
119     }
120   };
121 }
122 
HandleX86ForceAlignArgPointerAttr(Decl * D,const AttributeList & Attr,Sema & S)123 static void HandleX86ForceAlignArgPointerAttr(Decl *D,
124                                               const AttributeList& Attr,
125                                               Sema &S) {
126   // Check the attribute arguments.
127   if (Attr.getNumArgs() != 0) {
128     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 0;
129     return;
130   }
131 
132   // If we try to apply it to a function pointer, don't warn, but don't
133   // do anything, either. It doesn't matter anyway, because there's nothing
134   // special about calling a force_align_arg_pointer function.
135   ValueDecl *VD = dyn_cast<ValueDecl>(D);
136   if (VD && VD->getType()->isFunctionPointerType())
137     return;
138   // Also don't warn on function pointer typedefs.
139   TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(D);
140   if (TD && (TD->getUnderlyingType()->isFunctionPointerType() ||
141              TD->getUnderlyingType()->isFunctionType()))
142     return;
143   // Attribute can only be applied to function types.
144   if (!isa<FunctionDecl>(D)) {
145     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
146       << Attr.getName() << /* function */0;
147     return;
148   }
149 
150   D->addAttr(::new (S.Context) X86ForceAlignArgPointerAttr(Attr.getLoc(), S.Context));
151 }
152 
HandleDLLImportAttr(Decl * D,const AttributeList & Attr,Sema & S)153 static void HandleDLLImportAttr(Decl *D, const AttributeList &Attr, Sema &S) {
154   // check the attribute arguments.
155   if (Attr.getNumArgs() != 0) {
156     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 0;
157     return;
158   }
159 
160   // Attribute can be applied only to functions or variables.
161   if (isa<VarDecl>(D)) {
162     D->addAttr(::new (S.Context) DLLImportAttr(Attr.getLoc(), S.Context));
163     return;
164   }
165 
166   FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
167   if (!FD) {
168     // Apparently Visual C++ thinks it is okay to not emit a warning
169     // in this case, so only emit a warning when -fms-extensions is not
170     // specified.
171     if (!S.getLangOptions().Microsoft)
172       S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
173         << Attr.getName() << 2 /*variable and function*/;
174     return;
175   }
176 
177   // Currently, the dllimport attribute is ignored for inlined functions.
178   // Warning is emitted.
179   if (FD->isInlineSpecified()) {
180     S.Diag(Attr.getLoc(), diag::warn_attribute_ignored) << "dllimport";
181     return;
182   }
183 
184   // The attribute is also overridden by a subsequent declaration as dllexport.
185   // Warning is emitted.
186   for (AttributeList *nextAttr = Attr.getNext(); nextAttr;
187        nextAttr = nextAttr->getNext()) {
188     if (nextAttr->getKind() == AttributeList::AT_dllexport) {
189       S.Diag(Attr.getLoc(), diag::warn_attribute_ignored) << "dllimport";
190       return;
191     }
192   }
193 
194   if (D->getAttr<DLLExportAttr>()) {
195     S.Diag(Attr.getLoc(), diag::warn_attribute_ignored) << "dllimport";
196     return;
197   }
198 
199   D->addAttr(::new (S.Context) DLLImportAttr(Attr.getLoc(), S.Context));
200 }
201 
HandleDLLExportAttr(Decl * D,const AttributeList & Attr,Sema & S)202 static void HandleDLLExportAttr(Decl *D, const AttributeList &Attr, Sema &S) {
203   // check the attribute arguments.
204   if (Attr.getNumArgs() != 0) {
205     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 0;
206     return;
207   }
208 
209   // Attribute can be applied only to functions or variables.
210   if (isa<VarDecl>(D)) {
211     D->addAttr(::new (S.Context) DLLExportAttr(Attr.getLoc(), S.Context));
212     return;
213   }
214 
215   FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
216   if (!FD) {
217     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
218       << Attr.getName() << 2 /*variable and function*/;
219     return;
220   }
221 
222   // Currently, the dllexport attribute is ignored for inlined functions, unless
223   // the -fkeep-inline-functions flag has been used. Warning is emitted;
224   if (FD->isInlineSpecified()) {
225     // FIXME: ... unless the -fkeep-inline-functions flag has been used.
226     S.Diag(Attr.getLoc(), diag::warn_attribute_ignored) << "dllexport";
227     return;
228   }
229 
230   D->addAttr(::new (S.Context) DLLExportAttr(Attr.getLoc(), S.Context));
231 }
232 
233 namespace {
234   class X86AttributesSema : public TargetAttributesSema {
235   public:
X86AttributesSema()236     X86AttributesSema() { }
ProcessDeclAttribute(Scope * scope,Decl * D,const AttributeList & Attr,Sema & S) const237     bool ProcessDeclAttribute(Scope *scope, Decl *D,
238                               const AttributeList &Attr, Sema &S) const {
239       const llvm::Triple &Triple(S.Context.Target.getTriple());
240       if (Triple.getOS() == llvm::Triple::Win32 ||
241           Triple.getOS() == llvm::Triple::MinGW32) {
242         switch (Attr.getKind()) {
243         case AttributeList::AT_dllimport: HandleDLLImportAttr(D, Attr, S);
244                                           return true;
245         case AttributeList::AT_dllexport: HandleDLLExportAttr(D, Attr, S);
246                                           return true;
247         default:                          break;
248         }
249       }
250       if (Attr.getName()->getName() == "force_align_arg_pointer" ||
251           Attr.getName()->getName() == "__force_align_arg_pointer__") {
252         HandleX86ForceAlignArgPointerAttr(D, Attr, S);
253         return true;
254       }
255       return false;
256     }
257   };
258 }
259 
getTargetAttributesSema() const260 const TargetAttributesSema &Sema::getTargetAttributesSema() const {
261   if (TheTargetAttributesSema)
262     return *TheTargetAttributesSema;
263 
264   const llvm::Triple &Triple(Context.Target.getTriple());
265   switch (Triple.getArch()) {
266   default:
267     return *(TheTargetAttributesSema = new TargetAttributesSema);
268 
269   case llvm::Triple::msp430:
270     return *(TheTargetAttributesSema = new MSP430AttributesSema);
271   case llvm::Triple::mblaze:
272     return *(TheTargetAttributesSema = new MBlazeAttributesSema);
273   case llvm::Triple::x86:
274     return *(TheTargetAttributesSema = new X86AttributesSema);
275   }
276 }
277