TargetAttributesSema.cpp revision f0122fe49329cb439d55a6712bfcaad9a6570428 
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 "Sema.h"
16#include "TargetAttributesSema.h"
17#include "clang/Basic/TargetInfo.h"
18#include "llvm/ADT/Triple.h"
19
20using namespace clang;
21
22TargetAttributesSema::~TargetAttributesSema() {}
23bool TargetAttributesSema::ProcessDeclAttribute(Scope *scope, Decl *D,
24                                    const AttributeList &Attr, Sema &S) const {
25  return false;
26}
27
28static void HandleMSP430InterruptAttr(Decl *d,
29                                      const AttributeList &Attr, Sema &S) {
30    // Check the attribute arguments.
31    if (Attr.getNumArgs() != 1) {
32      S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 1;
33      return;
34    }
35
36    // FIXME: Check for decl - it should be void ()(void).
37
38    Expr *NumParamsExpr = static_cast<Expr *>(Attr.getArg(0));
39    llvm::APSInt NumParams(32);
40    if (!NumParamsExpr->isIntegerConstantExpr(NumParams, S.Context)) {
41      S.Diag(Attr.getLoc(), diag::err_attribute_argument_not_int)
42        << "interrupt" << NumParamsExpr->getSourceRange();
43      return;
44    }
45
46    unsigned Num = NumParams.getLimitedValue(255);
47    if ((Num & 1) || Num > 30) {
48      S.Diag(Attr.getLoc(), diag::err_attribute_argument_out_of_bounds)
49        << "interrupt" << (int)NumParams.getSExtValue()
50        << NumParamsExpr->getSourceRange();
51      return;
52    }
53
54    d->addAttr(::new (S.Context) MSP430InterruptAttr(Num));
55    d->addAttr(::new (S.Context) UsedAttr());
56  }
57
58namespace {
59  class MSP430AttributesSema : public TargetAttributesSema {
60  public:
61    MSP430AttributesSema() { }
62    bool ProcessDeclAttribute(Scope *scope, Decl *D,
63                              const AttributeList &Attr, Sema &S) const {
64      if (Attr.getName()->getName() == "interrupt") {
65        HandleMSP430InterruptAttr(D, Attr, S);
66        return true;
67      }
68      return false;
69    }
70  };
71}
72
73static void HandleX86ForceAlignArgPointerAttr(Decl *D,
74                                              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) << 0;
79    return;
80  }
81
82  // If we try to apply it to a function pointer, warn. This is a special
83  // instance of the warn_attribute_ignored warning that can be turned
84  // off with -Wno-force-align-arg-pointer.
85  ValueDecl* VD = dyn_cast<ValueDecl>(D);
86  if (VD && VD->getType()->isFunctionPointerType()) {
87    S.Diag(Attr.getLoc(), diag::warn_faap_attribute_ignored);
88    return;
89  }
90  // Attribute can only be applied to function types.
91  if (!isa<FunctionDecl>(D)) {
92    S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
93      << Attr.getName() << /* function */0;
94    return;
95  }
96
97  D->addAttr(::new (S.Context) X86ForceAlignArgPointerAttr());
98}
99
100static void HandleDLLImportAttr(Decl *D, const AttributeList &Attr, Sema &S) {
101  // check the attribute arguments.
102  if (Attr.getNumArgs() != 0) {
103    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 0;
104    return;
105  }
106
107  // Attribute can be applied only to functions or variables.
108  if (isa<VarDecl>(D)) {
109    D->addAttr(::new (S.Context) DLLImportAttr());
110    return;
111  }
112
113  FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
114  if (!FD) {
115    S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
116      << Attr.getName() << 2 /*variable and function*/;
117    return;
118  }
119
120  // Currently, the dllimport attribute is ignored for inlined functions.
121  // Warning is emitted.
122  if (FD->isInlineSpecified()) {
123    S.Diag(Attr.getLoc(), diag::warn_attribute_ignored) << "dllimport";
124    return;
125  }
126
127  // The attribute is also overridden by a subsequent declaration as dllexport.
128  // Warning is emitted.
129  for (AttributeList *nextAttr = Attr.getNext(); nextAttr;
130       nextAttr = nextAttr->getNext()) {
131    if (nextAttr->getKind() == AttributeList::AT_dllexport) {
132      S.Diag(Attr.getLoc(), diag::warn_attribute_ignored) << "dllimport";
133      return;
134    }
135  }
136
137  if (D->getAttr<DLLExportAttr>()) {
138    S.Diag(Attr.getLoc(), diag::warn_attribute_ignored) << "dllimport";
139    return;
140  }
141
142  D->addAttr(::new (S.Context) DLLImportAttr());
143}
144
145static void HandleDLLExportAttr(Decl *D, const AttributeList &Attr, Sema &S) {
146  // check the attribute arguments.
147  if (Attr.getNumArgs() != 0) {
148    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 0;
149    return;
150  }
151
152  // Attribute can be applied only to functions or variables.
153  if (isa<VarDecl>(D)) {
154    D->addAttr(::new (S.Context) DLLExportAttr());
155    return;
156  }
157
158  FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
159  if (!FD) {
160    S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
161      << Attr.getName() << 2 /*variable and function*/;
162    return;
163  }
164
165  // Currently, the dllexport attribute is ignored for inlined functions, unless
166  // the -fkeep-inline-functions flag has been used. Warning is emitted;
167  if (FD->isInlineSpecified()) {
168    // FIXME: ... unless the -fkeep-inline-functions flag has been used.
169    S.Diag(Attr.getLoc(), diag::warn_attribute_ignored) << "dllexport";
170    return;
171  }
172
173  D->addAttr(::new (S.Context) DLLExportAttr());
174}
175
176namespace {
177  class X86AttributesSema : public TargetAttributesSema {
178  public:
179    X86AttributesSema() { }
180    bool ProcessDeclAttribute(Scope *scope, Decl *D,
181                              const AttributeList &Attr, Sema &S) const {
182      const llvm::Triple &Triple(S.Context.Target.getTriple());
183      if (Triple.getOS() == llvm::Triple::Win32 ||
184          Triple.getOS() == llvm::Triple::MinGW32 ||
185          Triple.getOS() == llvm::Triple::MinGW64) {
186        switch (Attr.getKind()) {
187        case AttributeList::AT_dllimport: HandleDLLImportAttr(D, Attr, S);
188                                          return true;
189        case AttributeList::AT_dllexport: HandleDLLExportAttr(D, Attr, S);
190                                          return true;
191        default:                          break;
192        }
193      }
194      if (Attr.getName()->getName() == "force_align_arg_pointer") {
195        HandleX86ForceAlignArgPointerAttr(D, Attr, S);
196        return true;
197      }
198      return false;
199    }
200  };
201}
202
203const TargetAttributesSema &Sema::getTargetAttributesSema() const {
204  if (TheTargetAttributesSema)
205    return *TheTargetAttributesSema;
206
207  const llvm::Triple &Triple(Context.Target.getTriple());
208  switch (Triple.getArch()) {
209  default:
210    return *(TheTargetAttributesSema = new TargetAttributesSema);
211
212  case llvm::Triple::msp430:
213    return *(TheTargetAttributesSema = new MSP430AttributesSema);
214  case llvm::Triple::x86:
215    return *(TheTargetAttributesSema = new X86AttributesSema);
216  }
217}
218
219