1193326Sed//===--- SemaAttr.cpp - Semantic Analysis for Attributes ------------------===// 2193326Sed// 3193326Sed// The LLVM Compiler Infrastructure 4193326Sed// 5193326Sed// This file is distributed under the University of Illinois Open Source 6193326Sed// License. See LICENSE.TXT for details. 7193326Sed// 8193326Sed//===----------------------------------------------------------------------===// 9193326Sed// 10193326Sed// This file implements semantic analysis for non-trivial attributes and 11193326Sed// pragmas. 12193326Sed// 13193326Sed//===----------------------------------------------------------------------===// 14193326Sed 15212904Sdim#include "clang/Sema/SemaInternal.h" 16263508Sdim#include "clang/AST/ASTConsumer.h" 17212904Sdim#include "clang/AST/Attr.h" 18193326Sed#include "clang/AST/Expr.h" 19208600Srdivacky#include "clang/Basic/TargetInfo.h" 20208600Srdivacky#include "clang/Lex/Preprocessor.h" 21249423Sdim#include "clang/Sema/Lookup.h" 22193326Sedusing namespace clang; 23193326Sed 24193326Sed//===----------------------------------------------------------------------===// 25208600Srdivacky// Pragma 'pack' and 'options align' 26193326Sed//===----------------------------------------------------------------------===// 27193326Sed 28193326Sednamespace { 29208600Srdivacky struct PackStackEntry { 30208600Srdivacky // We just use a sentinel to represent when the stack is set to mac68k 31208600Srdivacky // alignment. 32208600Srdivacky static const unsigned kMac68kAlignmentSentinel = ~0U; 33208600Srdivacky 34208600Srdivacky unsigned Alignment; 35208600Srdivacky IdentifierInfo *Name; 36208600Srdivacky }; 37208600Srdivacky 38193326Sed /// PragmaPackStack - Simple class to wrap the stack used by #pragma 39193326Sed /// pack. 40193326Sed class PragmaPackStack { 41208600Srdivacky typedef std::vector<PackStackEntry> stack_ty; 42193326Sed 43193326Sed /// Alignment - The current user specified alignment. 44193326Sed unsigned Alignment; 45193326Sed 46193326Sed /// Stack - Entries in the #pragma pack stack, consisting of saved 47193326Sed /// alignments and optional names. 48193326Sed stack_ty Stack; 49198092Srdivacky 50198092Srdivacky public: 51193326Sed PragmaPackStack() : Alignment(0) {} 52193326Sed 53193326Sed void setAlignment(unsigned A) { Alignment = A; } 54193326Sed unsigned getAlignment() { return Alignment; } 55193326Sed 56193326Sed /// push - Push the current alignment onto the stack, optionally 57193326Sed /// using the given \arg Name for the record, if non-zero. 58193326Sed void push(IdentifierInfo *Name) { 59208600Srdivacky PackStackEntry PSE = { Alignment, Name }; 60208600Srdivacky Stack.push_back(PSE); 61193326Sed } 62193326Sed 63193326Sed /// pop - Pop a record from the stack and restore the current 64193326Sed /// alignment to the previous value. If \arg Name is non-zero then 65193326Sed /// the first such named record is popped, otherwise the top record 66193326Sed /// is popped. Returns true if the pop succeeded. 67212904Sdim bool pop(IdentifierInfo *Name, bool IsReset); 68193326Sed }; 69193326Sed} // end anonymous namespace. 70193326Sed 71212904Sdimbool PragmaPackStack::pop(IdentifierInfo *Name, bool IsReset) { 72193326Sed // If name is empty just pop top. 73193326Sed if (!Name) { 74212904Sdim // An empty stack is a special case... 75212904Sdim if (Stack.empty()) { 76212904Sdim // If this isn't a reset, it is always an error. 77212904Sdim if (!IsReset) 78212904Sdim return false; 79212904Sdim 80212904Sdim // Otherwise, it is an error only if some alignment has been set. 81212904Sdim if (!Alignment) 82212904Sdim return false; 83212904Sdim 84212904Sdim // Otherwise, reset to the default alignment. 85212904Sdim Alignment = 0; 86212904Sdim } else { 87212904Sdim Alignment = Stack.back().Alignment; 88212904Sdim Stack.pop_back(); 89212904Sdim } 90212904Sdim 91193326Sed return true; 92198092Srdivacky } 93198092Srdivacky 94193326Sed // Otherwise, find the named record. 95193326Sed for (unsigned i = Stack.size(); i != 0; ) { 96193326Sed --i; 97208600Srdivacky if (Stack[i].Name == Name) { 98193326Sed // Found it, pop up to and including this record. 99208600Srdivacky Alignment = Stack[i].Alignment; 100193326Sed Stack.erase(Stack.begin() + i, Stack.end()); 101193326Sed return true; 102193326Sed } 103193326Sed } 104198092Srdivacky 105193326Sed return false; 106193326Sed} 107193326Sed 108193326Sed 109193326Sed/// FreePackedContext - Deallocate and null out PackContext. 110193326Sedvoid Sema::FreePackedContext() { 111193326Sed delete static_cast<PragmaPackStack*>(PackContext); 112193326Sed PackContext = 0; 113193326Sed} 114193326Sed 115208600Srdivackyvoid Sema::AddAlignmentAttributesForRecord(RecordDecl *RD) { 116208600Srdivacky // If there is no pack context, we don't need any attributes. 117208600Srdivacky if (!PackContext) 118208600Srdivacky return; 119208600Srdivacky 120208600Srdivacky PragmaPackStack *Stack = static_cast<PragmaPackStack*>(PackContext); 121208600Srdivacky 122208600Srdivacky // Otherwise, check to see if we need a max field alignment attribute. 123208600Srdivacky if (unsigned Alignment = Stack->getAlignment()) { 124208600Srdivacky if (Alignment == PackStackEntry::kMac68kAlignmentSentinel) 125212904Sdim RD->addAttr(::new (Context) AlignMac68kAttr(SourceLocation(), Context)); 126208600Srdivacky else 127212904Sdim RD->addAttr(::new (Context) MaxFieldAlignmentAttr(SourceLocation(), 128212904Sdim Context, 129212904Sdim Alignment * 8)); 130208600Srdivacky } 131193326Sed} 132193326Sed 133221345Sdimvoid Sema::AddMsStructLayoutForRecord(RecordDecl *RD) { 134221345Sdim if (!MSStructPragmaOn) 135221345Sdim return; 136221345Sdim RD->addAttr(::new (Context) MsStructAttr(SourceLocation(), Context)); 137221345Sdim} 138221345Sdim 139208600Srdivackyvoid Sema::ActOnPragmaOptionsAlign(PragmaOptionsAlignKind Kind, 140243830Sdim SourceLocation PragmaLoc) { 141208600Srdivacky if (PackContext == 0) 142208600Srdivacky PackContext = new PragmaPackStack(); 143208600Srdivacky 144208600Srdivacky PragmaPackStack *Context = static_cast<PragmaPackStack*>(PackContext); 145208600Srdivacky 146208600Srdivacky switch (Kind) { 147210299Sed // For all targets we support native and natural are the same. 148210299Sed // 149210299Sed // FIXME: This is not true on Darwin/PPC. 150210299Sed case POAK_Native: 151210299Sed case POAK_Power: 152208600Srdivacky case POAK_Natural: 153208600Srdivacky Context->push(0); 154208600Srdivacky Context->setAlignment(0); 155208600Srdivacky break; 156208600Srdivacky 157210299Sed // Note that '#pragma options align=packed' is not equivalent to attribute 158210299Sed // packed, it has a different precedence relative to attribute aligned. 159210299Sed case POAK_Packed: 160210299Sed Context->push(0); 161210299Sed Context->setAlignment(1); 162210299Sed break; 163210299Sed 164208600Srdivacky case POAK_Mac68k: 165208600Srdivacky // Check if the target supports this. 166208600Srdivacky if (!PP.getTargetInfo().hasAlignMac68kSupport()) { 167208600Srdivacky Diag(PragmaLoc, diag::err_pragma_options_align_mac68k_target_unsupported); 168208600Srdivacky return; 169208600Srdivacky } 170208600Srdivacky Context->push(0); 171208600Srdivacky Context->setAlignment(PackStackEntry::kMac68kAlignmentSentinel); 172208600Srdivacky break; 173208600Srdivacky 174243830Sdim case POAK_Reset: 175243830Sdim // Reset just pops the top of the stack, or resets the current alignment to 176243830Sdim // default. 177243830Sdim if (!Context->pop(0, /*IsReset=*/true)) { 178243830Sdim Diag(PragmaLoc, diag::warn_pragma_options_align_reset_failed) 179243830Sdim << "stack empty"; 180243830Sdim } 181208600Srdivacky break; 182208600Srdivacky } 183208600Srdivacky} 184208600Srdivacky 185198092Srdivackyvoid Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name, 186226633Sdim Expr *alignment, SourceLocation PragmaLoc, 187193326Sed SourceLocation LParenLoc, SourceLocation RParenLoc) { 188193326Sed Expr *Alignment = static_cast<Expr *>(alignment); 189193326Sed 190193326Sed // If specified then alignment must be a "small" power of two. 191193326Sed unsigned AlignmentVal = 0; 192193326Sed if (Alignment) { 193193326Sed llvm::APSInt Val; 194198092Srdivacky 195193326Sed // pack(0) is like pack(), which just works out since that is what 196193326Sed // we use 0 for in PackAttr. 197208600Srdivacky if (Alignment->isTypeDependent() || 198208600Srdivacky Alignment->isValueDependent() || 199208600Srdivacky !Alignment->isIntegerConstantExpr(Val, Context) || 200193326Sed !(Val == 0 || Val.isPowerOf2()) || 201193326Sed Val.getZExtValue() > 16) { 202193326Sed Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment); 203193326Sed return; // Ignore 204193326Sed } 205193326Sed 206193326Sed AlignmentVal = (unsigned) Val.getZExtValue(); 207193326Sed } 208198092Srdivacky 209193326Sed if (PackContext == 0) 210193326Sed PackContext = new PragmaPackStack(); 211198092Srdivacky 212193326Sed PragmaPackStack *Context = static_cast<PragmaPackStack*>(PackContext); 213198092Srdivacky 214193326Sed switch (Kind) { 215212904Sdim case Sema::PPK_Default: // pack([n]) 216193326Sed Context->setAlignment(AlignmentVal); 217193326Sed break; 218193326Sed 219212904Sdim case Sema::PPK_Show: // pack(show) 220193326Sed // Show the current alignment, making sure to show the right value 221193326Sed // for the default. 222193326Sed AlignmentVal = Context->getAlignment(); 223193326Sed // FIXME: This should come from the target. 224193326Sed if (AlignmentVal == 0) 225193326Sed AlignmentVal = 8; 226208600Srdivacky if (AlignmentVal == PackStackEntry::kMac68kAlignmentSentinel) 227208600Srdivacky Diag(PragmaLoc, diag::warn_pragma_pack_show) << "mac68k"; 228208600Srdivacky else 229208600Srdivacky Diag(PragmaLoc, diag::warn_pragma_pack_show) << AlignmentVal; 230193326Sed break; 231193326Sed 232212904Sdim case Sema::PPK_Push: // pack(push [, id] [, [n]) 233193326Sed Context->push(Name); 234193326Sed // Set the new alignment if specified. 235193326Sed if (Alignment) 236198092Srdivacky Context->setAlignment(AlignmentVal); 237193326Sed break; 238193326Sed 239212904Sdim case Sema::PPK_Pop: // pack(pop [, id] [, n]) 240193326Sed // MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack: 241193326Sed // "#pragma pack(pop, identifier, n) is undefined" 242193326Sed if (Alignment && Name) 243198092Srdivacky Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment); 244198092Srdivacky 245193326Sed // Do the pop. 246212904Sdim if (!Context->pop(Name, /*IsReset=*/false)) { 247193326Sed // If a name was specified then failure indicates the name 248193326Sed // wasn't found. Otherwise failure indicates the stack was 249193326Sed // empty. 250193326Sed Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed) 251193326Sed << (Name ? "no record matching name" : "stack empty"); 252193326Sed 253193326Sed // FIXME: Warn about popping named records as MSVC does. 254193326Sed } else { 255193326Sed // Pop succeeded, set the new alignment if specified. 256193326Sed if (Alignment) 257193326Sed Context->setAlignment(AlignmentVal); 258193326Sed } 259193326Sed break; 260193326Sed } 261193326Sed} 262193326Sed 263221345Sdimvoid Sema::ActOnPragmaMSStruct(PragmaMSStructKind Kind) { 264221345Sdim MSStructPragmaOn = (Kind == PMSST_ON); 265221345Sdim} 266221345Sdim 267263508Sdimvoid Sema::ActOnPragmaMSComment(PragmaMSCommentKind Kind, StringRef Arg) { 268263508Sdim // FIXME: Serialize this. 269263508Sdim switch (Kind) { 270263508Sdim case PCK_Unknown: 271263508Sdim llvm_unreachable("unexpected pragma comment kind"); 272263508Sdim case PCK_Linker: 273263508Sdim Consumer.HandleLinkerOptionPragma(Arg); 274263508Sdim return; 275263508Sdim case PCK_Lib: 276263508Sdim Consumer.HandleDependentLibrary(Arg); 277263508Sdim return; 278263508Sdim case PCK_Compiler: 279263508Sdim case PCK_ExeStr: 280263508Sdim case PCK_User: 281263508Sdim return; // We ignore all of these. 282263508Sdim } 283263508Sdim llvm_unreachable("invalid pragma comment kind"); 284263508Sdim} 285263508Sdim 286263508Sdimvoid Sema::ActOnPragmaDetectMismatch(StringRef Name, StringRef Value) { 287263508Sdim // FIXME: Serialize this. 288263508Sdim Consumer.HandleDetectMismatch(Name, Value); 289263508Sdim} 290263508Sdim 291218893Sdimvoid Sema::ActOnPragmaUnused(const Token &IdTok, Scope *curScope, 292218893Sdim SourceLocation PragmaLoc) { 293198092Srdivacky 294218893Sdim IdentifierInfo *Name = IdTok.getIdentifierInfo(); 295218893Sdim LookupResult Lookup(*this, Name, IdTok.getLocation(), LookupOrdinaryName); 296218893Sdim LookupParsedName(Lookup, curScope, NULL, true); 297198092Srdivacky 298218893Sdim if (Lookup.empty()) { 299218893Sdim Diag(PragmaLoc, diag::warn_pragma_unused_undeclared_var) 300218893Sdim << Name << SourceRange(IdTok.getLocation()); 301218893Sdim return; 302218893Sdim } 303193326Sed 304218893Sdim VarDecl *VD = Lookup.getAsSingle<VarDecl>(); 305218893Sdim if (!VD) { 306218893Sdim Diag(PragmaLoc, diag::warn_pragma_unused_expected_var_arg) 307218893Sdim << Name << SourceRange(IdTok.getLocation()); 308218893Sdim return; 309218893Sdim } 310193326Sed 311218893Sdim // Warn if this was used before being marked unused. 312218893Sdim if (VD->isUsed()) 313218893Sdim Diag(PragmaLoc, diag::warn_used_but_marked_unused) << Name; 314218893Sdim 315218893Sdim VD->addAttr(::new (Context) UnusedAttr(IdTok.getLocation(), Context)); 316193326Sed} 317212904Sdim 318226633Sdimvoid Sema::AddCFAuditedAttribute(Decl *D) { 319226633Sdim SourceLocation Loc = PP.getPragmaARCCFCodeAuditedLoc(); 320226633Sdim if (!Loc.isValid()) return; 321226633Sdim 322226633Sdim // Don't add a redundant or conflicting attribute. 323226633Sdim if (D->hasAttr<CFAuditedTransferAttr>() || 324226633Sdim D->hasAttr<CFUnknownTransferAttr>()) 325226633Sdim return; 326226633Sdim 327226633Sdim D->addAttr(::new (Context) CFAuditedTransferAttr(Loc, Context)); 328226633Sdim} 329226633Sdim 330218893Sdimtypedef std::vector<std::pair<unsigned, SourceLocation> > VisStack; 331218893Sdimenum { NoVisibility = (unsigned) -1 }; 332212904Sdim 333212904Sdimvoid Sema::AddPushedVisibilityAttribute(Decl *D) { 334212904Sdim if (!VisContext) 335212904Sdim return; 336212904Sdim 337249423Sdim NamedDecl *ND = dyn_cast<NamedDecl>(D); 338249423Sdim if (ND && ND->getExplicitVisibility(NamedDecl::VisibilityForValue)) 339212904Sdim return; 340212904Sdim 341212904Sdim VisStack *Stack = static_cast<VisStack*>(VisContext); 342218893Sdim unsigned rawType = Stack->back().first; 343218893Sdim if (rawType == NoVisibility) return; 344218893Sdim 345218893Sdim VisibilityAttr::VisibilityType type 346218893Sdim = (VisibilityAttr::VisibilityType) rawType; 347212904Sdim SourceLocation loc = Stack->back().second; 348212904Sdim 349212904Sdim D->addAttr(::new (Context) VisibilityAttr(loc, Context, type)); 350212904Sdim} 351212904Sdim 352212904Sdim/// FreeVisContext - Deallocate and null out VisContext. 353212904Sdimvoid Sema::FreeVisContext() { 354212904Sdim delete static_cast<VisStack*>(VisContext); 355212904Sdim VisContext = 0; 356212904Sdim} 357212904Sdim 358218893Sdimstatic void PushPragmaVisibility(Sema &S, unsigned type, SourceLocation loc) { 359212904Sdim // Put visibility on stack. 360212904Sdim if (!S.VisContext) 361212904Sdim S.VisContext = new VisStack; 362212904Sdim 363212904Sdim VisStack *Stack = static_cast<VisStack*>(S.VisContext); 364212904Sdim Stack->push_back(std::make_pair(type, loc)); 365212904Sdim} 366212904Sdim 367234353Sdimvoid Sema::ActOnPragmaVisibility(const IdentifierInfo* VisType, 368212904Sdim SourceLocation PragmaLoc) { 369234353Sdim if (VisType) { 370212904Sdim // Compute visibility to use. 371263508Sdim VisibilityAttr::VisibilityType T; 372263508Sdim if (!VisibilityAttr::ConvertStrToVisibilityType(VisType->getName(), T)) { 373263508Sdim Diag(PragmaLoc, diag::warn_attribute_unknown_visibility) << VisType; 374212904Sdim return; 375212904Sdim } 376263508Sdim PushPragmaVisibility(*this, T, PragmaLoc); 377212904Sdim } else { 378234353Sdim PopPragmaVisibility(false, PragmaLoc); 379212904Sdim } 380212904Sdim} 381212904Sdim 382218893Sdimvoid Sema::ActOnPragmaFPContract(tok::OnOffSwitch OOS) { 383218893Sdim switch (OOS) { 384218893Sdim case tok::OOS_ON: 385218893Sdim FPFeatures.fp_contract = 1; 386218893Sdim break; 387218893Sdim case tok::OOS_OFF: 388218893Sdim FPFeatures.fp_contract = 0; 389218893Sdim break; 390218893Sdim case tok::OOS_DEFAULT: 391234353Sdim FPFeatures.fp_contract = getLangOpts().DefaultFPContract; 392218893Sdim break; 393218893Sdim } 394212904Sdim} 395212904Sdim 396234353Sdimvoid Sema::PushNamespaceVisibilityAttr(const VisibilityAttr *Attr, 397234353Sdim SourceLocation Loc) { 398218893Sdim // Visibility calculations will consider the namespace's visibility. 399218893Sdim // Here we just want to note that we're in a visibility context 400218893Sdim // which overrides any enclosing #pragma context, but doesn't itself 401218893Sdim // contribute visibility. 402234353Sdim PushPragmaVisibility(*this, NoVisibility, Loc); 403218893Sdim} 404218893Sdim 405234353Sdimvoid Sema::PopPragmaVisibility(bool IsNamespaceEnd, SourceLocation EndLoc) { 406234353Sdim if (!VisContext) { 407234353Sdim Diag(EndLoc, diag::err_pragma_pop_visibility_mismatch); 408234353Sdim return; 409234353Sdim } 410212904Sdim 411234353Sdim // Pop visibility from stack 412234353Sdim VisStack *Stack = static_cast<VisStack*>(VisContext); 413234353Sdim 414234353Sdim const std::pair<unsigned, SourceLocation> *Back = &Stack->back(); 415234353Sdim bool StartsWithPragma = Back->first != NoVisibility; 416234353Sdim if (StartsWithPragma && IsNamespaceEnd) { 417234353Sdim Diag(Back->second, diag::err_pragma_push_visibility_mismatch); 418234353Sdim Diag(EndLoc, diag::note_surrounding_namespace_ends_here); 419234353Sdim 420234353Sdim // For better error recovery, eat all pushes inside the namespace. 421234353Sdim do { 422234353Sdim Stack->pop_back(); 423234353Sdim Back = &Stack->back(); 424234353Sdim StartsWithPragma = Back->first != NoVisibility; 425234353Sdim } while (StartsWithPragma); 426234353Sdim } else if (!StartsWithPragma && !IsNamespaceEnd) { 427234353Sdim Diag(EndLoc, diag::err_pragma_pop_visibility_mismatch); 428234353Sdim Diag(Back->second, diag::note_surrounding_namespace_starts_here); 429234353Sdim return; 430212904Sdim } 431234353Sdim 432234353Sdim Stack->pop_back(); 433234353Sdim // To simplify the implementation, never keep around an empty stack. 434234353Sdim if (Stack->empty()) 435234353Sdim FreeVisContext(); 436212904Sdim} 437