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      1 //===--- Builtins.cpp - Builtin function implementation -------------------===//
      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 implements various things for builtin functions.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "clang/Basic/Builtins.h"
     15 #include "clang/Basic/IdentifierTable.h"
     16 #include "clang/Basic/LangOptions.h"
     17 #include "clang/Basic/TargetInfo.h"
     18 #include "llvm/ADT/SmallVector.h"
     19 #include "llvm/ADT/StringRef.h"
     20 using namespace clang;
     21 
     22 static const Builtin::Info BuiltinInfo[] = {
     23   { "not a builtin function", nullptr, nullptr, nullptr, ALL_LANGUAGES},
     24 #define BUILTIN(ID, TYPE, ATTRS) { #ID, TYPE, ATTRS, 0, ALL_LANGUAGES },
     25 #define LANGBUILTIN(ID, TYPE, ATTRS, BUILTIN_LANG) { #ID, TYPE, ATTRS, 0, BUILTIN_LANG },
     26 #define LIBBUILTIN(ID, TYPE, ATTRS, HEADER, BUILTIN_LANG) { #ID, TYPE, ATTRS, HEADER,\
     27                                                             BUILTIN_LANG },
     28 #include "clang/Basic/Builtins.def"
     29 };
     30 
     31 const Builtin::Info &Builtin::Context::GetRecord(unsigned ID) const {
     32   if (ID < Builtin::FirstTSBuiltin)
     33     return BuiltinInfo[ID];
     34   assert(ID - Builtin::FirstTSBuiltin < NumTSRecords && "Invalid builtin ID!");
     35   return TSRecords[ID - Builtin::FirstTSBuiltin];
     36 }
     37 
     38 Builtin::Context::Context() {
     39   // Get the target specific builtins from the target.
     40   TSRecords = nullptr;
     41   NumTSRecords = 0;
     42 }
     43 
     44 void Builtin::Context::InitializeTarget(const TargetInfo &Target) {
     45   assert(NumTSRecords == 0 && "Already initialized target?");
     46   Target.getTargetBuiltins(TSRecords, NumTSRecords);
     47 }
     48 
     49 bool Builtin::Context::BuiltinIsSupported(const Builtin::Info &BuiltinInfo,
     50                                           const LangOptions &LangOpts) {
     51   bool BuiltinsUnsupported = LangOpts.NoBuiltin &&
     52                              strchr(BuiltinInfo.Attributes, 'f');
     53   bool MathBuiltinsUnsupported =
     54     LangOpts.NoMathBuiltin && BuiltinInfo.HeaderName &&
     55     llvm::StringRef(BuiltinInfo.HeaderName).equals("math.h");
     56   bool GnuModeUnsupported = !LangOpts.GNUMode &&
     57                             (BuiltinInfo.builtin_lang & GNU_LANG);
     58   bool MSModeUnsupported = !LangOpts.MicrosoftExt &&
     59                            (BuiltinInfo.builtin_lang & MS_LANG);
     60   bool ObjCUnsupported = !LangOpts.ObjC1 &&
     61                          BuiltinInfo.builtin_lang == OBJC_LANG;
     62   return !BuiltinsUnsupported && !MathBuiltinsUnsupported &&
     63          !GnuModeUnsupported && !MSModeUnsupported && !ObjCUnsupported;
     64 }
     65 
     66 /// InitializeBuiltins - Mark the identifiers for all the builtins with their
     67 /// appropriate builtin ID # and mark any non-portable builtin identifiers as
     68 /// such.
     69 void Builtin::Context::InitializeBuiltins(IdentifierTable &Table,
     70                                           const LangOptions& LangOpts) {
     71   // Step #1: mark all target-independent builtins with their ID's.
     72   for (unsigned i = Builtin::NotBuiltin+1; i != Builtin::FirstTSBuiltin; ++i)
     73     if (BuiltinIsSupported(BuiltinInfo[i], LangOpts)) {
     74       Table.get(BuiltinInfo[i].Name).setBuiltinID(i);
     75     }
     76 
     77   // Step #2: Register target-specific builtins.
     78   for (unsigned i = 0, e = NumTSRecords; i != e; ++i)
     79     if (BuiltinIsSupported(TSRecords[i], LangOpts))
     80       Table.get(TSRecords[i].Name).setBuiltinID(i+Builtin::FirstTSBuiltin);
     81 }
     82 
     83 void
     84 Builtin::Context::GetBuiltinNames(SmallVectorImpl<const char *> &Names) {
     85   // Final all target-independent names
     86   for (unsigned i = Builtin::NotBuiltin+1; i != Builtin::FirstTSBuiltin; ++i)
     87     if (!strchr(BuiltinInfo[i].Attributes, 'f'))
     88       Names.push_back(BuiltinInfo[i].Name);
     89 
     90   // Find target-specific names.
     91   for (unsigned i = 0, e = NumTSRecords; i != e; ++i)
     92     if (!strchr(TSRecords[i].Attributes, 'f'))
     93       Names.push_back(TSRecords[i].Name);
     94 }
     95 
     96 void Builtin::Context::ForgetBuiltin(unsigned ID, IdentifierTable &Table) {
     97   Table.get(GetRecord(ID).Name).setBuiltinID(0);
     98 }
     99 
    100 bool Builtin::Context::isLike(unsigned ID, unsigned &FormatIdx,
    101                               bool &HasVAListArg, const char *Fmt) const {
    102   assert(Fmt && "Not passed a format string");
    103   assert(::strlen(Fmt) == 2 &&
    104          "Format string needs to be two characters long");
    105   assert(::toupper(Fmt[0]) == Fmt[1] &&
    106          "Format string is not in the form \"xX\"");
    107 
    108   const char *Like = ::strpbrk(GetRecord(ID).Attributes, Fmt);
    109   if (!Like)
    110     return false;
    111 
    112   HasVAListArg = (*Like == Fmt[1]);
    113 
    114   ++Like;
    115   assert(*Like == ':' && "Format specifier must be followed by a ':'");
    116   ++Like;
    117 
    118   assert(::strchr(Like, ':') && "Format specifier must end with a ':'");
    119   FormatIdx = ::strtol(Like, nullptr, 10);
    120   return true;
    121 }
    122 
    123 bool Builtin::Context::isPrintfLike(unsigned ID, unsigned &FormatIdx,
    124                                     bool &HasVAListArg) {
    125   return isLike(ID, FormatIdx, HasVAListArg, "pP");
    126 }
    127 
    128 bool Builtin::Context::isScanfLike(unsigned ID, unsigned &FormatIdx,
    129                                    bool &HasVAListArg) {
    130   return isLike(ID, FormatIdx, HasVAListArg, "sS");
    131 }
    132