10f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner//===--- HeaderMap.cpp - A file that acts like dir of symlinks ------------===// 20f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner// 30f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner// The LLVM Compiler Infrastructure 40f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner// 50bc735ffcfb223c0186419547abaa5c84482663eChris Lattner// This file is distributed under the University of Illinois Open Source 60bc735ffcfb223c0186419547abaa5c84482663eChris Lattner// License. See LICENSE.TXT for details. 70f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner// 80f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner//===----------------------------------------------------------------------===// 90f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner// 100f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner// This file implements the HeaderMap interface. 110f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner// 120f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner//===----------------------------------------------------------------------===// 130f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner 140f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner#include "clang/Lex/HeaderMap.h" 154967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar#include "clang/Lex/HeaderMapTypes.h" 16223f0ff6a9a5d0eaf63b98b3aa92888b4c088868Jordan Rose#include "clang/Basic/CharInfo.h" 171bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner#include "clang/Basic/FileManager.h" 185fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner#include "llvm/ADT/SmallString.h" 194967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar#include "llvm/Support/Compiler.h" 2003013fa9a0bf1ef4b907f5fec006c8f4000fdd21Michael J. Spencer#include "llvm/Support/DataTypes.h" 211bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner#include "llvm/Support/MathExtras.h" 221bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner#include "llvm/Support/MemoryBuffer.h" 234967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar#include "llvm/Support/SwapByteOrder.h" 244967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar#include "llvm/Support/Debug.h" 254967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar#include <cstring> 26651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines#include <memory> 270f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattnerusing namespace clang; 280f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner 295fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner/// HashHMapKey - This is the 'well known' hash function required by the file 305fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner/// format, used to look up keys in the hash table. The hash table uses simple 315fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner/// linear probing based on this function. 325f9e272e632e951b1efe824cd16acb4d96077930Chris Lattnerstatic inline unsigned HashHMapKey(StringRef Str) { 335fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner unsigned Result = 0; 34a139481e62fdb209d9d87a54a5733f989d2e8d51Chris Lattner const char *S = Str.begin(), *End = Str.end(); 351eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump 365fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner for (; S != End; S++) 37223f0ff6a9a5d0eaf63b98b3aa92888b4c088868Jordan Rose Result += toLowercase(*S) * 13; 385fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner return Result; 395fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner} 405fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner 415fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner 425fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner 431adbf6349d4701771a814542008386ad39e3d614Chris Lattner//===----------------------------------------------------------------------===// 441adbf6349d4701771a814542008386ad39e3d614Chris Lattner// Verification and Construction 451adbf6349d4701771a814542008386ad39e3d614Chris Lattner//===----------------------------------------------------------------------===// 461bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner 471bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner/// HeaderMap::Create - This attempts to load the specified file as a header 481bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner/// map. If it doesn't look like a HeaderMap, it gives up and returns null. 491bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner/// If it looks like a HeaderMap but is obviously corrupted, it puts a reason 501bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner/// into the string error argument and returns null. 5139b49bcaaddb1049234fca9500c0ac02c088e23dChris Lattnerconst HeaderMap *HeaderMap::Create(const FileEntry *FE, FileManager &FM) { 521bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner // If the file is too small to be a header map, ignore it. 531bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner unsigned FileSize = FE->getSize(); 546bcf27bb9a4b5c3f79cb44c0e4654a6d7619ad89Stephen Hines if (FileSize <= sizeof(HMapHeader)) return nullptr; 551eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump 56176edba5311f6eff0cad2631449885ddf4fbc9eaStephen Hines auto FileBuffer = FM.getBufferForFile(FE); 574967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar if (!FileBuffer || !*FileBuffer) 584967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return nullptr; 594967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar bool NeedsByteSwap; 604967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar if (!checkHeader(**FileBuffer, NeedsByteSwap)) 614967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return nullptr; 624967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return new HeaderMap(std::move(*FileBuffer), NeedsByteSwap); 634967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar} 644967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar 654967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainarbool HeaderMapImpl::checkHeader(const llvm::MemoryBuffer &File, 664967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar bool &NeedsByteSwap) { 674967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar if (File.getBufferSize() <= sizeof(HMapHeader)) 684967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return false; 694967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar const char *FileStart = File.getBufferStart(); 701bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner 711bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner // We know the file is at least as big as the header, check it now. 721bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner const HMapHeader *Header = reinterpret_cast<const HMapHeader*>(FileStart); 731eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump 74ba8326517548d1d7773c4040aef4a4d91bb99df0Chris Lattner // Sniff it to see if it's a headermap by checking the magic number and 75ba8326517548d1d7773c4040aef4a4d91bb99df0Chris Lattner // version. 761eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump if (Header->Magic == HMAP_HeaderMagicNumber && 771adbf6349d4701771a814542008386ad39e3d614Chris Lattner Header->Version == HMAP_HeaderVersion) 781bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner NeedsByteSwap = false; 791adbf6349d4701771a814542008386ad39e3d614Chris Lattner else if (Header->Magic == llvm::ByteSwap_32(HMAP_HeaderMagicNumber) && 801adbf6349d4701771a814542008386ad39e3d614Chris Lattner Header->Version == llvm::ByteSwap_16(HMAP_HeaderVersion)) 811bfd4a6313ea8ebf710c46c10111732cc65d51f6Chris Lattner NeedsByteSwap = true; // Mixed endianness headermap. 821eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump else 834967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return false; // Not a header map. 844967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar 854967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar if (Header->Reserved != 0) 864967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return false; 874967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar 884967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar // Check the number of buckets. It should be a power of two, and there 894967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar // should be enough space in the file for all of them. 904967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar uint32_t NumBuckets = NeedsByteSwap 914967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar ? llvm::sys::getSwappedBytes(Header->NumBuckets) 924967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar : Header->NumBuckets; 934967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar if (!llvm::isPowerOf2_32(NumBuckets)) 944967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return false; 954967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar if (File.getBufferSize() < 964967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar sizeof(HMapHeader) + sizeof(HMapBucket) * NumBuckets) 974967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return false; 984967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar 994967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar // Okay, everything looks good. 1004967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return true; 10198751314c4ba596860b574c3d3551030f01ff7d8Chris Lattner} 10298751314c4ba596860b574c3d3551030f01ff7d8Chris Lattner 1031adbf6349d4701771a814542008386ad39e3d614Chris Lattner//===----------------------------------------------------------------------===// 1041adbf6349d4701771a814542008386ad39e3d614Chris Lattner// Utility Methods 1051adbf6349d4701771a814542008386ad39e3d614Chris Lattner//===----------------------------------------------------------------------===// 1061adbf6349d4701771a814542008386ad39e3d614Chris Lattner 10798751314c4ba596860b574c3d3551030f01ff7d8Chris Lattner 10898751314c4ba596860b574c3d3551030f01ff7d8Chris Lattner/// getFileName - Return the filename of the headermap. 1094967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainarconst char *HeaderMapImpl::getFileName() const { 11098751314c4ba596860b574c3d3551030f01ff7d8Chris Lattner return FileBuffer->getBufferIdentifier(); 1110f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner} 1120f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner 1134967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainarunsigned HeaderMapImpl::getEndianAdjustedWord(unsigned X) const { 1141adbf6349d4701771a814542008386ad39e3d614Chris Lattner if (!NeedsBSwap) return X; 1151adbf6349d4701771a814542008386ad39e3d614Chris Lattner return llvm::ByteSwap_32(X); 1161adbf6349d4701771a814542008386ad39e3d614Chris Lattner} 1171adbf6349d4701771a814542008386ad39e3d614Chris Lattner 1181adbf6349d4701771a814542008386ad39e3d614Chris Lattner/// getHeader - Return a reference to the file header, in unbyte-swapped form. 1191adbf6349d4701771a814542008386ad39e3d614Chris Lattner/// This method cannot fail. 1204967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainarconst HMapHeader &HeaderMapImpl::getHeader() const { 1211adbf6349d4701771a814542008386ad39e3d614Chris Lattner // We know the file is at least as big as the header. Return it. 1221adbf6349d4701771a814542008386ad39e3d614Chris Lattner return *reinterpret_cast<const HMapHeader*>(FileBuffer->getBufferStart()); 1231adbf6349d4701771a814542008386ad39e3d614Chris Lattner} 1241adbf6349d4701771a814542008386ad39e3d614Chris Lattner 1251adbf6349d4701771a814542008386ad39e3d614Chris Lattner/// getBucket - Return the specified hash table bucket from the header map, 1261adbf6349d4701771a814542008386ad39e3d614Chris Lattner/// bswap'ing its fields as appropriate. If the bucket number is not valid, 1271adbf6349d4701771a814542008386ad39e3d614Chris Lattner/// this return a bucket with an empty key (0). 1284967a710c84587c654b56c828382219c3937dacbPirama Arumuga NainarHMapBucket HeaderMapImpl::getBucket(unsigned BucketNo) const { 1294967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar assert(FileBuffer->getBufferSize() >= 1304967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar sizeof(HMapHeader) + sizeof(HMapBucket) * BucketNo && 1314967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar "Expected bucket to be in range"); 1324967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar 1331adbf6349d4701771a814542008386ad39e3d614Chris Lattner HMapBucket Result; 1341adbf6349d4701771a814542008386ad39e3d614Chris Lattner Result.Key = HMAP_EmptyBucketKey; 1351eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump 1361eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump const HMapBucket *BucketArray = 1371adbf6349d4701771a814542008386ad39e3d614Chris Lattner reinterpret_cast<const HMapBucket*>(FileBuffer->getBufferStart() + 1381adbf6349d4701771a814542008386ad39e3d614Chris Lattner sizeof(HMapHeader)); 1391adbf6349d4701771a814542008386ad39e3d614Chris Lattner const HMapBucket *BucketPtr = BucketArray+BucketNo; 1401adbf6349d4701771a814542008386ad39e3d614Chris Lattner 1414967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar // Load the values, bswapping as needed. 1421adbf6349d4701771a814542008386ad39e3d614Chris Lattner Result.Key = getEndianAdjustedWord(BucketPtr->Key); 1431adbf6349d4701771a814542008386ad39e3d614Chris Lattner Result.Prefix = getEndianAdjustedWord(BucketPtr->Prefix); 1441adbf6349d4701771a814542008386ad39e3d614Chris Lattner Result.Suffix = getEndianAdjustedWord(BucketPtr->Suffix); 1451adbf6349d4701771a814542008386ad39e3d614Chris Lattner return Result; 1461adbf6349d4701771a814542008386ad39e3d614Chris Lattner} 1471adbf6349d4701771a814542008386ad39e3d614Chris Lattner 1484967a710c84587c654b56c828382219c3937dacbPirama Arumuga NainarOptional<StringRef> HeaderMapImpl::getString(unsigned StrTabIdx) const { 1491adbf6349d4701771a814542008386ad39e3d614Chris Lattner // Add the start of the string table to the idx. 1501adbf6349d4701771a814542008386ad39e3d614Chris Lattner StrTabIdx += getEndianAdjustedWord(getHeader().StringsOffset); 1511eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump 1521adbf6349d4701771a814542008386ad39e3d614Chris Lattner // Check for invalid index. 1531adbf6349d4701771a814542008386ad39e3d614Chris Lattner if (StrTabIdx >= FileBuffer->getBufferSize()) 1544967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return None; 1551eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump 1564967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar const char *Data = FileBuffer->getBufferStart() + StrTabIdx; 1574967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar unsigned MaxLen = FileBuffer->getBufferSize() - StrTabIdx; 1584967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar unsigned Len = strnlen(Data, MaxLen); 1594967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar 1604967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar // Check whether the buffer is null-terminated. 1614967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar if (Len == MaxLen && Data[Len - 1]) 1624967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return None; 1634967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar 1644967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return StringRef(Data, Len); 1651adbf6349d4701771a814542008386ad39e3d614Chris Lattner} 1661adbf6349d4701771a814542008386ad39e3d614Chris Lattner 1671adbf6349d4701771a814542008386ad39e3d614Chris Lattner//===----------------------------------------------------------------------===// 1681adbf6349d4701771a814542008386ad39e3d614Chris Lattner// The Main Drivers 1691adbf6349d4701771a814542008386ad39e3d614Chris Lattner//===----------------------------------------------------------------------===// 1701adbf6349d4701771a814542008386ad39e3d614Chris Lattner 1711adbf6349d4701771a814542008386ad39e3d614Chris Lattner/// dump - Print the contents of this headermap to stderr. 1724967a710c84587c654b56c828382219c3937dacbPirama Arumuga NainarLLVM_DUMP_METHOD void HeaderMapImpl::dump() const { 1731adbf6349d4701771a814542008386ad39e3d614Chris Lattner const HMapHeader &Hdr = getHeader(); 1741adbf6349d4701771a814542008386ad39e3d614Chris Lattner unsigned NumBuckets = getEndianAdjustedWord(Hdr.NumBuckets); 1751eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump 1764967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar llvm::dbgs() << "Header Map " << getFileName() << ":\n " << NumBuckets 1774967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar << ", " << getEndianAdjustedWord(Hdr.NumEntries) << "\n"; 1784967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar 1794967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar auto getStringOrInvalid = [this](unsigned Id) -> StringRef { 1804967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar if (Optional<StringRef> S = getString(Id)) 1814967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return *S; 1824967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar return "<invalid>"; 1834967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar }; 1841eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump 1851adbf6349d4701771a814542008386ad39e3d614Chris Lattner for (unsigned i = 0; i != NumBuckets; ++i) { 1861adbf6349d4701771a814542008386ad39e3d614Chris Lattner HMapBucket B = getBucket(i); 1871adbf6349d4701771a814542008386ad39e3d614Chris Lattner if (B.Key == HMAP_EmptyBucketKey) continue; 1881eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump 1894967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar StringRef Key = getStringOrInvalid(B.Key); 1904967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar StringRef Prefix = getStringOrInvalid(B.Prefix); 1914967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar StringRef Suffix = getStringOrInvalid(B.Suffix); 1924967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar llvm::dbgs() << " " << i << ". " << Key << " -> '" << Prefix << "' '" 1934967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar << Suffix << "'\n"; 1941adbf6349d4701771a814542008386ad39e3d614Chris Lattner } 1951adbf6349d4701771a814542008386ad39e3d614Chris Lattner} 1961adbf6349d4701771a814542008386ad39e3d614Chris Lattner 1970f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner/// LookupFile - Check to see if the specified relative filename is located in 1980f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner/// this HeaderMap. If so, open it and return its FileEntry. 199b5142bb7af5c70fffd09f05172a1379a35a9c29aChandler Carruthconst FileEntry *HeaderMap::LookupFile( 2005f9e272e632e951b1efe824cd16acb4d96077930Chris Lattner StringRef Filename, FileManager &FM) const { 201651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines 202651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines SmallString<1024> Path; 2034967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar StringRef Dest = HeaderMapImpl::lookupFilename(Filename, Path); 204651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines if (Dest.empty()) 2056bcf27bb9a4b5c3f79cb44c0e4654a6d7619ad89Stephen Hines return nullptr; 206651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines 207651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines return FM.getFile(Dest); 208651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines} 209651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines 2104967a710c84587c654b56c828382219c3937dacbPirama Arumuga NainarStringRef HeaderMapImpl::lookupFilename(StringRef Filename, 2114967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar SmallVectorImpl<char> &DestPath) const { 2125fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner const HMapHeader &Hdr = getHeader(); 2135fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner unsigned NumBuckets = getEndianAdjustedWord(Hdr.NumBuckets); 2145fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner 2154967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar // Don't probe infinitely. This should be checked before constructing. 2164967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar assert(llvm::isPowerOf2_32(NumBuckets) && "Expected power of 2"); 2171eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump 2185fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner // Linearly probe the hash table. 219a139481e62fdb209d9d87a54a5733f989d2e8d51Chris Lattner for (unsigned Bucket = HashHMapKey(Filename);; ++Bucket) { 2205fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner HMapBucket B = getBucket(Bucket & (NumBuckets-1)); 221651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines if (B.Key == HMAP_EmptyBucketKey) return StringRef(); // Hash miss. 2221eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump 2235fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner // See if the key matches. If not, probe on. 2244967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar Optional<StringRef> Key = getString(B.Key); 2254967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar if (LLVM_UNLIKELY(!Key)) 2264967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar continue; 2274967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar if (!Filename.equals_lower(*Key)) 2285fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner continue; 2291eb4433ac451dc16f4133a88af2d002ac26c58efMike Stump 2305fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner // If so, we have a match in the hash table. Construct the destination 2315fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner // path. 2324967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar Optional<StringRef> Prefix = getString(B.Prefix); 2334967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar Optional<StringRef> Suffix = getString(B.Suffix); 2344967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar 235651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines DestPath.clear(); 2364967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar if (LLVM_LIKELY(Prefix && Suffix)) { 2374967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar DestPath.append(Prefix->begin(), Prefix->end()); 2384967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar DestPath.append(Suffix->begin(), Suffix->end()); 2394967a710c84587c654b56c828382219c3937dacbPirama Arumuga Nainar } 240651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines return StringRef(DestPath.begin(), DestPath.size()); 2415fb125c2556cb9d914493b1ef1bd5eee2d2843afChris Lattner } 2420f441ab20ccd8d21fd3d034de866bfcaf6cb72b2Chris Lattner} 243