diff --git a/llvm/lib/Support/FileUtilities.cpp b/llvm/lib/Support/FileUtilities.cpp index 234cf7d2604d..79cca8fda1dc 100644 --- a/llvm/lib/Support/FileUtilities.cpp +++ b/llvm/lib/Support/FileUtilities.cpp @@ -14,6 +14,9 @@ #include "llvm/Support/FileUtilities.h" #include "llvm/System/Path.h" +#include "llvm/System/MappedFile.h" +#include "llvm/ADT/StringExtras.h" +#include #include #include @@ -64,3 +67,184 @@ void llvm::MoveFileOverIfUpdated(const std::string &New, std::remove(New.c_str()); } } + +static bool isNumberChar(char C) { + switch (C) { + case '0': case '1': case '2': case '3': case '4': + case '5': case '6': case '7': case '8': case '9': + case '.': case '+': case '-': + case 'e': + case 'E': return true; + default: return false; + } +} + +static char *BackupNumber(char *Pos, char *FirstChar) { + // If we didn't stop in the middle of a number, don't backup. + if (!isNumberChar(*Pos)) return Pos; + + // Otherwise, return to the start of the number. + while (Pos > FirstChar && isNumberChar(Pos[-1])) + --Pos; + return Pos; +} + +/// CompareNumbers - compare two numbers, returning true if they are different. +static bool CompareNumbers(char *&F1P, char *&F2P, char *F1End, char *F2End, + double AbsTolerance, double RelTolerance, + std::string *ErrorMsg) { + char *F1NumEnd, *F2NumEnd; + double V1 = 0.0, V2 = 0.0; + // If we stop on numbers, compare their difference. + if (isNumberChar(*F1P) && isNumberChar(*F2P)) { + V1 = strtod(F1P, &F1NumEnd); + V2 = strtod(F2P, &F2NumEnd); + } else { + // Otherwise, the diff failed. + F1NumEnd = F1P; + F2NumEnd = F2P; + } + + if (F1NumEnd == F1P || F2NumEnd == F2P) { + if (ErrorMsg) *ErrorMsg = "Comparison failed, not a numeric difference."; + return true; + } + + // Check to see if these are inside the absolute tolerance + if (AbsTolerance < std::abs(V1-V2)) { + // Nope, check the relative tolerance... + double Diff; + if (V2) + Diff = std::abs(V1/V2 - 1.0); + else if (V1) + Diff = std::abs(V2/V1 - 1.0); + else + Diff = 0; // Both zero. + if (Diff > RelTolerance) { + if (ErrorMsg) { + *ErrorMsg = "Compared: " + ftostr(V1) + " and " + ftostr(V2) + + ": diff = " + ftostr(Diff) + "\n"; + *ErrorMsg += "Out of tolerance: rel/abs: " + ftostr(RelTolerance) + + "/" + ftostr(AbsTolerance); + } + return true; + } + } + + // Otherwise, advance our read pointers to the end of the numbers. + F1P = F1NumEnd; F2P = F2NumEnd; + return false; +} + +// PadFileIfNeeded - If the files are not identical, we will have to be doing +// numeric comparisons in here. There are bad cases involved where we (i.e., +// strtod) might run off the beginning or end of the file if it starts or ends +// with a number. Because of this, if needed, we pad the file so that it starts +// and ends with a null character. +static void PadFileIfNeeded(char *&FileStart, char *&FileEnd, char *&FP) { + if (isNumberChar(FileStart[0]) || isNumberChar(FileEnd[-1])) { + unsigned FileLen = FileEnd-FileStart; + char *NewFile = new char[FileLen+2]; + NewFile[0] = 0; // Add null padding + NewFile[FileLen+1] = 0; // Add null padding + memcpy(NewFile+1, FileStart, FileLen); + FP = NewFile+(FP-FileStart)+1; + FileStart = NewFile+1; + FileEnd = FileStart+FileLen; + } +} + +/// DiffFilesWithTolerance - Compare the two files specified, returning 0 if the +/// files match, 1 if they are different, and 2 if there is a file error. This +/// function differs from DiffFiles in that you can specify an absolete and +/// relative FP error that is allowed to exist. If you specify a string to fill +/// in for the error option, it will set the string to an error message if an +/// error occurs, allowing the caller to distinguish between a failed diff and a +/// file system error. +/// +int llvm::DiffFilesWithTolerance(const std::string &FileA, + const std::string &FileB, + double AbsTol, double RelTol, + std::string *Error) { + try { + // Map in the files into memory. + sys::MappedFile F1((sys::Path(FileA))); + sys::MappedFile F2((sys::Path(FileB))); + F1.map(); + F2.map(); + + // Okay, now that we opened the files, scan them for the first difference. + char *File1Start = F1.charBase(); + char *File2Start = F2.charBase(); + char *File1End = File1Start+F1.size(); + char *File2End = File2Start+F2.size(); + char *F1P = File1Start; + char *F2P = File2Start; + + // Scan for the end of file or first difference. + while (F1P < File1End && F2P < File2End && *F1P == *F2P) + ++F1P, ++F2P; + + // Common case: identifical files. + if (F1P == File1End && F2P == File2End) return 0; + + char *OrigFile1Start = File1Start; + char *OrigFile2Start = File2Start; + + // If the files need padding, do so now. + PadFileIfNeeded(File1Start, File1End, F1P); + PadFileIfNeeded(File2Start, File2End, F2P); + + bool CompareFailed = false; + while (1) { + // Scan for the end of file or next difference. + while (F1P < File1End && F2P < File2End && *F1P == *F2P) + ++F1P, ++F2P; + + if (F1P >= File1End || F2P >= File2End) break; + + // Okay, we must have found a difference. Backup to the start of the + // current number each stream is at so that we can compare from the + // beginning. + F1P = BackupNumber(F1P, File1Start); + F2P = BackupNumber(F2P, File2Start); + + // Now that we are at the start of the numbers, compare them, exiting if + // they don't match. + if (CompareNumbers(F1P, F2P, File1End, File2End, AbsTol, RelTol, Error)) { + CompareFailed = true; + break; + } + } + + // Okay, we reached the end of file. If both files are at the end, we + // succeeded. + bool F1AtEnd = F1P >= File1End; + bool F2AtEnd = F2P >= File2End; + if (!CompareFailed && (!F1AtEnd || !F2AtEnd)) { + // Else, we might have run off the end due to a number: backup and retry. + if (F1AtEnd && isNumberChar(F1P[-1])) --F1P; + if (F2AtEnd && isNumberChar(F2P[-1])) --F2P; + F1P = BackupNumber(F1P, File1Start); + F2P = BackupNumber(F2P, File2Start); + + // Now that we are at the start of the numbers, compare them, exiting if + // they don't match. + if (CompareNumbers(F1P, F2P, File1End, File2End, AbsTol, RelTol, Error)) + CompareFailed = true; + + // If we found the end, we succeeded. + if (F1P < File1End || F2P < File2End) + CompareFailed = true; + } + + if (OrigFile1Start != File1Start) + delete[] File1Start; + if (OrigFile2Start != File2Start) + delete[] File2Start; + return CompareFailed; + } catch (const std::string &Msg) { + if (Error) *Error = Msg; + return 2; + } +}