Make fpcmp handle running off of the beginning or end of the file correctly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14259 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-06-20 03:12:18 +00:00
parent 218a8223e6
commit 8e6d2bb8fa

View File

@ -104,6 +104,23 @@ static void CompareNumbers(char *&F1P, char *&F2P, char *F1End, char *F2End) {
F1P = F1NumEnd; F2P = F2NumEnd;
}
// 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;
}
}
int main(int argc, char **argv) {
cl::ParseCommandLineOptions(argc, argv);
@ -120,11 +137,22 @@ int main(int argc, char **argv) {
char *F1P = File1Start;
char *F2P = File2Start;
while (1) {
// 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;
// If the files need padding, do so now.
PadFileIfNeeded(File1Start, File1End, F1P);
PadFileIfNeeded(File2Start, File2End, F2P);
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
@ -140,9 +168,13 @@ int main(int argc, char **argv) {
// Okay, we reached the end of file. If both files are at the end, we
// succeeded.
if (F1P >= File1End && F2P >= File2End) return 0;
bool F1AtEnd = F1P >= File1End;
bool F2AtEnd = F2P >= File2End;
if (F1AtEnd & F2AtEnd) return 0;
// Otherwise, we might have run off the end due to a number, backup and retry.
// Otherwise, 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);