Add support for zero length files

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13866 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-05-28 00:34:42 +00:00
parent 531b802e13
commit e53477e56c

View File

@ -230,11 +230,17 @@ void *llvm::ReadFileIntoAddressSpace(const std::string &Filename,
FDHandle FD(open(Filename.c_str(), O_RDONLY));
if (FD == -1) return 0;
// If the file has a length of zero, mmap might return a null pointer. In
// this case, allocate a single byte of memory and return it instead.
if (Length == 0)
return malloc(1);
// mmap in the file all at once...
void *Buffer = (void*)mmap(0, Length, PROT_READ, MAP_PRIVATE, FD, 0);
if (Buffer == (void*)MAP_FAILED)
return 0;
return Buffer;
#else
// FIXME: implement with read/write
@ -246,7 +252,10 @@ void *llvm::ReadFileIntoAddressSpace(const std::string &Filename,
/// address space.
void llvm::UnmapFileFromAddressSpace(void *Buffer, unsigned Length) {
#ifdef HAVE_MMAP_FILE
munmap((char*)Buffer, Length);
if (Length)
munmap((char*)Buffer, Length);
else
free(Buffer); // Zero byte files are malloc(1)'s.
#else
free(Buffer);
#endif