diff options
Diffstat (limited to 'bfd/wasm-module.c')
| -rw-r--r-- | bfd/wasm-module.c | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/bfd/wasm-module.c b/bfd/wasm-module.c index dc13564..a8f6547 100644 --- a/bfd/wasm-module.c +++ b/bfd/wasm-module.c @@ -28,11 +28,17 @@ #include "sysdep.h" #include "alloca-conf.h" #include "bfd.h" -#include <limits.h> #include "libiberty.h" #include "libbfd.h" #include "wasm-module.h" +#ifdef HAVE_LIMITS_H +#include <limits.h> +#endif +#ifndef CHAR_BIT +#define CHAR_BIT 8 +#endif + typedef struct { asymbol * symbols; @@ -111,27 +117,34 @@ wasm_read_leb128 (bfd * abfd, unsigned int num_read = 0; unsigned int shift = 0; unsigned char byte = 0; + unsigned char lost, mask; int status = 1; while (bfd_bread (&byte, 1, abfd) == 1) { num_read++; - if (shift < sizeof (result) * 8) + if (shift < CHAR_BIT * sizeof (result)) { result |= ((bfd_vma) (byte & 0x7f)) << shift; - if ((result >> shift) != (byte & 0x7f)) - /* Overflow. */ - status |= 2; + /* These bits overflowed. */ + lost = byte ^ (result >> shift); + /* And this is the mask of possible overflow bits. */ + mask = 0x7f ^ ((bfd_vma) 0x7f << shift >> shift); shift += 7; } - else if ((byte & 0x7f) != 0) + else + { + lost = byte; + mask = 0x7f; + } + if ((lost & mask) != (sign && (bfd_signed_vma) result < 0 ? mask : 0)) status |= 2; if ((byte & 0x80) == 0) { status &= ~1; - if (sign && (shift < 8 * sizeof (result)) && (byte & 0x40)) + if (sign && shift < CHAR_BIT * sizeof (result) && (byte & 0x40)) result |= -((bfd_vma) 1 << shift); break; } |