diff options
| author | ruki <[email protected]> | 2026-01-30 21:01:00 +0800 |
|---|---|---|
| committer | ruki <[email protected]> | 2026-01-30 21:01:00 +0800 |
| commit | b62d053691005d2615ff89635a447627d1d6e188 (patch) | |
| tree | 2e1da7020f3036c5345048cb59336efad0545c98 | |
| parent | cd457f20862b02da001857ab2bcfb5f1ce97fed5 (diff) | |
improve comments
| -rw-r--r-- | core/src/xmake/binutils/format.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/core/src/xmake/binutils/format.c b/core/src/xmake/binutils/format.c index 6d076a5b1..4decff29f 100644 --- a/core/src/xmake/binutils/format.c +++ b/core/src/xmake/binutils/format.c @@ -32,17 +32,24 @@ /* ////////////////////////////////////////////////////////////////////////////////////// * private implementation */ +/* check PE by validating DOS header (MZ/ZM) and PE signature at e_lfanew + * + * note: unlike ELF/Mach-O/AR, PE needs an additional read/peek to locate the PE signature. + */ static tb_bool_t xm_binutils_format_is_pe(tb_stream_ref_t istream, tb_byte_t* first8) { tb_assert_and_check_return_val(istream && first8, tb_false); tb_bool_t ok = tb_false; do { + // fast reject: DOS magic tb_check_break((first8[0] == 'M' && first8[1] == 'Z') || (first8[0] == 'Z' && first8[1] == 'M')); + // ensure we can read enough for DOS stub + PE signature tb_hong_t size = tb_stream_size(istream); if (size > 0 && size < XM_BINUTILS_PE_DOS_STUB_MIN_SIZE + 4) { break; } + // peek a bounded prefix to locate e_lfanew and PE\\0\\0 signature tb_size_t max_peek = 4096; if (size > 0) { max_peek = (tb_size_t)tb_min((tb_hize_t)max_peek, (tb_hize_t)size); @@ -53,6 +60,7 @@ static tb_bool_t xm_binutils_format_is_pe(tb_stream_ref_t istream, tb_byte_t* fi break; } + // e_lfanew points to PE signature offset tb_uint32_t e_lfanew = (tb_uint32_t)( (tb_uint32_t)p[XM_BINUTILS_PE_DOS_ELFANEW_OFFSET] | ((tb_uint32_t)p[XM_BINUTILS_PE_DOS_ELFANEW_OFFSET + 1] << 8) | ((tb_uint32_t)p[XM_BINUTILS_PE_DOS_ELFANEW_OFFSET + 2] << 16) @@ -68,6 +76,7 @@ static tb_bool_t xm_binutils_format_is_pe(tb_stream_ref_t istream, tb_byte_t* fi return ok; } +// quick header checks from the first 8 bytes static __tb_inline__ tb_bool_t xm_binutils_format_is_ar(tb_byte_t const* first8) { return first8[0] == '!' && first8[1] == '<' && first8[2] == 'a' && first8[3] == 'r' && first8[4] == 'c' && first8[5] == 'h' && @@ -108,7 +117,7 @@ static __tb_inline__ tb_bool_t xm_binutils_format_is_coff(tb_byte_t const* first * * @param istream the input stream * @return XM_BINUTILS_FORMAT_COFF, XM_BINUTILS_FORMAT_ELF, XM_BINUTILS_FORMAT_MACHO, - * XM_BINUTILS_FORMAT_AR, XM_BINUTILS_FORMAT_PE, XM_BINUTILS_FORMAT_UNKNOWN, or -1 on error + * XM_BINUTILS_FORMAT_AR, XM_BINUTILS_FORMAT_PE, XM_BINUTILS_FORMAT_UNKNOWN, or -1 on error */ tb_int_t xm_binutils_format_detect(tb_stream_ref_t istream) { tb_assert_and_check_return_val(istream, -1); |