diff options
| author | Jakub Konka <kubkon@jakubkonka.com> | 2022-08-22 19:48:14 +0200 |
|---|---|---|
| committer | Jakub Konka <kubkon@jakubkonka.com> | 2022-08-23 08:55:04 +0200 |
| commit | c84e5ee87852eafff0cbf986bf02c5221cbcec35 (patch) | |
| tree | a978b80bbcc7273ad3a0e3d4de843a8a3ec947e9 /src | |
| parent | 9043e665a549b87fa73ade7af06682368092d8a9 (diff) | |
| download | zig-c84e5ee87852eafff0cbf986bf02c5221cbcec35.tar.gz zig-c84e5ee87852eafff0cbf986bf02c5221cbcec35.zip | |
coff: improve default COFF/PE object parser
We now do not allocate memory for headers and other metadata unless
requested by the caller. Instead, we read-in the entire contents
of the image into memory and operate on pointers and casts wherever
possible. I have a left a TODO to hook up Windows' memory-mapped API
here in-place of standard `readToEndAlloc` which should be more memory
proof on memory constrained hosts.
This commit also supplements our `std.coff` with a lot missing basic
extern structs required to make our COFF linker.
Diffstat (limited to 'src')
| -rw-r--r-- | src/link/Coff.zig | 29 |
1 files changed, 18 insertions, 11 deletions
diff --git a/src/link/Coff.zig b/src/link/Coff.zig index a01b9cf7c3..6536fbd1ac 100644 --- a/src/link/Coff.zig +++ b/src/link/Coff.zig @@ -204,15 +204,18 @@ pub fn openPath(allocator: Allocator, sub_path: []const u8, options: link.Option index += 2; // Characteristics - var characteristics: u16 = std.coff.IMAGE_FILE_DEBUG_STRIPPED | std.coff.IMAGE_FILE_RELOCS_STRIPPED; // TODO Remove debug info stripped flag when necessary + var characteristics: std.coff.CoffHeaderFlags = .{ + .DEBUG_STRIPPED = 1, // TODO remove debug info stripped flag when necessary + .RELOCS_STRIPPED = 1, + }; if (options.output_mode == .Exe) { - characteristics |= std.coff.IMAGE_FILE_EXECUTABLE_IMAGE; + characteristics.EXECUTABLE_IMAGE = 1; } switch (self.ptr_width) { - .p32 => characteristics |= std.coff.IMAGE_FILE_32BIT_MACHINE, - .p64 => characteristics |= std.coff.IMAGE_FILE_LARGE_ADDRESS_AWARE, + .p32 => characteristics.@"32BIT_MACHINE" = 1, + .p64 => characteristics.LARGE_ADDRESS_AWARE = 1, } - mem.writeIntLittle(u16, hdr_data[index..][0..2], characteristics); + mem.writeIntLittle(u16, hdr_data[index..][0..2], @bitCast(u16, characteristics)); index += 2; assert(index == 20); @@ -352,7 +355,10 @@ pub fn openPath(allocator: Allocator, sub_path: []const u8, options: link.Option mem.set(u8, hdr_data[index..][0..12], 0); index += 12; // Section flags - mem.writeIntLittle(u32, hdr_data[index..][0..4], std.coff.IMAGE_SCN_CNT_INITIALIZED_DATA | std.coff.IMAGE_SCN_MEM_READ); + mem.writeIntLittle(u32, hdr_data[index..][0..4], @bitCast(u32, std.coff.SectionHeaderFlags{ + .CNT_INITIALIZED_DATA = 1, + .MEM_READ = 1, + })); index += 4; // Then, the .text section hdr_data[index..][0..8].* = ".text\x00\x00\x00".*; @@ -378,11 +384,12 @@ pub fn openPath(allocator: Allocator, sub_path: []const u8, options: link.Option mem.set(u8, hdr_data[index..][0..12], 0); index += 12; // Section flags - mem.writeIntLittle( - u32, - hdr_data[index..][0..4], - std.coff.IMAGE_SCN_CNT_CODE | std.coff.IMAGE_SCN_MEM_EXECUTE | std.coff.IMAGE_SCN_MEM_READ | std.coff.IMAGE_SCN_MEM_WRITE, - ); + mem.writeIntLittle(u32, hdr_data[index..][0..4], @bitCast(u32, std.coff.SectionHeaderFlags{ + .CNT_CODE = 1, + .MEM_EXECUTE = 1, + .MEM_READ = 1, + .MEM_WRITE = 1, + })); index += 4; assert(index == optional_header_size + section_table_size); |