| author |  Andrew Kelley <andrew@ziglang.org> 2020-09-28 15:42:09-07:00 |
| committer | Andrew Kelley <andrew@ziglang.org> 2020-09-28 15:42:09-07:00 |
| log | 412a2f966e18aa792089ac1f41482222d7f2434f |
| tree | 36f4d7f00ce93bc3f10844e3bbf56f75c8ddba8d |
| parent | 91a73a177bc20fa0219dbb6c3cf3dda1c2a465db |
store stage1 flags in a trailing byte in the hash id symlink
When we get a cache hit for a stage1 compilation, we need to know about
some of the flags such as have_winmain or have_dllmain to know which
subsystem to infer during linking.
To do this, we append a hex-encoded byte into the intentionally-dangling
symlink which contains the cache hash digest rather than a filename. The
hex-encoded byte contains the flags we need to infer the subsystem
during linking.4 files changed, 56 insertions(+), 27 deletions(-)
BRANCH_TODO+3
| ... | ... | @@ -1,3 +1,6 @@ |
| 1 | * the have_foo flags that we get from stage1 have to be stored in the cache otherwise we get | |
| 2 | a different result for subsystem when we have a cached stage1 execution result. | |
| 3 | same deal with extern "foo" libraries used | |
| 1 | 4 | * add jobs to build import libs for windows DLLs for explicitly linked libs |
| 2 | 5 | * add jobs to build import libs for windows DLLs for extern "foo" functions used |
| 3 | 6 | * MachO LLD linking |
src/Compilation.zig+36-14
| ... | ... | @@ -2512,16 +2512,25 @@ fn updateStage1Module(comp: *Compilation) !void { |
| 2512 | 2512 | if (try man.hit()) { |
| 2513 | 2513 | const digest = man.final(); |
| 2514 | 2514 | |
| 2515 | var prev_digest_buf: [digest.len]u8 = undefined; | |
| 2515 | // We use an extra hex-encoded byte here to store some flags. | |
| 2516 | var prev_digest_buf: [digest.len + 2]u8 = undefined; | |
| 2516 | 2517 | const prev_digest: []u8 = directory.handle.readLink(id_symlink_basename, &prev_digest_buf) catch |err| blk: { |
| 2517 | 2518 | log.debug("stage1 {} new_digest={} readlink error: {}", .{ mod.root_pkg.root_src_path, digest, @errorName(err) }); |
| 2518 | 2519 | // Handle this as a cache miss. |
| 2519 | 2520 | break :blk prev_digest_buf[0..0]; |
| 2520 | 2521 | }; |
| 2521 | if (mem.eql(u8, prev_digest, &digest)) { | |
| 2522 | log.debug("stage1 {} digest={} match - skipping invocation", .{ mod.root_pkg.root_src_path, digest }); | |
| 2523 | comp.stage1_lock = man.toOwnedLock(); | |
| 2524 | return; | |
| 2522 | if (prev_digest.len >= digest.len + 2) { | |
| 2523 | if (mem.eql(u8, prev_digest[0..digest.len], &digest)) { | |
| 2524 | log.debug("stage1 {} digest={} match - skipping invocation", .{ mod.root_pkg.root_src_path, digest }); | |
| 2525 | var flags_bytes: [1]u8 = undefined; | |
| 2526 | if (std.fmt.hexToBytes(&flags_bytes, prev_digest[digest.len..])) |_| { | |
| 2527 | comp.stage1_lock = man.toOwnedLock(); | |
| 2528 | mod.stage1_flags = @bitCast(@TypeOf(mod.stage1_flags), flags_bytes[0]); | |
| 2529 | return; | |
| 2530 | } else |err| { | |
| 2531 | log.warn("bad cache stage1 digest: '{s}'", .{prev_digest}); | |
| 2532 | } | |
| 2533 | } | |
| 2525 | 2534 | } |
| 2526 | 2535 | log.debug("stage1 {} prev_digest={} new_digest={}", .{ mod.root_pkg.root_src_path, prev_digest, digest }); |
| 2527 | 2536 | man.unhit(prev_hash_state, input_file_count); |
| ... | ... | @@ -2642,22 +2651,35 @@ fn updateStage1Module(comp: *Compilation) !void { |
| 2642 | 2651 | }; |
| 2643 | 2652 | stage1_module.build_object(); |
| 2644 | 2653 | |
| 2645 | mod.have_c_main = stage1_module.have_c_main; | |
| 2646 | mod.have_winmain = stage1_module.have_winmain; | |
| 2647 | mod.have_wwinmain = stage1_module.have_wwinmain; | |
| 2648 | mod.have_winmain_crt_startup = stage1_module.have_winmain_crt_startup; | |
| 2649 | mod.have_wwinmain_crt_startup = stage1_module.have_wwinmain_crt_startup; | |
| 2650 | mod.have_dllmain_crt_startup = stage1_module.have_dllmain_crt_startup; | |
| 2654 | mod.stage1_flags = .{ | |
| 2655 | .have_c_main = stage1_module.have_c_main, | |
| 2656 | .have_winmain = stage1_module.have_winmain, | |
| 2657 | .have_wwinmain = stage1_module.have_wwinmain, | |
| 2658 | .have_winmain_crt_startup = stage1_module.have_winmain_crt_startup, | |
| 2659 | .have_wwinmain_crt_startup = stage1_module.have_wwinmain_crt_startup, | |
| 2660 | .have_dllmain_crt_startup = stage1_module.have_dllmain_crt_startup, | |
| 2661 | }; | |
| 2651 | 2662 | |
| 2652 | 2663 | stage1_module.destroy(); |
| 2653 | 2664 | |
| 2654 | 2665 | const digest = man.final(); |
| 2655 | 2666 | |
| 2656 | log.debug("stage1 {} final digest={}", .{ mod.root_pkg.root_src_path, digest }); | |
| 2657 | ||
| 2658 | 2667 | // Update the dangling symlink with the digest. If it fails we can continue; it only |
| 2659 | 2668 | // means that the next invocation will have an unnecessary cache miss. |
| 2660 | directory.handle.symLink(&digest, id_symlink_basename, .{}) catch |err| { | |
| 2669 | const stage1_flags_byte = @bitCast(u8, mod.stage1_flags); | |
| 2670 | log.debug("stage1 {} final digest={} flags={x}", .{ | |
| 2671 | mod.root_pkg.root_src_path, digest, stage1_flags_byte, | |
| 2672 | }); | |
| 2673 | var digest_plus_flags: [digest.len + 2]u8 = undefined; | |
| 2674 | digest_plus_flags[0..digest.len].* = digest; | |
| 2675 | assert(std.fmt.formatIntBuf(digest_plus_flags[digest.len..], stage1_flags_byte, 16, false, .{ | |
| 2676 | .width = 2, | |
| 2677 | .fill = '0', | |
| 2678 | }) == 2); | |
| 2679 | log.debug("saved digest + flags: '{s}' (byte = {}) have_winmain_crt_startup={}", .{ | |
| 2680 | digest_plus_flags, stage1_flags_byte, mod.stage1_flags.have_winmain_crt_startup, | |
| 2681 | }); | |
| 2682 | directory.handle.symLink(&digest_plus_flags, id_symlink_basename, .{}) catch |err| { | |
| 2661 | 2683 | log.warn("failed to save stage1 hash digest symlink: {}", .{@errorName(err)}); |
| 2662 | 2684 | }; |
| 2663 | 2685 | // Again failure here only means an unnecessary cache miss. |
src/Module.zig+9-6
| ... | ... | @@ -75,12 +75,15 @@ global_error_set: std.StringHashMapUnmanaged(u16) = .{}, |
| 75 | 75 | /// previous analysis. |
| 76 | 76 | generation: u32 = 0, |
| 77 | 77 | |
| 78 | have_winmain: bool = false, | |
| 79 | have_wwinmain: bool = false, | |
| 80 | have_winmain_crt_startup: bool = false, | |
| 81 | have_wwinmain_crt_startup: bool = false, | |
| 82 | have_dllmain_crt_startup: bool = false, | |
| 83 | have_c_main: bool = false, | |
| 78 | stage1_flags: packed struct { | |
| 79 | have_winmain: bool = false, | |
| 80 | have_wwinmain: bool = false, | |
| 81 | have_winmain_crt_startup: bool = false, | |
| 82 | have_wwinmain_crt_startup: bool = false, | |
| 83 | have_dllmain_crt_startup: bool = false, | |
| 84 | have_c_main: bool = false, | |
| 85 | reserved: u2 = 0, | |
| 86 | } = .{}, | |
| 84 | 87 | |
| 85 | 88 | pub const Export = struct { |
| 86 | 89 | options: std.builtin.ExportOptions, |
src/link/Coff.zig+8-7
| ... | ... | @@ -943,14 +943,15 @@ fn linkWithLLD(self: *Coff, comp: *Compilation) !void { |
| 943 | 943 | switch (target.os.tag) { |
| 944 | 944 | .windows => { |
| 945 | 945 | if (self.base.options.module) |module| { |
| 946 | if (module.have_dllmain_crt_startup or is_dyn_lib) | |
| 946 | if (module.stage1_flags.have_dllmain_crt_startup or is_dyn_lib) | |
| 947 | 947 | break :blk null; |
| 948 | if (module.have_c_main or self.base.options.is_test or | |
| 949 | module.have_winmain_crt_startup or module.have_wwinmain_crt_startup) | |
| 948 | if (module.stage1_flags.have_c_main or self.base.options.is_test or | |
| 949 | module.stage1_flags.have_winmain_crt_startup or | |
| 950 | module.stage1_flags.have_wwinmain_crt_startup) | |
| 950 | 951 | { |
| 951 | 952 | break :blk .Console; |
| 952 | 953 | } |
| 953 | if (module.have_winmain or module.have_wwinmain) | |
| 954 | if (module.stage1_flags.have_winmain or module.stage1_flags.have_wwinmain) | |
| 954 | 955 | break :blk .Windows; |
| 955 | 956 | } |
| 956 | 957 | }, |
| ... | ... | @@ -1068,11 +1069,11 @@ fn linkWithLLD(self: *Coff, comp: *Compilation) !void { |
| 1068 | 1069 | try argv.append("-NODEFAULTLIB"); |
| 1069 | 1070 | if (!is_lib) { |
| 1070 | 1071 | if (self.base.options.module) |module| { |
| 1071 | if (module.have_winmain) { | |
| 1072 | if (module.stage1_flags.have_winmain) { | |
| 1072 | 1073 | try argv.append("-ENTRY:WinMain"); |
| 1073 | } else if (module.have_wwinmain) { | |
| 1074 | } else if (module.stage1_flags.have_wwinmain) { | |
| 1074 | 1075 | try argv.append("-ENTRY:wWinMain"); |
| 1075 | } else if (module.have_wwinmain_crt_startup) { | |
| 1076 | } else if (module.stage1_flags.have_wwinmain_crt_startup) { | |
| 1076 | 1077 | try argv.append("-ENTRY:wWinMainCRTStartup"); |
| 1077 | 1078 | } else { |
| 1078 | 1079 | try argv.append("-ENTRY:WinMainCRTStartup"); |