Fix libc conformance gaps

Author: ItsMeSamey

README.md

@@ -10,6 +10,11 @@
   - macOS targets executed through `darling`
   - Windows GNU targets executed through `wineconsole`
 - `zig build conformance` passes on the same matrix.
+- The in-tree parity runner compares ziglibc and the platform libc for the validated matrix on:
+  - process execution (`system`, `popen`, `pclose`)
+  - signal/sigaction basics
+  - `strtol`/`strtod` no-digit behavior
+  - `setitimer`, `select`, `pselect`, and `utimes` where the platform libc exposes them
 
 ## Repository Setup
 
@@ -96,5 +101,6 @@ zig cc \
 
 ## Notes
 
-- The implementation is still incomplete in some non-conformance areas.
+- The validated Linux/macOS/Windows matrix is green for both `test` and `conformance`.
+- Remaining `ENOSYS` paths are scoped to unsupported targets or unsupported OS-specific features outside that matrix.
 - The build will fail fast if required submodules are missing rather than cloning repositories during `zig build`.

build.zig

@@ -157,8 +157,8 @@ pub fn build(b: *std.Build) void {
         .optimize = optimize,
     });
     b.step("libc-full-shared", "").dependOn(&installArtifact(b, libc_full_shared).step);
-    // TODO: create a specs file?
-    //       you can add -specs=file to the gcc command line to override values in the spec
+    // GCC specs generation is not wired into the build yet.
+    // You can still pass `-specs=file` manually to override GCC defaults.
 
     const libc_only_std_static = libcbuild.addLibc(b, .{
         .variant = .only_std,
@@ -236,6 +236,14 @@ pub fn build(b: *std.Build) void {
         run_step.addCheck(.{ .expect_stdout_exact = "Success!\n" });
         test_step.dependOn(&run_step.step);
     }
+    const header_conformance_run = blk: {
+        const exe = addTest("header_conformance", b, target, optimize, libc_only_std_static, zig_start);
+        addPosix(exe, libc_only_posix);
+        const run_step = addRunArtifactCompat(b, exe);
+        run_step.addCheck(.{ .expect_stdout_exact = "Success!\n" });
+        test_step.dependOn(&run_step.step);
+        break :blk run_step;
+    };
     {
         const exe = addTest("signal_extensive", b, target, optimize, libc_only_std_static, zig_start);
         addPosix(exe, libc_only_posix);
@@ -346,15 +354,16 @@ pub fn build(b: *std.Build) void {
         }
     }
 
-    {
+    const parity_run = blk: {
         const system_exe = addSystemParityProbe(b, target, optimize);
         const zig_exe = addZigParityProbe(b, target, optimize, libc_only_std_static, zig_start, libc_only_posix);
         const run_step = addRunArtifactCompat(b, parity_env_exe);
         addArtifactArgCompat(run_step, b, system_exe);
         addArtifactArgCompat(run_step, b, zig_exe);
         run_step.addCheck(.{ .expect_stdout_exact = "Success!\n" });
         test_step.dependOn(&run_step.step);
-    }
+        break :blk run_step;
+    };
 
     if (supportsSetjmp(target.result)) {
         const exe = addTest("jmp", b, target, optimize, libc_only_std_static, zig_start);
@@ -406,6 +415,8 @@ pub fn build(b: *std.Build) void {
         conformance_step.dependOn(posix_test_suite_step);
         conformance_step.dependOn(austin_group_tests_step);
     }
+    conformance_step.dependOn(&header_conformance_run.step);
+    conformance_step.dependOn(&parity_run.step);
     _ = addLua(b, target, optimize, libc_only_std_static, libc_only_posix, zig_start);
     _ = addCmph(b, target, optimize, libc_only_std_static, zig_start, libc_only_posix);
     _ = addYacc(b, target, optimize, libc_only_std_static, zig_start, libc_only_posix);
@@ -474,7 +485,7 @@ fn addTest(
     exe.addIncludePath(lazyPath(b, "inc" ++ std.fs.path.sep_str ++ "posix"));
     exe.linkLibrary(libc_only_std_static);
     exe.linkLibrary(zig_start);
-    // TODO: should libc_only_std_static and zig_start be able to add library dependencies?
+    // These static artifacts do not currently propagate system-library dependencies.
     if (target.result.os.tag == .windows) {
         exe.linkSystemLibrary("ntdll");
         exe.linkSystemLibrary("kernel32");
@@ -486,13 +497,19 @@ const ParityFeatures = struct {
     sigaction: bool,
     setitimer: bool,
     select: bool,
+    strsignal: bool,
+    pselect: bool,
+    utimes: bool,
 };
 
 fn parityFeaturesFor(target: std.Target) ParityFeatures {
     return .{
         .sigaction = target.os.tag != .windows and target.os.tag != .wasi,
         .setitimer = target.os.tag == .linux or target.os.tag.isDarwin(),
         .select = target.os.tag == .linux or target.os.tag.isDarwin(),
+        .strsignal = target.os.tag == .linux or target.os.tag.isDarwin(),
+        .pselect = target.os.tag == .linux or target.os.tag.isDarwin(),
+        .utimes = target.os.tag == .linux or target.os.tag.isDarwin(),
     };
 }
 
@@ -512,6 +529,9 @@ fn addParityProbeCommon(
         b.fmt("-DLIBC_PARITY_HAVE_SIGACTION={d}", .{@intFromBool(parity.sigaction)}),
         b.fmt("-DLIBC_PARITY_HAVE_SETITIMER={d}", .{@intFromBool(parity.setitimer)}),
         b.fmt("-DLIBC_PARITY_HAVE_SELECT={d}", .{@intFromBool(parity.select)}),
+        b.fmt("-DLIBC_PARITY_HAVE_STRSIGNAL={d}", .{@intFromBool(parity.strsignal)}),
+        b.fmt("-DLIBC_PARITY_HAVE_PSELECT={d}", .{@intFromBool(parity.pselect)}),
+        b.fmt("-DLIBC_PARITY_HAVE_UTIMES={d}", .{@intFromBool(parity.utimes)}),
     };
     addCSourceFilesCompat(exe, &.{"test" ++ std.fs.path.sep_str ++ "libc_parity.c"}, flags[0..]);
     if (target.result.os.tag == .windows) {
@@ -716,7 +736,7 @@ fn addLibcTest(
         exe.linkLibrary(libc_only_std_static);
         exe.linkLibrary(zig_start);
         exe.linkLibrary(libc_only_posix);
-        // TODO: should libc_only_std_static and zig_start be able to add library dependencies?
+        // These static artifacts do not currently propagate system-library dependencies.
         if (target.result.os.tag == .windows) {
             exe.linkSystemLibrary("ntdll");
             exe.linkSystemLibrary("kernel32");
@@ -761,7 +781,7 @@ fn addTinyRegexCTests(
         exe.linkLibrary(libc_only_std_static);
         exe.linkLibrary(zig_start);
         exe.linkLibrary(zig_posix);
-        // TODO: should libc_only_std_static and zig_start be able to add library dependencies?
+        // These static artifacts do not currently propagate system-library dependencies.
         if (target.result.os.tag == .windows) {
             exe.linkSystemLibrary("ntdll");
             exe.linkSystemLibrary("kernel32");
@@ -823,7 +843,7 @@ fn addLua(
     lua_exe.linkLibrary(libc_only_std_static);
     lua_exe.linkLibrary(libc_only_posix);
     lua_exe.linkLibrary(zig_start);
-    // TODO: should libc_only_std_static and zig_start be able to add library dependencies?
+    // These static artifacts do not currently propagate system-library dependencies.
     if (target.result.os.tag == .windows) {
         lua_exe.addIncludePath(lazyPath(b, "inc/win32"));
         lua_exe.linkSystemLibrary("ntdll");
@@ -895,7 +915,7 @@ fn addCmph(
     exe.linkLibrary(libc_only_std_static);
     exe.linkLibrary(zig_start);
     exe.linkLibrary(zig_posix);
-    // TODO: should libc_only_std_static and zig_start be able to add library dependencies?
+    // These static artifacts do not currently propagate system-library dependencies.
     if (target.result.os.tag == .windows) {
         exe.linkSystemLibrary("ntdll");
         exe.linkSystemLibrary("kernel32");
@@ -970,7 +990,7 @@ fn addYacc(
     exe.linkLibrary(libc_only_std_static);
     exe.linkLibrary(zig_start);
     exe.linkLibrary(zig_posix);
-    // TODO: should libc_only_std_static and zig_start be able to add library dependencies?
+    // These static artifacts do not currently propagate system-library dependencies.
     if (target.result.os.tag == .windows) {
         exe.linkSystemLibrary("ntdll");
         exe.linkSystemLibrary("kernel32");
@@ -1025,7 +1045,7 @@ fn addYabfc(
     exe.linkLibrary(zig_start);
     exe.linkLibrary(zig_posix);
     exe.linkLibrary(zig_gnu);
-    // TODO: should libc_only_std_static and zig_start be able to add library dependencies?
+    // These static artifacts do not currently propagate system-library dependencies.
     if (target.result.os.tag == .windows) {
         exe.linkSystemLibrary("ntdll");
         exe.linkSystemLibrary("kernel32");
@@ -1080,7 +1100,7 @@ fn addSecretGame(
     exe.linkLibrary(zig_start);
     exe.linkLibrary(zig_posix);
     exe.linkLibrary(zig_gnu);
-    // TODO: should libc_only_std_static and zig_start be able to add library dependencies?
+    // These static artifacts do not currently propagate system-library dependencies.
     if (target.result.os.tag == .windows) {
         exe.linkSystemLibrary("ntdll");
         exe.linkSystemLibrary("kernel32");

docs/CONFORMANCE.md

@@ -41,3 +41,16 @@ zig build conformance
 zig build conformance -Dtarget=x86_64-macos
 zig build conformance -Dtarget=x86_64-windows-gnu
 ```
+
+## Parity Coverage
+
+The normal `zig build test` step also runs an in-repo parity probe that compares ziglibc against the host platform libc for supported APIs on the selected target. The current parity probe covers:
+
+- `system`, `popen`, `pclose`
+- `signal`, `sigaction`, `strsignal`
+- `strtol` and `strtod` no-digit edge cases
+- `setitimer`
+- `select` and `pselect`
+- `utimes`
+
+Some probes remain target-gated because the corresponding API is not exposed uniformly by every system libc, especially on Windows.

inc/gnu/argp.h

@@ -23,7 +23,9 @@ struct argp_option {
 #define ARGP_KEY_ARGS 0x1000006
 #define ARGP_KEY_NO_ARGS 0x1000002
 
-#define ARGP_ERR_UNKNOWN 999 /* TODO: what to put here? */
+#include "../libc/errno.h"
+
+#define ARGP_ERR_UNKNOWN E2BIG
 
 struct argp_state {
     int argc;

inc/libc/assert.h

@@ -4,9 +4,9 @@
 #ifdef NDEBUG
     #define assert(ignore) ((void)0)
 #else
+    #include "private/noreturn.h"
     #define assert(expression) ((void)((expression) || (__zassert_fail(#expression, __FILE__, __LINE__, __func__),0)))
-    // TODO: mark __assert_fail as noreturn
-    void __zassert_fail(const char *expression, const char *file, int line, const char *func);
+    __znoreturn void __zassert_fail(const char *expression, const char *file, int line, const char *func);
 #endif
 
 #endif /* _ASSERT_H */

inc/libc/errno.h

@@ -4,28 +4,46 @@
 extern int errno;
 
 #if __STDC_VERSION__ >= 199901L
-    /* TODO: these can change based on platform */
-    #define EILSEQ 84
+    #ifdef _WIN32
+        #define EILSEQ 42
+    #elif defined(__APPLE__)
+        #define EILSEQ 92
+    #else
+        #define EILSEQ 84
+    #endif
 #endif
 
 /* NOTE: these are defined by posix */
 #if 1
-    /* TODO: these can change based on platform, for now I'm just worrying about x86 */
     #define EPERM 1
     #define ENOENT 2
     #define EINTR 4
-    #define EAGAIN 11
+    #ifdef __APPLE__
+        #define EAGAIN 35
+    #else
+        #define EAGAIN 11
+    #endif
     #define ENOMEM 12
     #define EACCES 13
     #define EEXIST 17
     #define EINVAL 22
-    #define ENOSYS 38
     #define ENOTTY 25
     #define EPIPE 32
     #define EDOM 33
     #define ERANGE 34
-    #define EWOULDBLOCK 140
-    #define ECONNREFUSED 111
+    #ifdef _WIN32
+        #define ENOSYS 40
+        #define EWOULDBLOCK 140
+        #define ECONNREFUSED 107
+    #elif defined(__APPLE__)
+        #define ENOSYS 78
+        #define EWOULDBLOCK EAGAIN
+        #define ECONNREFUSED 61
+    #else
+        #define ENOSYS 38
+        #define EWOULDBLOCK EAGAIN
+        #define ECONNREFUSED 111
+    #endif
 #endif
 
 #endif /* _ERRNO_H */

inc/libc/float.h

@@ -3,40 +3,38 @@
 
 #include "private/limits_and_float_shared.h"
 
-// TODO: I pulled these values from the C Standard, I need to look into them to see what
-//       the values should actually be
-#define DBL_DIG           10
-#define DBL_EPSILON       1E-9
-#define DBL_MANT_DIG      53
-#define DBL_MAX           1E+37
-#define DBL_MAX_10_EXP    37
-#define DBL_MAX_EXP       TODO_DEFINE_DBL_MAX_EXP
-#define DBL_MIN           1E-37
-#define DBL_MIN_10_EXP    -37
-#define DBL_MIN_EXP       TODO_DEFINE_DBL_MIN_EXP
-#define FLT_DIG           6
-#define FLT_EPSILON       1E-5
-#define FLT_MANT_DIG      TODO_DEFINE_FLT_MANT_DIG
-#define FLT_MAX           1E+37
-#define FLT_MAX_10_EXP    37
-#define FLT_MAX_EXP       TODO_DEFINE_FLT_MAX_EXP
-#define FLT_MIN           1E-37
-#define FLT_MIN_10_EXP    -37
-#define FLT_MIN_EXP       TODO_DEFINE_FLT_MIN_EXP
-#define FLT_RADIX         2
-#define FLT_ROUNDS        TODO_DEFINE_FLT_ROUNDS
-#define LDBL_DIG          10
-#define LDBL_EPSILON      1E-9
-#define LDBL_MANT_DIG     TODO_DEFINE_LDBL_MANT_DIG
-#define LDBL_MAX          1E+37
-#define LDBL_MAX_10_EXP   37
-#define LDBL_MAX_EXP      TODO_DEFINE_LDBL_MAX_EXP
-#define LDBL_MIN          1E-37
-#define LDBL_MIN_10_EXP   -37
-#define LDBL_MIN_EXP      TODO_DEFINE_LDBL_MIN_EXP
+#define DBL_DIG           __DBL_DIG__
+#define DBL_EPSILON       __DBL_EPSILON__
+#define DBL_MANT_DIG      __DBL_MANT_DIG__
+#define DBL_MAX           __DBL_MAX__
+#define DBL_MAX_10_EXP    __DBL_MAX_10_EXP__
+#define DBL_MAX_EXP       __DBL_MAX_EXP__
+#define DBL_MIN           __DBL_MIN__
+#define DBL_MIN_10_EXP    __DBL_MIN_10_EXP__
+#define DBL_MIN_EXP       __DBL_MIN_EXP__
+#define FLT_DIG           __FLT_DIG__
+#define FLT_EPSILON       __FLT_EPSILON__
+#define FLT_MANT_DIG      __FLT_MANT_DIG__
+#define FLT_MAX           __FLT_MAX__
+#define FLT_MAX_10_EXP    __FLT_MAX_10_EXP__
+#define FLT_MAX_EXP       __FLT_MAX_EXP__
+#define FLT_MIN           __FLT_MIN__
+#define FLT_MIN_10_EXP    __FLT_MIN_10_EXP__
+#define FLT_MIN_EXP       __FLT_MIN_EXP__
+#define FLT_RADIX         __FLT_RADIX__
+#define FLT_ROUNDS        1
+#define LDBL_DIG          __LDBL_DIG__
+#define LDBL_EPSILON      __LDBL_EPSILON__
+#define LDBL_MANT_DIG     __LDBL_MANT_DIG__
+#define LDBL_MAX          __LDBL_MAX__
+#define LDBL_MAX_10_EXP   __LDBL_MAX_10_EXP__
+#define LDBL_MAX_EXP      __LDBL_MAX_EXP__
+#define LDBL_MIN          __LDBL_MIN__
+#define LDBL_MIN_10_EXP   __LDBL_MIN_10_EXP__
+#define LDBL_MIN_EXP      __LDBL_MIN_EXP__
 
 #if __STDC_VERSION__ >= 199901L
-    #define FLT_EVAL_METHOD TODO_DEFINE_FLT_EVAL_METHOD
+    #define FLT_EVAL_METHOD __FLT_EVAL_METHOD__
 #endif
 
 #endif /* _FLOAT_H */

inc/libc/limits.h

@@ -4,14 +4,15 @@
 #include "private/limits_and_float_shared.h"
 
 #if __STDC_VERSION__ >= 199901L
-    /* assume 64-bit long long for now */
-    #define LLONG_MAX  9223372036854775807
-    #define LLONG_MIN -9223372036854775807
-    #define ULLONG_MAX 18446744073709551615
+    #define LLONG_MAX __LONG_LONG_MAX__
+    #define LLONG_MIN (-__LONG_LONG_MAX__ - 1LL)
+    #define ULLONG_MAX (__LONG_LONG_MAX__ * 2ULL + 1ULL)
 #endif
 
-/* TODO: fixme */
-/* TODO: I think PATH_MAX is supposed to be in "linux/limits.h" rather than "limits.h"?? */
-#define PATH_MAX 1024
+#ifdef _WIN32
+    #define PATH_MAX 260
+#else
+    #define PATH_MAX 4096
+#endif
 
 #endif /* _LIMITS_H */

inc/libc/private/noreturn.h

@@ -1,7 +1,14 @@
 #ifndef _NORETURN_H_
 #define _NORETURN_H_
 
-// TODO: change this depending on toolchain
-#define __znoreturn _Noreturn
+#if defined(__cplusplus)
+    #define __znoreturn [[noreturn]]
+#elif __STDC_VERSION__ >= 201112L
+    #define __znoreturn _Noreturn
+#elif defined(__GNUC__) || defined(__clang__)
+    #define __znoreturn __attribute__((__noreturn__))
+#else
+    #define __znoreturn
+#endif
 
 #endif /* _NORETURN_H_ */

inc/libc/private/uint64_t.h

@@ -2,7 +2,6 @@
 #define _UINT64_T_H
 
 typedef unsigned long long uint64_t;
-// TODO: define this correctly
-#define UINT64_C(c) c ## ULL
+#define UINT64_C(c) c##ULL
 
 #endif /* _UINT64_T_H */