Build with zig (#431)

* build with Zig

Add the necessary files to build a static library with Zig.
The build also includes producing execuable that can be cross-compiled

Signed-off-by: inge4pres <fgualazzi@gmail.com>

* ci: add zig build workflow

Signed-off-by: inge4pres <fgualazzi@gmail.com>

* build(zig): aarch64 macros on Linux

* CI: split zig build by platform

Signed-off-by: inge4pres <fgualazzi@gmail.com>

* CI: release script updates version in build.zig.zon

Signed-off-by: inge4pres <fgualazzi@gmail.com>

---------

Signed-off-by: inge4pres <fgualazzi@gmail.com>

.github/workflows/aarch64_linux_zig.yml

@@ -0,0 +1,21 @@
+name: aarch64 Linux Zig
+
+on: [push, pull_request]
+
+jobs:
+  run:
+    strategy:
+      matrix:
+        target:
+          - aarch64-linux-musl
+          - aarch64-linux-gnu
+    runs-on: ubuntu-24.04-arm
+    steps:
+      - uses: actions/checkout@v5
+      - uses: mlugg/setup-zig@v2
+        with:
+          version: latest
+      - name: Build
+        run: zig build -Dtarget=${{ matrix.target }}
+      - name: Run list_cpu_features
+        run: ./zig-out/bin/list_cpu_features --json

.github/workflows/amd64_linux_zig.yml

@@ -0,0 +1,21 @@
+name: amd64 Linux Zig
+
+on: [push, pull_request]
+
+jobs:
+  run:
+    strategy:
+      matrix:
+        target:
+          - x86_64-linux-musl
+          - x86_64-linux-gnu
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - uses: mlugg/setup-zig@v2
+        with:
+          version: latest
+      - name: Build
+        run: zig build -Dtarget=${{ matrix.target }}
+      - name: Run list_cpu_features
+        run: ./zig-out/bin/list_cpu_features --json

.github/workflows/zig.yml

@@ -0,0 +1,13 @@
+name: Zig Check
+
+on: [push, pull_request]
+
+jobs:
+  zig-fmt:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - uses: mlugg/setup-zig@v2
+        with:
+          version: latest
+      - run: zig fmt --check .

.gitignore

@@ -18,3 +18,7 @@ MODULE.bazel.lock
 
 # Per-user bazelrc files
 user.bazelrc
+
+# Zig build artifacts
+.zig-cache
+zig-out

build.zig

@@ -0,0 +1,248 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) void {
+    // Standard target and optimization options
+    const target = b.standardTargetOptions(.{});
+    const optimize = b.standardOptimizeOption(.{});
+
+    // Build options (mirroring CMake options)
+    const build_executable = b.option(bool, "BUILD_EXECUTABLE", "Build list_cpu_features executable") orelse true;
+    const enable_install = b.option(bool, "ENABLE_INSTALL", "Enable install targets") orelse true;
+
+    // Create the cpu_features static library
+    const cpu_features = b.addLibrary(.{
+        .name = "cpu_features",
+        .linkage = .static,
+        .root_module = b.createModule(.{
+            .target = target,
+            .optimize = optimize,
+            .link_libc = true,
+        }),
+    });
+
+    cpu_features.addIncludePath(b.path("include"));
+    cpu_features.addIncludePath(b.path("include/internal"));
+
+    // Public compile definitions
+    cpu_features.root_module.addCMacro("STACK_LINE_READER_BUFFER_SIZE", "1024");
+
+    // Platform-specific defines
+    const os_tag = target.result.os.tag;
+    const cpu_arch = target.result.cpu.arch;
+
+    if (os_tag.isDarwin()) {
+        cpu_features.root_module.addCMacro("HAVE_SYSCTLBYNAME", "1");
+    } else if (os_tag == .linux) {
+        // Linux (including musl) provides getauxval() for hardware capability detection
+        cpu_features.root_module.addCMacro("HAVE_STRONG_GETAUXVAL", "1");
+        cpu_features.root_module.addCMacro("HAVE_DLFCN_H", "1");
+    }
+
+    // Utility sources (always included)
+    const utility_sources = [_][]const u8{
+        "src/filesystem.c",
+        "src/stack_line_reader.c",
+        "src/string_view.c",
+    };
+
+    // Common C flags for all source files
+    const c_flags = [_][]const u8{
+        "-Wall",
+        "-Wextra",
+        "-Wmissing-declarations",
+        "-Wmissing-prototypes",
+        "-Wno-implicit-fallthrough",
+        "-Wno-unused-function",
+        "-Wold-style-definition",
+        "-Wshadow",
+        "-Wsign-compare",
+        "-Wstrict-prototypes",
+        "-std=c99",
+        "-fno-sanitize=undefined", // Disable UBSan for C code with intentional unaligned access
+    };
+
+    for (utility_sources) |source| {
+        cpu_features.addCSourceFile(.{
+            .file = b.path(source),
+            .flags = &c_flags,
+        });
+    }
+
+    // Unix-based hardware detection (for non-x86 Unix platforms)
+    // Note: Android is represented as Linux in Zig's target system
+    if (os_tag != .windows and !cpu_arch.isX86()) {
+        const hwcaps_sources = [_][]const u8{
+            "src/hwcaps.c",
+            "src/hwcaps_linux_or_android.c",
+            "src/hwcaps_freebsd_or_openbsd.c",
+        };
+
+        for (hwcaps_sources) |source| {
+            cpu_features.addCSourceFile(.{
+                .file = b.path(source),
+                .flags = &c_flags,
+            });
+        }
+    }
+
+    // Architecture-specific implementation files
+    // Determine which implementation files to include based on target architecture
+    // Note: Android is represented as Linux in Zig's target system
+    switch (cpu_arch) {
+        .x86, .x86_64 => {
+            // x86/x86_64 architecture
+            const source: ?[]const u8 = if (os_tag == .linux)
+                "src/impl_x86_linux_or_android.c"
+            else if (os_tag.isDarwin())
+                "src/impl_x86_macos.c"
+            else if (os_tag == .windows)
+                "src/impl_x86_windows.c"
+            else if (os_tag == .freebsd)
+                "src/impl_x86_freebsd.c"
+            else
+                null;
+
+            if (source) |s| {
+                cpu_features.addCSourceFile(.{
+                    .file = b.path(s),
+                    .flags = &c_flags,
+                });
+            }
+        },
+        .aarch64, .aarch64_be => {
+            // AArch64 architecture - always needs cpuid
+            cpu_features.addCSourceFile(.{
+                .file = b.path("src/impl_aarch64_cpuid.c"),
+                .flags = &c_flags,
+            });
+
+            const source: ?[]const u8 = if (os_tag == .linux)
+                "src/impl_aarch64_linux_or_android.c"
+            else if (os_tag.isDarwin())
+                "src/impl_aarch64_macos_or_iphone.c"
+            else if (os_tag == .windows)
+                "src/impl_aarch64_windows.c"
+            else if (os_tag == .freebsd or os_tag == .openbsd)
+                "src/impl_aarch64_freebsd_or_openbsd.c"
+            else
+                null;
+
+            if (source) |s| {
+                cpu_features.addCSourceFile(.{
+                    .file = b.path(s),
+                    .flags = &c_flags,
+                });
+            }
+        },
+        .arm, .armeb, .thumb, .thumbeb => {
+            // ARM (32-bit) architecture
+            if (os_tag == .linux) {
+                cpu_features.addCSourceFile(.{
+                    .file = b.path("src/impl_arm_linux_or_android.c"),
+                    .flags = &c_flags,
+                });
+            }
+        },
+        .mips, .mipsel, .mips64, .mips64el => {
+            // MIPS architecture
+            if (os_tag == .linux) {
+                cpu_features.addCSourceFile(.{
+                    .file = b.path("src/impl_mips_linux_or_android.c"),
+                    .flags = &c_flags,
+                });
+            }
+        },
+        .powerpc, .powerpcle, .powerpc64, .powerpc64le => {
+            // PowerPC architecture
+            if (os_tag == .linux) {
+                cpu_features.addCSourceFile(.{
+                    .file = b.path("src/impl_ppc_linux.c"),
+                    .flags = &c_flags,
+                });
+            }
+        },
+        .riscv32, .riscv64 => {
+            // RISC-V architecture
+            if (os_tag == .linux) {
+                cpu_features.addCSourceFile(.{
+                    .file = b.path("src/impl_riscv_linux.c"),
+                    .flags = &c_flags,
+                });
+            }
+        },
+        .s390x => {
+            // s390x architecture
+            if (os_tag == .linux) {
+                cpu_features.addCSourceFile(.{
+                    .file = b.path("src/impl_s390x_linux.c"),
+                    .flags = &c_flags,
+                });
+            }
+        },
+        .loongarch64 => {
+            // LoongArch architecture
+            if (os_tag == .linux) {
+                cpu_features.addCSourceFile(.{
+                    .file = b.path("src/impl_loongarch_linux.c"),
+                    .flags = &c_flags,
+                });
+            }
+        },
+        else => {
+            std.debug.print("Warning: Unsupported architecture {s}\n", .{@tagName(cpu_arch)});
+        },
+    }
+
+    // Link against dl library on Unix-like systems
+    if (os_tag != .windows and os_tag != .wasi) {
+        cpu_features.linkSystemLibrary("dl");
+    }
+
+    // Install the library if enabled
+    if (enable_install) {
+        b.installArtifact(cpu_features);
+
+        // Install headers
+        const install_headers = b.addInstallDirectory(.{
+            .source_dir = b.path("include"),
+            .install_dir = .header,
+            .install_subdir = "cpu_features",
+            .exclude_extensions = &.{},
+        });
+        b.getInstallStep().dependOn(&install_headers.step);
+    }
+
+    // Build list_cpu_features executable if requested
+    if (build_executable) {
+        const list_cpu_features = b.addExecutable(.{
+            .name = "list_cpu_features",
+            .root_module = b.createModule(.{
+                .target = target,
+                .optimize = optimize,
+                .link_libc = true,
+            }),
+        });
+
+        list_cpu_features.linkLibrary(cpu_features);
+        list_cpu_features.addIncludePath(b.path("include"));
+
+        list_cpu_features.addCSourceFile(.{
+            .file = b.path("src/utils/list_cpu_features.c"),
+            .flags = &c_flags,
+        });
+
+        if (enable_install) {
+            b.installArtifact(list_cpu_features);
+        }
+
+        // Add a run step for convenience
+        const run_cmd = b.addRunArtifact(list_cpu_features);
+        run_cmd.step.dependOn(b.getInstallStep());
+        if (b.args) |args| {
+            run_cmd.addArgs(args);
+        }
+
+        const run_step = b.step("run", "Run list_cpu_features");
+        run_step.dependOn(&run_cmd.step);
+    }
+}

build.zig.zon

@@ -0,0 +1,12 @@
+.{
+    .name = .cpu_features,
+    .version = "0.0.1",
+    .minimum_zig_version = "0.15.1",
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+        "src",
+        "include",
+    },
+    .fingerprint = 0xbd52e965d3c20004,
+}

scripts/make_release.sh

@@ -65,6 +65,9 @@ sed -i "s/CpuFeatures VERSION ${LATEST_VERSION}/CpuFeatures VERSION ${VERSION}/g
 echo -e "${ACTION}Modifying MODULE.bazel${NOCOLOR}"
 sed -i "s/CPU_FEATURES_VERSION = \"${LATEST_VERSION}\"/CPU_FEATURES_VERSION = \"${VERSION}\"/g" MODULE.bazel
 
+echo -e "${ACTION}Modifying build.zig.zon${NOCOLOR}" 
+sed -i "s/.version = \"${LATEST_VERSION}\"/.version = \"${VERSION}\"/g" build.zig.zon 
+
 echo -e "${ACTION}Commit new revision${NOCOLOR}"
 git add CMakeLists.txt MODULE.bazel
 git commit -m"Release ${GIT_TAG}"