Add support for wasm32-freestanding

.github/workflows/ci.yml

@@ -69,6 +69,7 @@ jobs:
           zig build -Dtarget=x86_64-freebsd
           zig build -Dtarget=aarch64-freebsd
           zig build -Dtarget=wasm32-wasi
+          zig build -Dtarget=wasm32-freestanding
           zig build -Doptimize=ReleaseFast
           rm -fr zig-cache zig-out
 

build.zig

@@ -10,6 +10,7 @@ const Dir = if (pre_zig17) std.Io.Dir else std.fs.Dir;
 const Io = if (pre_zig17) std.Io else void;
 
 const has_build_root_handle = @hasField(std.Build, "build_root");
+const wasm_libc_path = "builds/wasm32-freestanding";
 
 fn initLibConfig(b: *std.Build, target: std.Build.ResolvedTarget, lib: *Compile) void {
     lib.root_module.link_libc = true;
@@ -103,6 +104,12 @@ fn initLibConfig(b: *std.Build, target: std.Build.ResolvedTarget, lib: *Compile)
             lib.root_module.addCMacro("HAVE_SYS_PARAM_H", "1");
             lib.root_module.addCMacro("HAVE_SYS_RANDOM_H", "1");
         },
+        .freestanding => {
+            if (target.result.cpu.arch.isWasm()) {
+                lib.root_module.link_libc = false;
+                lib.root_module.addSystemIncludePath(b.path(wasm_libc_path ++ "/include"));
+            }
+        },
         .freebsd => {
             lib.root_module.addCMacro("ASM_HIDE_SYMBOL", ".hidden");
             lib.root_module.addCMacro("TLS", "_Thread_local");
@@ -197,11 +204,19 @@ pub fn build(b: *std.Build) !void {
     var build_static = b.option(bool, "static", "Build libsodium as a static library.") orelse true;
     var build_shared = b.option(bool, "shared", "Build libsodium as a shared library.") orelse true;
 
-    const build_tests = b.option(bool, "test", "Build the tests (implies -Dstatic=true)") orelse true;
+    var build_tests = b.option(bool, "test", "Build the tests (implies -Dstatic=true)") orelse true;
+
+    const wasm_freestanding =
+        target.result.cpu.arch.isWasm() and target.result.os.tag == .freestanding;
 
     if (target.result.cpu.arch.isWasm()) {
         build_shared = false;
     }
+    // The test programs need a hosted environment: standard input and output,
+    // and files to read the expected results from.
+    if (wasm_freestanding) {
+        build_tests = false;
+    }
     if (build_tests) {
         build_static = true;
     }
@@ -268,6 +283,13 @@ pub fn build(b: *std.Build) !void {
             "-Werror=vla",
         };
 
+        if (wasm_freestanding) {
+            lib.root_module.addCSourceFiles(.{
+                .files = &.{wasm_libc_path ++ "/libc.c"},
+                .flags = flags,
+            });
+        }
+
         const allocator = heap.page_allocator;
 
         var walker = try src_dir.walk(allocator);

builds/Makefile.am

@@ -84,4 +84,15 @@ EXTRA_DIST = \
 	msvc/vs2026/libsodium/libsodium.xml \
 	msvc/vs2026/libsodium.import.props \
 	msvc/vs2026/libsodium.import.xml \
-	msvc/vs2026/libsodium.sln
+	msvc/vs2026/libsodium.sln \
+	wasm32-freestanding/libc.c \
+	wasm32-freestanding/include/assert.h \
+	wasm32-freestanding/include/errno.h \
+	wasm32-freestanding/include/fcntl.h \
+	wasm32-freestanding/include/stdlib.h \
+	wasm32-freestanding/include/string.h \
+	wasm32-freestanding/include/time.h \
+	wasm32-freestanding/include/unistd.h \
+	wasm32-freestanding/include/sys/stat.h \
+	wasm32-freestanding/include/sys/time.h \
+	wasm32-freestanding/include/sys/types.h

builds/Makefile.in

@@ -389,7 +389,18 @@ EXTRA_DIST = \
 	msvc/vs2026/libsodium/libsodium.xml \
 	msvc/vs2026/libsodium.import.props \
 	msvc/vs2026/libsodium.import.xml \
-	msvc/vs2026/libsodium.sln
+	msvc/vs2026/libsodium.sln \
+	wasm32-freestanding/libc.c \
+	wasm32-freestanding/include/assert.h \
+	wasm32-freestanding/include/errno.h \
+	wasm32-freestanding/include/fcntl.h \
+	wasm32-freestanding/include/stdlib.h \
+	wasm32-freestanding/include/string.h \
+	wasm32-freestanding/include/time.h \
+	wasm32-freestanding/include/unistd.h \
+	wasm32-freestanding/include/sys/stat.h \
+	wasm32-freestanding/include/sys/time.h \
+	wasm32-freestanding/include/sys/types.h
 
 all: all-am
 

builds/wasm32-freestanding/include/assert.h

@@ -0,0 +1,7 @@
+#undef assert
+
+#ifdef NDEBUG
+#define assert(cond) ((void)0)
+#else
+#define assert(cond) ((cond) ? (void)0 : __builtin_trap())
+#endif

builds/wasm32-freestanding/include/errno.h

@@ -0,0 +1,17 @@
+#ifndef _ERRNO_H
+#define _ERRNO_H
+
+extern int errno;
+
+#define EPERM 1
+#define EINTR 4
+#define EIO 5
+#define ENXIO 6
+#define EAGAIN 11
+#define ENOMEM 12
+#define EINVAL 22
+#define EFBIG 27
+#define ERANGE 34
+#define ENOSYS 38
+
+#endif

builds/wasm32-freestanding/include/fcntl.h

@@ -0,0 +1,3 @@
+#ifndef _FCNTL_H
+#define _FCNTL_H
+#endif

builds/wasm32-freestanding/include/stdlib.h

@@ -0,0 +1,17 @@
+#ifndef _STDLIB_H
+#define _STDLIB_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+/* arc4random_buf, malloc and free come from the embedder. */
+
+_Noreturn void abort(void);
+
+uint32_t arc4random(void);
+void arc4random_buf(void *buf, size_t size);
+void *calloc(size_t nmemb, size_t size);
+void free(void *ptr);
+void *malloc(size_t size);
+
+#endif

builds/wasm32-freestanding/include/string.h

@@ -0,0 +1,16 @@
+#ifndef _STRING_H
+#define _STRING_H
+
+#include <stddef.h>
+
+void *memchr(const void *s, int c, size_t n);
+int memcmp(const void *s1, const void *s2, size_t n);
+void *memcpy(void *dest, const void *src, size_t n);
+void *memmove(void *dest, const void *src, size_t n);
+void *memset(void *s, int c, size_t n);
+char *strchr(const char *s, int c);
+size_t strlen(const char *s);
+int strncmp(const char *s1, const char *s2, size_t n);
+char *strrchr(const char *s, int c);
+
+#endif

builds/wasm32-freestanding/include/sys/stat.h

@@ -0,0 +1,3 @@
+#ifndef _SYS_STAT_H
+#define _SYS_STAT_H
+#endif

builds/wasm32-freestanding/include/sys/time.h

@@ -0,0 +1,11 @@
+#ifndef _SYS_TIME_H
+#define _SYS_TIME_H
+
+struct timeval {
+  long long tv_sec;
+  long tv_usec;
+};
+
+int gettimeofday(struct timeval *tv, void *tz);
+
+#endif

builds/wasm32-freestanding/include/sys/types.h

@@ -0,0 +1,8 @@
+#ifndef _SYS_TYPES_H
+#define _SYS_TYPES_H
+
+#include <stddef.h>
+
+typedef ptrdiff_t ssize_t;
+
+#endif

builds/wasm32-freestanding/include/time.h

@@ -0,0 +1,3 @@
+#ifndef _TIME_H
+#define _TIME_H
+#endif

builds/wasm32-freestanding/include/unistd.h

@@ -0,0 +1,3 @@
+#ifndef _UNISTD_H
+#define _UNISTD_H
+#endif

builds/wasm32-freestanding/libc.c

@@ -0,0 +1,94 @@
+#include <stddef.h>
+#include <stdint.h>
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+int errno;
+
+void *calloc(size_t nmemb, size_t size) {
+    void *ptr;
+
+    if (nmemb > (size_t)0U && size > SIZE_MAX / nmemb) {
+        return NULL;
+    }
+    if ((ptr = malloc(nmemb * size)) != NULL) {
+        memset(ptr, 0, nmemb * size);
+    }
+    return ptr;
+}
+
+_Noreturn void abort(void) {
+    __builtin_trap();
+}
+
+uint32_t arc4random(void) {
+    uint32_t r;
+
+    arc4random_buf(&r, sizeof r);
+
+    return r;
+}
+
+void *memchr(const void *s, int c, size_t n) {
+    const unsigned char *p = (const unsigned char *)s;
+
+    while (n-- > (size_t)0U) {
+        if (*p == (unsigned char) c) {
+            return (void *) (uintptr_t) p;
+        }
+        p++;
+    }
+    return NULL;
+}
+
+size_t strlen(const char *s) {
+    const char *p = s;
+
+    while (*p != 0) {
+        p++;
+    }
+    return (size_t)(p - s);
+}
+
+int strncmp(const char *s1, const char *s2, size_t n) {
+    while (n-- > (size_t) 0U) {
+        if (*s1 != *s2) {
+            return (int) (unsigned char) *s1 - (int) (unsigned char) *s2;
+        }
+        if (*s1 == 0) {
+            break;
+        }
+        s1++;
+        s2++;
+    }
+    return 0;
+}
+
+char *strchr(const char *s, int c) {
+    for (;;) {
+        if (*s == (char) c) {
+            return (char *) (uintptr_t) s;
+        }
+        if (*s == 0) {
+            return NULL;
+        }
+        s++;
+    }
+}
+
+char *strrchr(const char *s, int c) {
+    const char *found = NULL;
+
+    for (;;) {
+        if (*s == (char) c) {
+            found = s;
+        }
+        if (*s == 0) {
+            break;
+        }
+        s++;
+    }
+    return (char *) (uintptr_t) found;
+}

src/libsodium/crypto_pwhash/argon2/argon2-core.c

@@ -12,8 +12,8 @@
  */
 
 #include <errno.h>
+#include <stddef.h>
 #include <stdint.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 

src/libsodium/crypto_pwhash/argon2/argon2-encoding.c

@@ -2,7 +2,7 @@
 #include "argon2-core.h"
 #include "utils.h"
 #include <limits.h>
-#include <stdio.h>
+#include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
 

src/libsodium/crypto_pwhash/argon2/argon2.c

@@ -12,8 +12,8 @@
  */
 
 #include <limits.h>
+#include <stddef.h>
 #include <stdint.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 

src/libsodium/include/sodium/crypto_onetimeauth_poly1305.h

@@ -1,8 +1,8 @@
 #ifndef crypto_onetimeauth_poly1305_H
 #define crypto_onetimeauth_poly1305_H
 
+#include <stddef.h>
 #include <stdint.h>
-#include <stdio.h>
 #include <stdlib.h>
 
 #include <sys/types.h>

src/libsodium/randombytes/internal/randombytes_internal_random.c

@@ -73,7 +73,8 @@ BOOLEAN NTAPI RtlGenRandom(PVOID RandomBuffer, ULONG RandomBufferLength);
 
 #define INTERNAL_RANDOM_BLOCK_SIZE crypto_core_hchacha20_OUTPUTBYTES
 
-#if defined(__OpenBSD__) || defined(__CloudABI__) || defined(__wasi__)
+#if defined(__OpenBSD__) || defined(__CloudABI__) || \
+    (defined(__wasm__) && !defined(__EMSCRIPTEN__))
 # define HAVE_SAFE_ARC4RANDOM 1
 #endif
 #if defined(__CloudABI__) || defined(__wasm__)
@@ -503,7 +504,7 @@ randombytes_internal_random_close(void)
     if (global.getrandom_available != 0) {
         ret = 0;
     }
-# elif !defined(NONEXISTENT_DEV_RANDOM) && defined(HAVE_SAFE_ARC4RANDOM)
+# elif defined(HAVE_SAFE_ARC4RANDOM)
     ret = 0;
 # else
     if (global.random_data_source_fd != -1 &&

src/libsodium/randombytes/sysrandom/randombytes_sysrandom.c

@@ -75,7 +75,8 @@ BOOLEAN NTAPI RtlGenRandom(PVOID RandomBuffer, ULONG RandomBufferLength);
 # pragma comment(lib, "advapi32.lib")
 #endif
 
-#if defined(__OpenBSD__) || defined(__CloudABI__) || defined(__wasi__)
+#if defined(__OpenBSD__) || defined(__CloudABI__) || \
+    (defined(__wasm__) && !defined(__EMSCRIPTEN__))
 # define HAVE_SAFE_ARC4RANDOM 1
 #endif