thirdparty.zstd: upgrade to v1.5.7 release, add the local changes to a reusable .patch file (#24611)

thirdparty/zstd/fix.md

@@ -1,28 +1,9 @@
-1. replace all `abs64` with `zstd_abs64`.
+1. Get `zstd` from https://github.com/facebook/zstd/releases
+2. Download and extract `zstd`, and goto `zstd-1.5.7/build/single_file_libs/`, run `create_single_file_library.sh`
+3. Copy generated `zstd.c` to v's `thirdparty/zstd/zstd-1.5.7.c`
+4. In `thirdparty/zstd/`, apply patch by `patch -p0 -i zstd_v.patch -o zstd.c`
+5. Remove `zstd-1.5.7.c`
 
-2. add following at header of the file:
+You can generate a new patch by `diff -u zstd-1.5.7.c zstd_modified.c > zstd_custom.patch`
-#if defined(__TINYC__)
-#if defined(_WIN32)
-#undef ZSTD_MULTITHREAD
-#define ZSTD_NO_INTRINSICS
-#endif
-#if defined(__arm__) || defined(__aarch64__)
-#define NO_PREFETCH
-#endif
-#endif
-
-3. replace `qsort_r` with `qsort`, as there is no way detect __MUSL__ macro. add following at header of the file:
-#ifndef ZDICT_QSORT
-# if defined(__APPLE__)
-#   define ZDICT_QSORT ZDICT_QSORT_APPLE /* uses qsort_r() with a different order for parameters */
-# elif defined(__GLIBC__)
-#   define ZDICT_QSORT ZDICT_QSORT_GNU /* uses qsort_r() */
-# elif defined(_WIN32) && defined(_MSC_VER)
-#   define ZDICT_QSORT ZDICT_QSORT_MSVC /* uses qsort_s() with a different order for parameters */
-# elif defined(STDC_LIB_EXT1) && (STDC_LIB_EXT1 > 0) /* C11 Annex K */
-#   define ZDICT_QSORT ZDICT_QSORT_C11 /* uses qsort_s() */
-# else
-#   define ZDICT_QSORT ZDICT_QSORT_C90 /* uses standard qsort() which is not re-entrant (requires global variable) */
-# endif
-#endif
 
+BTW, patch is between `/* >> v_patch start */` and `/* << v_patch end */` mostly.

thirdparty/zstd/zstd_v.patch

@@ -0,0 +1,87 @@
+--- zstd-1.5.7.c	2025-05-30 16:39:46.374765970 +0800
++++ zstd.c	2025-05-30 21:02:30.710831777 +0800
+@@ -50,6 +50,27 @@
+ /* TODO: Can't amalgamate ASM function */
+ #define ZSTD_DISABLE_ASM 1
+ 
++/* >> v_patch start */
++#if defined(__TINYC__)
++
++#if defined(_WIN32)
++#undef ZSTD_MULTITHREAD
++#define ZSTD_NO_INTRINSICS
++#endif
++
++/* tcc doesn't support ARM asm */
++#if defined(__arm__) || defined(__aarch64__)
++#define NO_PREFETCH
++#endif
++
++#if defined(__FreeBSD__) || defined(__OpenBSD__)
++/* tcc on FreeBSD/OpenBSD define __GNUC__, but it can't work here */
++#undef __GNUC__
++#endif
++
++#endif /* __TINYC__ */
++/* << v_patch end */
++
+ /* Include zstd_deps.h first with all the options we need enabled. */
+ #define ZSTD_DEPS_NEED_MALLOC
+ #define ZSTD_DEPS_NEED_MATH64
+@@ -22353,7 +22374,7 @@
+ ZSTD_GEN_RECORD_FINGERPRINT(43, 8)
+ 
+ 
+-static U64 abs64(S64 s64) { return (U64)((s64 < 0) ? -s64 : s64); }
++static U64 zstd_abs64(S64 s64) { return (U64)((s64 < 0) ? -s64 : s64); }
+ 
+ static U64 fpDistance(const Fingerprint* fp1, const Fingerprint* fp2, unsigned hashLog)
+ {
+@@ -22362,7 +22383,7 @@
+     assert(hashLog <= HASHLOG_MAX);
+     for (n = 0; n < ((size_t)1 << hashLog); n++) {
+         distance +=
+-            abs64((S64)fp1->events[n] * (S64)fp2->nbEvents - (S64)fp2->events[n] * (S64)fp1->nbEvents);
++            zstd_abs64((S64)fp1->events[n] * (S64)fp2->nbEvents - (S64)fp2->events[n] * (S64)fp1->nbEvents);
+     }
+     return distance;
+ }
+@@ -22482,7 +22503,7 @@
+     {   U64 const distFromBegin = fpDistance(&fpstats->pastEvents, middleEvents, 8);
+         U64 const distFromEnd = fpDistance(&fpstats->newEvents, middleEvents, 8);
+         U64 const minDistance = SEGMENT_SIZE * SEGMENT_SIZE / 3;
+-        if (abs64((S64)distFromBegin - (S64)distFromEnd) < minDistance)
++        if (zstd_abs64((S64)distFromBegin - (S64)distFromEnd) < minDistance)
+             return 64 KB;
+         return (distFromBegin > distFromEnd) ? 32 KB : 96 KB;
+     }
+@@ -47318,8 +47339,9 @@
+   unsigned d;
+ } COVER_ctx_t;
+ 
+-#if !defined(_GNU_SOURCE) && !defined(__APPLE__) && !defined(_MSC_VER)
+-/* C90 only offers qsort() that needs a global context. */
++#if defined(ZSTD_USE_C90_QSORT) \
++  || (!defined(_GNU_SOURCE) && !defined(__APPLE__) && !defined(_MSC_VER))
++/* Use global context for non-reentrant sort functions */
+ static COVER_ctx_t *g_coverCtx = NULL;
+ #endif
+ 
+@@ -47405,7 +47427,7 @@
+     qsort_r(ctx->suffix, ctx->suffixSize, sizeof(U32),
+             ctx,
+             (ctx->d <= 8 ? &COVER_strict_cmp8 : &COVER_strict_cmp));
+-#elif defined(_GNU_SOURCE)
++#elif defined(_GNU_SOURCE) && !defined(ZSTD_USE_C90_QSORT)
+     qsort_r(ctx->suffix, ctx->suffixSize, sizeof(U32),
+             (ctx->d <= 8 ? &COVER_strict_cmp8 : &COVER_strict_cmp),
+             ctx);
+@@ -47419,7 +47441,7 @@
+           (ctx->d <= 8 ? &COVER_strict_cmp8 : &COVER_strict_cmp));
+ #else /* C90 fallback.*/
+     g_coverCtx = ctx;
+-    /* TODO(cavalcanti): implement a reentrant qsort() when is not available. */
++    /* TODO(cavalcanti): implement a reentrant qsort() when _r is not available. */
+     qsort(ctx->suffix, ctx->suffixSize, sizeof(U32),
+           (ctx->d <= 8 ? &COVER_strict_cmp8 : &COVER_strict_cmp));
+ #endif

vlib/compress/zstd/zstd.c.v

@@ -365,7 +365,7 @@ pub fn version_number() u32 {
 	return C.ZSTD_versionNumber()
 }
 
-// version_string returns runtime library version, like "1.5.8".
+// version_string returns runtime library version, like "1.5.7".
 pub fn version_string() string {
 	return unsafe { tos_clone(C.ZSTD_versionString()) }
 }

vlib/compress/zstd/zstd_d_musl.c.v

@@ -0,0 +1,4 @@
+module zstd
+
+// As MUSL has no `qsort_r()` as GLIBC, so fallback to `qsort()`
+#flag -DZSTD_USE_C90_QSORT