Add runtime compatibility patch set

Add an LLVM 22.1.6 runtimes patch for building libc++, libc++abi, and llvm-libgcc together. The patch lets libc++abi accept llvm-libgcc as the provider of the LLVM unwinder, keeps the libgcc_s version script private to libunwind so it does not leak into libc++abi links, and adds an opt-out for building compiler-rt inside llvm-libgcc when an exported external builtins archive is available. Add libxcrypt patches for current Clang/glibc builds: avoid treating Clang as old GCC in yescrypt assembly selection and adjust yescrypt strchr call sites for the newer glibc const-correct prototype behavior. Add a mandoc 1.14.6 patch for zstd-compressed manual pages, including configure checks, linker flags, documentation, section matching, and decompression handling. Remove the obsolete Perl 5.42.2 LBI patch from the patch set.
2026-05-29 22:23:57 -05:00
parent 90076fecfc
commit accdf3d3fb
5 changed files with 666 additions and 188 deletions
@@ -0,0 +1,13 @@
+diff -ruN a/lib/alg-yescrypt-opt.c b/lib/alg-yescrypt-opt.c
+--- a/lib/alg-yescrypt-opt.c	2025-11-05 03:49:40.000000000 -0600
+++ b/lib/alg-yescrypt-opt.c	2026-05-29 16:10:57.694185418 -0500
+@@ -464,7 +464,8 @@
+ #endif
+ 
+ #if defined(__x86_64__) && \
+-    __GNUC__ == 4 && __GNUC_MINOR__ < 6 && !defined(__ICC)
+    __GNUC__ == 4 && __GNUC_MINOR__ < 6 && !defined(__clang__) && \
+    !defined(__ICC)
+ #ifdef __AVX__
+ #define MOVQ "vmovq"
+ #else
@@ -0,0 +1,24 @@
+diff -ruN a/lib/crypt-gost-yescrypt.c b/lib/crypt-gost-yescrypt.c
+--- a/lib/crypt-gost-yescrypt.c	2025-01-03 12:08:44.000000000 -0600
+++ b/lib/crypt-gost-yescrypt.c	2026-05-29 16:07:10.245211533 -0500
+@@ -131,7 +131,7 @@
+   intbuf->outbuf[1] = 'g';
+ 
+   /* extract yescrypt output from "$y$param$salt$output" */
+-  char *hptr = strchr ((const char *) intbuf->retval + 3, '$');
+  char *hptr = strchr (( char *) intbuf->retval + 3, '$');
+   if (!hptr)
+     {
+       errno = EINVAL;
+diff -ruN a/lib/crypt-sm3-yescrypt.c b/lib/crypt-sm3-yescrypt.c
+--- a/lib/crypt-sm3-yescrypt.c	2025-11-05 03:49:40.000000000 -0600
+++ b/lib/crypt-sm3-yescrypt.c	2026-05-29 16:07:10.245128194 -0500
+@@ -136,7 +136,7 @@
+   intbuf->outbuf[3] = '3';
+ 
+   /* extract yescrypt output from "$y$param$salt$output" */
+-  char *hptr = strchr ((const char *) intbuf->retval + 3, '$');
+  char *hptr = strchr (( char *) intbuf->retval + 3, '$');
+   if (!hptr)
+     {
+       errno = EINVAL;
@@ -0,0 +1,169 @@
+diff --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
+index 2b67c59..02124de 100644
+--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
+@@ -53,8 +53,10 @@ option(LIBCXXABI_ENABLE_ASSERTIONS "Enable assertions independent of build mode.
+ option(LIBCXXABI_ENABLE_PEDANTIC "Compile with pedantic enabled." OFF)
+ option(LIBCXXABI_ENABLE_WERROR "Fail and stop if a warning is triggered." OFF)
+ option(LIBCXXABI_USE_LLVM_UNWINDER "Build and use the LLVM unwinder." ON)
+-if (LIBCXXABI_USE_LLVM_UNWINDER AND NOT "libunwind" IN_LIST LLVM_ENABLE_RUNTIMES)
+-  message(FATAL_ERROR "LIBCXXABI_USE_LLVM_UNWINDER is set to ON, but libunwind is not specified in LLVM_ENABLE_RUNTIMES.")
+if (LIBCXXABI_USE_LLVM_UNWINDER AND
+    NOT "libunwind" IN_LIST LLVM_ENABLE_RUNTIMES AND
+    NOT "llvm-libgcc" IN_LIST LLVM_ENABLE_RUNTIMES)
+  message(FATAL_ERROR "LIBCXXABI_USE_LLVM_UNWINDER is set to ON, but neither libunwind nor llvm-libgcc is specified in LLVM_ENABLE_RUNTIMES.")
+ endif()
+ option(LIBCXXABI_ENABLE_STATIC_UNWINDER "Statically link the LLVM unwinder." OFF)
+ option(LIBCXXABI_USE_COMPILER_RT "Use compiler-rt instead of libgcc" OFF)
+diff --git a/llvm-libgcc/CMakeLists.txt b/llvm-libgcc/CMakeLists.txt
+index 47208fc..9f31762 100644
+--- a/llvm-libgcc/CMakeLists.txt
+++ b/llvm-libgcc/CMakeLists.txt
+@@ -32,8 +32,13 @@ set(LLVM_LIBGCC_LIBUNWIND_PATH "${CMAKE_CURRENT_LIST_DIR}/../libunwind"
+   CACHE PATH "Specify path to libunwind source.")
+ set(LLVM_LIBGCC_COMPILER_RT_PATH "${CMAKE_CURRENT_LIST_DIR}/../compiler-rt"
+   CACHE PATH "Specify path to compiler-rt source.")
+option(LLVM_LIBGCC_BUILD_COMPILER_RT
+  "Build compiler-rt builtins as part of llvm-libgcc." ON)
+ 
+ include(GNUInstallDirs)
+list(APPEND CMAKE_MODULE_PATH "${LLVM_LIBGCC_COMPILER_RT_PATH}/cmake/Modules")
+include(CompilerRTUtils)
+include(HandleCompilerRT)
+ 
+ if(NOT LLVM_LIBGCC_EXPLICIT_OPT_IN)
+   message(FATAL_ERROR
+@@ -88,9 +93,11 @@ set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${LLVM_LIBGCC_LIBRARY_DIR})
+ # Build libraries
+ #===============================================================================
+ 
+-set(COMPILER_RT_BUILD_BUILTINS ON)
+-set(COMPILER_RT_BUILTINS_HIDE_SYMBOLS OFF)
+-add_subdirectory(${LLVM_LIBGCC_COMPILER_RT_PATH} ${LLVM_LIBGCC_COMPILER_RT_BINARY_DIR})
+if(LLVM_LIBGCC_BUILD_COMPILER_RT)
+  set(COMPILER_RT_BUILD_BUILTINS ON)
+  set(COMPILER_RT_BUILTINS_HIDE_SYMBOLS OFF)
+  add_subdirectory(${LLVM_LIBGCC_COMPILER_RT_PATH} ${LLVM_LIBGCC_COMPILER_RT_BINARY_DIR})
+endif()
+ 
+ set(LIBUNWIND_ENABLE_STATIC ON)
+ set(LIBUNWIND_ENABLE_SHARED ON)
+@@ -108,33 +115,65 @@ add_custom_target(gcc_s.ver
+ 
+ add_dependencies(unwind_shared gcc_s.ver)
+ 
+if(NOT LLVM_TARGET_TRIPLE)
+  set(LLVM_TARGET_TRIPLE "${LLVM_DEFAULT_TARGET_TRIPLE}")
+endif()
+ construct_compiler_rt_default_triple()
+ 
+-target_link_options(unwind_shared PUBLIC
+target_link_options(unwind_shared PRIVATE
+   -Wl,--version-script,${CMAKE_CURRENT_BINARY_DIR}/gcc_s.ver
+ )
+ 
+-target_link_libraries(unwind_shared PUBLIC
+-  $<TARGET_OBJECTS:clang_rt.builtins-${COMPILER_RT_DEFAULT_TARGET_ARCH}>
+-  m
+-)
+if(LLVM_LIBGCC_BUILD_COMPILER_RT)
+  set(LLVM_LIBGCC_COMPILER_RT_DEPS clang_rt.builtins-${COMPILER_RT_DEFAULT_TARGET_ARCH})
+  set(LLVM_LIBGCC_COMPILER_RT_OBJECTS
+    $<TARGET_OBJECTS:clang_rt.builtins-${COMPILER_RT_DEFAULT_TARGET_ARCH}>)
+else()
+  set(LLVM_LIBGCC_COMPILER_RT_BUILTINS_LIBRARY "" CACHE FILEPATH
+    "Path to an existing compiler-rt builtins archive when LLVM_LIBGCC_BUILD_COMPILER_RT is OFF.")
+  if(NOT LLVM_LIBGCC_COMPILER_RT_BUILTINS_LIBRARY)
+    find_compiler_rt_library(builtins LLVM_LIBGCC_COMPILER_RT_BUILTINS_LIBRARY
+      TARGET ${COMPILER_RT_DEFAULT_TARGET_TRIPLE})
+  endif()
+  if(NOT LLVM_LIBGCC_COMPILER_RT_BUILTINS_LIBRARY OR
+     LLVM_LIBGCC_COMPILER_RT_BUILTINS_LIBRARY STREQUAL "NOTFOUND")
+    message(FATAL_ERROR
+      "LLVM_LIBGCC_BUILD_COMPILER_RT is OFF, but compiler-rt builtins could not "
+      "be found. Set LLVM_LIBGCC_COMPILER_RT_BUILTINS_LIBRARY to an existing "
+      "libclang_rt.builtins archive.")
+  endif()
+  set(LLVM_LIBGCC_COMPILER_RT_LINK_TARGET
+    "${LLVM_LIBGCC_COMPILER_RT_BUILTINS_LIBRARY}" CACHE STRING
+    "Install-tree target used by the libgcc.a symlink when LLVM_LIBGCC_BUILD_COMPILER_RT is OFF.")
+  set(LLVM_LIBGCC_COMPILER_RT_OBJECTS
+    -Wl,--whole-archive
+    ${LLVM_LIBGCC_COMPILER_RT_BUILTINS_LIBRARY}
+    -Wl,--no-whole-archive)
+endif()
+
+target_link_libraries(unwind_shared PRIVATE ${LLVM_LIBGCC_COMPILER_RT_OBJECTS})
+target_link_libraries(unwind_shared PUBLIC m)
+ 
+ #===============================================================================
+ # Install Symlinks
+ #===============================================================================
+ 
+-get_compiler_rt_install_dir(${COMPILER_RT_DEFAULT_TARGET_ARCH} install_dir_builtins)
+-string(REGEX REPLACE "^lib/" "" install_dir_builtins "${install_dir_builtins}")
+-string(FIND "${install_dir_builtins}" "clang" install_path_contains_triple)
+-if(install_path_contains_triple EQUAL -1)
+-  set(builtins_suffix "-${COMPILER_RT_DEFAULT_TARGET_ARCH}")
+if(LLVM_LIBGCC_BUILD_COMPILER_RT)
+  get_compiler_rt_install_dir(${COMPILER_RT_DEFAULT_TARGET_ARCH} install_dir_builtins)
+  string(REGEX REPLACE "^lib/" "" install_dir_builtins "${install_dir_builtins}")
+  string(FIND "${install_dir_builtins}" "clang" install_path_contains_triple)
+  if(install_path_contains_triple EQUAL -1)
+    set(builtins_suffix "-${COMPILER_RT_DEFAULT_TARGET_ARCH}")
+  else()
+    string(PREPEND install_dir_builtins "../")
+  endif()
+  set(LLVM_LIBGCC_COMPILER_RT ${install_dir_builtins}/libclang_rt.builtins${builtins_suffix}.a)
+ else()
+-  string(PREPEND install_dir_builtins "../")
+  set(LLVM_LIBGCC_COMPILER_RT "${LLVM_LIBGCC_COMPILER_RT_LINK_TARGET}")
+ endif()
+-set(LLVM_LIBGCC_COMPILER_RT ${install_dir_builtins}/libclang_rt.builtins${builtins_suffix}.a)
+ 
+ add_custom_target(llvm-libgcc ALL
+-  DEPENDS unwind_shared unwind_static clang_rt.builtins-${COMPILER_RT_DEFAULT_TARGET_ARCH}
+  DEPENDS unwind_shared unwind_static ${LLVM_LIBGCC_COMPILER_RT_DEPS}
+   COMMAND ${CMAKE_COMMAND} -E create_symlink ${LLVM_LIBGCC_COMPILER_RT} libgcc.a
+   COMMAND ${CMAKE_COMMAND} -E create_symlink libunwind.a libgcc_eh.a
+   COMMAND ${CMAKE_COMMAND} -E create_symlink libunwind.so libgcc_s.so.1.0
+@@ -147,10 +186,12 @@ install(TARGETS unwind_shared unwind_static
+   ARCHIVE DESTINATION ${LLVM_LIBGCC_INSTALL_LIBRARY_DIR} COMPONENT llvm-libgcc
+   RUNTIME DESTINATION ${LLVM_LIBGCC_INSTALL_RUNTIME_DIR} COMPONENT llvm-libgcc)
+ 
+-install(TARGETS clang_rt.builtins-${COMPILER_RT_DEFAULT_TARGET_ARCH}
+-  LIBRARY DESTINATION ${LLVM_LIBGCC_INSTALL_LIBRARY_DIR}/${install_dir_builtins} COMPONENT llvm-libgcc
+-  ARCHIVE DESTINATION ${LLVM_LIBGCC_INSTALL_LIBRARY_DIR}/${install_dir_builtins} COMPONENT llvm-libgcc
+-  RUNTIME DESTINATION ${LLVM_LIBGCC_INSTALL_RUNTIME_DIR}/${install_dir_builtins} COMPONENT llvm-libgcc)
+if(LLVM_LIBGCC_BUILD_COMPILER_RT)
+  install(TARGETS clang_rt.builtins-${COMPILER_RT_DEFAULT_TARGET_ARCH}
+    LIBRARY DESTINATION ${LLVM_LIBGCC_INSTALL_LIBRARY_DIR}/${install_dir_builtins} COMPONENT llvm-libgcc
+    ARCHIVE DESTINATION ${LLVM_LIBGCC_INSTALL_LIBRARY_DIR}/${install_dir_builtins} COMPONENT llvm-libgcc
+    RUNTIME DESTINATION ${LLVM_LIBGCC_INSTALL_RUNTIME_DIR}/${install_dir_builtins} COMPONENT llvm-libgcc)
+endif()
+ 
+ foreach(VAR libgcc.a libgcc_eh.a libgcc_s.so.1.0 libgcc_s.so.1 libgcc_s.so)
+   install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${VAR}
+diff --git a/llvm-libgcc/docs/LLVMLibgcc.rst b/llvm-libgcc/docs/LLVMLibgcc.rst
+index 22dae7a..88e3fa2 100644
+--- a/llvm-libgcc/docs/LLVMLibgcc.rst
+++ b/llvm-libgcc/docs/LLVMLibgcc.rst
+@@ -72,6 +72,18 @@ CMake options
+   Since llvm-libgcc is such a fundamental, low-level component, we have made it
+   difficult to accidentally build, by requiring you to set an opt-in flag.
+ 
+.. option:: `LLVM_LIBGCC_BUILD_COMPILER_RT`
+
+  **Default**: ``ON``
+
+  Build the compiler-rt builtins archive as part of llvm-libgcc. When set to
+  ``OFF``, llvm-libgcc finds an existing compiler-rt builtins archive with the
+  compiler driver, links it into ``libunwind.so``, and only creates the
+  compatibility symlinks instead of installing compiler-rt. Set
+  ``LLVM_LIBGCC_COMPILER_RT_BUILTINS_LIBRARY`` if the compiler driver cannot
+  find the archive, and set ``LLVM_LIBGCC_COMPILER_RT_LINK_TARGET`` if the
+  installed symlink should point at a different path.
+
+ .. _Building llvm-libgcc
+ 
+ Building llvm-libgcc
@@ -0,0 +1,460 @@
+diff -ruN a/INSTALL b/INSTALL
+--- a/INSTALL	2021-09-23 13:03:23.000000000 -0500
+++ b/INSTALL	2026-05-29 18:09:12.237717849 -0500
+@@ -103,7 +103,9 @@
+ 
+ 1. zlib for decompressing gzipped manual pages.
+ 
+-2. The fts(3) directory traversion functions.
+2. libzstd for decompressing zstd-compressed manual pages.
+
+3. The fts(3) directory traversion functions.
+ If your system does not have them, the bundled compatibility version
+ will be used, so you need not worry in that case.  But be careful: old
+ glibc versions of fts(3) were known to be broken on 32bit platforms,
+@@ -111,7 +113,7 @@
+ That was presumably fixed in glibc-2.23.
+ If you run into that problem, set "HAVE_FTS=0" in configure.local.
+ 
+-3. Marc Espie's ohash(3) library.
+4. Marc Espie's ohash(3) library.
+ If your system does not have it, the bundled compatibility version
+ will be used, so you probably need not worry about it.
+ 
+diff -ruN a/Makefile b/Makefile
+--- a/Makefile	2021-09-23 13:03:23.000000000 -0500
+++ b/Makefile	2026-05-29 18:06:59.682203510 -0500
+@@ -54,7 +54,8 @@
+ 		   test-strsep.c \
+ 		   test-strtonum.c \
+ 		   test-vasprintf.c \
+-		   test-wchar.c
+		   test-wchar.c \
+		   test-zstd.c
+ 
+ SRCS		 = arch.c \
+ 		   att.c \
+diff -ruN a/configure b/configure
+--- a/configure	2021-09-23 13:03:23.000000000 -0500
+++ b/configure	2026-05-29 18:06:59.682203510 -0500
+@@ -50,6 +50,7 @@
+ LD_NANOSLEEP=
+ LD_OHASH=
+ LD_RECVMSG=
+LD_ZSTD=-lzstd
+ STATIC=
+ 
+ BUILD_CGI=0
+@@ -94,6 +95,7 @@
+ HAVE_SYS_ENDIAN=
+ HAVE_VASPRINTF=
+ HAVE_WCHAR=
+HAVE_ZSTD=
+ 
+ NEED_GNU_SOURCE=0
+ NEED_OPENBSD_SOURCE=0
+@@ -331,6 +333,7 @@
+ runtest strsep		STRSEP		|| true
+ runtest strtonum	STRTONUM	"" -D_OPENBSD_SOURCE || true
+ runtest vasprintf	VASPRINTF	"" -D_GNU_SOURCE || true
+runtest zstd		ZSTD		"${LD_ZSTD}" || true
+ 
+ # --- fts ---
+ if [ "${1}" = "-depend" ]; then
+@@ -415,6 +418,11 @@
+ 	echo "FATAL: nanosleep: no" 1>&3
+ 	FATAL=1
+ fi
+if [ "${HAVE_ZSTD}" -eq 0 ]; then
+	echo "FATAL: zstd: no" 1>&2
+	echo "FATAL: zstd: no" 1>&3
+	FATAL=1
+fi
+ if [ ${BUILD_CATMAN} -gt 0 -a "${HAVE_RECVMSG}" -eq 0 ]; then
+ 	echo "FATAL: recvmsg: no" 1>&2
+ 	echo "FATAL: recvmsg: no" 1>&3
+@@ -430,7 +438,7 @@
+ [ "${FATAL}" -eq 0 ] || exit 1
+ 
+ # --- LDADD ---
+-LDADD="${LDADD} ${LD_NANOSLEEP} ${LD_RECVMSG} ${LD_OHASH} -lz"
+LDADD="${LDADD} ${LD_NANOSLEEP} ${LD_RECVMSG} ${LD_OHASH} -lz ${LD_ZSTD}"
+ echo "selected LDADD=\"${LDADD}\"" 1>&2
+ echo "selected LDADD=\"${LDADD}\"" 1>&3
+ echo 1>&3
+@@ -506,6 +514,7 @@
+ #define HAVE_SYS_ENDIAN ${HAVE_SYS_ENDIAN}
+ #define HAVE_VASPRINTF ${HAVE_VASPRINTF}
+ #define HAVE_WCHAR ${HAVE_WCHAR}
+#define HAVE_ZSTD ${HAVE_ZSTD}
+ #define HAVE_OHASH ${HAVE_OHASH}
+ #define NEED_XPG4_2 ${NEED_XPG4_2}
+ 
+diff -ruN a/main.c b/main.c
+--- a/main.c	2021-09-23 13:03:23.000000000 -0500
+++ b/main.c	2026-05-29 18:08:19.108307544 -0500
+@@ -538,7 +538,10 @@
+ 					prio += 10; /* Wrong dir name. */
+ 				if (search.sec != NULL) {
+ 					ep = strchr(sec, '\0');
+-					if (ep - sec > 3 &&
+					if (ep - sec > 4 &&
+					    strncmp(ep - 4, ".zst", 4) == 0)
+						ep -= 4;
+					else if (ep - sec > 3 &&
+ 					    strncmp(ep - 3, ".gz", 3) == 0)
+ 						ep -= 3;
+ 					if ((size_t)(ep - sec) < ssz + 3 ||
+diff -ruN a/mandoc.3 b/mandoc.3
+--- a/mandoc.3	2021-09-23 13:03:23.000000000 -0500
+++ b/mandoc.3	2026-05-29 18:09:19.497910732 -0500
+@@ -273,10 +273,14 @@
+ If that fails and
+ .Fa fname
+ does not already end in
+-.Ql .gz ,
+.Ql .gz
+or
+.Ql .zst ,
+ try again after appending
+-.Ql .gz .
+-Save the information whether the file is zipped or not.
+.Ql .gz
+and
+.Ql .zst .
+Save the information whether the file is compressed or not.
+ Return a file descriptor open for reading or -1 on failure.
+ It can be passed to
+ .Fn mparse_readfd
+diff -ruN a/mandocdb.c b/mandocdb.c
+--- a/mandocdb.c	2021-09-23 13:03:23.000000000 -0500
+++ b/mandocdb.c	2026-05-29 18:09:00.199398109 -0500
+@@ -102,7 +102,7 @@
+ 	char		*fsec;    /* section from file name suffix */
+ 	struct mlink	*next;    /* singly linked list */
+ 	struct mpage	*mpage;   /* parent */
+-	int		 gzip;	  /* filename has a .gz suffix */
+	int		 gzip;	  /* filename has a compression suffix */
+ 	enum form	 dform;   /* format from directory */
+ 	enum form	 fform;   /* format from file name suffix */
+ };
+@@ -580,7 +580,7 @@
+ 	FTS		*f;
+ 	FTSENT		*ff;
+ 	struct mlink	*mlink;
+-	int		 gzip;
+	int		 compressed;
+ 	enum form	 dform;
+ 	char		*dsec, *arch, *fsec, *cp;
+ 	const char	*path;
+@@ -645,13 +645,15 @@
+ 					say(path, "Extraneous file");
+ 				continue;
+ 			}
+-			gzip = 0;
+			compressed = 0;
+ 			fsec = NULL;
+ 			while (fsec == NULL) {
+ 				fsec = strrchr(ff->fts_name, '.');
+-				if (fsec == NULL || strcmp(fsec+1, "gz"))
+				if (fsec == NULL ||
+				    (strcmp(fsec + 1, "gz") &&
+				     strcmp(fsec + 1, "zst")))
+ 					break;
+-				gzip = 1;
+				compressed = 1;
+ 				*fsec = '\0';
+ 				fsec = NULL;
+ 			}
+@@ -697,7 +699,7 @@
+ 			mlink->arch = arch;
+ 			mlink->name = ff->fts_name;
+ 			mlink->fsec = fsec;
+-			mlink->gzip = gzip;
+			mlink->gzip = compressed;
+ 			mlink_add(mlink, ff->fts_statp);
+ 			continue;
+ 
+@@ -962,9 +964,19 @@
+ 	 * Now check the file suffix.
+ 	 * Suffix of `.0' indicates a catpage, `.1-9' is a manpage.
+ 	 */
+-	p = strrchr(start, '\0');
+-	while (p-- > start && *p != '/' && *p != '.')
+-		continue;
+	if ((p = strrchr(start, '/')) == NULL)
+		p = start;
+	else
+		p++;
+	if ((p = strrchr(p, '.')) != NULL &&
+	    (strcmp(p + 1, "gz") == 0 || strcmp(p + 1, "zst") == 0))
+		*p = '\0';
+
+	for (p = strchr(start, '\0'); p > start; ) {
+		p--;
+		if (*p == '/' || *p == '.')
+			break;
+	}
+ 
+ 	if (*p == '.') {
+ 		*p++ = '\0';
+@@ -1213,6 +1225,12 @@
+ 				mlink_dest = ohash_find(&mlinks,
+ 				    ohash_qlookup(&mlinks, cp));
+ 				free(cp);
+			}
+			if (mlink_dest == NULL) {
+				mandoc_asprintf(&cp, "%s.zst", meta->sodest);
+				mlink_dest = ohash_find(&mlinks,
+				    ohash_qlookup(&mlinks, cp));
+				free(cp);
+ 			}
+ 			if (mlink_dest != NULL) {
+ 
+diff -ruN a/read.c b/read.c
+--- a/read.c	2021-09-23 13:03:23.000000000 -0500
+++ b/read.c	2026-05-29 18:09:41.222488117 -0500
+@@ -38,6 +38,7 @@
+ #include <string.h>
+ #include <unistd.h>
+ #include <zlib.h>
+#include <zstd.h>
+ 
+ #include "mandoc_aux.h"
+ #include "mandoc.h"
+@@ -60,6 +61,7 @@
+ 	const char	 *os_s; /* default operating system */
+ 	int		  options; /* parser options */
+ 	int		  gzip; /* current input file is gzipped */
+	int		  zstd; /* current input file is zstd-compressed */
+ 	int		  filenc; /* encoding of the current file */
+ 	int		  reparse_count; /* finite interp. stack */
+ 	int		  line; /* line number in the file */
+@@ -70,6 +72,7 @@
+ static	void	  resize_buf(struct buf *, size_t);
+ static	int	  mparse_buf_r(struct mparse *, struct buf, size_t, int);
+ static	int	  read_whole_file(struct mparse *, int, struct buf *, int *);
+static	int	  read_zstd_file(struct mparse *, int, struct buf *);
+ static	void	  mparse_end(struct mparse *);
+ 
+ 
+@@ -432,6 +435,89 @@
+ }
+ 
+ static int
+read_zstd_file(struct mparse *curp, int fd, struct buf *fb)
+{
+	ZSTD_DStream	*zds;
+	ZSTD_inBuffer	 zin;
+	ZSTD_outBuffer	 zout;
+	char		*ibuf;
+	size_t		 ibufsz, off, ret;
+	ssize_t		 ssz;
+	int		 eof, retval;
+
+	if ((zds = ZSTD_createDStream()) == NULL) {
+		mandoc_msg(MANDOCERR_READ, 0, 0,
+		    "zstd: unable to allocate decompressor");
+		return -1;
+	}
+
+	ibufsz = ZSTD_DStreamInSize();
+	ibuf = mandoc_malloc(ibufsz);
+	zin.src = ibuf;
+	zin.size = 0;
+	zin.pos = 0;
+
+	fb->sz = 0;
+	fb->buf = NULL;
+	off = 0;
+	ret = 1;
+	eof = 0;
+	retval = -1;
+
+	while (eof == 0 || zin.pos < zin.size) {
+		if (zin.pos == zin.size && eof == 0) {
+			if ((ssz = read(fd, ibuf, ibufsz)) == -1) {
+				mandoc_msg(MANDOCERR_READ, 0, 0,
+				    "%s", strerror(errno));
+				goto out;
+			}
+			if (ssz == 0) {
+				eof = 1;
+				continue;
+			}
+			zin.size = (size_t)ssz;
+			zin.pos = 0;
+		}
+
+		if (off == fb->sz) {
+			if (fb->sz == (1U << 31)) {
+				mandoc_msg(MANDOCERR_TOOLARGE, 0, 0, NULL);
+				goto out;
+			}
+			resize_buf(fb, 65536);
+		}
+
+		zout.dst = fb->buf + off;
+		zout.size = fb->sz - off;
+		zout.pos = 0;
+		ret = ZSTD_decompressStream(zds, &zout, &zin);
+		if (ZSTD_isError(ret)) {
+			mandoc_msg(MANDOCERR_READ, 0, 0,
+			    "zstd: %s", ZSTD_getErrorName(ret));
+			goto out;
+		}
+		off += zout.pos;
+	}
+
+	if (ret != 0)
+		mandoc_msg(MANDOCERR_READ, 0, 0,
+		    "zstd: unexpected end of file");
+	else {
+		fb->sz = off;
+		retval = 0;
+	}
+
+out:
+	free(ibuf);
+	ZSTD_freeDStream(zds);
+	if (retval == -1) {
+		free(fb->buf);
+		fb->buf = NULL;
+	}
+	return retval;
+}
+
+static int
+ read_whole_file(struct mparse *curp, int fd, struct buf *fb, int *with_mmap)
+ {
+ 	struct stat	 st;
+@@ -452,7 +538,7 @@
+ 	 * concerned that this is going to tank any machines.
+ 	 */
+ 
+-	if (curp->gzip == 0 && S_ISREG(st.st_mode)) {
+	if (curp->gzip == 0 && curp->zstd == 0 && S_ISREG(st.st_mode)) {
+ 		if (st.st_size > 0x7fffffff) {
+ 			mandoc_msg(MANDOCERR_TOOLARGE, 0, 0, NULL);
+ 			return -1;
+@@ -464,6 +550,11 @@
+ 			return 0;
+ 	}
+ 
+	if (curp->zstd) {
+		*with_mmap = 0;
+		return read_zstd_file(curp, fd, fb);
+	}
+
+ 	if (curp->gzip) {
+ 		/*
+ 		 * Duplicating the file descriptor is required
+@@ -557,7 +648,7 @@
+ 
+ 	struct buf	 blk;
+ 	struct buf	*save_primary;
+-	const char	*save_filename, *cp;
+	const char	*save_filename, *cp, *ep;
+ 	size_t		 offset;
+ 	int		 save_filenc, save_lineno;
+ 	int		 with_mmap;
+@@ -565,12 +656,26 @@
+ 	if (recursion_depth > 64) {
+ 		mandoc_msg(MANDOCERR_ROFFLOOP, curp->line, 0, NULL);
+ 		return;
+-	} else if (recursion_depth == 0 &&
+-	    (cp = strrchr(filename, '.')) != NULL &&
+-            cp[1] >= '1' && cp[1] <= '9')
+-                curp->man->filesec = cp[1];
+-        else
+-                curp->man->filesec = '\0';
+	} else if (recursion_depth == 0) {
+		ep = strrchr(filename, '.');
+		if (ep != NULL &&
+		    (strcmp(ep + 1, "gz") == 0 ||
+		     strcmp(ep + 1, "zst") == 0)) {
+			for (cp = ep; cp > filename; cp--)
+				if (cp[-1] == '.') {
+					cp--;
+					break;
+				}
+			if (cp == filename)
+				cp = NULL;
+		} else
+			cp = ep;
+		if (cp != NULL && cp[1] >= '1' && cp[1] <= '9')
+			curp->man->filesec = cp[1];
+		else
+			curp->man->filesec = '\0';
+	} else
+		curp->man->filesec = '\0';
+ 
+ 	if (read_whole_file(curp, fd, &blk, &with_mmap) == -1)
+ 		return;
+@@ -623,11 +728,13 @@
+ int
+ mparse_open(struct mparse *curp, const char *file)
+ {
+	const char	 *ep;
+ 	char		 *cp;
+ 	int		  fd, save_errno;
+ 
+-	cp = strrchr(file, '.');
+-	curp->gzip = (cp != NULL && ! strcmp(cp + 1, "gz"));
+	ep = strrchr(file, '.');
+	curp->gzip = (ep != NULL && ! strcmp(ep + 1, "gz"));
+	curp->zstd = (ep != NULL && ! strcmp(ep + 1, "zst"));
+ 
+ 	/* First try to use the filename as it is. */
+ 
+@@ -635,20 +742,27 @@
+ 		return fd;
+ 
+ 	/*
+-	 * If that doesn't work and the filename doesn't
+-	 * already  end in .gz, try appending .gz.
+	 * If that doesn't work and the filename doesn't already
+	 * end in .gz or .zst, try appending these suffixes.
+ 	 */
+ 
+-	if ( ! curp->gzip) {
+	if ( ! curp->gzip && ! curp->zstd) {
+ 		save_errno = errno;
+ 		mandoc_asprintf(&cp, "%s.gz", file);
+ 		fd = open(cp, O_RDONLY);
+ 		free(cp);
+-		errno = save_errno;
+ 		if (fd != -1) {
+ 			curp->gzip = 1;
+ 			return fd;
+ 		}
+		mandoc_asprintf(&cp, "%s.zst", file);
+		fd = open(cp, O_RDONLY);
+		free(cp);
+		errno = save_errno;
+		if (fd != -1) {
+			curp->zstd = 1;
+			return fd;
+		}
+ 	}
+ 
+ 	/* Neither worked, give up. */
+@@ -693,6 +807,7 @@
+ 	free_buf_list(curp->secondary);
+ 	curp->secondary = NULL;
+ 	curp->gzip = 0;
+	curp->zstd = 0;
+ 	tag_alloc();
+ }
+ 
+diff -ruN a/test-zstd.c b/test-zstd.c
+--- a/test-zstd.c	1969-12-31 18:00:00.000000000 -0600
+++ b/test-zstd.c	2026-05-29 18:06:59.682203510 -0500
+@@ -0,0 +1,7 @@
+#include <zstd.h>
+
+int
+main(void)
+{
+	return ZSTD_versionNumber() == 0;
+}
@@ -1,188 +0,0 @@
--- a/Makefile.SH
-+++ b/Makefile.SH
-@@ -373,16 +373,64 @@
- 	$spitshell >>$Makefile <<!GROK!THIS!
- # Macros to invoke a copy of our fully operational perl during the build.
- PERL_EXE = perl\$(EXE_EXT)
-RUN_PERL = \$(LDLIBPTH) \$(RUN) $perl\$(EXE_EXT)
-+BUILD_PERL_INC = -Ilib -I. \
-+	-Icpan/AutoLoader/lib \
-+	-Idist/Carp/lib \
-+	-Idist/PathTools \
-+	-Idist/PathTools/lib \
-+	-Icpan/ExtUtils-Install/lib \
-+	-Icpan/ExtUtils-MakeMaker/lib \
-+	-Icpan/ExtUtils-Manifest/lib \
-+	-Icpan/File-Path/lib \
-+	-Iext/re \
-+	-Idist/Term-ReadLine/lib \
-+	-Idist/Exporter/lib \
-+	-Iext/File-Find/lib \
-+	-Icpan/Text-Tabs/lib \
-+	-Idist/constant/lib \
-+	-Icpan/version/lib \
-+	-Icpan/Getopt-Long/lib \
-+	-Icpan/Text-ParseWords/lib \
-+	-Icpan/ExtUtils-PL2Bat/lib \
-+	-Icpan/parent/lib \
-+	-Idist/ExtUtils-ParseXS/lib \
-+	-Idist/base/lib \
-+	-Idist/XSLoader
-+RUN_PERL = \$(LDLIBPTH) \$(RUN) $perl\$(EXE_EXT) \$(BUILD_PERL_INC)
-+RUN_MINIPERL = \$(LDLIBPTH) ./miniperl\$(EXE_EXT) \$(BUILD_PERL_INC)
- !GROK!THIS!
- 	;;
- *)
- 	$spitshell >>$Makefile <<!GROK!THIS!
- # Macros to invoke a copy of our fully operational perl during the build.
- PERL_EXE = perl\$(EXE_EXT)
-RUN_PERL = \$(LDLIBPTH) \$(RUN) ./perl\$(EXE_EXT) -Ilib -I.
-!GROK!THIS!
-	;;
-+BUILD_PERL_INC = -Ilib -I. \
-+	-Icpan/AutoLoader/lib \
-+	-Idist/Carp/lib \
-+	-Idist/PathTools \
-+	-Idist/PathTools/lib \
-+	-Icpan/ExtUtils-Install/lib \
-+	-Icpan/ExtUtils-MakeMaker/lib \
-+	-Icpan/ExtUtils-Manifest/lib \
-+	-Icpan/File-Path/lib \
-+	-Iext/re \
-+	-Idist/Term-ReadLine/lib \
-+	-Idist/Exporter/lib \
-+	-Iext/File-Find/lib \
-+	-Icpan/Text-Tabs/lib \
-+	-Idist/constant/lib \
-+	-Icpan/version/lib \
-+	-Icpan/Getopt-Long/lib \
-+	-Icpan/Text-ParseWords/lib \
-+	-Icpan/ExtUtils-PL2Bat/lib \
-+	-Icpan/parent/lib \
-+	-Idist/ExtUtils-ParseXS/lib \
-+	-Idist/base/lib \
-+	-Idist/XSLoader
-+RUN_PERL = \$(LDLIBPTH) \$(RUN) ./perl\$(EXE_EXT) \$(BUILD_PERL_INC)
-+RUN_MINIPERL = \$(LDLIBPTH) ./miniperl\$(EXE_EXT) \$(BUILD_PERL_INC)
-+!GROK!THIS!
-+		;;
- esac
- 
- $spitshell >>$Makefile <<!GROK!THIS!
-@@ -706,12 +754,20 @@
- 
- !NO!SUBS!
- 
-# Making utilities requires Cwd.  If we have dynamic
-# loading, we only need miniperl and Cwd.$dlext.  If we have static
-# loading, we need to build perl first.
-+# Making utilities requires Cwd.  If we have dynamic loading, we only need
-+# miniperl and the Cwd extension.  If we have static loading, we need to
-+# build perl first.  Use an explicit helper target for the dynamic case so
-+# makes that do not know how to drive the lib/auto/Cwd output directly still
-+# have a concrete dependency to build.
- case "$usedl$static_cwd" in
- defineundef)
-    util_deps='$(MINIPERL_EXE) $(CONFIGPM) lib/auto/Cwd/Cwd$(DLSUFFIX) FORCE'
-+	util_deps='$(MINIPERL_EXE) $(CONFIGPM) buildext-Cwd FORCE'
-+	$spitshell >>$Makefile <<'!NO!SUBS!'
-+.PHONY: buildext-Cwd
-+buildext-Cwd: $(MINIPERL_EXE) lib/buildcustomize.pl preplibrary makeppport $(DYNALOADER) FORCE $(PERLEXPORT) $(LIBPERL)
-+	$(MINIPERL) make_ext.pl lib/auto/Cwd/Cwd$(DLSUFFIX) $(MAKE_EXT_ARGS) MAKE="$(MAKE)" LIBPERL_A=$(LIBPERL) LINKTYPE=dynamic
-+
-+!NO!SUBS!
-     ;;
- definedefine)
-     util_deps='$(PERL_EXE) $(CONFIGPM) FORCE'
-@@ -820,8 +876,8 @@
- case "$osname" in
- amigaos*)
- $spitshell >>$Makefile <<'!NO!SUBS!'
-perlmain.c: $(MINIPERL_EXE) ext/ExtUtils-Miniperl/pm_to_blib
-	$(MINIPERL) -MExtUtils::Miniperl -e 'writemain(\\"perlmain.c", @ARGV)' DynaLoader $(static_ext)
-+perlmain.c: $(MINIPERL_EXE) $(CONFIGPM) ext/ExtUtils-Miniperl/lib/ExtUtils/Miniperl.pm
-+	$(MINIPERL) -Iext/ExtUtils-Miniperl/lib -MExtUtils::Miniperl -e 'writemain(\\"perlmain.c", @ARGV)' DynaLoader $(static_ext)
- 
- # The file ext.libs is a list of libraries that must be linked in
- # for static extensions, e.g. -lm -lgdbm, etc.  The individual
-@@ -829,18 +885,24 @@
- ext.libs: $(static_ext)
- 	-@test -f ext.libs || touch ext.libs
- 
-+dist/XSLoader/XSLoader.pm: $(MINIPERL_EXE) $(CONFIGPM) dist/XSLoader/XSLoader_pm.PL
-+	cd dist/XSLoader && ../../$(MINIPERL_EXE) -I../../lib XSLoader_pm.PL
-+
- !NO!SUBS!
- ;;
- *)
- $spitshell >>$Makefile <<'!NO!SUBS!'
-perlmain.c: $(MINIPERL_EXE) ext/ExtUtils-Miniperl/pm_to_blib
-	$(MINIPERL) -MExtUtils::Miniperl -e 'writemain(\"perlmain.c", @ARGV)' DynaLoader $(static_ext)
-+perlmain.c: $(MINIPERL_EXE) $(CONFIGPM) ext/ExtUtils-Miniperl/lib/ExtUtils/Miniperl.pm
-+	$(MINIPERL) -Iext/ExtUtils-Miniperl/lib -MExtUtils::Miniperl -e 'writemain(\"perlmain.c", @ARGV)' DynaLoader $(static_ext)
- 
- # The file ext.libs is a list of libraries that must be linked in
- # for static extensions, e.g. -lm -lgdbm, etc.  The individual
- # static extension Makefile's add to it.
- ext.libs: $(static_ext)
- 	-@test -f ext.libs || touch ext.libs
-+
-+dist/XSLoader/XSLoader.pm: $(MINIPERL_EXE) $(CONFIGPM) dist/XSLoader/XSLoader_pm.PL
-+	cd dist/XSLoader && ../../$(MINIPERL_EXE) -I../../lib XSLoader_pm.PL
- 
- !NO!SUBS!
- ;;
-@@ -1130,11 +1192,12 @@
- #	can in this makefile to decide if needs to run or not
- #	touch uni.data
- 
-# $(PERL_EXE) and ext because pod_lib.pl needs Digest::MD5
-# But also this ensures that all extensions are built before we try to scan
-+# Build this with miniperl plus the same expanded \@INC as RUN_PERL so
-+# File::Spec can load PathTools without needing the XS Cwd extension.
-+# $(ext) still ensures that all extensions are built before we try to scan
- # them, which picks up Devel::PPPort's documentation.
-pod/perltoc.pod: $(perltoc_pod_prereqs) $(PERL_EXE) $(ext) pod/buildtoc
-	$(RUN_PERL) -f pod/buildtoc -q
-+pod/perltoc.pod: $(perltoc_pod_prereqs) $(MINIPERL_EXE) $(ext) pod/buildtoc
-+	$(RUN_MINIPERL) -f pod/buildtoc -q
- 
- pod/perlapi.pod: pod/perlintern.pod
- 
-@@ -1300,11 +1363,11 @@
- .PHONY:	manisort manicheck
- 
- manisort:	FORCE
-	@perl Porting/manisort -q || (echo "WARNING: re-sorting MANIFEST"; \
-		perl Porting/manisort -q -o MANIFEST; sh -c true)
-+	@$(RUN_PERL) Porting/manisort -q || (echo "WARNING: re-sorting MANIFEST"; \
-+		$(RUN_PERL) Porting/manisort -q -o MANIFEST; sh -c true)
- 
- manicheck:	FORCE
-	perl Porting/manicheck
-+	$(RUN_PERL) Porting/manicheck
- 
- # Extensions:
- # Names added to $(dynamic_ext) or $(static_ext) or $(nonxs_ext) will
--- a/write_buildcustomize.pl
-+++ b/write_buildcustomize.pl
-@@ -47,15 +47,16 @@
-     cpan/Getopt-Long/lib
-     cpan/Text-ParseWords/lib
-     cpan/ExtUtils-PL2Bat/lib
-+    cpan/parent/lib
-+    dist/ExtUtils-ParseXS/lib
-+    dist/base/lib
-+    dist/XSLoader
- );
- 
- # These are for XS building on Win32, since nonxs and xs build simultaneously
- # on Win32 if parallel building
- push @toolchain, qw(
-    dist/ExtUtils-ParseXS/lib
-    cpan/parent/lib
-     cpan/ExtUtils-Constant/lib
-    dist/base/lib
- ) if $^O eq 'MSWin32';
- push @toolchain, 'ext/VMS-Filespec/lib' if $^O eq 'VMS';
-