Upstream patch: fix build for Hurd (#52) (closes: #1009066)

Since d5a61ee8 (Patch to detect (and ignore) symlink loops in
pcre2grep., 2021-08-28), there is optional code that depends
on readlink and PATH_MAX but that had only detection added for
the first.

GNU Hurd doesn't have the later so it fails to build.

Improve the detection to include both dependencies in autotools
and cmake to fix that.

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Matthew Vernon <matthew@debian.org>

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8010497f569a22c57caa151fb18fd4c3a0898d53..542fe0ef51c1d02dc5e89bf195be2bf36cc19831 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -142,10 +142,16 @@ CHECK_INCLUDE_FILE(windows.h    HAVE_WINDOWS_H)
 CHECK_SYMBOL_EXISTS(bcopy         "strings.h"  HAVE_BCOPY)
 CHECK_SYMBOL_EXISTS(memfd_create  "sys/mman.h" HAVE_MEMFD_CREATE)
 CHECK_SYMBOL_EXISTS(memmove       "string.h"   HAVE_MEMMOVE)
-CHECK_SYMBOL_EXISTS(realpath      "stdlib.h"   HAVE_REALPATH)
 CHECK_SYMBOL_EXISTS(secure_getenv "stdlib.h"   HAVE_SECURE_GETENV)
 CHECK_SYMBOL_EXISTS(strerror      "string.h"   HAVE_STRERROR)
 
+CHECK_C_SOURCE_COMPILES(
+  "#include <stdlib.h>
+   #include <limits.h>
+   int main(int c, char *v[]) { char buf[PATH_MAX]; realpath(v[1], buf); return 0; }"
+  HAVE_REALPATH
+)
+
 set(ORIG_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror")
 CHECK_C_SOURCE_COMPILES(

diff --git a/configure.ac b/configure.ac
index d3721c22a058e3eec273d56f7773fe978eb3452b..86bf3cac75d2f285063a0e0b8e5fe286fb4f768d 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -512,7 +512,20 @@ AC_TYPE_SIZE_T
 
 # Checks for library functions.
 
-AC_CHECK_FUNCS(bcopy memfd_create memmove mkostemp realpath secure_getenv strerror)
+AC_CHECK_FUNCS(bcopy memfd_create memmove mkostemp secure_getenv strerror)
+AC_MSG_CHECKING([for realpath])
+AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+#include <stdlib.h>
+#include <limits.h>
+]],[[
+char buffer[PATH_MAX];
+realpath(".", buffer);
+]])],
+[AC_MSG_RESULT([yes])
+ AC_DEFINE([HAVE_REALPATH], 1,
+  [Define to 1 if you have the `realpath' function.])
+],
+AC_MSG_RESULT([no]))
 
 # Check for the availability of libz (aka zlib)