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* [PATCH] gdbserver/linux: probe for libiconv in configure
@ 2024-02-28 23:15 Simon Marchi
  2024-02-29 17:40 ` Tom Tromey
  0 siblings, 1 reply; 4+ messages in thread
From: Simon Marchi @ 2024-02-28 23:15 UTC (permalink / raw)
  To: gdb-patches; +Cc: Simon Marchi

From: Simon Marchi <simon.marchi@efficios.com>

Make gdbserver's build system locate libiconv when building for Linux.

Commit 07b3255c3bae ("Filter invalid encodings from Linux thread names")
made libiconv madantory for building gdbserver on Linux.

While trying to cross-compile gdb for xtensa-fsf-linux-uclibc (with a
toolchain generated with crosstool-ng), I got:

    /home/smarchi/src/binutils-gdb/gdbserver/linux-low.cc:48:10: fatal error: iconv.h: No such file or directory
       48 | #include <iconv.h>
          |          ^~~~~~~~~

I downloaded GNU libiconv, built it for that host, and installed it in
an arbitrary directory.  To make gdbserver use it, I had to modify the
gdbserver build system to locate libiconv and use it, the result is this
patch.

I eventually found that crosstool-ng has an config option to make uclibc
provide an implementation of iconv, which is of course much easier.  But
given that this patch is now written, I think it would be worth merging
it.  It could help some people who do not have iconv built in their libc
and may not have the luxury of rebuilding their libc like I do.

Using AM_ICONV in configure.ac adds these options for configure (the
same we have for gdb):

    --with-libiconv-prefix[=DIR]  search for libiconv in DIR/include and DIR/lib
    --without-libiconv-prefix     don't search for libiconv in includedir and libdir
    --with-libiconv-type=TYPE     type of library to search for (auto/static/shared)

AM_ICONV sets the `LIBICONV` variable with whatever is needed to link
with libiconv, and adds the necessary `-I` flag to `CPPFLAGS`.

To avoid unnecessarily linking against libiconv on hosts that don't need
it, set `MAYBE_LIBICONV` with the contents of `LIBICONV` only if the
host is Linux, and use `MAYBE_LIBICONV` in `Makefile.in`.  I considered
putting `AM_ICONV` in the case, to avoid unnecessarily doing the
configure checks for the hosts that don't need libiconv, but I'm not
sure it's safe.  So as-is, for these other hosts, configure will check
for libiconv even if it's not needed.  It won't be an error if libiconv
is not found though, so not such a big deal.  Just one unnecessary
check.  But if someone confidently tells me that it's fine to put
`AM_ICONV` in the case, I can do it.

The bits in acinclude.m4 are similar to what we have in
gdb/acinclude.m4.

Change-Id: I90f8ef88dd4917df5a68b45550d93622fc9cfed4
---
 gdbserver/Makefile.in  |   4 +-
 gdbserver/acinclude.m4 |   7 +
 gdbserver/aclocal.m4   |   4 -
 gdbserver/config.in    |   3 +
 gdbserver/configure    | 351 +++++++++++++++++++++++++++++++++++++++++
 gdbserver/configure.ac |  15 ++
 6 files changed, 379 insertions(+), 5 deletions(-)

diff --git a/gdbserver/Makefile.in b/gdbserver/Makefile.in
index d12f8746611b..c7120895a26d 100644
--- a/gdbserver/Makefile.in
+++ b/gdbserver/Makefile.in
@@ -152,6 +152,8 @@ PTHREAD_LIBS = @PTHREAD_LIBS@
 
 WIN32APILIBS = @WIN32APILIBS@
 
+MAYBE_LIBICONV = @MAYBE_LIBICONV@
+
 # INTERNAL_CFLAGS is the aggregate of all other *CFLAGS macros.
 INTERNAL_CFLAGS_BASE = ${GLOBAL_CFLAGS} \
 	${PROFILE_CFLAGS} ${INCLUDE_CFLAGS} ${CPPFLAGS} $(PTHREAD_CFLAGS)
@@ -354,7 +356,7 @@ gdbserver$(EXEEXT): $(sort $(OBS)) ${CDEPS} $(LIBGNU) $(LIBIBERTY) \
 		$(CXXFLAGS) \
 		-o gdbserver$(EXEEXT) $(OBS) $(GDBSUPPORT) $(LIBGNU) \
 		$(LIBGNU_EXTRA_LIBS) $(LIBIBERTY) $(INTL) \
-		$(GDBSERVER_LIBS) $(XM_CLIBS) $(WIN32APILIBS)
+		$(GDBSERVER_LIBS) $(XM_CLIBS) $(WIN32APILIBS) $(MAYBE_LIBICONV)
 
 gdbreplay$(EXEEXT): $(sort $(GDBREPLAY_OBS)) $(LIBGNU) $(LIBIBERTY) \
 		$(INTL_DEPS) $(GDBSUPPORT)
diff --git a/gdbserver/acinclude.m4 b/gdbserver/acinclude.m4
index db69b7d243b1..5a00c6e9878b 100644
--- a/gdbserver/acinclude.m4
+++ b/gdbserver/acinclude.m4
@@ -18,6 +18,13 @@ dnl anything else in gdbserver.
 m4_include(../config/codeset.m4)
 m4_include(../gdbsupport/common.m4)
 
+dnl For AM_ICONV.  We need to explicitly include these other files before
+dnl iconv.m4 to avoid warnings.
+m4_include([../config/lib-ld.m4])
+m4_include([../config/lib-prefix.m4])
+m4_include([../config/lib-link.m4])
+m4_include([../config/iconv.m4])
+
 dnl For libiberty_INIT.
 m4_include(../gdbsupport/libiberty.m4)
 
diff --git a/gdbserver/aclocal.m4 b/gdbserver/aclocal.m4
index db9266266bed..fe94a5bffc05 100644
--- a/gdbserver/aclocal.m4
+++ b/gdbserver/aclocal.m4
@@ -204,12 +204,8 @@ m4_include([../config/ax_pthread.m4])
 m4_include([../config/depstand.m4])
 m4_include([../config/gettext-sister.m4])
 m4_include([../config/gettext.m4])
-m4_include([../config/iconv.m4])
 m4_include([../config/intlmacosx.m4])
 m4_include([../config/lead-dot.m4])
-m4_include([../config/lib-ld.m4])
-m4_include([../config/lib-link.m4])
-m4_include([../config/lib-prefix.m4])
 m4_include([../config/nls.m4])
 m4_include([../config/override.m4])
 m4_include([../config/po.m4])
diff --git a/gdbserver/config.in b/gdbserver/config.in
index ca4b9f4d6f20..47e1e722fe0a 100644
--- a/gdbserver/config.in
+++ b/gdbserver/config.in
@@ -402,6 +402,9 @@
 /* Define to 1 if you have the <ws2tcpip.h> header file. */
 #undef HAVE_WS2TCPIP_H
 
+/* Define as const if the declaration of iconv() needs const. */
+#undef ICONV_CONST
+
 /* Define to the address where bug reports for this package should be sent. */
 #undef PACKAGE_BUGREPORT
 
diff --git a/gdbserver/configure b/gdbserver/configure
index 0942ef173d45..ae8dfdc3a7e0 100755
--- a/gdbserver/configure
+++ b/gdbserver/configure
@@ -623,6 +623,7 @@ ac_header_list=
 gt_needs=
 ac_subst_vars='LTLIBOBJS
 LIBOBJS
+MAYBE_LIBICONV
 GNULIB_STDINT_H
 extra_libraries
 IPA_DEPFILES
@@ -14736,6 +14737,356 @@ if test x"$STDINT_H" != x; then
 fi
 
 
+# Check for libiconv if needed for the host.
+
+
+
+
+
+          am_save_CPPFLAGS="$CPPFLAGS"
+
+  for element in $INCICONV; do
+    haveit=
+    for x in $CPPFLAGS; do
+
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  acl_save_exec_prefix="$exec_prefix"
+  exec_prefix="$acl_final_exec_prefix"
+  eval x=\"$x\"
+  exec_prefix="$acl_save_exec_prefix"
+  prefix="$acl_save_prefix"
+
+      if test "X$x" = "X$element"; then
+        haveit=yes
+        break
+      fi
+    done
+    if test -z "$haveit"; then
+      CPPFLAGS="${CPPFLAGS}${CPPFLAGS:+ }$element"
+    fi
+  done
+
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for iconv" >&5
+$as_echo_n "checking for iconv... " >&6; }
+if ${am_cv_func_iconv+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+    am_cv_func_iconv="no, consider installing GNU libiconv"
+    am_cv_lib_iconv=no
+    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#include <stdlib.h>
+#include <iconv.h>
+
+int
+main ()
+{
+iconv_t cd = iconv_open("","");
+           iconv(cd,NULL,NULL,NULL,NULL);
+           iconv_close(cd);
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  am_cv_func_iconv=yes
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+    if test "$am_cv_func_iconv" != yes; then
+      am_save_LIBS="$LIBS"
+      LIBS="$LIBS $LIBICONV"
+      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#include <stdlib.h>
+#include <iconv.h>
+
+int
+main ()
+{
+iconv_t cd = iconv_open("","");
+             iconv(cd,NULL,NULL,NULL,NULL);
+             iconv_close(cd);
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  am_cv_lib_iconv=yes
+        am_cv_func_iconv=yes
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+      LIBS="$am_save_LIBS"
+    fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $am_cv_func_iconv" >&5
+$as_echo "$am_cv_func_iconv" >&6; }
+  if test "$am_cv_func_iconv" = yes; then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for working iconv" >&5
+$as_echo_n "checking for working iconv... " >&6; }
+if ${am_cv_func_iconv_works+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+                  am_save_LIBS="$LIBS"
+      if test $am_cv_lib_iconv = yes; then
+        LIBS="$LIBS $LIBICONV"
+      fi
+      am_cv_func_iconv_works=no
+      for ac_iconv_const in '' 'const'; do
+        if test "$cross_compiling" = yes; then :
+  case "$host_os" in
+             aix* | hpux*) am_cv_func_iconv_works="guessing no" ;;
+             *)            am_cv_func_iconv_works="guessing yes" ;;
+           esac
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#include <iconv.h>
+#include <string.h>
+
+#ifndef ICONV_CONST
+# define ICONV_CONST $ac_iconv_const
+#endif
+
+int
+main ()
+{
+int result = 0;
+  /* Test against AIX 5.1...7.2 bug: Failures are not distinguishable from
+     successful returns.  This is even documented in
+     <https://www.ibm.com/support/knowledgecenter/ssw_aix_72/i_bostechref/iconv.html> */
+  {
+    iconv_t cd_utf8_to_88591 = iconv_open ("ISO8859-1", "UTF-8");
+    if (cd_utf8_to_88591 != (iconv_t)(-1))
+      {
+        static ICONV_CONST char input[] = "\342\202\254"; /* EURO SIGN */
+        char buf[10];
+        ICONV_CONST char *inptr = input;
+        size_t inbytesleft = strlen (input);
+        char *outptr = buf;
+        size_t outbytesleft = sizeof (buf);
+        size_t res = iconv (cd_utf8_to_88591,
+                            &inptr, &inbytesleft,
+                            &outptr, &outbytesleft);
+        if (res == 0)
+          result |= 1;
+        iconv_close (cd_utf8_to_88591);
+      }
+  }
+  /* Test against Solaris 10 bug: Failures are not distinguishable from
+     successful returns.  */
+  {
+    iconv_t cd_ascii_to_88591 = iconv_open ("ISO8859-1", "646");
+    if (cd_ascii_to_88591 != (iconv_t)(-1))
+      {
+        static ICONV_CONST char input[] = "\263";
+        char buf[10];
+        ICONV_CONST char *inptr = input;
+        size_t inbytesleft = strlen (input);
+        char *outptr = buf;
+        size_t outbytesleft = sizeof (buf);
+        size_t res = iconv (cd_ascii_to_88591,
+                            &inptr, &inbytesleft,
+                            &outptr, &outbytesleft);
+        if (res == 0)
+          result |= 2;
+        iconv_close (cd_ascii_to_88591);
+      }
+  }
+  /* Test against AIX 6.1..7.1 bug: Buffer overrun.  */
+  {
+    iconv_t cd_88591_to_utf8 = iconv_open ("UTF-8", "ISO-8859-1");
+    if (cd_88591_to_utf8 != (iconv_t)(-1))
+      {
+        static ICONV_CONST char input[] = "\304";
+        static char buf[2] = { (char)0xDE, (char)0xAD };
+        ICONV_CONST char *inptr = input;
+        size_t inbytesleft = 1;
+        char *outptr = buf;
+        size_t outbytesleft = 1;
+        size_t res = iconv (cd_88591_to_utf8,
+                            &inptr, &inbytesleft,
+                            &outptr, &outbytesleft);
+        if (res != (size_t)(-1) || outptr - buf > 1 || buf[1] != (char)0xAD)
+          result |= 4;
+        iconv_close (cd_88591_to_utf8);
+      }
+  }
+#if 0 /* This bug could be worked around by the caller.  */
+  /* Test against HP-UX 11.11 bug: Positive return value instead of 0.  */
+  {
+    iconv_t cd_88591_to_utf8 = iconv_open ("utf8", "iso88591");
+    if (cd_88591_to_utf8 != (iconv_t)(-1))
+      {
+        static ICONV_CONST char input[] = "\304rger mit b\366sen B\374bchen ohne Augenma\337";
+        char buf[50];
+        ICONV_CONST char *inptr = input;
+        size_t inbytesleft = strlen (input);
+        char *outptr = buf;
+        size_t outbytesleft = sizeof (buf);
+        size_t res = iconv (cd_88591_to_utf8,
+                            &inptr, &inbytesleft,
+                            &outptr, &outbytesleft);
+        if ((int)res > 0)
+          result |= 8;
+        iconv_close (cd_88591_to_utf8);
+      }
+  }
+#endif
+  /* Test against HP-UX 11.11 bug: No converter from EUC-JP to UTF-8 is
+     provided.  */
+  {
+    /* Try standardized names.  */
+    iconv_t cd1 = iconv_open ("UTF-8", "EUC-JP");
+    /* Try IRIX, OSF/1 names.  */
+    iconv_t cd2 = iconv_open ("UTF-8", "eucJP");
+    /* Try AIX names.  */
+    iconv_t cd3 = iconv_open ("UTF-8", "IBM-eucJP");
+    /* Try HP-UX names.  */
+    iconv_t cd4 = iconv_open ("utf8", "eucJP");
+    if (cd1 == (iconv_t)(-1) && cd2 == (iconv_t)(-1)
+        && cd3 == (iconv_t)(-1) && cd4 == (iconv_t)(-1))
+      result |= 16;
+    if (cd1 != (iconv_t)(-1))
+      iconv_close (cd1);
+    if (cd2 != (iconv_t)(-1))
+      iconv_close (cd2);
+    if (cd3 != (iconv_t)(-1))
+      iconv_close (cd3);
+    if (cd4 != (iconv_t)(-1))
+      iconv_close (cd4);
+  }
+  return result;
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  am_cv_func_iconv_works=yes
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+        test "$am_cv_func_iconv_works" = no || break
+      done
+      LIBS="$am_save_LIBS"
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $am_cv_func_iconv_works" >&5
+$as_echo "$am_cv_func_iconv_works" >&6; }
+    case "$am_cv_func_iconv_works" in
+      *no) am_func_iconv=no am_cv_lib_iconv=no ;;
+      *)   am_func_iconv=yes ;;
+    esac
+  else
+    am_func_iconv=no am_cv_lib_iconv=no
+  fi
+  if test "$am_func_iconv" = yes; then
+
+$as_echo "#define HAVE_ICONV 1" >>confdefs.h
+
+  fi
+  if test "$am_cv_lib_iconv" = yes; then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking how to link with libiconv" >&5
+$as_echo_n "checking how to link with libiconv... " >&6; }
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $LIBICONV" >&5
+$as_echo "$LIBICONV" >&6; }
+  else
+            CPPFLAGS="$am_save_CPPFLAGS"
+    LIBICONV=
+    LTLIBICONV=
+  fi
+
+
+
+  if test "$am_cv_func_iconv" = yes; then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether iconv is compatible with its POSIX signature" >&5
+$as_echo_n "checking whether iconv is compatible with its POSIX signature... " >&6; }
+if ${gl_cv_iconv_nonconst+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#include <stdlib.h>
+#include <iconv.h>
+extern
+#ifdef __cplusplus
+"C"
+#endif
+size_t iconv (iconv_t cd, char * *inbuf, size_t *inbytesleft, char * *outbuf, size_t *outbytesleft);
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  gl_cv_iconv_nonconst=yes
+else
+  gl_cv_iconv_nonconst=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_iconv_nonconst" >&5
+$as_echo "$gl_cv_iconv_nonconst" >&6; }
+  else
+            gl_cv_iconv_nonconst=yes
+  fi
+  if test $gl_cv_iconv_nonconst = yes; then
+    iconv_arg1=""
+  else
+    iconv_arg1="const"
+  fi
+
+cat >>confdefs.h <<_ACEOF
+#define ICONV_CONST $iconv_arg1
+_ACEOF
+
+
+
+      if test "$am_func_iconv" = yes; then
+    if test -n "$LIBICONV"; then
+      am_cv_func_iconv_summary='yes, in libiconv'
+    else
+      am_cv_func_iconv_summary='yes, in libc'
+    fi
+  else
+    if test "$am_cv_func_iconv" = yes; then
+      am_cv_func_iconv_summary='not working, consider installing GNU libiconv'
+    else
+      am_cv_func_iconv_summary='no, consider installing GNU libiconv'
+    fi
+  fi
+
+MAYBE_LIBICONV=
+case "$host" in
+  *linux*)
+    if test "$am_cv_func_iconv" != yes; then
+      as_fn_error $? "could not find libiconv (required for host $host)" "$LINENO" 5
+    fi
+
+    MAYBE_LIBICONV="$LIBICONV"
+    ;;
+esac
+
+
+
 ac_config_files="$ac_config_files Makefile"
 
 
diff --git a/gdbserver/configure.ac b/gdbserver/configure.ac
index 280043dd7fc3..d9f61ac137f4 100644
--- a/gdbserver/configure.ac
+++ b/gdbserver/configure.ac
@@ -456,6 +456,21 @@ if test x"$STDINT_H" != x; then
 fi
 AC_SUBST(GNULIB_STDINT_H)
 
+# Check for libiconv if needed for the host.
+AM_ICONV
+MAYBE_LIBICONV=
+case "$host" in
+  *linux*)
+    if test "$am_cv_func_iconv" != yes; then
+      AC_MSG_ERROR([could not find libiconv (required for host $host)])
+    fi
+
+    MAYBE_LIBICONV="$LIBICONV"
+    ;;
+esac
+
+AC_SUBST(MAYBE_LIBICONV)
+
 AC_CONFIG_FILES([Makefile])
 
 AC_OUTPUT

base-commit: 62143ef92c28e64f3e4438b6dd4e8bb04a0fed12
-- 
2.44.0


^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2024-02-29 20:45 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2024-02-28 23:15 [PATCH] gdbserver/linux: probe for libiconv in configure Simon Marchi
2024-02-29 17:40 ` Tom Tromey
2024-02-29 20:21   ` Simon Marchi
2024-02-29 20:45     ` Tom Tromey

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