Add multiarch dirs to linker search path

By default, tcc search libraries in /lib and /usr/local/lib while crt*.o
files are searched in /usr/lib and ld.so is searched in /lib.
Unfortunetely the path are hardcoded in source code. This patch allow
tcc to look in an other directory and also to look in extra directories.
It's then possible to make tcc search libraries in /lib/x86_64-linux-gnu
and /usr/local/lib/x86_64-linux-gnu while crt*.o files are searched in
/usr/lib/x86_64-linux-gnu and ld.so is searched in
/lib/x86_64-linux-gnu.

configure

@@ -26,6 +26,8 @@ prefix=""
 execprefix=""
 bindir=""
 libdir=""
+lddir=""
+extralddir=""
 tccdir=""
 includedir=""
 mandir=""
@@ -108,6 +110,10 @@ for opt do
   ;;
   --libdir=*) libdir=`echo $opt | cut -d '=' -f 2`
   ;;
+  --lddir=*) lddir=`echo $opt | cut -d '=' -f 2`
+  ;;
+  --extralddir=*) extralddir="$extralddir:`echo $opt | cut -d '=' -f 2`"
+  ;;
   --includedir=*) includedir=`echo $opt | cut -d '=' -f 2`
   ;;
   --sharedir=*) sharedir=`echo $opt | cut -d '=' -f 2`
@@ -241,6 +247,8 @@ echo "  --exec-prefix=EPREFIX    install architecture-dependent files in EPREFIX
 echo "                           [same as prefix]"
 echo "  --bindir=DIR             user executables in DIR [EPREFIX/bin]"
 echo "  --libdir=DIR             object code libraries in DIR [EPREFIX/lib]"
+echo "  --lddir=DIR              loader library search path in DIR [/lib]"
+echo "  --extralddir=DIR         extra loader library search path in DIR []"
 echo "  --tccdir=DIR             installation directory [EPREFIX/lib/tcc]"
 echo "  --includedir=DIR         C header files in DIR [PREFIX/include]"
 echo "  --sharedir=DIR           documentation root DIR [PREFIX]/share"
@@ -322,21 +330,23 @@ if test x"$includedir" = x""; then
 includedir="${prefix}/include"
 fi
 
-echo "Binary  directory   $bindir"
+echo "Binary  directory                      $bindir"
-echo "TinyCC directory    $tccdir"
+echo "TinyCC directory                       $tccdir"
-echo "Library directory   $libdir"
+echo "Library directory                      $libdir"
-echo "Include directory   $includedir"
+echo "Loader library search directory        ${lddir:-default value (see tcc.h)}"
-echo "Manual directory    $mandir"
+echo "Extra loader library search directory  ${extralddir:-(none)}"
-echo "Info directory      $infodir"
+echo "Include directory                      $includedir"
-echo "Doc directory       $docdir"
+echo "Manual directory                       $mandir"
-echo "Target root prefix  $sysroot"
+echo "Info directory                         $infodir"
-echo "Source path      $source_path"
+echo "Doc directory                          $docdir"
-echo "C compiler       $cc"
+echo "Target root prefix                     $sysroot"
-echo "CPU              $cpu"
+echo "Source path                            $source_path"
-echo "Big Endian       $bigendian"
+echo "C compiler                             $cc"
-echo "gprof enabled    $gprof"
+echo "CPU                                    $cpu"
-echo "cross compilers  $build_cross"
+echo "Big Endian                             $bigendian"
-echo "use libgcc       $use_libgcc"
+echo "gprof enabled                          $gprof"
+echo "cross compilers                        $build_cross"
+echo "use libgcc                             $use_libgcc"
 
 echo "Creating config.mak and config.h"
 
@@ -356,6 +366,8 @@ echo "docdir=\$(DESTDIR)$docdir" >> config.mak
 echo "#define CONFIG_SYSROOT \"$sysroot\"" >> $TMPH
 echo "#ifndef CONFIG_TCCDIR" >> $TMPH
 echo "#define CONFIG_TCCDIR \"$tccdir\"" >> $TMPH
+echo "#define CONFIG_TCC_LDDIR \"$lddir\"" >> $TMPH
+echo "#define CONFIG_TCC_EXTRA_LDDIR \"$extralddir\"" >> $TMPH
 echo "#endif" >> $TMPH
 echo "CC=$cc" >> config.mak
 echo "GCC_MAJOR=$gcc_major" >> config.mak

libtcc.c

@@ -971,6 +971,30 @@ LIBTCCAPI TCCState *tcc_new(void)
     tcc_add_library_path(s, CONFIG_TCC_CRT_PREFIX);
     tcc_add_library_path(s, CONFIG_SYSROOT CONFIG_TCC_LDDIR);
     tcc_add_library_path(s, CONFIG_SYSROOT "/usr/local"CONFIG_TCC_LDDIR);
+#ifdef CONFIG_TCC_EXTRA_LDDIR
+    {
+        const char delim[] = ":";
+        char *tok, *tok_extra_libdir = NULL, *tok_save_ptr, *extra_libdir_str;
+        size_t toklen = 0, old_toklen = 0;
+
+        extra_libdir_str = tcc_strdup(CONFIG_TCC_EXTRA_LDDIR);
+        tok = strtok_r(extra_libdir_str, delim, &tok_save_ptr);
+        while (tok != NULL)
+        {
+            toklen = strlen(CONFIG_SYSROOT "/usr/local") + strlen(tok);
+            if (toklen > old_toklen)
+                tok_extra_libdir = tcc_realloc(tok_extra_libdir,
+                                               toklen * sizeof(char));
+            /* No need for snprintf: value in tok comes from tcc compilation */
+            sprintf(tok_extra_libdir, CONFIG_SYSROOT "%s", tok);
+            tcc_add_library_path(s, tok_extra_libdir);
+            sprintf(tok_extra_libdir, CONFIG_SYSROOT "/usr/local%s", tok);
+            tcc_add_library_path(s, tok_extra_libdir);
+            tok = strtok_r(NULL, delim, &tok_save_ptr);
+        }
+        tcc_free(tok_extra_libdir);
+    }
+#endif
 #endif
 
     /* no section zero */

tcc.h

@@ -142,13 +142,14 @@ typedef int BOOL;
 /* path to find crt1.o, crti.o and crtn.o. Only needed when generating
    executables or dlls */
 
-#if defined(TCC_TARGET_X86_64_CENTOS)
+#ifndef CONFIG_TCC_LDDIR
-# define CONFIG_TCC_CRT_PREFIX CONFIG_SYSROOT "/usr/lib64"
+  #if defined(TCC_TARGET_X86_64_CENTOS)
-# define CONFIG_TCC_LDDIR "/lib64"
+    #define CONFIG_TCC_LDDIR "/lib64"
-#else
+  #else
-# define CONFIG_TCC_CRT_PREFIX CONFIG_SYSROOT "/usr/lib"
+    #define CONFIG_TCC_LDDIR "/lib"
-# define CONFIG_TCC_LDDIR "/lib"
+  #endif
 #endif
+#define CONFIG_TCC_CRT_PREFIX CONFIG_SYSROOT "/usr" CONFIG_TCC_LDDIR
 
 #define INCLUDE_STACK_SIZE  32
 #define IFDEF_STACK_SIZE    64