Add support for declaring elf visibility attributes.  Used to
help cleanup TEXTRELs in misc libraries (like libsdl).

Syntax to declare function foo hidden:
GLOBAL foo:function hidden

Patch by Mike Frysinger <vapier@gentoo.org>

http://sourceforge.net/mailarchive/forum.php?thread_id=9230919&forum_id=4978

--- nasm/output/outelf.c
+++ nasm/output/outelf.c
@@ -50,6 +50,7 @@ struct Symbol {
     long strpos;                /* string table position of name */
     long section;               /* section ID of the symbol */
     int type;                   /* symbol type */
+    int other;                  /* symbol visibility */
     long value;                 /* address, or COMMON variable align */
     long size;                  /* size of symbol */
     long globnum;               /* symbol table offset if global */
@@ -113,9 +114,15 @@ extern struct ofmt of_elf;
 
 #define SYM_SECTION 0x04
 #define SYM_GLOBAL 0x10
+#define SYM_NOTYPE 0x00
 #define SYM_DATA 0x01
 #define SYM_FUNCTION 0x02
 
+#define STV_DEFAULT 0
+#define STV_INTERNAL 1
+#define STV_HIDDEN 2
+#define STV_PROTECTED 3
+
 #define GLOBAL_TEMP_BASE 16     /* bigger than any constant sym id */
 
 #define SEG_ALIGN 16            /* alignment of sections in file */
@@ -493,6 +500,7 @@ static void elf_deflabel(char *name, lon
 
     sym->strpos = pos;
     sym->type = is_global ? SYM_GLOBAL : 0;
+    sym->other = STV_DEFAULT;
     sym->size = 0;
     if (segment == NO_SEG)
         sym->section = SHN_ABS;
@@ -570,18 +578,39 @@ static void elf_deflabel(char *name, lon
             sym->next = sects[sym->section - 1]->gsyms;
             sects[sym->section - 1]->gsyms = sym;
 
+            /* ELF syntax: GLOBAL name[:type [visibility]] */
             if (special) {
-                int n = strcspn(special, " ");
-
+                int n = strcspn(special, " \t");
                 if (!nasm_strnicmp(special, "function", n))
                     sym->type |= SYM_FUNCTION;
                 else if (!nasm_strnicmp(special, "data", n) ||
                          !nasm_strnicmp(special, "object", n))
                     sym->type |= SYM_DATA;
+                else if (!nasm_strnicmp(special, "notype", n))
+                    sym->type |= SYM_NOTYPE;
                 else
                     error(ERR_NONFATAL, "unrecognised symbol type `%.*s'",
                           n, special);
+                special += n;
+
+                while (isspace(*special))
+                    ++special;
+                if (*special) {
+                    n = strcspn(special, " \t");
+                    if (!nasm_strnicmp(special, "default", n))
+                        sym->other = STV_DEFAULT;
+                    else if (!nasm_strnicmp(special, "internal", n))
+                        sym->other = STV_INTERNAL;
+                    else if (!nasm_strnicmp(special, "hidden", n))
+                        sym->other = STV_HIDDEN;
+                    else if (!nasm_strnicmp(special, "protected", n))
+                        sym->other = STV_PROTECTED;
+                    else
+                        n = 0;
+                    special += n;
+                }
+
-                if (special[n]) {
+                if (*special) {
                     struct tokenval tokval;
                     expr *e;
                     int fwd = FALSE;
@@ -1120,7 +1149,8 @@ static struct SAA *elf_build_symtab(long
         WRITELONG(p, sym->strpos);
         WRITELONG(p, sym->value);
         WRITELONG(p, sym->size);
-        WRITESHORT(p, sym->type);       /* local non-typed thing */
+        WRITECHAR(p, sym->type);       /* local non-typed thing */
+        WRITECHAR(p, sym->other);
         WRITESHORT(p, sym->section);
         saa_wbytes(s, entry, 16L);
         *len += 16;
@@ -1138,7 +1168,8 @@ static struct SAA *elf_build_symtab(long
         WRITELONG(p, sym->strpos);
         WRITELONG(p, sym->value);
         WRITELONG(p, sym->size);
-        WRITESHORT(p, sym->type);       /* global non-typed thing */
+        WRITECHAR(p, sym->type);       /* global non-typed thing */
+        WRITECHAR(p, sym->other);
         WRITESHORT(p, sym->section);
         saa_wbytes(s, entry, 16L);
         *len += 16;