Issue #1824 - Support SunOS Linker mapfiles.

Generating OS-appropriate mapfiles from a provided SYMBOL_FILE is
apparently required to work with newer ffvpx. Nothing else in our
codebase actually seemed to require it. Also seems to reduce the amount
of console spam I see relating to symbol visibility during the build
process, and I think it even makes libxul.so link a bit faster.

Signed-off-by: athenian200 <athenian200@outlook.com>

config/rules.mk

@@ -411,6 +411,10 @@ EXTRA_DSO_LDOPTS += -Wl,--version-script,$(SYMBOLS_FILE)
 else
 ifeq ($(OS_TARGET),Darwin)
 EXTRA_DSO_LDOPTS += -Wl,-exported_symbols_list,$(SYMBOLS_FILE)
+else
+ifeq ($(OS_TARGET),SunOS)
+EXTRA_DSO_LDOPTS += -Wl,-M,$(SYMBOLS_FILE)
+endif
 endif
 endif
 endif

python/mozbuild/mozbuild/action/generate_symbols_file.py

@@ -83,6 +83,20 @@ def generate_symbols_file(output, *args):
         # };
         output.write('{\nglobal:\n  %s;\nlocal:\n  *;\n};'
                      % ';\n  '.join(symbols))
+    elif buildconfig.substs['OS_TARGET'] == 'SunOS':
+        # A linker version script is generated for Sun LD that looks like the
+        # following:
+        # $mapfile_version 2
+        # SYMBOL_VERSION SUNW_1.1 {
+        # global:
+        #   symbol1;
+        #   symbol2;
+        #   ...
+        # local:
+        #   *;
+        # };
+        output.write('$mapfile_version 2\nSYMBOL_VERSION SUNW_1.1 {\nglobal:\n  %s;\nlocal:\n  *;\n};'
+                     % ';\n  '.join(symbols))
     elif buildconfig.substs['OS_TARGET'] == 'Darwin':
         # A list of symbols is generated for Apple ld that simply lists all
         # symbols, with an underscore prefix.