diff --git a/expat/examples/elements.c b/expat/examples/elements.c
index bc04b6b1..0ca1abd9 100644
--- a/expat/examples/elements.c
+++ b/expat/examples/elements.c
@@ -27,6 +27,8 @@ startElement(void *userData, const char *name, const char **atts)
 {
   int i;
   int *depthPtr = (int *)userData;
+  (void)atts;
+
   for (i = 0; i < *depthPtr; i++)
     putchar('\t');
   puts(name);
@@ -37,6 +39,8 @@ static void XMLCALL
 endElement(void *userData, const char *name)
 {
   int *depthPtr = (int *)userData;
+  (void)name;
+
   *depthPtr -= 1;
 }
 
@@ -47,6 +51,9 @@ main(int argc, char *argv[])
   XML_Parser parser = XML_ParserCreate(NULL);
   int done;
   int depth = 0;
+  (void)argc;
+  (void)argv;
+
   XML_SetUserData(parser, &depth);
   XML_SetElementHandler(parser, startElement, endElement);
   do {
diff --git a/expat/examples/outline.c b/expat/examples/outline.c
index 3a3c8385..d9b09176 100644
--- a/expat/examples/outline.c
+++ b/expat/examples/outline.c
@@ -49,6 +49,7 @@ static void XMLCALL
 start(void *data, const char *el, const char **attr)
 {
   int i;
+  (void)data;
 
   for (i = 0; i < Depth; i++)
     printf("  ");
@@ -66,6 +67,9 @@ start(void *data, const char *el, const char **attr)
 static void XMLCALL
 end(void *data, const char *el)
 {
+  (void)data;
+  (void)el;
+
   Depth--;
 }
 
@@ -73,6 +77,9 @@ int
 main(int argc, char *argv[])
 {
   XML_Parser p = XML_ParserCreate(NULL);
+  (void)argc;
+  (void)argv;
+
   if (! p) {
     fprintf(stderr, "Couldn't allocate memory for parser\n");
     exit(-1);
diff --git a/expat/lib/internal.h b/expat/lib/internal.h
index dd545483..8eb71900 100644
--- a/expat/lib/internal.h
+++ b/expat/lib/internal.h
@@ -71,3 +71,11 @@
 #define inline
 #endif
 #endif
+
+#ifndef UNUSED_P
+# ifdef __GNUC__
+#  define UNUSED_P(p) UNUSED_ ## p __attribute__((__unused__))
+# else
+#  define UNUSED_P(p) UNUSED_ ## p
+# endif
+#endif
diff --git a/expat/lib/xmlparse.c b/expat/lib/xmlparse.c
index c0e8f6e2..7586b240 100644
--- a/expat/lib/xmlparse.c
+++ b/expat/lib/xmlparse.c
@@ -4960,9 +4960,9 @@ internalEntityProcessor(XML_Parser parser,
 
 static enum XML_Error PTRCALL
 errorProcessor(XML_Parser parser,
-               const char *s,
-               const char *end,
-               const char **nextPtr)
+               const char *UNUSED_P(s),
+               const char *UNUSED_P(end),
+               const char **UNUSED_P(nextPtr))
 {
   return errorCode;
 }
diff --git a/expat/lib/xmlrole.c b/expat/lib/xmlrole.c
index f6e66ab6..4e79ffdf 100644
--- a/expat/lib/xmlrole.c
+++ b/expat/lib/xmlrole.c
@@ -195,9 +195,9 @@ prolog1(PROLOG_STATE *state,
 static int PTRCALL
 prolog2(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -216,9 +216,9 @@ prolog2(PROLOG_STATE *state,
 static int PTRCALL
 doctype0(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -264,9 +264,9 @@ doctype1(PROLOG_STATE *state,
 static int PTRCALL
 doctype2(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -281,9 +281,9 @@ doctype2(PROLOG_STATE *state,
 static int PTRCALL
 doctype3(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -298,9 +298,9 @@ doctype3(PROLOG_STATE *state,
 static int PTRCALL
 doctype4(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -318,9 +318,9 @@ doctype4(PROLOG_STATE *state,
 static int PTRCALL
 doctype5(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -437,9 +437,9 @@ externalSubset1(PROLOG_STATE *state,
 static int PTRCALL
 entity0(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -457,9 +457,9 @@ entity0(PROLOG_STATE *state,
 static int PTRCALL
 entity1(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -502,9 +502,9 @@ entity2(PROLOG_STATE *state,
 static int PTRCALL
 entity3(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -519,9 +519,9 @@ entity3(PROLOG_STATE *state,
 static int PTRCALL
 entity4(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -559,9 +559,9 @@ entity5(PROLOG_STATE *state,
 static int PTRCALL
 entity6(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -605,9 +605,9 @@ entity7(PROLOG_STATE *state,
 static int PTRCALL
 entity8(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -622,9 +622,9 @@ entity8(PROLOG_STATE *state,
 static int PTRCALL
 entity9(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -639,9 +639,9 @@ entity9(PROLOG_STATE *state,
 static int PTRCALL
 entity10(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -656,9 +656,9 @@ entity10(PROLOG_STATE *state,
 static int PTRCALL
 notation0(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -697,9 +697,9 @@ notation1(PROLOG_STATE *state,
 static int PTRCALL
 notation2(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -714,9 +714,9 @@ notation2(PROLOG_STATE *state,
 static int PTRCALL
 notation3(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -732,9 +732,9 @@ notation3(PROLOG_STATE *state,
 static int PTRCALL
 notation4(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -753,9 +753,9 @@ notation4(PROLOG_STATE *state,
 static int PTRCALL
 attlist0(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -771,9 +771,9 @@ attlist0(PROLOG_STATE *state,
 static int PTRCALL
 attlist1(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -833,9 +833,9 @@ attlist2(PROLOG_STATE *state,
 static int PTRCALL
 attlist3(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -852,9 +852,9 @@ attlist3(PROLOG_STATE *state,
 static int PTRCALL
 attlist4(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -872,9 +872,9 @@ attlist4(PROLOG_STATE *state,
 static int PTRCALL
 attlist5(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -889,9 +889,9 @@ attlist5(PROLOG_STATE *state,
 static int PTRCALL
 attlist6(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -906,9 +906,9 @@ attlist6(PROLOG_STATE *state,
 static int PTRCALL
 attlist7(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -967,9 +967,9 @@ attlist8(PROLOG_STATE *state,
 static int PTRCALL
 attlist9(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -984,9 +984,9 @@ attlist9(PROLOG_STATE *state,
 static int PTRCALL
 element0(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1072,9 +1072,9 @@ element2(PROLOG_STATE *state,
 static int PTRCALL
 element3(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1097,9 +1097,9 @@ element3(PROLOG_STATE *state,
 static int PTRCALL
 element4(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1115,9 +1115,9 @@ element4(PROLOG_STATE *state,
 static int PTRCALL
 element5(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1136,9 +1136,9 @@ element5(PROLOG_STATE *state,
 static int PTRCALL
 element6(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1166,9 +1166,9 @@ element6(PROLOG_STATE *state,
 static int PTRCALL
 element7(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1240,9 +1240,9 @@ condSect0(PROLOG_STATE *state,
 static int PTRCALL
 condSect1(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1258,9 +1258,9 @@ condSect1(PROLOG_STATE *state,
 static int PTRCALL
 condSect2(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1277,9 +1277,9 @@ condSect2(PROLOG_STATE *state,
 static int PTRCALL
 declClose(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1292,11 +1292,11 @@ declClose(PROLOG_STATE *state,
 }
 
 static int PTRCALL
-error(PROLOG_STATE *state,
-      int tok,
-      const char *ptr,
-      const char *end,
-      const ENCODING *enc)
+error(PROLOG_STATE *UNUSED_P(state),
+      int UNUSED_P(tok),
+      const char *UNUSED_P(ptr),
+      const char *UNUSED_P(end),
+      const ENCODING *UNUSED_P(enc))
 {
   return XML_ROLE_NONE;
 }
diff --git a/expat/lib/xmltok.c b/expat/lib/xmltok.c
index 814fe92c..9a8e3adb 100644
--- a/expat/lib/xmltok.c
+++ b/expat/lib/xmltok.c
@@ -122,19 +122,19 @@
     ((*p) == 0xF4 ? (p)[1] > 0x8F : ((p)[1] & 0xC0) == 0xC0)))
 
 static int PTRFASTCALL
-isNever(const ENCODING *enc, const char *p)
+isNever(const ENCODING *UNUSED_P(enc), const char *UNUSED_P(p))
 {
   return 0;
 }
 
 static int PTRFASTCALL
-utf8_isName2(const ENCODING *enc, const char *p)
+utf8_isName2(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_GET_NAMING2(namePages, (const unsigned char *)p);
 }
 
 static int PTRFASTCALL
-utf8_isName3(const ENCODING *enc, const char *p)
+utf8_isName3(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_GET_NAMING3(namePages, (const unsigned char *)p);
 }
@@ -142,13 +142,13 @@ utf8_isName3(const ENCODING *enc, const char *p)
 #define utf8_isName4 isNever
 
 static int PTRFASTCALL
-utf8_isNmstrt2(const ENCODING *enc, const char *p)
+utf8_isNmstrt2(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_GET_NAMING2(nmstrtPages, (const unsigned char *)p);
 }
 
 static int PTRFASTCALL
-utf8_isNmstrt3(const ENCODING *enc, const char *p)
+utf8_isNmstrt3(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_GET_NAMING3(nmstrtPages, (const unsigned char *)p);
 }
@@ -156,19 +156,19 @@ utf8_isNmstrt3(const ENCODING *enc, const char *p)
 #define utf8_isNmstrt4 isNever
 
 static int PTRFASTCALL
-utf8_isInvalid2(const ENCODING *enc, const char *p)
+utf8_isInvalid2(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_INVALID2((const unsigned char *)p);
 }
 
 static int PTRFASTCALL
-utf8_isInvalid3(const ENCODING *enc, const char *p)
+utf8_isInvalid3(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_INVALID3((const unsigned char *)p);
 }
 
 static int PTRFASTCALL
-utf8_isInvalid4(const ENCODING *enc, const char *p)
+utf8_isInvalid4(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_INVALID4((const unsigned char *)p);
 }
@@ -330,7 +330,7 @@ enum {  /* UTF8_cvalN is value of masked first byte of N byte sequence */
 };
 
 static void PTRCALL
-utf8_toUtf8(const ENCODING *enc,
+utf8_toUtf8(const ENCODING *UNUSED_P(enc),
             const char **fromP, const char *fromLim,
             char **toP, const char *toLim)
 {
@@ -437,7 +437,7 @@ static const struct normal_encoding internal_utf8_encoding = {
 };
 
 static void PTRCALL
-latin1_toUtf8(const ENCODING *enc,
+latin1_toUtf8(const ENCODING *UNUSED_P(enc),
               const char **fromP, const char *fromLim,
               char **toP, const char *toLim)
 {
@@ -462,7 +462,7 @@ latin1_toUtf8(const ENCODING *enc,
 }
 
 static void PTRCALL
-latin1_toUtf16(const ENCODING *enc,
+latin1_toUtf16(const ENCODING *UNUSED_P(enc),
                const char **fromP, const char *fromLim,
                unsigned short **toP, const unsigned short *toLim)
 {
@@ -495,7 +495,7 @@ static const struct normal_encoding latin1_encoding = {
 };
 
 static void PTRCALL
-ascii_toUtf8(const ENCODING *enc,
+ascii_toUtf8(const ENCODING *UNUSED_P(enc),
              const char **fromP, const char *fromLim,
              char **toP, const char *toLim)
 {
@@ -548,7 +548,7 @@ unicode_byte_type(char hi, char lo)
 
 #define DEFINE_UTF16_TO_UTF8(E) \
 static void  PTRCALL \
-E ## toUtf8(const ENCODING *enc, \
+E ## toUtf8(const ENCODING *UNUSED_P(enc), \
             const char **fromP, const char *fromLim, \
             char **toP, const char *toLim) \
 { \
@@ -611,7 +611,7 @@ E ## toUtf8(const ENCODING *enc, \
 
 #define DEFINE_UTF16_TO_UTF16(E) \
 static void  PTRCALL \
-E ## toUtf16(const ENCODING *enc, \
+E ## toUtf16(const ENCODING *UNUSED_P(enc), \
              const char **fromP, const char *fromLim, \
              unsigned short **toP, const unsigned short *toLim) \
 { \
@@ -949,7 +949,7 @@ streqci(const char *s1, const char *s2)
 }
 
 static void PTRCALL
-initUpdatePosition(const ENCODING *enc, const char *ptr,
+initUpdatePosition(const ENCODING *UNUSED_P(enc), const char *ptr,
                    const char *end, POSITION *pos)
 {
   normal_updatePosition(&utf8_encoding.enc, ptr, end, pos);
diff --git a/expat/lib/xmltok_impl.c b/expat/lib/xmltok_impl.c
index 9c2895b8..bddec76f 100644
--- a/expat/lib/xmltok_impl.c
+++ b/expat/lib/xmltok_impl.c
@@ -175,7 +175,7 @@ PREFIX(scanDecl)(const ENCODING *enc, const char *ptr,
 }
 
 static int PTRCALL
-PREFIX(checkPiTarget)(const ENCODING *enc, const char *ptr,
+PREFIX(checkPiTarget)(const ENCODING *UNUSED_P(enc), const char *ptr,
                       const char *end, int *tokPtr)
 {
   int upper = 0;
@@ -282,7 +282,7 @@ PREFIX(scanPi)(const ENCODING *enc, const char *ptr,
 }
 
 static int PTRCALL
-PREFIX(scanCdataSection)(const ENCODING *enc, const char *ptr,
+PREFIX(scanCdataSection)(const ENCODING *UNUSED_P(enc), const char *ptr,
                          const char *end, const char **nextTokPtr)
 {
   static const char CDATA_LSQB[] = { ASCII_C, ASCII_D, ASCII_A,
@@ -1521,7 +1521,7 @@ PREFIX(getAtts)(const ENCODING *enc, const char *ptr,
 }
 
 static int PTRFASTCALL
-PREFIX(charRefNumber)(const ENCODING *enc, const char *ptr)
+PREFIX(charRefNumber)(const ENCODING *UNUSED_P(enc), const char *ptr)
 {
   int result = 0;
   /* skip &# */
@@ -1565,7 +1565,7 @@ PREFIX(charRefNumber)(const ENCODING *enc, const char *ptr)
 }
 
 static int PTRCALL
-PREFIX(predefinedEntityName)(const ENCODING *enc, const char *ptr,
+PREFIX(predefinedEntityName)(const ENCODING *UNUSED_P(enc), const char *ptr,
                              const char *end)
 {
   switch ((end - ptr)/MINBPC(enc)) {
@@ -1683,7 +1683,7 @@ PREFIX(sameName)(const ENCODING *enc, const char *ptr1, const char *ptr2)
 }
 
 static int PTRCALL
-PREFIX(nameMatchesAscii)(const ENCODING *enc, const char *ptr1,
+PREFIX(nameMatchesAscii)(const ENCODING *UNUSED_P(enc), const char *ptr1,
                          const char *end1, const char *ptr2)
 {
   for (; *ptr2; ptr1 += MINBPC(enc), ptr2++) {
diff --git a/expat/tests/minicheck.c b/expat/tests/minicheck.c
index f745b509..5a1f5ed0 100644
--- a/expat/tests/minicheck.c
+++ b/expat/tests/minicheck.c
@@ -10,6 +10,7 @@
 #include <setjmp.h>
 #include <assert.h>
 
+#include "internal.h"  /* for UNUSED_P only */
 #include "minicheck.h"
 
 Suite *
@@ -156,7 +157,7 @@ srunner_run_all(SRunner *runner, int verbosity)
 }
 
 void
-_fail_unless(int condition, const char *file, int line, const char *msg)
+_fail_unless(int UNUSED_P(condition), const char *UNUSED_P(file), int UNUSED_P(line), const char *msg)
 {
     /* Always print the error message so it isn't lost.  In this case,
        we have a failure, so there's no reason to be quiet about what
diff --git a/expat/tests/runtests.c b/expat/tests/runtests.c
index a8a6cc26..45adfa5a 100644
--- a/expat/tests/runtests.c
+++ b/expat/tests/runtests.c
@@ -16,6 +16,7 @@
 
 #include "expat.h"
 #include "chardata.h"
+#include "internal.h"  /* for UNUSED_P only */
 #include "minicheck.h"
 
 #if defined(__amigaos__) && defined(__USE_INLINE__)
@@ -110,63 +111,63 @@ _expect_failure(const char *text, enum XML_Error errorCode, const char *errorMes
 */
 
 static void XMLCALL
-dummy_start_doctype_handler(void           *userData,
-                            const XML_Char *doctypeName,
-                            const XML_Char *sysid,
-                            const XML_Char *pubid,
-                            int            has_internal_subset)
+dummy_start_doctype_handler(void           *UNUSED_P(userData),
+                            const XML_Char *UNUSED_P(doctypeName),
+                            const XML_Char *UNUSED_P(sysid),
+                            const XML_Char *UNUSED_P(pubid),
+                            int            UNUSED_P(has_internal_subset))
 {}
 
 static void XMLCALL
-dummy_end_doctype_handler(void *userData)
+dummy_end_doctype_handler(void *UNUSED_P(userData))
 {}
 
 static void XMLCALL
-dummy_entity_decl_handler(void           *userData,
-                          const XML_Char *entityName,
-                          int            is_parameter_entity,
-                          const XML_Char *value,
-                          int            value_length,
-                          const XML_Char *base,
-                          const XML_Char *systemId,
-                          const XML_Char *publicId,
-                          const XML_Char *notationName)
+dummy_entity_decl_handler(void           *UNUSED_P(userData),
+                          const XML_Char *UNUSED_P(entityName),
+                          int            UNUSED_P(is_parameter_entity),
+                          const XML_Char *UNUSED_P(value),
+                          int            UNUSED_P(value_length),
+                          const XML_Char *UNUSED_P(base),
+                          const XML_Char *UNUSED_P(systemId),
+                          const XML_Char *UNUSED_P(publicId),
+                          const XML_Char *UNUSED_P(notationName))
 {}
 
 static void XMLCALL
-dummy_notation_decl_handler(void *userData,
-                            const XML_Char *notationName,
-                            const XML_Char *base,
-                            const XML_Char *systemId,
-                            const XML_Char *publicId)
+dummy_notation_decl_handler(void *UNUSED_P(userData),
+                            const XML_Char *UNUSED_P(notationName),
+                            const XML_Char *UNUSED_P(base),
+                            const XML_Char *UNUSED_P(systemId),
+                            const XML_Char *UNUSED_P(publicId))
 {}
 
 static void XMLCALL
-dummy_element_decl_handler(void *userData,
-                           const XML_Char *name,
-                           XML_Content *model)
+dummy_element_decl_handler(void *UNUSED_P(userData),
+                           const XML_Char *UNUSED_P(name),
+                           XML_Content *UNUSED_P(model))
 {}
 
 static void XMLCALL
-dummy_attlist_decl_handler(void           *userData,
-                           const XML_Char *elname,
-                           const XML_Char *attname,
-                           const XML_Char *att_type,
-                           const XML_Char *dflt,
-                           int            isrequired)
+dummy_attlist_decl_handler(void           *UNUSED_P(userData),
+                           const XML_Char *UNUSED_P(elname),
+                           const XML_Char *UNUSED_P(attname),
+                           const XML_Char *UNUSED_P(att_type),
+                           const XML_Char *UNUSED_P(dflt),
+                           int            UNUSED_P(isrequired))
 {}
 
 static void XMLCALL
-dummy_comment_handler(void *userData, const XML_Char *data)
+dummy_comment_handler(void *UNUSED_P(userData), const XML_Char *UNUSED_P(data))
 {}
 
 static void XMLCALL
-dummy_pi_handler(void *userData, const XML_Char *target, const XML_Char *data)
+dummy_pi_handler(void *UNUSED_P(userData), const XML_Char *UNUSED_P(target), const XML_Char *UNUSED_P(data))
 {}
 
 static void XMLCALL
-dummy_start_element(void *userData,
-                    const XML_Char *name, const XML_Char **atts)
+dummy_start_element(void *UNUSED_P(userData),
+                    const XML_Char *UNUSED_P(name), const XML_Char **UNUSED_P(atts))
 {}
 
 
@@ -231,7 +232,7 @@ accumulate_characters(void *userData, const XML_Char *s, int len)
 }
 
 static void XMLCALL
-accumulate_attribute(void *userData, const XML_Char *name,
+accumulate_attribute(void *userData, const XML_Char *UNUSED_P(name),
                      const XML_Char **atts)
 {
     CharData *storage = (CharData *)userData;
@@ -465,7 +466,7 @@ END_TEST
 
 static void XMLCALL
 start_element_event_handler2(void *userData, const XML_Char *name,
-			     const XML_Char **attr)
+			     const XML_Char **UNUSED_P(attr))
 {
     CharData *storage = (CharData *) userData;
     char buffer[100];
@@ -700,8 +701,8 @@ testhelper_is_whitespace_normalized(void)
 }
 
 static void XMLCALL
-check_attr_contains_normalized_whitespace(void *userData,
-                                          const XML_Char *name,
+check_attr_contains_normalized_whitespace(void *UNUSED_P(userData),
+                                          const XML_Char *UNUSED_P(name),
                                           const XML_Char **atts)
 {
     int i;
@@ -761,7 +762,7 @@ END_TEST
 
 /* Regression test for SF bug #584832. */
 static int XMLCALL
-UnknownEncodingHandler(void *data,const XML_Char *encoding,XML_Encoding *info)
+UnknownEncodingHandler(void *UNUSED_P(data),const XML_Char *encoding,XML_Encoding *info)
 {
     if (strcmp(encoding,"unsupported-encoding") == 0) {
         int i;
@@ -792,9 +793,9 @@ END_TEST
 static int XMLCALL
 external_entity_loader_set_encoding(XML_Parser parser,
                                     const XML_Char *context,
-                                    const XML_Char *base,
-                                    const XML_Char *systemId,
-                                    const XML_Char *publicId)
+                                    const XML_Char *UNUSED_P(base),
+                                    const XML_Char *UNUSED_P(systemId),
+                                    const XML_Char *UNUSED_P(publicId))
 {
     /* This text says it's an unsupported encoding, but it's really
        UTF-8, which we tell Expat using XML_SetEncoding().
@@ -872,9 +873,9 @@ END_TEST
 static int XMLCALL
 external_entity_loader(XML_Parser parser,
                        const XML_Char *context,
-                       const XML_Char *base,
-                       const XML_Char *systemId,
-                       const XML_Char *publicId)
+                       const XML_Char *UNUSED_P(base),
+                       const XML_Char *UNUSED_P(systemId),
+                       const XML_Char *UNUSED_P(publicId))
 {
     char *text = (char *)XML_GetUserData(parser);
     XML_Parser extparser;
@@ -1033,8 +1034,8 @@ static const char *long_character_data_text =
 static XML_Bool resumable = XML_FALSE;
 
 static void
-clearing_aborting_character_handler(void *userData,
-                                    const XML_Char *s, int len)
+clearing_aborting_character_handler(void *UNUSED_P(userData),
+                                    const XML_Char *UNUSED_P(s), int UNUSED_P(len))
 {
     XML_StopParser(parser, resumable);
     XML_SetCharacterDataHandler(parser, NULL);
@@ -1332,8 +1333,8 @@ END_TEST
 
 /* Regression test for SF bug #620343. */
 static void XMLCALL
-start_element_fail(void *userData,
-                   const XML_Char *name, const XML_Char **atts)
+start_element_fail(void *UNUSED_P(userData),
+                   const XML_Char *UNUSED_P(name), const XML_Char **UNUSED_P(atts))
 {
     /* We should never get here. */
     fail("should never reach start_element_fail()");
@@ -1341,8 +1342,8 @@ start_element_fail(void *userData,
 
 static void XMLCALL
 start_ns_clearing_start_element(void *userData,
-                                const XML_Char *prefix,
-                                const XML_Char *uri)
+                                const XML_Char *UNUSED_P(prefix),
+                                const XML_Char *UNUSED_P(uri))
 {
     XML_SetStartElementHandler((XML_Parser) userData, NULL);
 }
@@ -1367,9 +1368,9 @@ END_TEST
 static int XMLCALL
 external_entity_handler(XML_Parser parser,
                         const XML_Char *context,
-                        const XML_Char *base,
-                        const XML_Char *systemId,
-                        const XML_Char *publicId) 
+                        const XML_Char *UNUSED_P(base),
+                        const XML_Char *UNUSED_P(systemId),
+                        const XML_Char *UNUSED_P(publicId))
 {
     intptr_t callno = 1 + (intptr_t)XML_GetUserData(parser);
     const char *text;
diff --git a/expat/xmlwf/codepage.c b/expat/xmlwf/codepage.c
index 57e48ff2..91bd15e9 100644
--- a/expat/xmlwf/codepage.c
+++ b/expat/xmlwf/codepage.c
@@ -3,6 +3,7 @@
 */
 
 #include "codepage.h"
+#include "internal.h"  /* for UNUSED_P only */
 
 #if (defined(WIN32) || (defined(__WATCOMC__) && defined(__NT__)))
 #define STRICT 1
@@ -54,13 +55,13 @@ codepageConvert(int cp, const char *p)
 #else /* not WIN32 */
 
 int
-codepageMap(int cp, int *map)
+codepageMap(int UNUSED_P(cp), int *UNUSED_P(map))
 {
   return 0;
 }
 
 int
-codepageConvert(int cp, const char *p)
+codepageConvert(int UNUSED_P(cp), const char *UNUSED_P(p))
 {
   return -1;
 }
diff --git a/expat/xmlwf/xmlfile.c b/expat/xmlwf/xmlfile.c
index 86880f2c..010036d9 100644
--- a/expat/xmlwf/xmlfile.c
+++ b/expat/xmlwf/xmlfile.c
@@ -21,6 +21,7 @@
 #endif /* ndef COMPILING_FOR_WINDOWS */
 
 #include "expat.h"
+#include "internal.h"  /* for UNUSED_P only */
 #include "xmlfile.h"
 #include "xmltchar.h"
 #include "filemap.h"
@@ -132,7 +133,7 @@ externalEntityRefFilemap(XML_Parser parser,
                          const XML_Char *context,
                          const XML_Char *base,
                          const XML_Char *systemId,
-                         const XML_Char *publicId)
+                         const XML_Char *UNUSED_P(publicId))
 {
   int result;
   XML_Char *s;
@@ -200,7 +201,7 @@ externalEntityRefStream(XML_Parser parser,
                         const XML_Char *context,
                         const XML_Char *base,
                         const XML_Char *systemId,
-                        const XML_Char *publicId)
+                        const XML_Char *UNUSED_P(publicId))
 {
   XML_Char *s;
   const XML_Char *filename;
diff --git a/expat/xmlwf/xmlwf.c b/expat/xmlwf/xmlwf.c
index c4090b0e..360acb50 100644
--- a/expat/xmlwf/xmlwf.c
+++ b/expat/xmlwf/xmlwf.c
@@ -9,6 +9,7 @@
 
 #include "expat.h"
 #include "codepage.h"
+#include "internal.h"  /* for UNUSED_P only */
 #include "xmlfile.h"
 #include "xmltchar.h"
 
@@ -248,49 +249,49 @@ processingInstruction(void *userData, const XML_Char *target,
 #endif /* not W3C14N */
 
 static void XMLCALL
-defaultCharacterData(void *userData, const XML_Char *s, int len)
+defaultCharacterData(void *userData, const XML_Char *UNUSED_P(s), int UNUSED_P(len))
 {
   XML_DefaultCurrent((XML_Parser) userData);
 }
 
 static void XMLCALL
-defaultStartElement(void *userData, const XML_Char *name,
-                    const XML_Char **atts)
+defaultStartElement(void *userData, const XML_Char *UNUSED_P(name),
+                    const XML_Char **UNUSED_P(atts))
 {
   XML_DefaultCurrent((XML_Parser) userData);
 }
 
 static void XMLCALL
-defaultEndElement(void *userData, const XML_Char *name)
+defaultEndElement(void *userData, const XML_Char *UNUSED_P(name))
 {
   XML_DefaultCurrent((XML_Parser) userData);
 }
 
 static void XMLCALL
-defaultProcessingInstruction(void *userData, const XML_Char *target,
-                             const XML_Char *data)
+defaultProcessingInstruction(void *userData, const XML_Char *UNUSED_P(target),
+                             const XML_Char *UNUSED_P(data))
 {
   XML_DefaultCurrent((XML_Parser) userData);
 }
 
 static void XMLCALL
-nopCharacterData(void *userData, const XML_Char *s, int len)
+nopCharacterData(void *UNUSED_P(userData), const XML_Char *UNUSED_P(s), int UNUSED_P(len))
 {
 }
 
 static void XMLCALL
-nopStartElement(void *userData, const XML_Char *name, const XML_Char **atts)
+nopStartElement(void *UNUSED_P(userData), const XML_Char *UNUSED_P(name), const XML_Char **UNUSED_P(atts))
 {
 }
 
 static void XMLCALL
-nopEndElement(void *userData, const XML_Char *name)
+nopEndElement(void *UNUSED_P(userData), const XML_Char *UNUSED_P(name))
 {
 }
 
 static void XMLCALL
-nopProcessingInstruction(void *userData, const XML_Char *target,
-                         const XML_Char *data)
+nopProcessingInstruction(void *UNUSED_P(userData), const XML_Char *UNUSED_P(target),
+                         const XML_Char *UNUSED_P(data))
 {
 }
 
@@ -434,9 +435,9 @@ metaCharacterData(void *userData, const XML_Char *s, int len)
 static void XMLCALL
 metaStartDoctypeDecl(void *userData,
                      const XML_Char *doctypeName,
-                     const XML_Char *sysid,
-                     const XML_Char *pubid,
-                     int has_internal_subset)
+                     const XML_Char *UNUSED_P(sysid),
+                     const XML_Char *UNUSED_P(pubid),
+                     int UNUSED_P(has_internal_subset))
 {
   XML_Parser parser = (XML_Parser) userData;
   FILE *fp = (FILE *)XML_GetUserData(parser);
@@ -458,7 +459,7 @@ metaEndDoctypeDecl(void *userData)
 static void XMLCALL
 metaNotationDecl(void *userData,
                  const XML_Char *notationName,
-                 const XML_Char *base,
+                 const XML_Char *UNUSED_P(base),
                  const XML_Char *systemId,
                  const XML_Char *publicId)
 {
@@ -480,10 +481,10 @@ metaNotationDecl(void *userData,
 static void XMLCALL
 metaEntityDecl(void *userData,
                const XML_Char *entityName,
-               int  is_param,
+               int  UNUSED_P(is_param),
                const XML_Char *value,
                int  value_length,
-               const XML_Char *base,
+               const XML_Char *UNUSED_P(base),
                const XML_Char *systemId,
                const XML_Char *publicId,
                const XML_Char *notationName)
@@ -558,7 +559,7 @@ unknownEncodingConvert(void *data, const char *p)
 }
 
 static int XMLCALL
-unknownEncoding(void *userData, const XML_Char *name, XML_Encoding *info)
+unknownEncoding(void *UNUSED_P(userData), const XML_Char *name, XML_Encoding *info)
 {
   int cp;
   static const XML_Char prefixL[] = T("windows-");
@@ -594,7 +595,7 @@ unknownEncoding(void *userData, const XML_Char *name, XML_Encoding *info)
 }
 
 static int XMLCALL
-notStandalone(void *userData)
+notStandalone(void *UNUSED_P(userData))
 {
   return 0;
 }