Switch to a macro to avoid signed/const mismatches.

upb/json_encode.c

@@ -35,11 +35,6 @@ static void jsonenc_msgfields(jsonenc *e, const upb_msg *msg,
                               const upb_msgdef *m, bool first);
 static void jsonenc_value(jsonenc *e, const upb_msg *msg, const upb_msgdef *m);
 
-static char *jsonenc_ptradd(char *ptr, size_t size) {
-  // Generates the same code as "ptr + size" but avoids UB of NULL + 0.
-  return size ? ptr + size : ptr;
-}
-
 UPB_NORETURN static void jsonenc_err(jsonenc *e, const char *msg) {
   upb_status_seterrmsg(e->status, msg);
   longjmp(e->err, 1);
@@ -93,7 +88,7 @@ static void jsonenc_printf(jsonenc *e, const char *fmt, ...) {
   if (UPB_LIKELY(have > n)) {
     e->ptr += n;
   } else {
-    if (have) e->ptr += have;
+    e->ptr = UPB_PTRADD(e->ptr, have);
     e->overflow += (n - have);
   }
 }
@@ -197,7 +192,7 @@ static void jsonenc_bytes(jsonenc *e, upb_strview str) {
   static const char base64[] =
       "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
   const unsigned char *ptr = (unsigned char*)str.data;
-  const unsigned char *end = jsonenc_ptradd(ptr, str.size);
+  const unsigned char *end = UPB_PTRADD(ptr, str.size);
   char buf[4];
 
   jsonenc_putstr(e, "\"");
@@ -233,7 +228,7 @@ static void jsonenc_bytes(jsonenc *e, upb_strview str) {
 
 static void jsonenc_stringbody(jsonenc *e, upb_strview str) {
   const char *ptr = str.data;
-  const char *end = jsonenc_ptradd(ptr, str.size);
+  const char *end = UPB_PTRADD(ptr, str.size);
 
   while (ptr < end) {
     switch (*ptr) {
@@ -705,7 +700,7 @@ size_t upb_json_encode(const upb_msg *msg, const upb_msgdef *m,
 
   e.buf = buf;
   e.ptr = buf;
-  e.end = jsonenc_ptradd(buf, size);
+  e.end = UPB_PTRADD(buf, size);
   e.overflow = 0;
   e.options = options;
   e.ext_pool = ext_pool;

upb/port_def.inc

@@ -135,6 +135,9 @@
 #define UPB_LONGJMP(buf, val) longjmp(buf, val)
 #endif
 
+/* UPB_PTRADD(ptr, ofs): add pointer while avoiding "NULL + 0" UB */
+#define UPB_PTRADD(ptr, ofs) ((ofs) ? (ptr) + (ofs) : (ptr))
+
 /* Configure whether fasttable is switched on or not. *************************/
 
 #if (defined(__x86_64__) || defined(__aarch64__)) && defined(__GNUC__)

upb/port_undef.inc

@@ -1,24 +1,33 @@
 /* See port_def.inc.  This should #undef all macros #defined there. */
 
-#undef UPB_MAPTYPE_STRING
 #undef UPB_SIZE
 #undef UPB_PTR_AT
 #undef UPB_READ_ONEOF
 #undef UPB_WRITE_ONEOF
+#undef UPB_MAPTYPE_STRING
 #undef UPB_INLINE
 #undef UPB_ALIGN_UP
 #undef UPB_ALIGN_DOWN
 #undef UPB_ALIGN_MALLOC
 #undef UPB_ALIGN_OF
+#undef UPB_LIKELY
+#undef UPB_UNLIKELY
 #undef UPB_FORCEINLINE
 #undef UPB_NOINLINE
 #undef UPB_NORETURN
+#undef UPB_PRINTF
 #undef UPB_MAX
 #undef UPB_MIN
 #undef UPB_UNUSED
 #undef UPB_ASSUME
 #undef UPB_ASSERT
 #undef UPB_UNREACHABLE
+#undef UPB_SETJMP
+#undef UPB_LONGJMP
+#undef UPB_PTRADD
+#undef UPB_FASTTABLE_SUPPORTED
+#undef UPB_FASTTABLE
+#undef UPB_FASTTABLE_INIT
 #undef UPB_POISON_MEMORY_REGION
 #undef UPB_UNPOISON_MEMORY_REGION
 #undef UPB_ASAN

upb/text_encode.c

@@ -28,8 +28,10 @@ static void txtenc_putbytes(txtenc *e, const void *data, size_t len) {
     memcpy(e->ptr, data, len);
     e->ptr += len;
   } else {
-    if (have) memcpy(e->ptr, data, have);
-    e->ptr += have;
+    if (have) {
+      memcpy(e->ptr, data, have);
+      e->ptr += have;
+    }
     e->overflow += (len - have);
   }
 }
@@ -50,7 +52,7 @@ static void txtenc_printf(txtenc *e, const char *fmt, ...) {
   if (UPB_LIKELY(have > n)) {
     e->ptr += n;
   } else {
-    e->ptr += have;
+    e->ptr = UPB_PTRADD(e->ptr, have);
     e->overflow += (n - have);
   }
 }
@@ -408,7 +410,7 @@ size_t upb_text_encode(const upb_msg *msg, const upb_msgdef *m,
 
   e.buf = buf;
   e.ptr = buf;
-  e.end = buf + size;
+  e.end = UPB_PTRADD(buf, size);
   e.overflow = 0;
   e.indent_depth = 0;
   e.options = options;