Moved macros from upb.h to port_def.inc to avoid leaking them to users. (#160)

* Use port_def.inc to prevent macros from leaking to users.

* Added helpful comments to port_def.inc/port_undef.inc.

29 files changed, 259 insertions, 151 deletions

diff --git a/upb/bindings/lua/msg.c b/upb/bindings/lua/msg.c
index 1e5e47c..4b8a854 100644
--- a/upb/bindings/lua/msg.c
+++ b/upb/bindings/lua/msg.c
@@ -14,6 +14,8 @@
 #include "upb/legacy_msg_reflection.h"
 #include "upb/msg.h"
 
+#include "upb/port_def.inc"
+
 /*
  * Message/Array/Map objects can be constructed in one of two ways:
  *
diff --git a/upb/bindings/stdc++/string.h b/upb/bindings/stdc++/string.h
index 55b44cf..c346548 100644
--- a/upb/bindings/stdc++/string.h
+++ b/upb/bindings/stdc++/string.h
@@ -4,6 +4,8 @@
 
 #include "upb/sink.h"
 
+#include "upb/port_def.inc"
+
 namespace upb {
 
 template <class T>
@@ -62,4 +64,6 @@ class StringSink {
 
 }  // namespace upb
 
+#include "upb/port_undef.inc"
+
 #endif  // UPB_STDCPP_H_
diff --git a/upb/decode.c b/upb/decode.c
index 996f36a..96622f9 100644
--- a/upb/decode.c
+++ b/upb/decode.c
@@ -3,6 +3,8 @@
 #include "upb/upb.h"
 #include "upb/decode.h"
 
+#include "upb/port_def.inc"
+
 /* Maps descriptor type -> upb field type.  */
 const uint8_t upb_desctype_to_fieldtype[] = {
   UPB_WIRE_TYPE_END_GROUP,  /* ENDGROUP */
diff --git a/upb/def.c b/upb/def.c
index 6721bcb..b51f22a 100644
--- a/upb/def.c
+++ b/upb/def.c
@@ -7,6 +7,8 @@
 #include <string.h>
 #include "google/protobuf/descriptor.upb.h"
 
+#include "upb/port_def.inc"
+
 typedef struct {
   size_t len;
   char str[1];  /* Null-terminated string data follows. */
diff --git a/upb/def.h b/upb/def.h
index c585aa8..c88ce90 100644
--- a/upb/def.h
+++ b/upb/def.h
@@ -37,6 +37,8 @@ class SymbolTable;
 }
 #endif
 
+#include "upb/port_def.inc"
+
 struct upb_enumdef;
 typedef struct upb_enumdef upb_enumdef;
 struct upb_fielddef;
@@ -902,4 +904,6 @@ UPB_INLINE const char* upb_safecstr(const std::string& str) {
 
 #endif  /* __cplusplus */
 
+#include "upb/port_undef.inc"
+
 #endif /* UPB_DEF_H_ */
diff --git a/upb/encode.c b/upb/encode.c
index 2bcf550..576d238 100644
--- a/upb/encode.c
+++ b/upb/encode.c
@@ -7,6 +7,8 @@
 #include "upb/msg.h"
 #include "upb/upb.h"
 
+#include "upb/port_def.inc"
+
 #define UPB_PB_VARINT_MAX_LEN 10
 #define CHK(x) do { if (!(x)) { return false; } } while(0)
 
diff --git a/upb/generated_util.h b/upb/generated_util.h
index 0d5e6ba..314a6d5 100644
--- a/upb/generated_util.h
+++ b/upb/generated_util.h
@@ -9,6 +9,8 @@
 #include <stdint.h>
 #include "upb/msg.h"
 
+#include "upb/port_def.inc"
+
 #define PTR_AT(msg, ofs, type) (type*)((const char*)msg + ofs)
 
 UPB_INLINE const void *_upb_array_accessor(const void *msg, size_t ofs,
@@ -98,4 +100,6 @@ UPB_INLINE bool _upb_has_oneof_field(const void *msg, size_t case_ofs, int32_t n
 
 #undef PTR_AT
 
+#include "upb/port_undef.inc"
+
 #endif  /* UPB_GENERATED_UTIL_H_ */
diff --git a/upb/handlers.c b/upb/handlers.c
index a452663..844a360 100644
--- a/upb/handlers.c
+++ b/upb/handlers.c
@@ -9,6 +9,7 @@
 
 #include "upb/sink.h"
 
+#include "upb/port_def.inc"
 
 struct upb_handlers {
   upb_handlercache *cache;
diff --git a/upb/handlers.h b/upb/handlers.h
index cedd977..856be31 100644
--- a/upb/handlers.h
+++ b/upb/handlers.h
@@ -22,6 +22,8 @@
 #include "upb/def.h"
 #include "upb/table.int.h"
 
+#include "upb/port_def.inc"
+
 #ifdef __cplusplus
 namespace upb {
 class HandlersPtr;
@@ -725,4 +727,6 @@ bool upb_msg_getscalarhandlerdata(const upb_handlers *h,
 
 #include "upb/handlers-inl.h"
 
+#include "upb/port_undef.inc"
+
 #endif  /* UPB_HANDLERS_H */
diff --git a/upb/json/parser.c b/upb/json/parser.c
index 4040370..1e9d2fc 100644
--- a/upb/json/parser.c
+++ b/upb/json/parser.c
@@ -35,6 +35,8 @@
 #include "upb/json/parser.h"
 #include "upb/pb/encoder.h"
 
+#include "upb/port_def.inc"
+
 #define UPB_JSON_MAX_DEPTH 64
 
 /* Type of value message */
@@ -2542,11 +2544,11 @@ static bool does_fieldmask_end(upb_json_parser *p) {
  * final state once, when the closing '"' is seen. */
 
 
-#line 2747 "upb/json/parser.rl"
+#line 2749 "upb/json/parser.rl"
 
 
 
-#line 2550 "upb/json/parser.c"
+#line 2552 "upb/json/parser.c"
 static const char _json_actions[] = {
 	0, 1, 0, 1, 1, 1, 3, 1, 
 	4, 1, 6, 1, 7, 1, 8, 1, 
@@ -2801,7 +2803,7 @@ static const int json_en_value_machine = 78;
 static const int json_en_main = 1;
 
 
-#line 2750 "upb/json/parser.rl"
+#line 2752 "upb/json/parser.rl"
 
 size_t parse(void *closure, const void *hd, const char *buf, size_t size,
              const upb_bufhandle *handle) {
@@ -2824,7 +2826,7 @@ size_t parse(void *closure, const void *hd, const char *buf, size_t size,
   capture_resume(parser, buf);
 
   
-#line 2828 "upb/json/parser.c"
+#line 2830 "upb/json/parser.c"
 	{
 	int _klen;
 	unsigned int _trans;
@@ -2899,147 +2901,147 @@ _match:
 		switch ( *_acts++ )
 		{
 	case 1:
-#line 2555 "upb/json/parser.rl"
+#line 2557 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; goto _again;} }
 	break;
 	case 2:
-#line 2557 "upb/json/parser.rl"
+#line 2559 "upb/json/parser.rl"
 	{ p--; {stack[top++] = cs; cs = 23;goto _again;} }
 	break;
 	case 3:
-#line 2561 "upb/json/parser.rl"
+#line 2563 "upb/json/parser.rl"
 	{ start_text(parser, p); }
 	break;
 	case 4:
-#line 2562 "upb/json/parser.rl"
+#line 2564 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_text(parser, p)); }
 	break;
 	case 5:
-#line 2568 "upb/json/parser.rl"
+#line 2570 "upb/json/parser.rl"
 	{ start_hex(parser); }
 	break;
 	case 6:
-#line 2569 "upb/json/parser.rl"
+#line 2571 "upb/json/parser.rl"
 	{ hexdigit(parser, p); }
 	break;
 	case 7:
-#line 2570 "upb/json/parser.rl"
+#line 2572 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_hex(parser)); }
 	break;
 	case 8:
-#line 2576 "upb/json/parser.rl"
+#line 2578 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(escape(parser, p)); }
 	break;
 	case 9:
-#line 2582 "upb/json/parser.rl"
+#line 2584 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; goto _again;} }
 	break;
 	case 10:
-#line 2587 "upb/json/parser.rl"
+#line 2589 "upb/json/parser.rl"
 	{ start_year(parser, p); }
 	break;
 	case 11:
-#line 2588 "upb/json/parser.rl"
+#line 2590 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_year(parser, p)); }
 	break;
 	case 12:
-#line 2592 "upb/json/parser.rl"
+#line 2594 "upb/json/parser.rl"
 	{ start_month(parser, p); }
 	break;
 	case 13:
-#line 2593 "upb/json/parser.rl"
+#line 2595 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_month(parser, p)); }
 	break;
 	case 14:
-#line 2597 "upb/json/parser.rl"
+#line 2599 "upb/json/parser.rl"
 	{ start_day(parser, p); }
 	break;
 	case 15:
-#line 2598 "upb/json/parser.rl"
+#line 2600 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_day(parser, p)); }
 	break;
 	case 16:
-#line 2602 "upb/json/parser.rl"
+#line 2604 "upb/json/parser.rl"
 	{ start_hour(parser, p); }
 	break;
 	case 17:
-#line 2603 "upb/json/parser.rl"
+#line 2605 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_hour(parser, p)); }
 	break;
 	case 18:
-#line 2607 "upb/json/parser.rl"
+#line 2609 "upb/json/parser.rl"
 	{ start_minute(parser, p); }
 	break;
 	case 19:
-#line 2608 "upb/json/parser.rl"
+#line 2610 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_minute(parser, p)); }
 	break;
 	case 20:
-#line 2612 "upb/json/parser.rl"
+#line 2614 "upb/json/parser.rl"
 	{ start_second(parser, p); }
 	break;
 	case 21:
-#line 2613 "upb/json/parser.rl"
+#line 2615 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_second(parser, p)); }
 	break;
 	case 22:
-#line 2618 "upb/json/parser.rl"
+#line 2620 "upb/json/parser.rl"
 	{ start_duration_base(parser, p); }
 	break;
 	case 23:
-#line 2619 "upb/json/parser.rl"
+#line 2621 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_duration_base(parser, p)); }
 	break;
 	case 24:
-#line 2621 "upb/json/parser.rl"
+#line 2623 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; goto _again;} }
 	break;
 	case 25:
-#line 2626 "upb/json/parser.rl"
+#line 2628 "upb/json/parser.rl"
 	{ start_timestamp_base(parser); }
 	break;
 	case 26:
-#line 2628 "upb/json/parser.rl"
+#line 2630 "upb/json/parser.rl"
 	{ start_timestamp_fraction(parser, p); }
 	break;
 	case 27:
-#line 2629 "upb/json/parser.rl"
+#line 2631 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_timestamp_fraction(parser, p)); }
 	break;
 	case 28:
-#line 2631 "upb/json/parser.rl"
+#line 2633 "upb/json/parser.rl"
 	{ start_timestamp_zone(parser, p); }
 	break;
 	case 29:
-#line 2632 "upb/json/parser.rl"
+#line 2634 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_timestamp_zone(parser, p)); }
 	break;
 	case 30:
-#line 2634 "upb/json/parser.rl"
+#line 2636 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; goto _again;} }
 	break;
 	case 31:
-#line 2639 "upb/json/parser.rl"
+#line 2641 "upb/json/parser.rl"
 	{ start_fieldmask_path_text(parser, p); }
 	break;
 	case 32:
-#line 2640 "upb/json/parser.rl"
+#line 2642 "upb/json/parser.rl"
 	{ end_fieldmask_path_text(parser, p); }
 	break;
 	case 33:
-#line 2645 "upb/json/parser.rl"
+#line 2647 "upb/json/parser.rl"
 	{ start_fieldmask_path(parser); }
 	break;
 	case 34:
-#line 2646 "upb/json/parser.rl"
+#line 2648 "upb/json/parser.rl"
 	{ end_fieldmask_path(parser); }
 	break;
 	case 35:
-#line 2652 "upb/json/parser.rl"
+#line 2654 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; goto _again;} }
 	break;
 	case 36:
-#line 2657 "upb/json/parser.rl"
+#line 2659 "upb/json/parser.rl"
 	{
         if (is_wellknown_msg(parser, UPB_WELLKNOWN_TIMESTAMP)) {
           {stack[top++] = cs; cs = 47;goto _again;}
@@ -3053,11 +3055,11 @@ _match:
       }
 	break;
 	case 37:
-#line 2670 "upb/json/parser.rl"
+#line 2672 "upb/json/parser.rl"
 	{ p--; {stack[top++] = cs; cs = 78;goto _again;} }
 	break;
 	case 38:
-#line 2675 "upb/json/parser.rl"
+#line 2677 "upb/json/parser.rl"
 	{
         if (is_wellknown_msg(parser, UPB_WELLKNOWN_ANY)) {
           start_any_member(parser, p);
@@ -3067,11 +3069,11 @@ _match:
       }
 	break;
 	case 39:
-#line 2682 "upb/json/parser.rl"
+#line 2684 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_membername(parser)); }
 	break;
 	case 40:
-#line 2685 "upb/json/parser.rl"
+#line 2687 "upb/json/parser.rl"
 	{
         if (is_wellknown_msg(parser, UPB_WELLKNOWN_ANY)) {
           end_any_member(parser, p);
@@ -3081,7 +3083,7 @@ _match:
       }
 	break;
 	case 41:
-#line 2696 "upb/json/parser.rl"
+#line 2698 "upb/json/parser.rl"
 	{
         if (is_wellknown_msg(parser, UPB_WELLKNOWN_ANY)) {
           start_any_object(parser, p);
@@ -3091,7 +3093,7 @@ _match:
       }
 	break;
 	case 42:
-#line 2705 "upb/json/parser.rl"
+#line 2707 "upb/json/parser.rl"
 	{
         if (is_wellknown_msg(parser, UPB_WELLKNOWN_ANY)) {
           CHECK_RETURN_TOP(end_any_object(parser, p));
@@ -3101,54 +3103,54 @@ _match:
       }
 	break;
 	case 43:
-#line 2717 "upb/json/parser.rl"
+#line 2719 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(start_array(parser)); }
 	break;
 	case 44:
-#line 2721 "upb/json/parser.rl"
+#line 2723 "upb/json/parser.rl"
 	{ end_array(parser); }
 	break;
 	case 45:
-#line 2726 "upb/json/parser.rl"
+#line 2728 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(start_number(parser, p)); }
 	break;
 	case 46:
-#line 2727 "upb/json/parser.rl"
+#line 2729 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_number(parser, p)); }
 	break;
 	case 47:
-#line 2729 "upb/json/parser.rl"
+#line 2731 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(start_stringval(parser)); }
 	break;
 	case 48:
-#line 2730 "upb/json/parser.rl"
+#line 2732 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_stringval(parser)); }
 	break;
 	case 49:
-#line 2732 "upb/json/parser.rl"
+#line 2734 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_bool(parser, true)); }
 	break;
 	case 50:
-#line 2734 "upb/json/parser.rl"
+#line 2736 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_bool(parser, false)); }
 	break;
 	case 51:
-#line 2736 "upb/json/parser.rl"
+#line 2738 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_null(parser)); }
 	break;
 	case 52:
-#line 2738 "upb/json/parser.rl"
+#line 2740 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(start_subobject_full(parser)); }
 	break;
 	case 53:
-#line 2739 "upb/json/parser.rl"
+#line 2741 "upb/json/parser.rl"
 	{ end_subobject_full(parser); }
 	break;
 	case 54:
-#line 2744 "upb/json/parser.rl"
+#line 2746 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; goto _again;} }
 	break;
-#line 3152 "upb/json/parser.c"
+#line 3154 "upb/json/parser.c"
 		}
 	}
 
@@ -3165,32 +3167,32 @@ _again:
 	while ( __nacts-- > 0 ) {
 		switch ( *__acts++ ) {
 	case 0:
-#line 2553 "upb/json/parser.rl"
+#line 2555 "upb/json/parser.rl"
 	{ p--; {cs = stack[--top]; 	if ( p == pe )
 		goto _test_eof;
 goto _again;} }
 	break;
 	case 46:
-#line 2727 "upb/json/parser.rl"
+#line 2729 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_number(parser, p)); }
 	break;
 	case 49:
-#line 2732 "upb/json/parser.rl"
+#line 2734 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_bool(parser, true)); }
 	break;
 	case 50:
-#line 2734 "upb/json/parser.rl"
+#line 2736 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_bool(parser, false)); }
 	break;
 	case 51:
-#line 2736 "upb/json/parser.rl"
+#line 2738 "upb/json/parser.rl"
 	{ CHECK_RETURN_TOP(end_null(parser)); }
 	break;
 	case 53:
-#line 2739 "upb/json/parser.rl"
+#line 2741 "upb/json/parser.rl"
 	{ end_subobject_full(parser); }
 	break;
-#line 3194 "upb/json/parser.c"
+#line 3196 "upb/json/parser.c"
 		}
 	}
 	}
@@ -3198,7 +3200,7 @@ goto _again;} }
 	_out: {}
 	}
 
-#line 2772 "upb/json/parser.rl"
+#line 2774 "upb/json/parser.rl"
 
   if (p != pe) {
     upb_status_seterrf(parser->status, "Parse error at '%.*s'\n", pe - p, p);
@@ -3241,13 +3243,13 @@ static void json_parser_reset(upb_json_parser *p) {
 
   /* Emit Ragel initialization of the parser. */
   
-#line 3245 "upb/json/parser.c"
+#line 3247 "upb/json/parser.c"
 	{
 	cs = json_start;
 	top = 0;
 	}
 
-#line 2814 "upb/json/parser.rl"
+#line 2816 "upb/json/parser.rl"
   p->current_state = cs;
   p->parser_top = top;
   accumulate_clear(p);
diff --git a/upb/json/parser.rl b/upb/json/parser.rl
index a48a47d..7e260a4 100644
--- a/upb/json/parser.rl
+++ b/upb/json/parser.rl
@@ -33,6 +33,8 @@
 #include "upb/json/parser.h"
 #include "upb/pb/encoder.h"
 
+#include "upb/port_def.inc"
+
 #define UPB_JSON_MAX_DEPTH 64
 
 /* Type of value message */
diff --git a/upb/json/printer.c b/upb/json/printer.c
index 72f26b2..37482a8 100644
--- a/upb/json/printer.c
+++ b/upb/json/printer.c
@@ -10,6 +10,8 @@
 #include <string.h>
 #include <time.h>
 
+#include "upb/port_def.inc"
+
 struct upb_json_printer {
   upb_sink input_;
   /* BytesSink closure. */
diff --git a/upb/legacy_msg_reflection.c b/upb/legacy_msg_reflection.c
index 0140533..0683dde 100644
--- a/upb/legacy_msg_reflection.c
+++ b/upb/legacy_msg_reflection.c
@@ -5,6 +5,8 @@
 #include "upb/table.int.h"
 #include "upb/msg.h"
 
+#include "upb/port_def.inc"
+
 bool upb_fieldtype_mapkeyok(upb_fieldtype_t type) {
   return type == UPB_TYPE_BOOL || type == UPB_TYPE_INT32 ||
          type == UPB_TYPE_UINT32 || type == UPB_TYPE_INT64 ||
diff --git a/upb/legacy_msg_reflection.h b/upb/legacy_msg_reflection.h
index 66d3fba..32a621b 100644
--- a/upb/legacy_msg_reflection.h
+++ b/upb/legacy_msg_reflection.h
@@ -5,6 +5,8 @@
 #include "upb/upb.h"
 #include "upb/msg.h"
 
+#include "upb/port_def.inc"
+
 struct upb_map;
 typedef struct upb_map upb_map;
 
@@ -183,4 +185,6 @@ upb_msgval upb_mapiter_value(const upb_mapiter *i);
 void upb_mapiter_setdone(upb_mapiter *i);
 bool upb_mapiter_isequal(const upb_mapiter *i1, const upb_mapiter *i2);
 
-#endif  // UPB_LEGACY_MSG_REFLECTION_H_
+#include "upb/port_undef.inc"
+
+#endif /* UPB_LEGACY_MSG_REFLECTION_H_ */
diff --git a/upb/msg.c b/upb/msg.c
index d6ad8df..ca2766c 100644
--- a/upb/msg.c
+++ b/upb/msg.c
@@ -3,6 +3,8 @@
 
 #include "upb/table.int.h"
 
+#include "upb/port_def.inc"
+
 #define VOIDPTR_AT(msg, ofs) (void*)((char*)msg + ofs)
 
 /* Internal members of a upb_msg.  We can change this without breaking binary
diff --git a/upb/msgfactory.c b/upb/msgfactory.c
index 2e13199..4ecf272 100644
--- a/upb/msgfactory.c
+++ b/upb/msgfactory.c
@@ -1,6 +1,8 @@
 
 #include "upb/msgfactory.h"
 
+#include "upb/port_def.inc"
+
 static bool is_power_of_two(size_t val) {
   return (val & (val - 1)) == 0;
 }
diff --git a/upb/pb/compile_decoder.c b/upb/pb/compile_decoder.c
index 89f000a..a7d1ac3 100644
--- a/upb/pb/compile_decoder.c
+++ b/upb/pb/compile_decoder.c
@@ -15,6 +15,8 @@
 #include <stdio.h>
 #endif
 
+#include "upb/port_def.inc"
+
 #define MAXLABEL 5
 #define EMPTYLABEL -1
 
diff --git a/upb/pb/decoder.c b/upb/pb/decoder.c
index 2384312..a7a5e7b 100644
--- a/upb/pb/decoder.c
+++ b/upb/pb/decoder.c
@@ -22,6 +22,8 @@
 #include <stdio.h>
 #endif
 
+#include "upb/port_def.inc"
+
 #define CHECK_SUSPEND(x) if (!(x)) return upb_pbdecoder_suspend(d);
 
 /* Error messages that are shared between the bytecode and JIT decoders. */
diff --git a/upb/pb/decoder.int.h b/upb/pb/decoder.int.h
index 42fd7f8..3ed50df 100644
--- a/upb/pb/decoder.int.h
+++ b/upb/pb/decoder.int.h
@@ -11,6 +11,8 @@
 #include "upb/sink.h"
 #include "upb/table.int.h"
 
+#include "upb/port_def.inc"
+
 /* Opcode definitions.  The canonical meaning of each opcode is its
  * implementation in the interpreter (the JIT is written to match this).
  *
@@ -303,4 +305,6 @@ UPB_INLINE void upb_pbdecoder_unpackdispatch(uint64_t dispatch, uint64_t *ofs,
 
 #define CHECK_RETURN(x) { int32_t ret = x; if (ret >= 0) return ret; }
 
+#include "upb/port_undef.inc"
+
 #endif  /* UPB_DECODER_INT_H_ */
diff --git a/upb/pb/encoder.c b/upb/pb/encoder.c
index 5f74010..e7092a8 100644
--- a/upb/pb/encoder.c
+++ b/upb/pb/encoder.c
@@ -57,6 +57,7 @@
 #include "upb/pb/encoder.h"
 #include "upb/pb/varint.int.h"
 
+#include "upb/port_def.inc"
 
 /* The output buffer is divided into segments; a segment is a string of data
  * that is "ready to go" -- it does not need any varint lengths inserted into
diff --git a/upb/pb/textprinter.c b/upb/pb/textprinter.c
index 934130e..7aafffc 100644
--- a/upb/pb/textprinter.c
+++ b/upb/pb/textprinter.c
@@ -16,6 +16,8 @@
 
 #include "upb/sink.h"
 
+#include "upb/port_def.inc"
+
 struct upb_textprinter {
   upb_sink input_;
   upb_bytessink output_;
diff --git a/upb/pb/varint.int.h b/upb/pb/varint.int.h
index b216a94..ddda694 100644
--- a/upb/pb/varint.int.h
+++ b/upb/pb/varint.int.h
@@ -11,6 +11,8 @@
 #include <string.h>
 #include "upb/upb.h"
 
+#include "upb/port_def.inc"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -153,4 +155,6 @@ UPB_INLINE uint64_t upb_vencode32(uint32_t val) {
 }  /* extern "C" */
 #endif
 
+#include "upb/port_undef.inc"
+
 #endif  /* UPB_VARINT_DECODER_H_ */
diff --git a/upb/port_def.inc b/upb/port_def.inc
index fe975a0..1b343d8 100644
--- a/upb/port_def.inc
+++ b/upb/port_def.inc
@@ -1,4 +1,25 @@
-
+/*
+* This is where we define macros used across upb.
+*
+* All of these macros are undef'd in port_undef.inc to avoid leaking them to
+* users.
+*
+* The correct usage is:
+*
+*   #include "upb/foobar.h"
+*   #include "upb/baz.h"
+*
+*   // MUST be last included header.
+*   #include "upb/port_def.inc"
+*
+*   // Code for this file.
+*   // <...>
+*
+*   // Can be omitted for .c files, required for .h.
+*   #include "upb/port_undef.inc"
+*
+* This file is private and must not be included by users!
+*/
 #ifndef UINTPTR_MAX
 #error must include stdint.h first
 #endif
@@ -20,3 +41,83 @@
 #define UPB_WRITE_ONEOF(msg, fieldtype, offset, value, case_offset, case_val) \
   UPB_FIELD_AT(msg, int, case_offset) = case_val;                             \
   UPB_FIELD_AT(msg, fieldtype, offset) = value;
+
+/* UPB_INLINE: inline if possible, emit standalone code if required. */
+#ifdef __cplusplus
+#define UPB_INLINE inline
+#elif defined (__GNUC__)
+#define UPB_INLINE static __inline__
+#else
+#define UPB_INLINE static
+#endif
+
+/* Hints to the compiler about likely/unlikely branches. */
+#define UPB_LIKELY(x) __builtin_expect((x),1)
+
+/* Define UPB_BIG_ENDIAN manually if you're on big endian and your compiler
+ * doesn't provide these preprocessor symbols. */
+#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+#define UPB_BIG_ENDIAN
+#endif
+
+/* Macros for function attributes on compilers that support them. */
+#ifdef __GNUC__
+#define UPB_FORCEINLINE __inline__ __attribute__((always_inline))
+#define UPB_NOINLINE __attribute__((noinline))
+#define UPB_NORETURN __attribute__((__noreturn__))
+#else  /* !defined(__GNUC__) */
+#define UPB_FORCEINLINE
+#define UPB_NOINLINE
+#define UPB_NORETURN
+#endif
+
+#if __STDC_VERSION__ >= 199901L || __cplusplus >= 201103L
+/* C99/C++11 versions. */
+#include <stdio.h>
+#define _upb_snprintf snprintf
+#define _upb_vsnprintf vsnprintf
+#define _upb_va_copy(a, b) va_copy(a, b)
+#elif defined __GNUC__
+/* A few hacky workarounds for functions not in C89.
+ * For internal use only!
+ * TODO(haberman): fix these by including our own implementations, or finding
+ * another workaround.
+ */
+#define _upb_snprintf __builtin_snprintf
+#define _upb_vsnprintf __builtin_vsnprintf
+#define _upb_va_copy(a, b) __va_copy(a, b)
+#else
+#error Need implementations of [v]snprintf and va_copy
+#endif
+
+#ifdef __cplusplus
+#if __cplusplus >= 201103L || defined(__GXX_EXPERIMENTAL_CXX0X__) || \
+    (defined(_MSC_VER) && _MSC_VER >= 1900)
+// C++11 is present
+#else
+#error upb requires C++11 for C++ support
+#endif
+#endif
+
+#define UPB_MAX(x, y) ((x) > (y) ? (x) : (y))
+#define UPB_MIN(x, y) ((x) < (y) ? (x) : (y))
+
+#define UPB_UNUSED(var) (void)var
+
+/* UPB_ASSERT(): in release mode, we use the expression without letting it be
+ * evaluated.  This prevents "unused variable" warnings. */
+#ifdef NDEBUG
+#define UPB_ASSERT(expr) do {} while (false && (expr))
+#else
+#define UPB_ASSERT(expr) assert(expr)
+#endif
+
+/* UPB_ASSERT_DEBUGVAR(): assert that uses functions or variables that only
+ * exist in debug mode.  This turns into regular assert. */
+#define UPB_ASSERT_DEBUGVAR(expr) assert(expr)
+
+#ifdef __GNUC__
+#define UPB_UNREACHABLE() do { assert(0); __builtin_unreachable(); } while(0)
+#else
+#define UPB_UNREACHABLE() do { assert(0); } while(0)
+#endif
diff --git a/upb/port_undef.inc b/upb/port_undef.inc
index 7db97ca..bfd2a08 100644
--- a/upb/port_undef.inc
+++ b/upb/port_undef.inc
@@ -1,5 +1,19 @@
+/* See port_def.inc.  This should #undef all macros #defined there. */
 
 #undef UPB_SIZE
 #undef UPB_FIELD_AT
 #undef UPB_READ_ONEOF
 #undef UPB_WRITE_ONEOF
+#undef UPB_INLINE
+#undef UPB_FORCEINLINE
+#undef UPB_NOINLINE
+#undef UPB_NORETURN
+#undef UPB_MAX
+#undef UPB_MIN
+#undef UPB_UNUSED
+#undef UPB_ASSERT
+#undef UPB_ASSERT_DEBUGVAR
+#undef UPB_UNREACHABLE
+#undef _upb_snprintf
+#undef _upb_vsnprintf
+#undef _upb_va_copy
diff --git a/upb/sink.h b/upb/sink.h
index 4d6d0a3..47d218a 100644
--- a/upb/sink.h
+++ b/upb/sink.h
@@ -20,6 +20,8 @@
 
 #include "upb/handlers.h"
 
+#include "upb/port_def.inc"
+
 #ifdef __cplusplus
 namespace upb {
 class BytesSink;
@@ -509,4 +511,6 @@ template <class T> bool PutBuffer(const T& str, BytesSink sink) {
 
 #endif  /* __cplusplus */
 
+#include "upb/port_undef.inc"
+
 #endif
diff --git a/upb/table.c b/upb/table.c
index 128f607..429861e 100644
--- a/upb/table.c
+++ b/upb/table.c
@@ -8,6 +8,8 @@
 
 #include <string.h>
 
+#include "upb/port_def.inc"
+
 #define UPB_MAXARRSIZE 16  /* 64k. */
 
 /* From Chromium. */
diff --git a/upb/table.int.h b/upb/table.int.h
index 2b86390..762d449 100644
--- a/upb/table.int.h
+++ b/upb/table.int.h
@@ -24,6 +24,8 @@
 #include <string.h>
 #include "upb/upb.h"
 
+#include "upb/port_def.inc"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -500,4 +502,6 @@ bool upb_inttable_iter_isequal(const upb_inttable_iter *i1,
 }  /* extern "C" */
 #endif
 
+#include "upb/port_undef.inc"
+
 #endif  /* UPB_TABLE_H_ */
diff --git a/upb/upb.c b/upb/upb.c
index 0cf5b50..266ea7d 100644
--- a/upb/upb.c
+++ b/upb/upb.c
@@ -1,4 +1,6 @@
 
+#include "upb/upb.h"
+
 #include <errno.h>
 #include <stdarg.h>
 #include <stddef.h>
@@ -6,7 +8,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include "upb/upb.h"
+
+#include "upb/port_def.inc"
 
 /* Guarantee null-termination and provide ellipsis truncation.
  * It may be tempting to "optimize" this by initializing these final
diff --git a/upb/upb.h b/upb/upb.h
index 49bb757..7b5d1c1 100644
--- a/upb/upb.h
+++ b/upb/upb.h
@@ -24,85 +24,7 @@ template <int N> class InlinedArena;
 }
 #endif
 
-/* UPB_INLINE: inline if possible, emit standalone code if required. */
-#ifdef __cplusplus
-#define UPB_INLINE inline
-#elif defined (__GNUC__)
-#define UPB_INLINE static __inline__
-#else
-#define UPB_INLINE static
-#endif
-
-/* Hints to the compiler about likely/unlikely branches. */
-#define UPB_LIKELY(x) __builtin_expect((x),1)
-
-/* Define UPB_BIG_ENDIAN manually if you're on big endian and your compiler
- * doesn't provide these preprocessor symbols. */
-#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
-#define UPB_BIG_ENDIAN
-#endif
-
-/* Macros for function attributes on compilers that support them. */
-#ifdef __GNUC__
-#define UPB_FORCEINLINE __inline__ __attribute__((always_inline))
-#define UPB_NOINLINE __attribute__((noinline))
-#define UPB_NORETURN __attribute__((__noreturn__))
-#else  /* !defined(__GNUC__) */
-#define UPB_FORCEINLINE
-#define UPB_NOINLINE
-#define UPB_NORETURN
-#endif
-
-#if __STDC_VERSION__ >= 199901L || __cplusplus >= 201103L
-/* C99/C++11 versions. */
-#include <stdio.h>
-#define _upb_snprintf snprintf
-#define _upb_vsnprintf vsnprintf
-#define _upb_va_copy(a, b) va_copy(a, b)
-#elif defined __GNUC__
-/* A few hacky workarounds for functions not in C89.
- * For internal use only!
- * TODO(haberman): fix these by including our own implementations, or finding
- * another workaround.
- */
-#define _upb_snprintf __builtin_snprintf
-#define _upb_vsnprintf __builtin_vsnprintf
-#define _upb_va_copy(a, b) __va_copy(a, b)
-#else
-#error Need implementations of [v]snprintf and va_copy
-#endif
-
-#ifdef __cplusplus
-#if __cplusplus >= 201103L || defined(__GXX_EXPERIMENTAL_CXX0X__) || \
-    (defined(_MSC_VER) && _MSC_VER >= 1900)
-// C++11 is present
-#else
-#error upb requires C++11 for C++ support
-#endif
-#endif
-
-#define UPB_MAX(x, y) ((x) > (y) ? (x) : (y))
-#define UPB_MIN(x, y) ((x) < (y) ? (x) : (y))
-
-#define UPB_UNUSED(var) (void)var
-
-/* UPB_ASSERT(): in release mode, we use the expression without letting it be
- * evaluated.  This prevents "unused variable" warnings. */
-#ifdef NDEBUG
-#define UPB_ASSERT(expr) do {} while (false && (expr))
-#else
-#define UPB_ASSERT(expr) assert(expr)
-#endif
-
-/* UPB_ASSERT_DEBUGVAR(): assert that uses functions or variables that only
- * exist in debug mode.  This turns into regular assert. */
-#define UPB_ASSERT_DEBUGVAR(expr) assert(expr)
-
-#ifdef __GNUC__
-#define UPB_UNREACHABLE() do { assert(0); __builtin_unreachable(); } while(0)
-#else
-#define UPB_UNREACHABLE() do { assert(0); } while(0)
-#endif
+#include "upb/port_def.inc"
 
 /* upb_status *****************************************************************/
 
@@ -429,4 +351,6 @@ typedef enum {
 
 extern const uint8_t upb_desctype_to_fieldtype[];
 
+#include "upb/port_undef.inc"
+
 #endif  /* UPB_H_ */