Specify C99 explicitly until/unless we stop using bool.

BUILD

@@ -25,12 +25,6 @@ exports_files([
     "build_defs",
 ])
 
-config_setting(
-    name = "darwin",
-    values = {"cpu": "darwin"},
-    visibility = ["//visibility:public"],
-)
-
 config_setting(
     name = "windows",
     constraint_values = ["@bazel_tools//platforms:windows"],

bazel/build_defs.bzl

@@ -18,8 +18,7 @@ UPB_DEFAULT_COPTS = select({
     "//:windows": [],
     "//conditions:default": [
         # copybara:strip_for_google3_begin
-        "-pedantic",
-        "-Werror=pedantic",
+        "-std=c99",
         "-Wstrict-prototypes",
         # copybara:strip_end
     ],

upb/decode_fast.h

@@ -3,7 +3,7 @@
 //
 // The function names are encoded with names like:
 //
-//   //  123
+//   //  123 4
 //   upb_pss_1bt();   // Parse singular string, 1 byte tag.
 //
 // In position 1:
@@ -25,7 +25,11 @@
 //   - 'f4' for 4-byte fixed
 //   - 'f8' for 8-byte fixed
 //   - 'm' for sub-message
-//   - 's' for string
+//   - 's' for string/bytes
+//
+// In position 4 (tag length):
+//   - '1' for one-byte tags (field numbers 1-15)
+//   - '2' for two-byte tags (field numbers 16-2048)
 
 #ifndef UPB_DECODE_FAST_H_
 #define UPB_DECODE_FAST_H_