Internal change.

PiperOrigin-RevId: 551564132

upbc/BUILD

@@ -213,9 +213,11 @@ cc_library(
     srcs = [
         "code_generator_request.c",
         "code_generator_request.h",
+        "get_used_fields.c",
         "upbdev.c",
     ],
     hdrs = [
+        "get_used_fields.h",
         "upbdev.h",
     ],
     copts = UPB_DEFAULT_COPTS,
@@ -226,11 +228,14 @@ cc_library(
         ":plugin_upb_proto",
         ":plugin_upb_proto_reflection",
         "//:base",
+        "//:descriptor_upb_proto",
         "//:json",
         "//:mem",
         "//:mini_table",
         "//:port",
         "//:reflection",
+        "//:reflection_internal",
+        "//:wire",
         "//upb/json",
         "//upb/mini_descriptor",
     ],

upbc/get_used_fields.c

@@ -0,0 +1,140 @@
+/*
+ * Copyright (c) 2009-2023, Google LLC
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of Google LLC nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL Google LLC BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "upbc/get_used_fields.h"
+
+#include "google/protobuf/descriptor.upb.h"
+#include "google/protobuf/compiler/plugin.upb.h"
+#include "upb/reflection/def_pool.h"
+#include "upb/reflection/field_def.h"
+#include "upb/reflection/message.h"
+#include "upb/reflection/message_def.h"
+#include "upb/wire/decode.h"
+
+// Must be last.
+#include "upb/port/def.inc"
+
+#define upbdev_Err(...)           \
+  {                               \
+    fprintf(stderr, __VA_ARGS__); \
+    exit(1);                      \
+  }
+
+typedef struct {
+  char* buf;
+  size_t size;
+  size_t capacity;
+  upb_Arena* arena;
+} upbdev_StringBuf;
+
+void upbdev_StringBuf_Add(upbdev_StringBuf* buf, const char* sym) {
+  size_t len = strlen(sym);
+  size_t need = buf->size + len + (buf->size != 0);
+  if (need > buf->capacity) {
+    size_t new_cap = UPB_MAX(buf->capacity, 32);
+    while (need > new_cap) new_cap *= 2;
+    buf->buf = upb_Arena_Realloc(buf->arena, buf->buf, buf->capacity, new_cap);
+    buf->capacity = new_cap;
+  }
+  if (buf->size != 0) {
+    buf->buf[buf->size++] = '\n';  // Separator
+  }
+  memcpy(buf->buf + buf->size, sym, len);
+  buf->size = need;
+}
+
+void upbdev_VisitMessage(upbdev_StringBuf* buf, const upb_Message* msg,
+                         const upb_MessageDef* m) {
+  size_t iter = kUpb_Message_Begin;
+  const upb_FieldDef* f;
+  upb_MessageValue val;
+  while (upb_Message_Next(msg, m, NULL, &f, &val, &iter)) {
+    // This could be a duplicate, but we don't worry about it; we'll dedupe
+    // one level up.
+    upbdev_StringBuf_Add(buf, upb_FieldDef_FullName(f));
+
+    if (upb_FieldDef_CType(f) != kUpb_CType_Message) continue;
+    const upb_MessageDef* sub = upb_FieldDef_MessageSubDef(f);
+
+    if (upb_FieldDef_IsMap(f)) {
+      const upb_Map* map = val.map_val;
+      size_t iter = kUpb_Map_Begin;
+      upb_MessageValue map_key, map_val;
+      while (upb_Map_Next(map, &map_key, &map_val, &iter)) {
+        upbdev_VisitMessage(buf, map_val.msg_val, sub);
+      }
+    } else if (upb_FieldDef_IsRepeated(f)) {
+      const upb_Array* arr = val.array_val;
+      size_t n = upb_Array_Size(arr);
+      for (size_t i = 0; i < n; i++) {
+        upb_MessageValue val = upb_Array_Get(arr, i);
+        upbdev_VisitMessage(buf, val.msg_val, sub);
+      }
+    } else {
+      upbdev_VisitMessage(buf, val.msg_val, sub);
+    }
+  }
+}
+
+upb_StringView upbdev_GetUsedFields(const char* request, size_t request_size,
+                                    const char* payload, size_t payload_size,
+                                    const char* message_name,
+                                    upb_Arena* arena) {
+  upb_Arena* tmp_arena = upb_Arena_New();
+  google_protobuf_compiler_CodeGeneratorRequest* request_proto =
+      google_protobuf_compiler_CodeGeneratorRequest_parse(request, request_size,
+                                                 tmp_arena);
+  if (!request_proto) upbdev_Err("Couldn't parse request proto\n");
+
+  size_t len;
+  const google_protobuf_FileDescriptorProto* const* files =
+      google_protobuf_compiler_CodeGeneratorRequest_proto_file(request_proto, &len);
+
+  upb_DefPool* pool = upb_DefPool_New();
+  for (size_t i = 0; i < len; i++) {
+    const upb_FileDef* f = upb_DefPool_AddFile(pool, files[i], NULL);
+    if (!f) upbdev_Err("could not add file to def pool\n");
+  }
+
+  const upb_MessageDef* m = upb_DefPool_FindMessageByName(pool, message_name);
+  if (!m) upbdev_Err("Couldn't find message name\n");
+
+  const upb_MiniTable* mt = upb_MessageDef_MiniTable(m);
+  upb_Message* msg = upb_Message_New(mt, tmp_arena);
+  upb_DecodeStatus st =
+      upb_Decode(payload, payload_size, msg, mt, NULL, 0, tmp_arena);
+  if (st != kUpb_DecodeStatus_Ok) upbdev_Err("Error parsing payload: %d\n", st);
+
+  upbdev_StringBuf buf = {
+      .buf = NULL,
+      .size = 0,
+      .capacity = 0,
+      .arena = arena,
+  };
+  upbdev_VisitMessage(&buf, msg, m);
+  return upb_StringView_FromDataAndSize(buf.buf, buf.size);
+}

upbc/get_used_fields.h

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2009-2023, Google LLC
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of Google LLC nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL Google LLC BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef UPBC_GET_USED_FIELDS
+#define UPBC_GET_USED_FIELDS
+
+#include "upb/base/status.h"
+#include "upb/base/string_view.h"
+#include "upb/mem/arena.h"
+
+// Must be last.
+#include "upb/port/def.inc"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Consume |buf|, deserialize it to a Code_Generator_Request proto, then
+// upbc_Code_Generator_Request, and return it as a JSON-encoded string.
+UPB_API upb_StringView upbdev_GetUsedFields(
+    const char* request, size_t request_size, const char* payload,
+    size_t payload_size, const char* message_name, upb_Arena* arena);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#include "upb/port/undef.inc"
+
+#endif  // UPBC_GET_USED_FIELDS

upbc/upbc_so.c

@@ -27,4 +27,5 @@
 
 // These headers form a spanning tree for the upbc defs needed by FFI layers.
 
+#include "upbc/get_used_fields.h"
 #include "upbc/upbdev.h"