Introduce static init

PiperOrigin-RevId: 791228365

c/enc/static_init.c

@@ -0,0 +1,47 @@
+/* Copyright 2025 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+/* Central point for static initialization. */
+
+#include "static_init.h"
+
+#include "../common/platform.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+#if (BROTLI_STATIC_INIT != BROTLI_STATIC_INIT_NONE)
+static BROTLI_BOOL DoBrotliEncoderStaticInit(void) {
+  return BROTLI_TRUE;
+}
+#endif
+
+#if (BROTLI_STATIC_INIT == BROTLI_STATIC_INIT_EARLY)
+static BROTLI_BOOL kEarlyInitOk;
+static __attribute__((constructor)) void BrotliEncoderStaticInitEarly(void) {
+  kEarlyInitOk = DoBrotliEncoderStaticInit();
+}
+#elif (BROTLI_STATIC_INIT == BROTLI_STATIC_INIT_LAZY)
+static BROTLI_BOOL kLazyInitOk;
+void BrotliEncoderLazyStaticInitInner(void) {
+  kLazyInitOk = DoBrotliEncoderStaticInit();
+}
+#endif
+
+BROTLI_BOOL BrotliEncoderEnsureStaticInit(void) {
+#if (BROTLI_STATIC_INIT == BROTLI_STATIC_INIT_NONE)
+  return BROTLI_TRUE;
+#elif (BROTLI_STATIC_INIT == BROTLI_STATIC_INIT_EARLY)
+  return kEarlyInitOk;
+#else
+  return kLazyInitOk;
+#endif
+}
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}  /* extern "C" */
+#endif

c/enc/static_init.h

@@ -0,0 +1,66 @@
+/* Copyright 2025 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+/* Central point for static initialization. */
+
+#ifndef THIRD_PARTY_BROTLI_ENC_STATIC_INIT_H_
+#define THIRD_PARTY_BROTLI_ENC_STATIC_INIT_H_
+
+#include "../common/platform.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+/* Static data is "initialized" in compile time. */
+#define BROTLI_STATIC_INIT_NONE 0
+/* Static data is initialized before "main". */
+#define BROTLI_STATIC_INIT_EARLY 1
+/* Static data is initialized when first encoder is created. */
+#define BROTLI_STATIC_INIT_LAZY 2
+
+#if BROTLI_GNUC_HAS_ATTRIBUTE(constructor, 2, 7, 0) && \
+    !defined(BROTLI_EXTERNAL_DICTIONARY_DATA)
+#define BROTLI_STATIC_INIT_DEFAULT BROTLI_STATIC_INIT_EARLY
+#else
+#define BROTLI_STATIC_INIT_DEFAULT BROTLI_STATIC_INIT_NONE
+#endif
+
+#if !defined(BROTLI_STATIC_INIT)
+#define BROTLI_STATIC_INIT BROTLI_STATIC_INIT_DEFAULT
+#endif
+
+#if (BROTLI_STATIC_INIT != BROTLI_STATIC_INIT_NONE) && \
+    (BROTLI_STATIC_INIT != BROTLI_STATIC_INIT_EARLY) && \
+    (BROTLI_STATIC_INIT != BROTLI_STATIC_INIT_LAZY)
+#error Invalid value for BROTLI_STATIC_INIT
+#endif
+
+#if (BROTLI_STATIC_INIT == BROTLI_STATIC_INIT_EARLY)
+#if defined(BROTLI_EXTERNAL_DICTIONARY_DATA)
+#error BROTLI_STATIC_INIT_EARLY will fail with BROTLI_EXTERNAL_DICTIONARY_DATA
+#endif
+#elif (BROTLI_STATIC_INIT == BROTLI_STATIC_INIT_LAZY)
+BROTLI_INTERNAL void BrotliEncoderLazyStaticInitInner(void);
+/* This function is not provided by library. Embedder is responsible for
+   providing it. This function should call `BrotliEncoderLazyStaticInitInner` on
+   the first invocation. This function should not return until execution of
+   `BrotliEncoderLazyStaticInitInner` is finished. In C or before C++11 it is
+   possible to call `BrotliEncoderLazyStaticInitInner` on start-up path and then
+   `BrotliEncoderLazyStaticInit` is no-op; another option is to use available
+   thread execution controls to meet the requirements.
+   For possible C++11 implementation see static_init_lazy.cc.
+ */
+BROTLI_INTERNAL void BrotliEncoderLazyStaticInit(void);
+#endif  /* BROTLI_STATIC_INIT */
+
+BROTLI_INTERNAL BROTLI_BOOL BrotliEncoderEnsureStaticInit(void);
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}  /* extern "C" */
+#endif
+
+#endif  // THIRD_PARTY_BROTLI_ENC_STATIC_INIT_H_

c/enc/static_init_lazy.cc

@@ -0,0 +1,9 @@
+#include "third_party/brotli/enc/static_init.h"
+
+void BrotliEncoderLazyStaticInit(void) {
+  static bool ok = [](){
+    BrotliEncoderLazyStaticInit();
+    return true;
+  }();
+  if (!ok) __builtin_trap();
+}