Merge branch 'rightlib' into mergelibs-241016-1210

1 files changed, 355 insertions, 130 deletions

diff --git a/contrib/libs/cxxsupp/builtins/emutls.c b/contrib/libs/cxxsupp/builtins/emutls.c
index 09e79568bd..390ffb25f6 100644
--- a/contrib/libs/cxxsupp/builtins/emutls.c
+++ b/contrib/libs/cxxsupp/builtins/emutls.c
@@ -1,183 +1,408 @@
-/* ===---------- emutls.c - Implements __emutls_get_address ---------------===
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is dual licensed under the MIT and the University of Illinois Open
- * Source Licenses. See LICENSE.TXT for details.
- *
- * ===----------------------------------------------------------------------===
- */
-#include <pthread.h>
+//===---------- emutls.c - Implements __emutls_get_address ---------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "int_lib.h"
-#include "int_util.h"
 
-/* Default is not to use posix_memalign, so systems like Android
- * can use thread local data without heavier POSIX memory allocators.
- */
+#ifdef __BIONIC__
+// There are 4 pthread key cleanup rounds on Bionic. Delay emutls deallocation
+// to round 2. We need to delay deallocation because:
+//  - Android versions older than M lack __cxa_thread_atexit_impl, so apps
+//    use a pthread key destructor to call C++ destructors.
+//  - Apps might use __thread/thread_local variables in pthread destructors.
+// We can't wait until the final two rounds, because jemalloc needs two rounds
+// after the final malloc/free call to free its thread-specific data (see
+// https://reviews.llvm.org/D46978#1107507).
+#define EMUTLS_SKIP_DESTRUCTOR_ROUNDS 1
+#else
+#define EMUTLS_SKIP_DESTRUCTOR_ROUNDS 0
+#endif
+
+#if defined(_MSC_VER) && !defined(__clang__)
+// MSVC raises a warning about a nonstandard extension being used for the 0
+// sized element in this array. Disable this for warn-as-error builds.
+#pragma warning(push)
+#pragma warning(disable : 4200)
+#endif
+
+typedef struct emutls_address_array {
+  uintptr_t skip_destructor_rounds;
+  uintptr_t size; // number of elements in the 'data' array
+  void *data[];
+} emutls_address_array;
+
+#if defined(_MSC_VER) && !defined(__clang__)
+#pragma warning(pop)
+#endif
+
+static void emutls_shutdown(emutls_address_array *array);
+
+#ifndef _WIN32
+
+#include <pthread.h>
+
+static pthread_mutex_t emutls_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_key_t emutls_pthread_key;
+static bool emutls_key_created = false;
+
+typedef unsigned int gcc_word __attribute__((mode(word)));
+typedef unsigned int gcc_pointer __attribute__((mode(pointer)));
+
+// Default is not to use posix_memalign, so systems like Android
+// can use thread local data without heavier POSIX memory allocators.
 #ifndef EMUTLS_USE_POSIX_MEMALIGN
 #define EMUTLS_USE_POSIX_MEMALIGN 0
 #endif
 
-/* For every TLS variable xyz,
- * there is one __emutls_control variable named __emutls_v.xyz.
- * If xyz has non-zero initial value, __emutls_v.xyz's "value"
- * will point to __emutls_t.xyz, which has the initial value.
- */
-typedef struct __emutls_control {
-    size_t size;  /* size of the object in bytes */
-    size_t align;  /* alignment of the object in bytes */
-    union {
-        uintptr_t index;  /* data[index-1] is the object address */
-        void* address;  /* object address, when in single thread env */
-    } object;
-    void* value;  /* null or non-zero initial value for the object */
-} __emutls_control;
-
 static __inline void *emutls_memalign_alloc(size_t align, size_t size) {
-    void *base;
+  void *base;
 #if EMUTLS_USE_POSIX_MEMALIGN
-    if (posix_memalign(&base, align, size) != 0)
-        abort();
+  if (posix_memalign(&base, align, size) != 0)
+    abort();
 #else
-    #define EXTRA_ALIGN_PTR_BYTES (align - 1 + sizeof(void*))
-    char* object;
-    if ((object = malloc(EXTRA_ALIGN_PTR_BYTES + size)) == NULL)
-        abort();
-    base = (void*)(((uintptr_t)(object + EXTRA_ALIGN_PTR_BYTES))
-                    & ~(uintptr_t)(align - 1));
-
-    ((void**)base)[-1] = object;
+#define EXTRA_ALIGN_PTR_BYTES (align - 1 + sizeof(void *))
+  char *object;
+  if ((object = (char *)malloc(EXTRA_ALIGN_PTR_BYTES + size)) == NULL)
+    abort();
+  base = (void *)(((uintptr_t)(object + EXTRA_ALIGN_PTR_BYTES)) &
+                  ~(uintptr_t)(align - 1));
+
+  ((void **)base)[-1] = object;
 #endif
-    return base;
+  return base;
 }
 
 static __inline void emutls_memalign_free(void *base) {
 #if EMUTLS_USE_POSIX_MEMALIGN
-    free(base);
+  free(base);
 #else
-    /* The mallocated address is in ((void**)base)[-1] */
-    free(((void**)base)[-1]);
+  // The mallocated address is in ((void**)base)[-1]
+  free(((void **)base)[-1]);
 #endif
 }
 
-/* Emulated TLS objects are always allocated at run-time. */
-static __inline void *emutls_allocate_object(__emutls_control *control) {
-    /* Use standard C types, check with gcc's emutls.o. */
-    typedef unsigned int gcc_word __attribute__((mode(word)));
-    typedef unsigned int gcc_pointer __attribute__((mode(pointer)));
-    COMPILE_TIME_ASSERT(sizeof(size_t) == sizeof(gcc_word));
-    COMPILE_TIME_ASSERT(sizeof(uintptr_t) == sizeof(gcc_pointer));
-    COMPILE_TIME_ASSERT(sizeof(uintptr_t) == sizeof(void*));
-
-    size_t size = control->size;
-    size_t align = control->align;
-    if (align < sizeof(void*))
-        align = sizeof(void*);
-    /* Make sure that align is power of 2. */
-    if ((align & (align - 1)) != 0)
-        abort();
-
-    void* base = emutls_memalign_alloc(align, size);
-    if (control->value)
-        memcpy(base, control->value, size);
-    else
-        memset(base, 0, size);
-    return base;
+static __inline void emutls_setspecific(emutls_address_array *value) {
+  pthread_setspecific(emutls_pthread_key, (void *)value);
 }
 
-static pthread_mutex_t emutls_mutex = PTHREAD_MUTEX_INITIALIZER;
+static __inline emutls_address_array *emutls_getspecific(void) {
+  return (emutls_address_array *)pthread_getspecific(emutls_pthread_key);
+}
 
-static size_t emutls_num_object = 0;  /* number of allocated TLS objects */
+static void emutls_key_destructor(void *ptr) {
+  emutls_address_array *array = (emutls_address_array *)ptr;
+  if (array->skip_destructor_rounds > 0) {
+    // emutls is deallocated using a pthread key destructor. These
+    // destructors are called in several rounds to accommodate destructor
+    // functions that (re)initialize key values with pthread_setspecific.
+    // Delay the emutls deallocation to accommodate other end-of-thread
+    // cleanup tasks like calling thread_local destructors (e.g. the
+    // __cxa_thread_atexit fallback in libc++abi).
+    array->skip_destructor_rounds--;
+    emutls_setspecific(array);
+  } else {
+    emutls_shutdown(array);
+    free(ptr);
+  }
+}
 
-typedef struct emutls_address_array {
-    uintptr_t size;  /* number of elements in the 'data' array */
-    void* data[];
-} emutls_address_array;
+static __inline void emutls_init(void) {
+  if (pthread_key_create(&emutls_pthread_key, emutls_key_destructor) != 0)
+    abort();
+  emutls_key_created = true;
+}
 
-static pthread_key_t emutls_pthread_key;
+static __inline void emutls_init_once(void) {
+  static pthread_once_t once = PTHREAD_ONCE_INIT;
+  pthread_once(&once, emutls_init);
+}
+
+static __inline void emutls_lock(void) { pthread_mutex_lock(&emutls_mutex); }
+
+static __inline void emutls_unlock(void) { pthread_mutex_unlock(&emutls_mutex); }
+
+#else // _WIN32
+
+#include <assert.h>
+#include <malloc.h>
+#include <stdio.h>
+#include <windows.h>
 
-static void emutls_key_destructor(void* ptr) {
-    emutls_address_array* array = (emutls_address_array*)ptr;
+static LPCRITICAL_SECTION emutls_mutex;
+static DWORD emutls_tls_index = TLS_OUT_OF_INDEXES;
+
+typedef uintptr_t gcc_word;
+typedef void *gcc_pointer;
+
+static void win_error(DWORD last_err, const char *hint) {
+  char *buffer = NULL;
+  if (FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+                         FORMAT_MESSAGE_FROM_SYSTEM |
+                         FORMAT_MESSAGE_MAX_WIDTH_MASK,
+                     NULL, last_err, 0, (LPSTR)&buffer, 1, NULL)) {
+    fprintf(stderr, "Windows error: %s\n", buffer);
+  } else {
+    fprintf(stderr, "Unknown Windows error: %s\n", hint);
+  }
+  LocalFree(buffer);
+}
+
+static __inline void win_abort(DWORD last_err, const char *hint) {
+  win_error(last_err, hint);
+  abort();
+}
+
+static __inline void *emutls_memalign_alloc(size_t align, size_t size) {
+  void *base = _aligned_malloc(size, align);
+  if (!base)
+    win_abort(GetLastError(), "_aligned_malloc");
+  return base;
+}
+
+static __inline void emutls_memalign_free(void *base) { _aligned_free(base); }
+
+static void emutls_exit(void) {
+  if (emutls_mutex) {
+    DeleteCriticalSection(emutls_mutex);
+    _aligned_free(emutls_mutex);
+    emutls_mutex = NULL;
+  }
+  if (emutls_tls_index != TLS_OUT_OF_INDEXES) {
+    emutls_shutdown((emutls_address_array *)TlsGetValue(emutls_tls_index));
+    TlsFree(emutls_tls_index);
+    emutls_tls_index = TLS_OUT_OF_INDEXES;
+  }
+}
+
+static BOOL CALLBACK emutls_init(PINIT_ONCE p0, PVOID p1, PVOID *p2) {
+  (void)p0;
+  (void)p1;
+  (void)p2;
+  emutls_mutex =
+      (LPCRITICAL_SECTION)_aligned_malloc(sizeof(CRITICAL_SECTION), 16);
+  if (!emutls_mutex) {
+    win_error(GetLastError(), "_aligned_malloc");
+    return FALSE;
+  }
+  InitializeCriticalSection(emutls_mutex);
+
+  emutls_tls_index = TlsAlloc();
+  if (emutls_tls_index == TLS_OUT_OF_INDEXES) {
+    emutls_exit();
+    win_error(GetLastError(), "TlsAlloc");
+    return FALSE;
+  }
+  atexit(&emutls_exit);
+  return TRUE;
+}
+
+static __inline void emutls_init_once(void) {
+  static INIT_ONCE once;
+  InitOnceExecuteOnce(&once, emutls_init, NULL, NULL);
+}
+
+static __inline void emutls_lock(void) { EnterCriticalSection(emutls_mutex); }
+
+static __inline void emutls_unlock(void) { LeaveCriticalSection(emutls_mutex); }
+
+static __inline void emutls_setspecific(emutls_address_array *value) {
+  if (TlsSetValue(emutls_tls_index, (LPVOID)value) == 0)
+    win_abort(GetLastError(), "TlsSetValue");
+}
+
+static __inline emutls_address_array *emutls_getspecific(void) {
+  LPVOID value = TlsGetValue(emutls_tls_index);
+  if (value == NULL) {
+    const DWORD err = GetLastError();
+    if (err != ERROR_SUCCESS)
+      win_abort(err, "TlsGetValue");
+  }
+  return (emutls_address_array *)value;
+}
+
+// Provide atomic load/store functions for emutls_get_index if built with MSVC.
+#if !defined(__ATOMIC_RELEASE)
+#include <intrin.h>
+
+enum { __ATOMIC_ACQUIRE = 2, __ATOMIC_RELEASE = 3 };
+
+static __inline uintptr_t __atomic_load_n(void *ptr, unsigned type) {
+  assert(type == __ATOMIC_ACQUIRE);
+  // These return the previous value - but since we do an OR with 0,
+  // it's equivalent to a plain load.
+#ifdef _WIN64
+  return InterlockedOr64(ptr, 0);
+#else
+  return InterlockedOr(ptr, 0);
+#endif
+}
+
+static __inline void __atomic_store_n(void *ptr, uintptr_t val, unsigned type) {
+  assert(type == __ATOMIC_RELEASE);
+  InterlockedExchangePointer((void *volatile *)ptr, (void *)val);
+}
+
+#endif // __ATOMIC_RELEASE
+
+#endif // _WIN32
+
+static size_t emutls_num_object = 0; // number of allocated TLS objects
+
+// Free the allocated TLS data
+static void emutls_shutdown(emutls_address_array *array) {
+  if (array) {
     uintptr_t i;
     for (i = 0; i < array->size; ++i) {
-        if (array->data[i])
-            emutls_memalign_free(array->data[i]);
+      if (array->data[i])
+        emutls_memalign_free(array->data[i]);
     }
-    free(ptr);
+  }
 }
 
-static void emutls_init(void) {
-    if (pthread_key_create(&emutls_pthread_key, emutls_key_destructor) != 0)
-        abort();
+// For every TLS variable xyz,
+// there is one __emutls_control variable named __emutls_v.xyz.
+// If xyz has non-zero initial value, __emutls_v.xyz's "value"
+// will point to __emutls_t.xyz, which has the initial value.
+typedef struct __emutls_control {
+  // Must use gcc_word here, instead of size_t, to match GCC.  When
+  // gcc_word is larger than size_t, the upper extra bits are all
+  // zeros.  We can use variables of size_t to operate on size and
+  // align.
+  gcc_word size;  // size of the object in bytes
+  gcc_word align; // alignment of the object in bytes
+  union {
+    uintptr_t index; // data[index-1] is the object address
+    void *address;   // object address, when in single thread env
+  } object;
+  void *value; // null or non-zero initial value for the object
+} __emutls_control;
+
+// Emulated TLS objects are always allocated at run-time.
+static __inline void *emutls_allocate_object(__emutls_control *control) {
+  // Use standard C types, check with gcc's emutls.o.
+  COMPILE_TIME_ASSERT(sizeof(uintptr_t) == sizeof(gcc_pointer));
+  COMPILE_TIME_ASSERT(sizeof(uintptr_t) == sizeof(void *));
+
+  size_t size = control->size;
+  size_t align = control->align;
+  void *base;
+  if (align < sizeof(void *))
+    align = sizeof(void *);
+  // Make sure that align is power of 2.
+  if ((align & (align - 1)) != 0)
+    abort();
+
+  base = emutls_memalign_alloc(align, size);
+  if (control->value)
+    memcpy(base, control->value, size);
+  else
+    memset(base, 0, size);
+  return base;
 }
 
-/* Returns control->object.index; set index if not allocated yet. */
+// Returns control->object.index; set index if not allocated yet.
 static __inline uintptr_t emutls_get_index(__emutls_control *control) {
-    uintptr_t index = __atomic_load_n(&control->object.index, __ATOMIC_ACQUIRE);
+  uintptr_t index = __atomic_load_n(&control->object.index, __ATOMIC_ACQUIRE);
+  if (!index) {
+    emutls_init_once();
+    emutls_lock();
+    index = control->object.index;
     if (!index) {
-        static pthread_once_t once = PTHREAD_ONCE_INIT;
-        pthread_once(&once, emutls_init);
-        pthread_mutex_lock(&emutls_mutex);
-        index = control->object.index;
-        if (!index) {
-            index = ++emutls_num_object;
-            __atomic_store_n(&control->object.index, index, __ATOMIC_RELEASE);
-        }
-        pthread_mutex_unlock(&emutls_mutex);
+      index = ++emutls_num_object;
+      __atomic_store_n(&control->object.index, index, __ATOMIC_RELEASE);
     }
-    return index;
+    emutls_unlock();
+  }
+  return index;
 }
 
-/* Updates newly allocated thread local emutls_address_array. */
+// Updates newly allocated thread local emutls_address_array.
 static __inline void emutls_check_array_set_size(emutls_address_array *array,
                                                  uintptr_t size) {
-    if (array == NULL)
-        abort();
-    array->size = size;
-    pthread_setspecific(emutls_pthread_key, (void*)array);
+  if (array == NULL)
+    abort();
+  array->size = size;
+  emutls_setspecific(array);
 }
 
-/* Returns the new 'data' array size, number of elements,
- * which must be no smaller than the given index.
- */
+// Returns the new 'data' array size, number of elements,
+// which must be no smaller than the given index.
 static __inline uintptr_t emutls_new_data_array_size(uintptr_t index) {
-   /* Need to allocate emutls_address_array with one extra slot
-    * to store the data array size.
-    * Round up the emutls_address_array size to multiple of 16.
-    */
-    return ((index + 1 + 15) & ~((uintptr_t)15)) - 1;
+  // Need to allocate emutls_address_array with extra slots
+  // to store the header.
+  // Round up the emutls_address_array size to multiple of 16.
+  uintptr_t header_words = sizeof(emutls_address_array) / sizeof(void *);
+  return ((index + header_words + 15) & ~((uintptr_t)15)) - header_words;
+}
+
+// Returns the size in bytes required for an emutls_address_array with
+// N number of elements for data field.
+static __inline uintptr_t emutls_asize(uintptr_t N) {
+  return N * sizeof(void *) + sizeof(emutls_address_array);
 }
 
-/* Returns the thread local emutls_address_array.
- * Extends its size if necessary to hold address at index.
- */
+// Returns the thread local emutls_address_array.
+// Extends its size if necessary to hold address at index.
 static __inline emutls_address_array *
 emutls_get_address_array(uintptr_t index) {
-    emutls_address_array* array = pthread_getspecific(emutls_pthread_key);
-    if (array == NULL) {
-        uintptr_t new_size = emutls_new_data_array_size(index);
-        array = calloc(new_size + 1, sizeof(void*));
-        emutls_check_array_set_size(array, new_size);
-    } else if (index > array->size) {
-        uintptr_t orig_size = array->size;
-        uintptr_t new_size = emutls_new_data_array_size(index);
-        array = realloc(array, (new_size + 1) * sizeof(void*));
-        if (array)
-            memset(array->data + orig_size, 0,
-                   (new_size - orig_size) * sizeof(void*));
-        emutls_check_array_set_size(array, new_size);
+  emutls_address_array *array = emutls_getspecific();
+  if (array == NULL) {
+    uintptr_t new_size = emutls_new_data_array_size(index);
+    array = (emutls_address_array *)malloc(emutls_asize(new_size));
+    if (array) {
+      memset(array->data, 0, new_size * sizeof(void *));
+      array->skip_destructor_rounds = EMUTLS_SKIP_DESTRUCTOR_ROUNDS;
     }
-    return array;
+    emutls_check_array_set_size(array, new_size);
+  } else if (index > array->size) {
+    uintptr_t orig_size = array->size;
+    uintptr_t new_size = emutls_new_data_array_size(index);
+    array = (emutls_address_array *)realloc(array, emutls_asize(new_size));
+    if (array)
+      memset(array->data + orig_size, 0,
+             (new_size - orig_size) * sizeof(void *));
+    emutls_check_array_set_size(array, new_size);
+  }
+  return array;
 }
 
-void* __emutls_get_address(__emutls_control* control) {
-    uintptr_t index = emutls_get_index(control);
-    emutls_address_array* array = emutls_get_address_array(index);
-    if (array->data[index - 1] == NULL)
-        array->data[index - 1] = emutls_allocate_object(control);
-    return array->data[index - 1];
+#ifndef _WIN32
+// Our emulated TLS implementation relies on local state (e.g. for the pthread
+// key), and if we duplicate this state across different shared libraries,
+// accesses to the same TLS variable from different shared libraries will yield
+// different results (see https://github.com/android/ndk/issues/1551 for an
+// example). __emutls_get_address is the only external entry point for emulated
+// TLS, and by making it default visibility and weak, we can rely on the dynamic
+// linker to coalesce multiple copies at runtime and ensure a single unique copy
+// of TLS state. This is a best effort; it won't work if the user is linking
+// with -Bsymbolic or -Bsymbolic-functions, and it also won't work on Windows,
+// where the dynamic linker has no notion of coalescing weak symbols at runtime.
+// A more robust solution would be to create a separate shared library for
+// emulated TLS, to ensure a single copy of its state.
+__attribute__((visibility("default"), weak))
+#endif
+void *__emutls_get_address(__emutls_control *control) {
+  uintptr_t index = emutls_get_index(control);
+  emutls_address_array *array = emutls_get_address_array(index--);
+  if (array->data[index] == NULL)
+    array->data[index] = emutls_allocate_object(control);
+  return array->data[index];
 }
+
+#ifdef __BIONIC__
+// Called by Bionic on dlclose to delete the emutls pthread key.
+__attribute__((visibility("hidden"))) void __emutls_unregister_key(void) {
+  if (emutls_key_created) {
+    pthread_key_delete(emutls_pthread_key);
+    emutls_key_created = false;
+  }
+}
+#endif