Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 505 insertions, 0 deletions

diff --git a/REORG.TODO/malloc/tst-mallocstate.c b/REORG.TODO/malloc/tst-mallocstate.c
new file mode 100644
index 0000000000..5cb39c0f3d
--- /dev/null
+++ b/REORG.TODO/malloc/tst-mallocstate.c
@@ -0,0 +1,505 @@
+/* Emulate Emacs heap dumping to test malloc_set_state.
+   Copyright (C) 2001-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Wolfram Gloger <wg@malloc.de>, 2001.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <libc-symbols.h>
+#include <shlib-compat.h>
+
+#include "malloc.h"
+
+/* Make the compatibility symbols availabile to this test case.  */
+void *malloc_get_state (void);
+compat_symbol_reference (libc, malloc_get_state, malloc_get_state, GLIBC_2_0);
+int malloc_set_state (void *);
+compat_symbol_reference (libc, malloc_set_state, malloc_set_state, GLIBC_2_0);
+
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
+
+/* Maximum object size in the fake heap.  */
+enum { max_size = 64 };
+
+/* Allocation actions.  These are randomized actions executed on the
+   dumped heap (see allocation_tasks below).  They are interspersed
+   with operations on the new heap (see heap_activity).  */
+enum allocation_action
+  {
+    action_free,                /* Dumped and freed.  */
+    action_realloc,             /* Dumped and realloc'ed.  */
+    action_realloc_same,        /* Dumped and realloc'ed, same size.  */
+    action_realloc_smaller,     /* Dumped and realloc'ed, shrinked.  */
+    action_count
+  };
+
+/* Dumped heap.  Initialize it, so that the object is placed into the
+   .data section, for increased realism.  The size is an upper bound;
+   we use about half of the space.  */
+static size_t dumped_heap[action_count * max_size * max_size
+                          / sizeof (size_t)] = {1};
+
+/* Next free space in the dumped heap.  Also top of the heap at the
+   end of the initialization procedure.  */
+static size_t *next_heap_chunk;
+
+/* Copied from malloc.c and hooks.c.  The version is deliberately
+   lower than the final version of malloc_set_state.  */
+#define NBINS 128
+#define MALLOC_STATE_MAGIC   0x444c4541l
+#define MALLOC_STATE_VERSION (0 * 0x100l + 4l)
+static struct
+{
+  long magic;
+  long version;
+  void *av[NBINS * 2 + 2];
+  char *sbrk_base;
+  int sbrked_mem_bytes;
+  unsigned long trim_threshold;
+  unsigned long top_pad;
+  unsigned int n_mmaps_max;
+  unsigned long mmap_threshold;
+  int check_action;
+  unsigned long max_sbrked_mem;
+  unsigned long max_total_mem;
+  unsigned int n_mmaps;
+  unsigned int max_n_mmaps;
+  unsigned long mmapped_mem;
+  unsigned long max_mmapped_mem;
+  int using_malloc_checking;
+  unsigned long max_fast;
+  unsigned long arena_test;
+  unsigned long arena_max;
+  unsigned long narenas;
+} save_state =
+  {
+    .magic = MALLOC_STATE_MAGIC,
+    .version = MALLOC_STATE_VERSION,
+  };
+
+/* Allocate a blob in the fake heap.  */
+static void *
+dumped_heap_alloc (size_t length)
+{
+  /* malloc needs three state bits in the size field, so the minimum
+     alignment is 8 even on 32-bit architectures.  malloc_set_state
+     should be compatible with such heaps even if it currently
+     provides more alignment to applications.  */
+  enum
+  {
+    heap_alignment = 8,
+    heap_alignment_mask = heap_alignment - 1
+  };
+  _Static_assert (sizeof (size_t) <= heap_alignment,
+                  "size_t compatible with heap alignment");
+
+  /* Need at least this many bytes for metadata and application
+     data. */
+  size_t chunk_size = sizeof (size_t) + length;
+  /* Round up the allocation size to the heap alignment.  */
+  chunk_size += heap_alignment_mask;
+  chunk_size &= ~heap_alignment_mask;
+  if ((chunk_size & 3) != 0)
+    {
+      /* The lower three bits in the chunk size have to be 0.  */
+      write_message ("error: dumped_heap_alloc computed invalid chunk size\n");
+      _exit (1);
+    }
+  if (next_heap_chunk == NULL)
+    /* Initialize the top of the heap.  Add one word of zero padding,
+       to match existing practice.  */
+    {
+      dumped_heap[0] = 0;
+      next_heap_chunk = dumped_heap + 1;
+    }
+  else
+    /* The previous chunk is allocated. */
+    chunk_size |= 1;
+  *next_heap_chunk = chunk_size;
+
+  /* User data starts after the chunk header.  */
+  void *result = next_heap_chunk + 1;
+  next_heap_chunk += chunk_size / sizeof (size_t);
+
+  /* Mark the previous chunk as used.   */
+  *next_heap_chunk = 1;
+  return result;
+}
+
+/* Global seed variable for the random number generator.  */
+static unsigned long long global_seed;
+
+/* Simple random number generator.  The numbers are in the range from
+   0 to UINT_MAX (inclusive).  */
+static unsigned int
+rand_next (unsigned long long *seed)
+{
+  /* Linear congruential generated as used for MMIX.  */
+  *seed = *seed * 6364136223846793005ULL + 1442695040888963407ULL;
+  return *seed >> 32;
+}
+
+/* Fill LENGTH bytes at BUFFER with random contents, as determined by
+   SEED.  */
+static void
+randomize_buffer (unsigned char *buffer, size_t length,
+                  unsigned long long seed)
+{
+  for (size_t i = 0; i < length; ++i)
+    buffer[i] = rand_next (&seed);
+}
+
+/* Dumps the buffer to standard output,  in hexadecimal.  */
+static void
+dump_hex (unsigned char *buffer, size_t length)
+{
+  for (int i = 0; i < length; ++i)
+    printf (" %02X", buffer[i]);
+}
+
+/* Set to true if an error is encountered.  */
+static bool errors = false;
+
+/* Keep track of object allocations.  */
+struct allocation
+{
+  unsigned char *data;
+  unsigned int size;
+  unsigned int seed;
+};
+
+/* Check that the allocation task allocation has the expected
+   contents.  */
+static void
+check_allocation (const struct allocation *alloc, int index)
+{
+  size_t size = alloc->size;
+  if (alloc->data == NULL)
+    {
+      printf ("error: NULL pointer for allocation of size %zu at %d, seed %u\n",
+              size, index, alloc->seed);
+      errors = true;
+      return;
+    }
+
+  unsigned char expected[4096];
+  if (size > sizeof (expected))
+    {
+      printf ("error: invalid allocation size %zu at %d, seed %u\n",
+              size, index, alloc->seed);
+      errors = true;
+      return;
+    }
+  randomize_buffer (expected, size, alloc->seed);
+  if (memcmp (alloc->data, expected, size) != 0)
+    {
+      printf ("error: allocation %d data mismatch, size %zu, seed %u\n",
+              index, size, alloc->seed);
+      printf ("  expected:");
+      dump_hex (expected, size);
+      putc ('\n', stdout);
+      printf ("    actual:");
+      dump_hex (alloc->data, size);
+      putc ('\n', stdout);
+      errors = true;
+    }
+}
+
+/* A heap allocation combined with pending actions on it.  */
+struct allocation_task
+{
+  struct allocation allocation;
+  enum allocation_action action;
+};
+
+/* Allocation tasks.  Initialized by init_allocation_tasks and used by
+   perform_allocations.  */
+enum { allocation_task_count = action_count * max_size };
+static struct allocation_task allocation_tasks[allocation_task_count];
+
+/* Fisher-Yates shuffle of allocation_tasks.  */
+static void
+shuffle_allocation_tasks (void)
+{
+  for (int i = 0; i < allocation_task_count - 1; ++i)
+    {
+      /* Pick pair in the tail of the array.  */
+      int j = i + (rand_next (&global_seed)
+                   % ((unsigned) (allocation_task_count - i)));
+      if (j < 0 || j >= allocation_task_count)
+        {
+          write_message ("error: test bug in shuffle\n");
+          _exit (1);
+        }
+      /* Exchange. */
+      struct allocation_task tmp = allocation_tasks[i];
+      allocation_tasks[i] = allocation_tasks[j];
+      allocation_tasks[j] = tmp;
+    }
+}
+
+/* Set up the allocation tasks and the dumped heap.  */
+static void
+initial_allocations (void)
+{
+  /* Initialize in a position-dependent way.  */
+  for (int i = 0; i < allocation_task_count; ++i)
+    allocation_tasks[i] = (struct allocation_task)
+      {
+        .allocation =
+          {
+            .size = 1 + (i / action_count),
+            .seed = i,
+          },
+        .action = i % action_count
+      };
+
+  /* Execute the tasks in a random order.  */
+  shuffle_allocation_tasks ();
+
+  /* Initialize the contents of the dumped heap.   */
+  for (int i = 0; i < allocation_task_count; ++i)
+    {
+      struct allocation_task *task = allocation_tasks + i;
+      task->allocation.data = dumped_heap_alloc (task->allocation.size);
+      randomize_buffer (task->allocation.data, task->allocation.size,
+                        task->allocation.seed);
+    }
+
+  for (int i = 0; i < allocation_task_count; ++i)
+    check_allocation (&allocation_tasks[i].allocation, i);
+}
+
+/* Indicates whether init_heap has run.  This variable needs to be
+   volatile because malloc is declared __THROW, which implies it is a
+   leaf function, but we expect it to run our hooks.  */
+static volatile bool heap_initialized;
+
+/* Executed by glibc malloc, through __malloc_initialize_hook
+   below.  */
+static void
+init_heap (void)
+{
+  write_message ("info: performing heap initialization\n");
+  heap_initialized = true;
+
+  /* Populate the dumped heap.  */
+  initial_allocations ();
+
+  /* Complete initialization of the saved heap data structure.  */
+  save_state.sbrk_base = (void *) dumped_heap;
+  save_state.sbrked_mem_bytes = sizeof (dumped_heap);
+  /* Top pointer.  Adjust so that it points to the start of struct
+     malloc_chunk.  */
+  save_state.av[2] = (void *) (next_heap_chunk - 1);
+
+  /* Integrate the dumped heap into the process heap.  */
+  if (malloc_set_state (&save_state) != 0)
+    {
+      write_message ("error: malloc_set_state failed\n");
+      _exit (1);
+    }
+}
+
+/* Interpose the initialization callback.  */
+void (*volatile __malloc_initialize_hook) (void) = init_heap;
+
+/* Simulate occasional unrelated heap activity in the non-dumped
+   heap.  */
+enum { heap_activity_allocations_count = 32 };
+static struct allocation heap_activity_allocations
+  [heap_activity_allocations_count] = {};
+static int heap_activity_seed_counter = 1000 * 1000;
+
+static void
+heap_activity (void)
+{
+  /* Only do this from time to time.  */
+  if ((rand_next (&global_seed) % 4) == 0)
+    {
+      int slot = rand_next (&global_seed) % heap_activity_allocations_count;
+      struct allocation *alloc = heap_activity_allocations + slot;
+      if (alloc->data == NULL)
+        {
+          alloc->size = rand_next (&global_seed) % (4096U + 1);
+          alloc->data = xmalloc (alloc->size);
+          alloc->seed = heap_activity_seed_counter++;
+          randomize_buffer (alloc->data, alloc->size, alloc->seed);
+          check_allocation (alloc, 1000 + slot);
+        }
+      else
+        {
+          check_allocation (alloc, 1000 + slot);
+          free (alloc->data);
+          alloc->data = NULL;
+        }
+    }
+}
+
+static void
+heap_activity_deallocate (void)
+{
+  for (int i = 0; i < heap_activity_allocations_count; ++i)
+    free (heap_activity_allocations[i].data);
+}
+
+/* Perform a full heap check across the dumped heap allocation tasks,
+   and the simulated heap activity directly above.  */
+static void
+full_heap_check (void)
+{
+  /* Dumped heap.  */
+  for (int i = 0; i < allocation_task_count; ++i)
+    if (allocation_tasks[i].allocation.data != NULL)
+      check_allocation (&allocation_tasks[i].allocation, i);
+
+  /* Heap activity allocations.  */
+  for (int i = 0; i < heap_activity_allocations_count; ++i)
+    if (heap_activity_allocations[i].data != NULL)
+      check_allocation (heap_activity_allocations + i, i);
+}
+
+/* Used as an optimization barrier to force a heap allocation.  */
+__attribute__ ((noinline, noclone))
+static void
+my_free (void *ptr)
+{
+  free (ptr);
+}
+
+static int
+do_test (void)
+{
+  my_free (malloc (1));
+  if (!heap_initialized)
+    {
+      printf ("error: heap was not initialized by malloc\n");
+      return 1;
+    }
+
+  /* The first pass performs the randomly generated allocation
+     tasks.  */
+  write_message ("info: first pass through allocation tasks\n");
+  full_heap_check ();
+
+  /* Execute the post-undump tasks in a random order.  */
+  shuffle_allocation_tasks ();
+
+  for (int i = 0; i < allocation_task_count; ++i)
+    {
+      heap_activity ();
+      struct allocation_task *task = allocation_tasks + i;
+      switch (task->action)
+        {
+        case action_free:
+          check_allocation (&task->allocation, i);
+          free (task->allocation.data);
+          task->allocation.data = NULL;
+          break;
+
+        case action_realloc:
+          check_allocation (&task->allocation, i);
+          task->allocation.data = xrealloc
+            (task->allocation.data, task->allocation.size + max_size);
+          check_allocation (&task->allocation, i);
+          break;
+
+        case action_realloc_same:
+          check_allocation (&task->allocation, i);
+          task->allocation.data = xrealloc
+            (task->allocation.data, task->allocation.size);
+          check_allocation (&task->allocation, i);
+          break;
+
+        case action_realloc_smaller:
+          check_allocation (&task->allocation, i);
+          size_t new_size = task->allocation.size - 1;
+          task->allocation.data = xrealloc (task->allocation.data, new_size);
+          if (new_size == 0)
+            {
+              if (task->allocation.data != NULL)
+                {
+                  printf ("error: realloc with size zero did not deallocate\n");
+                  errors = true;
+                }
+              /* No further action on this task.  */
+              task->action = action_free;
+            }
+          else
+            {
+              task->allocation.size = new_size;
+              check_allocation (&task->allocation, i);
+            }
+          break;
+
+        case action_count:
+          abort ();
+        }
+      full_heap_check ();
+    }
+
+  /* The second pass frees the objects which were allocated during the
+     first pass.  */
+  write_message ("info: second pass through allocation tasks\n");
+
+  shuffle_allocation_tasks ();
+  for (int i = 0; i < allocation_task_count; ++i)
+    {
+      heap_activity ();
+      struct allocation_task *task = allocation_tasks + i;
+      switch (task->action)
+        {
+        case action_free:
+          /* Already freed, nothing to do.  */
+          break;
+
+        case action_realloc:
+        case action_realloc_same:
+        case action_realloc_smaller:
+          check_allocation (&task->allocation, i);
+          free (task->allocation.data);
+          task->allocation.data = NULL;
+          break;
+
+        case action_count:
+          abort ();
+        }
+      full_heap_check ();
+    }
+
+  heap_activity_deallocate ();
+
+  /* Check that the malloc_get_state stub behaves in the intended
+     way.  */
+  errno = 0;
+  if (malloc_get_state () != NULL)
+    {
+      printf ("error: malloc_get_state succeeded\n");
+      errors = true;
+    }
+  if (errno != ENOSYS)
+    {
+      printf ("error: malloc_get_state: %m\n");
+      errors = true;
+    }
+
+  return errors;
+}