Merge pull request #1340 from elmart/remove-long_u

Remove project-specific integer types: long_u. (2)

9 files changed, 662 insertions, 770 deletions

diff --git a/clint-files.txt b/clint-files.txt
index 99f2fecc7c..a0aec7a31c 100644
--- a/clint-files.txt
+++ b/clint-files.txt
@@ -1,10 +1,10 @@
 src/nvim/api/buffer.c
 src/nvim/api/buffer.h
 src/nvim/api/private/defs.h
-src/nvim/api/private/helpers.c
-src/nvim/api/private/helpers.h
 src/nvim/api/private/handle.c
 src/nvim/api/private/handle.h
+src/nvim/api/private/helpers.c
+src/nvim/api/private/helpers.h
 src/nvim/api/tabpage.c
 src/nvim/api/tabpage.h
 src/nvim/api/vim.c
@@ -22,6 +22,15 @@ src/nvim/log.h
 src/nvim/map.c
 src/nvim/map.h
 src/nvim/map_defs.h
+src/nvim/memfile.c
+src/nvim/memfile.h
+src/nvim/memfile_defs.h
+src/nvim/msgpack_rpc/channel.c
+src/nvim/msgpack_rpc/channel.h
+src/nvim/msgpack_rpc/helpers.c
+src/nvim/msgpack_rpc/helpers.h
+src/nvim/msgpack_rpc/server.c
+src/nvim/msgpack_rpc/server.h
 src/nvim/os/env.c
 src/nvim/os/event.c
 src/nvim/os/event.h
@@ -42,13 +51,7 @@ src/nvim/os/signal.c
 src/nvim/os/signal.h
 src/nvim/os/time.c
 src/nvim/os/time.h
-src/nvim/msgpack_rpc/server.c
-src/nvim/msgpack_rpc/server.h
-src/nvim/msgpack_rpc/channel.c
-src/nvim/msgpack_rpc/channel.h
-src/nvim/msgpack_rpc/helpers.c
-src/nvim/msgpack_rpc/helpers.h
-src/nvim/tempfile.c
-src/nvim/tempfile.h
 src/nvim/profile.c
 src/nvim/profile.h
+src/nvim/tempfile.c
+src/nvim/tempfile.h
diff --git a/src/nvim/CMakeLists.txt b/src/nvim/CMakeLists.txt
index 57fb0fb50e..5b97cf5f40 100644
--- a/src/nvim/CMakeLists.txt
+++ b/src/nvim/CMakeLists.txt
@@ -45,6 +45,7 @@ set(CONV_SOURCES
   hashtab.c
   log.c
   map.c
+  memfile.c
   memory.c
   misc2.c
   profile.c
diff --git a/src/nvim/buffer_defs.h b/src/nvim/buffer_defs.h
index 4ea288c258..094d6dfd05 100644
--- a/src/nvim/buffer_defs.h
+++ b/src/nvim/buffer_defs.h
@@ -78,7 +78,6 @@ typedef struct wininfo_S wininfo_T;
 typedef struct frame_S frame_T;
 typedef int scid_T;                     /* script ID */
 typedef struct file_buffer buf_T;       /* forward declaration */
-typedef struct memfile memfile_T;
 
 // for struct memline (it needs memfile_T)
 #include "nvim/memline_defs.h"
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 3e7c3d05c1..d75807800c 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -10,6 +10,7 @@
  * eval.c: Expression evaluation.
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <inttypes.h>
 #include <stdarg.h>
@@ -3034,10 +3035,10 @@ static char_u *cat_prefix_varname(int prefix, char_u *name)
  */
 char_u *get_user_var_name(expand_T *xp, int idx)
 {
-  static long_u gdone;
-  static long_u bdone;
-  static long_u wdone;
-  static long_u tdone;
+  static size_t gdone;
+  static size_t bdone;
+  static size_t wdone;
+  static size_t tdone;
   static int vidx;
   static hashitem_T   *hi;
   hashtab_T           *ht;
@@ -11749,7 +11750,7 @@ static void f_readfile(typval_T *argvars, typval_T *rettv)
       if (*p == '\n' || readlen <= 0) {
         listitem_T  *li;
         char_u      *s  = NULL;
-        long_u len = p - start;
+        size_t len = p - start;
 
         /* Finished a line.  Remove CRs before NL. */
         if (readlen > 0 && !binary) {
@@ -11760,9 +11761,10 @@ static void f_readfile(typval_T *argvars, typval_T *rettv)
             while (prevlen > 0 && prev[prevlen - 1] == '\r')
               --prevlen;
         }
-        if (prevlen == 0)
+        if (prevlen == 0) {
+          assert(len < INT_MAX);
           s = vim_strnsave(start, (int)len);
-        else {
+        } else {
           /* Change "prev" buffer to be the right size.  This way
            * the bytes are only copied once, and very long lines are
            * allocated only once.  */
@@ -18152,7 +18154,7 @@ static char_u *autoload_name(char_u *name)
  */
 char_u *get_user_func_name(expand_T *xp, int idx)
 {
-  static long_u done;
+  static size_t done;
   static hashitem_T   *hi;
   ufunc_T             *fp;
 
diff --git a/src/nvim/memfile.c b/src/nvim/memfile.c
index 827cff2299..1656acb689 100644
--- a/src/nvim/memfile.c
+++ b/src/nvim/memfile.c
@@ -1,39 +1,54 @@
 /*
- * VIM - Vi IMproved	by Bram Moolenaar
+ * VIM - Vi IMproved    by Bram Moolenaar
  *
  * Do ":help uganda"  in Vim to read copying and usage conditions.
  * Do ":help credits" in Vim to see a list of people who contributed.
  * See README.txt for an overview of the Vim source code.
  */
 
-/*
- * memfile.c: Contains the functions for handling blocks of memory which can
- * be stored in a file. This is the implementation of a sort of virtual memory.
- *
- * A memfile consists of a sequence of blocks. The blocks numbered from 0
- * upwards have been assigned a place in the actual file. The block number
- * is equal to the page number in the file. The
- * blocks with negative numbers are currently in memory only. They can be
- * assigned a place in the file when too much memory is being used. At that
- * moment they get a new, positive, number. A list is used for translation of
- * negative to positive numbers.
- *
- * The size of a block is a multiple of a page size, normally the page size of
- * the device the file is on. Most blocks are 1 page long. A Block of multiple
- * pages is used for a line that does not fit in a single page.
- *
- * Each block can be in memory and/or in a file. The block stays in memory
- * as long as it is locked. If it is no longer locked it can be swapped out to
- * the file. It is only written to the file if it has been changed.
- *
- * Under normal operation the file is created when opening the memory file and
- * deleted when closing the memory file. Only with recovery an existing memory
- * file is opened.
- */
-
+/// An abstraction to handle blocks of memory which can be stored in a file.
+/// This is the implementation of a sort of virtual memory.
+///
+/// A memfile consists of a sequence of blocks:
+/// - Blocks numbered from 0 upwards have been assigned a place in the actual
+///   file. The block number is equal to the page number in the file.
+/// - Blocks with negative numbers are currently in memory only. They can be
+///   assigned a place in the file when too much memory is being used. At that
+///   moment, they get a new, positive, number. A list is used for translation
+///   of negative to positive numbers.
+///
+/// The size of a block is a multiple of a page size, normally the page size of
+/// the device the file is on. Most blocks are 1 page long. A block of multiple
+/// pages is used for a line that does not fit in a single page.
+///
+/// Each block can be in memory and/or in a file. The block stays in memory
+/// as long as it is locked. If it is no longer locked it can be swapped out to
+/// the file. It is only written to the file if it has been changed.
+///
+/// Under normal operation the file is created when opening the memory file and
+/// deleted when closing the memory file. Only with recovery an existing memory
+/// file is opened.
+///
+/// The functions for using a memfile:
+///
+/// mf_open()         open a new or existing memfile
+/// mf_open_file()    open a swap file for an existing memfile
+/// mf_close()        close (and delete) a memfile
+/// mf_new()          create a new block in a memfile and lock it
+/// mf_get()          get an existing block and lock it
+/// mf_put()          unlock a block, may be marked for writing
+/// mf_free()         remove a block
+/// mf_sync()         sync changed parts of memfile to disk
+/// mf_release_all()  release as much memory as possible
+/// mf_trans_del()    may translate negative to positive block number
+/// mf_fullname()     make file name full path (use before first :cd)
+
+#include <assert.h>
 #include <errno.h>
 #include <inttypes.h>
+#include <limits.h>
 #include <string.h>
+#include <stdbool.h>
 
 #include "nvim/vim.h"
 #include "nvim/ascii.h"
@@ -49,101 +64,88 @@
 #include "nvim/ui.h"
 #include "nvim/os/os.h"
 
-#define MEMFILE_PAGE_SIZE 4096          /* default page size */
+#define MEMFILE_PAGE_SIZE 4096       /// default page size
 
-static long_u total_mem_used = 0;       /* total memory used for memfiles */
 
+static size_t total_mem_used = 0;    /// total memory used for memfiles
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "memfile.c.generated.h"
 #endif
-/*
- * The functions for using a memfile:
- *
- * mf_open()	    open a new or existing memfile
- * mf_open_file()   open a swap file for an existing memfile
- * mf_close()	    close (and delete) a memfile
- * mf_new()	    create a new block in a memfile and lock it
- * mf_get()	    get an existing block and lock it
- * mf_put()	    unlock a block, may be marked for writing
- * mf_free()	    remove a block
- * mf_sync()	    sync changed parts of memfile to disk
- * mf_release_all() release as much memory as possible
- * mf_trans_del()   may translate negative to positive block number
- * mf_fullname()    make file name full path (use before first :cd)
- */
 
-/*
- * Open an existing or new memory block file.
- *
- *  fname:	name of file to use (NULL means no file at all)
- *		Note: fname must have been allocated, it is not copied!
- *			If opening the file fails, fname is freed.
- *  flags:	flags for open() call
- *
- *  If fname != NULL and file cannot be opened, fail.
- *
- * return value: identifier for this memory block file.
- */
+/// Open a new or existing memory block file.
+///
+/// @param fname  Name of file to use.
+///               - If NULL, it means no file (use memory only).
+///               - If not NULL:
+///                 * Should correspond to an existing file.
+///                 * String must have been allocated (it is not copied).
+///                 * If opening the file fails, it is freed and function fails.
+
+/// @param flags  Flags for open() call.
+///
+/// @return - The open memory file, on success.
+///         - NULL, on failure.
 memfile_T *mf_open(char_u *fname, int flags)
 {
   off_t size;
 
   memfile_T *mfp = xmalloc(sizeof(memfile_T));
 
-  if (fname == NULL) {      /* no file for this memfile, use memory only */
+  if (fname == NULL) {               // no file, use memory only
     mfp->mf_fname = NULL;
     mfp->mf_ffname = NULL;
     mfp->mf_fd = -1;
-  } else {
-    mf_do_open(mfp, fname, flags);      /* try to open the file */
+  } else {                           // try to open the file
+    mf_do_open(mfp, fname, flags);
 
-    /* if the file cannot be opened, return here */
-    if (mfp->mf_fd < 0) {
+    if (mfp->mf_fd < 0) {            // fail if file could not be opened
       free(mfp);
       return NULL;
     }
   }
 
-  mfp->mf_free_first = NULL;            /* free list is empty */
-  mfp->mf_used_first = NULL;            /* used list is empty */
+  mfp->mf_free_first = NULL;         // free list is empty
+  mfp->mf_used_first = NULL;         // used list is empty
   mfp->mf_used_last = NULL;
-  mfp->mf_dirty = FALSE;
+  mfp->mf_dirty = false;
   mfp->mf_used_count = 0;
   mf_hash_init(&mfp->mf_hash);
   mf_hash_init(&mfp->mf_trans);
   mfp->mf_page_size = MEMFILE_PAGE_SIZE;
 
-  /*
-   * Try to set the page size equal to the block size of the device.
-   * Speeds up I/O a lot.
-   * When recovering, the actual block size will be retrieved from block 0
-   * in ml_recover().  The size used here may be wrong, therefore
-   * mf_blocknr_max must be rounded up.
-   */
+  // Try to set the page size equal to device's block size. Speeds up I/O a lot.
   FileInfo file_info;
   if (mfp->mf_fd >= 0 && os_fileinfo_fd(mfp->mf_fd, &file_info)) {
     uint64_t blocksize = os_fileinfo_blocksize(&file_info);
     if (blocksize >= MIN_SWAP_PAGE_SIZE && blocksize <= MAX_SWAP_PAGE_SIZE) {
-      mfp->mf_page_size = blocksize;
+      assert(blocksize <= UINT_MAX);
+      mfp->mf_page_size = (unsigned)blocksize;
     }
   }
 
-  if (mfp->mf_fd < 0 || (flags & (O_TRUNC|O_EXCL))
-      || (size = lseek(mfp->mf_fd, (off_t)0L, SEEK_END)) <= 0)
-    mfp->mf_blocknr_max = 0;            /* no file or empty file */
-  else
-    mfp->mf_blocknr_max = (blocknr_T)((size + mfp->mf_page_size - 1)
-                                      / mfp->mf_page_size);
+  // When recovering, the actual block size will be retrieved from block 0
+  // in ml_recover(). The size used here may be wrong, therefore mf_blocknr_max
+  // must be rounded up.
+  if (mfp->mf_fd < 0
+      || (flags & (O_TRUNC|O_EXCL))
+      || (size = lseek(mfp->mf_fd, (off_t)0L, SEEK_END)) <= 0) {
+    // no file or empty file
+    mfp->mf_blocknr_max = 0;
+  } else {
+    assert(sizeof(off_t) <= sizeof(blocknr_T)
+           && mfp->mf_page_size > 0
+           && mfp->mf_page_size - 1 <= INT64_MAX - size);
+    mfp->mf_blocknr_max = (((blocknr_T)size + mfp->mf_page_size - 1)
+                           / mfp->mf_page_size);
+  }
   mfp->mf_blocknr_min = -1;
   mfp->mf_neg_count = 0;
   mfp->mf_infile_count = mfp->mf_blocknr_max;
 
-  /*
-   * Compute maximum number of pages ('maxmem' is in Kbyte):
-   *	'mammem' * 1Kbyte / page-size-in-bytes.
-   * Avoid overflow by first reducing page size as much as possible.
-   */
+  // Compute maximum number of pages ('maxmem' is in Kbytes):
+  //         'mammem' * 1Kbyte / page-size-in-bytes.
+  // Avoid overflow by first reducing page size as much as possible.
   {
     int shift = 10;
     unsigned page_size = mfp->mf_page_size;
@@ -152,7 +154,10 @@ memfile_T *mf_open(char_u *fname, int flags)
       page_size /= 2;
       --shift;
     }
-    mfp->mf_used_count_max = (p_mm << shift) / page_size;
+
+    assert(p_mm <= LONG_MAX >> shift);  // check we don't overflow
+    assert((uintmax_t)(p_mm << shift) <= UINT_MAX);  // check we can cast safely
+    mfp->mf_used_count_max = (unsigned)(p_mm << shift) / page_size;
     if (mfp->mf_used_count_max < 10)
       mfp->mf_used_count_max = 10;
   }
@@ -160,88 +165,84 @@ memfile_T *mf_open(char_u *fname, int flags)
   return mfp;
 }
 
-/*
- * Open a file for an existing memfile.  Used when updatecount set from 0 to
- * some value.
- * If the file already exists, this fails.
- * "fname" is the name of file to use (NULL means no file at all)
- * Note: "fname" must have been allocated, it is not copied!  If opening the
- * file fails, "fname" is freed.
- *
- * return value: FAIL if file could not be opened, OK otherwise
- */
+/// Open a file for an existing memfile.
+///
+/// Used when updatecount set from 0 to some value.
+///
+/// @param fname  Name of file to use.
+///               - If NULL, it means no file (use memory only).
+///               - If not NULL:
+///                 * Should correspond to an existing file.
+///                 * String must have been allocated (it is not copied).
+///                 * If opening the file fails, it is freed and function fails.
+///
+/// @return OK    On success.
+///         FAIL  If file could not be opened.
 int mf_open_file(memfile_T *mfp, char_u *fname)
 {
-  mf_do_open(mfp, fname, O_RDWR|O_CREAT|O_EXCL);   /* try to open the file */
+  mf_do_open(mfp, fname, O_RDWR|O_CREAT|O_EXCL);  // try to open the file
 
   if (mfp->mf_fd < 0)
     return FAIL;
 
-  mfp->mf_dirty = TRUE;
+  mfp->mf_dirty = true;
   return OK;
 }
 
-/*
- * Close a memory file and delete the associated file if 'del_file' is TRUE.
- */
-void mf_close(memfile_T *mfp, int del_file)
+/// Close a memory file and optionally delete the associated file.
+///
+/// @param del_file  Whether to delete associated file.
+void mf_close(memfile_T *mfp, bool del_file)
 {
   bhdr_T      *hp, *nextp;
 
-  if (mfp == NULL)                  /* safety check */
+  if (mfp == NULL) {                    // safety check
     return;
-  if (mfp->mf_fd >= 0) {
-    if (close(mfp->mf_fd) < 0)
+  }
+  if (mfp->mf_fd >= 0 && close(mfp->mf_fd) < 0) {
       EMSG(_(e_swapclose));
   }
   if (del_file && mfp->mf_fname != NULL)
     os_remove((char *)mfp->mf_fname);
-  /* free entries in used list */
+  // free entries in used list
   for (hp = mfp->mf_used_first; hp != NULL; hp = nextp) {
     total_mem_used -= hp->bh_page_count * mfp->mf_page_size;
     nextp = hp->bh_next;
     mf_free_bhdr(hp);
   }
-  while (mfp->mf_free_first != NULL)        /* free entries in free list */
+  while (mfp->mf_free_first != NULL)    // free entries in free list
     free(mf_rem_free(mfp));
   mf_hash_free(&mfp->mf_hash);
-  mf_hash_free_all(&mfp->mf_trans);         /* free hashtable and its items */
+  mf_hash_free_all(&mfp->mf_trans);     // free hashtable and its items
   free(mfp->mf_fname);
   free(mfp->mf_ffname);
   free(mfp);
 }
 
-/*
- * Close the swap file for a memfile.  Used when 'swapfile' is reset.
- */
-void 
-mf_close_file (
-    buf_T *buf,
-    int getlines                   /* get all lines into memory? */
-)
+/// Close the swap file for a memfile. Used when 'swapfile' is reset.
+///
+/// @param getlines  Whether to get all lines into memory.
+void mf_close_file(buf_T *buf, bool getlines)
 {
-  memfile_T   *mfp;
-  linenr_T lnum;
-
-  mfp = buf->b_ml.ml_mfp;
-  if (mfp == NULL || mfp->mf_fd < 0)            /* nothing to close */
+  memfile_T *mfp = buf->b_ml.ml_mfp;
+  if (mfp == NULL || mfp->mf_fd < 0)     // nothing to close
     return;
 
   if (getlines) {
-    /* get all blocks in memory by accessing all lines (clumsy!) */
-    mf_dont_release = TRUE;
-    for (lnum = 1; lnum <= buf->b_ml.ml_line_count; ++lnum)
-      (void)ml_get_buf(buf, lnum, FALSE);
-    mf_dont_release = FALSE;
-    /* TODO: should check if all blocks are really in core */
+    // get all blocks in memory by accessing all lines (clumsy!)
+    mf_dont_release = true;
+    for (linenr_T lnum = 1; lnum <= buf->b_ml.ml_line_count; ++lnum)
+      (void)ml_get_buf(buf, lnum, false);
+    mf_dont_release = false;
+    // TODO(elmart): should check if all blocks are really in core
   }
 
-  if (close(mfp->mf_fd) < 0)                    /* close the file */
+  if (close(mfp->mf_fd) < 0)             // close the file
     EMSG(_(e_swapclose));
   mfp->mf_fd = -1;
 
   if (mfp->mf_fname != NULL) {
-    os_remove((char *)mfp->mf_fname);  // delete the swap file
+    os_remove((char *)mfp->mf_fname);    // delete the swap file
     free(mfp->mf_fname);
     free(mfp->mf_ffname);
     mfp->mf_fname = NULL;
@@ -249,53 +250,45 @@ mf_close_file (
   }
 }
 
-/*
- * Set new size for a memfile.  Used when block 0 of a swapfile has been read
- * and the size it indicates differs from what was guessed.
- */
+/// Set new size for a memfile. Used when block 0 of a swapfile has been read
+/// and the size it indicates differs from what was guessed.
 void mf_new_page_size(memfile_T *mfp, unsigned new_size)
 {
-  /* Correct the memory used for block 0 to the new size, because it will be
-   * freed with that size later on. */
-  total_mem_used += new_size - mfp->mf_page_size;
+  // Correct the memory used for block 0 to the new size, because it will be
+  // freed with that size later on.
+  if (new_size >= mfp->mf_page_size) {
+    total_mem_used += new_size - mfp->mf_page_size;
+  } else {
+    total_mem_used -= mfp->mf_page_size - new_size;
+  }
   mfp->mf_page_size = new_size;
 }
 
-/*
- * get a new block
- *
- *   negative: TRUE if negative block number desired (data block)
- */
-bhdr_T *mf_new(memfile_T *mfp, int negative, int page_count)
+/// Get a new block
+///
+/// @param negative    Whether a negative block number is desired (data block).
+/// @param page_count  Desired number of pages.
+bhdr_T *mf_new(memfile_T *mfp, bool negative, unsigned page_count)
 {
-  bhdr_T      *hp;      /* new bhdr_T */
-  bhdr_T      *freep;   /* first block in free list */
-  char_u      *p;
-
-  /*
-   * If we reached the maximum size for the used memory blocks, release one
-   * If a bhdr_T is returned, use it and adjust the page_count if necessary.
-   */
-  hp = mf_release(mfp, page_count);
-
-  /*
-   * Decide on the number to use:
-   * If there is a free block, use its number.
-   * Otherwise use mf_block_min for a negative number, mf_block_max for
-   * a positive number.
-   */
-  freep = mfp->mf_free_first;
+  // If we reached the maximum size for the used memory blocks, release one.
+  // If a bhdr_T is returned, use it and adjust the page_count if necessary.
+  // If no bhdr_T is returned, a new one will be created.
+  bhdr_T *hp = mf_release(mfp, page_count);  // the block to be returned
+
+  // Decide on the number to use:
+  // If there is a free block, use its number.
+  // Otherwise use mf_block_min for a negative number, mf_block_max for
+  // a positive number.
+  bhdr_T *freep = mfp->mf_free_first;        // first free block
   if (!negative && freep != NULL && freep->bh_page_count >= page_count) {
-    /*
-     * If the block in the free list has more pages, take only the number
-     * of pages needed and allocate a new bhdr_T with data
-     *
-     * If the number of pages matches and mf_release() did not return a
-     * bhdr_T, use the bhdr_T from the free list and allocate the data
-     *
-     * If the number of pages matches and mf_release() returned a bhdr_T,
-     * just use the number and free the bhdr_T from the free list
-     */
+    // If the block in the free list has more pages, take only the number
+    // of pages needed and allocate a new bhdr_T with data.
+    //
+    // If the number of pages matches and mf_release() did not return a
+    // bhdr_T, use the bhdr_T from the free list and allocate the data.
+    //
+    // If the number of pages matches and mf_release() returned a bhdr_T,
+    // just use the number and free the bhdr_T from the free list
     if (freep->bh_page_count > page_count) {
       if (hp == NULL) {
         hp = mf_alloc_bhdr(mfp, page_count);
@@ -303,16 +296,16 @@ bhdr_T *mf_new(memfile_T *mfp, int negative, int page_count)
       hp->bh_bnum = freep->bh_bnum;
       freep->bh_bnum += page_count;
       freep->bh_page_count -= page_count;
-    } else if (hp == NULL) {      /* need to allocate memory for this block */
-      p = xmalloc(mfp->mf_page_size * page_count);
+    } else if (hp == NULL) {    // need to allocate memory for this block
+      void *p = xmalloc(mfp->mf_page_size * page_count);
       hp = mf_rem_free(mfp);
       hp->bh_data = p;
-    } else {              /* use the number, remove entry from free list */
+    } else {                    // use the number, remove entry from free list
       freep = mf_rem_free(mfp);
       hp->bh_bnum = freep->bh_bnum;
       free(freep);
     }
-  } else {    /* get a new number */
+  } else {                      // get a new number
     if (hp == NULL) {
       hp = mf_alloc_bhdr(mfp, page_count);
     }
@@ -324,49 +317,41 @@ bhdr_T *mf_new(memfile_T *mfp, int negative, int page_count)
       mfp->mf_blocknr_max += page_count;
     }
   }
-  hp->bh_flags = BH_LOCKED | BH_DIRTY;          /* new block is always dirty */
-  mfp->mf_dirty = TRUE;
+  hp->bh_flags = BH_LOCKED | BH_DIRTY;    // new block is always dirty
+  mfp->mf_dirty = true;
   hp->bh_page_count = page_count;
   mf_ins_used(mfp, hp);
   mf_ins_hash(mfp, hp);
 
-  /*
-   * Init the data to all zero, to avoid reading uninitialized data.
-   * This also avoids that the passwd file ends up in the swap file!
-   */
-  (void)memset((char *)(hp->bh_data), 0,
-      (size_t)mfp->mf_page_size * page_count);
+  // Init the data to all zero, to avoid reading uninitialized data.
+  // This also avoids that the passwd file ends up in the swap file!
+  (void)memset(hp->bh_data, 0, mfp->mf_page_size * page_count);
 
   return hp;
 }
 
-/*
- * Get existing block "nr" with "page_count" pages.
- *
- * Note: The caller should first check a negative nr with mf_trans_del()
- */
-bhdr_T *mf_get(memfile_T *mfp, blocknr_T nr, int page_count)
+// Get existing block "nr" with "page_count" pages.
+//
+// Caller should first check a negative nr with mf_trans_del().
+//
+// @return  NULL if not found
+bhdr_T *mf_get(memfile_T *mfp, blocknr_T nr, unsigned page_count)
 {
-  bhdr_T    *hp;
-  /* doesn't exist */
+  // check block number exists
   if (nr >= mfp->mf_blocknr_max || nr <= mfp->mf_blocknr_min)
     return NULL;
 
-  /*
-   * see if it is in the cache
-   */
-  hp = mf_find_hash(mfp, nr);
-  if (hp == NULL) {     /* not in the hash list */
-    if (nr < 0 || nr >= mfp->mf_infile_count)       /* can't be in the file */
+  // see if it is in the cache
+  bhdr_T *hp = mf_find_hash(mfp, nr);
+  if (hp == NULL) {                             // not in the hash list
+    if (nr < 0 || nr >= mfp->mf_infile_count)   // can't be in the file
       return NULL;
 
-    /* could check here if the block is in the free list */
+    // could check here if the block is in the free list
 
-    /*
-     * Check if we need to flush an existing block.
-     * If so, use that block.
-     * If not, allocate a new block.
-     */
+    // Check if we need to flush an existing block.
+    // If so, use that block.
+    // If not, allocate a new block.
     hp = mf_release(mfp, page_count);
     if (hp == NULL) {
       hp = mf_alloc_bhdr(mfp, page_count);
@@ -375,101 +360,88 @@ bhdr_T *mf_get(memfile_T *mfp, blocknr_T nr, int page_count)
     hp->bh_bnum = nr;
     hp->bh_flags = 0;
     hp->bh_page_count = page_count;
-    if (mf_read(mfp, hp) == FAIL) {         /* cannot read the block! */
+    if (mf_read(mfp, hp) == FAIL) {             // cannot read the block
       mf_free_bhdr(hp);
       return NULL;
     }
   } else {
-    mf_rem_used(mfp, hp);       /* remove from list, insert in front below */
+    mf_rem_used(mfp, hp);       // remove from list, insert in front below
     mf_rem_hash(mfp, hp);
   }
 
   hp->bh_flags |= BH_LOCKED;
-  mf_ins_used(mfp, hp);         /* put in front of used list */
-  mf_ins_hash(mfp, hp);         /* put in front of hash list */
+  mf_ins_used(mfp, hp);         // put in front of used list
+  mf_ins_hash(mfp, hp);         // put in front of hash list
 
   return hp;
 }
 
-/*
- * release the block *hp
- *
- *   dirty: Block must be written to file later
- *   infile: Block should be in file (needed for recovery)
- *
- *  no return value, function cannot fail
- */
-void mf_put(memfile_T *mfp, bhdr_T *hp, int dirty, int infile)
+/// Release the block *hp.
+///
+/// @param dirty   Whether block must be written to file later.
+/// @param infile  Whether block should be in file (needed for recovery).
+void mf_put(memfile_T *mfp, bhdr_T *hp, bool dirty, bool infile)
 {
-  int flags;
-
-  flags = hp->bh_flags;
+  unsigned flags = hp->bh_flags;
 
   if ((flags & BH_LOCKED) == 0)
     EMSG(_("E293: block was not locked"));
   flags &= ~BH_LOCKED;
   if (dirty) {
     flags |= BH_DIRTY;
-    mfp->mf_dirty = TRUE;
+    mfp->mf_dirty = true;
   }
   hp->bh_flags = flags;
   if (infile)
-    mf_trans_add(mfp, hp);          /* may translate negative in positive nr */
+    mf_trans_add(mfp, hp);      // may translate negative in positive nr
 }
 
-/*
- * block *hp is no longer in used, may put it in the free list of memfile *mfp
- */
+/// Signal block as no longer used (may put it in the free list).
 void mf_free(memfile_T *mfp, bhdr_T *hp)
 {
-  free(hp->bh_data);        /* free the memory */
-  mf_rem_hash(mfp, hp);         /* get *hp out of the hash list */
-  mf_rem_used(mfp, hp);         /* get *hp out of the used list */
+  free(hp->bh_data);            // free data
+  mf_rem_hash(mfp, hp);         // get *hp out of the hash list
+  mf_rem_used(mfp, hp);         // get *hp out of the used list
   if (hp->bh_bnum < 0) {
-    free(hp);               /* don't want negative numbers in free list */
+    free(hp);                   // don't want negative numbers in free list
     mfp->mf_neg_count--;
-  } else
-    mf_ins_free(mfp, hp);       /* put *hp in the free list */
+  } else {
+    mf_ins_free(mfp, hp);       // put *hp in the free list
+  }
 }
 
-/*
- * Sync the memory file *mfp to disk.
- * Flags:
- *  MFS_ALL	If not given, blocks with negative numbers are not synced,
- *		even when they are dirty!
- *  MFS_STOP	Stop syncing when a character becomes available, but sync at
- *		least one block.
- *  MFS_FLUSH	Make sure buffers are flushed to disk, so they will survive a
- *		system crash.
- *  MFS_ZERO	Only write block 0.
- *
- * Return FAIL for failure, OK otherwise
- */
+/// Sync memory file to disk.
+///
+/// @param flags  MFS_ALL    If not given, blocks with negative numbers are not
+///                          synced, even when they are dirty.
+///               MFS_STOP   Stop syncing when a character becomes available,
+///                          but sync at least one block.
+///               MFS_FLUSH  Make sure buffers are flushed to disk, so they will
+///                          survive a system crash.
+///               MFS_ZERO   Only write block 0.
+///
+/// @return FAIL  If failure. Possible causes:
+///               - No file (nothing to do).
+///               - Write error (probably full disk).
+///         OK    Otherwise.
 int mf_sync(memfile_T *mfp, int flags)
 {
-  int status;
-  bhdr_T      *hp;
-#if defined(SYNC_DUP_CLOSE)
-  int fd;
-#endif
   int got_int_save = got_int;
 
-  if (mfp->mf_fd < 0) {     /* there is no file, nothing to do */
-    mfp->mf_dirty = FALSE;
+  if (mfp->mf_fd < 0) {         // there is no file, nothing to do
+    mfp->mf_dirty = false;
     return FAIL;
   }
 
-  /* Only a CTRL-C while writing will break us here, not one typed
-   * previously. */
-  got_int = FALSE;
-
-  /*
-   * sync from last to first (may reduce the probability of an inconsistent
-   * file) If a write fails, it is very likely caused by a full filesystem.
-   * Then we only try to write blocks within the existing file. If that also
-   * fails then we give up.
-   */
-  status = OK;
+  // Only a CTRL-C while writing will break us here, not one typed previously.
+  got_int = false;
+
+  // Sync from last to first (may reduce the probability of an inconsistent
+  // file). If a write fails, it is very likely caused by a full filesystem.
+  // Then we only try to write blocks within the existing file. If that also
+  // fails then we give up.
+  int status = OK;
+  bhdr_T *hp;
   for (hp = mfp->mf_used_last; hp != NULL; hp = hp->bh_prev)
     if (((flags & MFS_ALL) || hp->bh_bnum >= 0)
         && (hp->bh_flags & BH_DIRTY)
@@ -478,26 +450,24 @@ int mf_sync(memfile_T *mfp, int flags)
       if ((flags & MFS_ZERO) && hp->bh_bnum != 0)
         continue;
       if (mf_write(mfp, hp) == FAIL) {
-        if (status == FAIL)             /* double error: quit syncing */
+        if (status == FAIL)     // double error: quit syncing
           break;
         status = FAIL;
       }
-      if (flags & MFS_STOP) {
-        /* Stop when char available now. */
+      if (flags & MFS_STOP) {   // Stop when char available now.
         if (ui_char_avail())
           break;
-      } else
+      } else {
         ui_breakcheck();
+      }
       if (got_int)
         break;
     }
 
-  /*
-   * If the whole list is flushed, the memfile is not dirty anymore.
-   * In case of an error this flag is also set, to avoid trying all the time.
-   */
+  // If the whole list is flushed, the memfile is not dirty anymore.
+  // In case of an error, dirty flag is also set, to avoid trying all the time.
   if (hp == NULL || status == FAIL)
-    mfp->mf_dirty = FALSE;
+    mfp->mf_dirty = false;
 
   if ((flags & MFS_FLUSH) && *p_sws != NUL) {
 #if defined(UNIX)
@@ -505,21 +475,23 @@ int mf_sync(memfile_T *mfp, int flags)
     if (STRCMP(p_sws, "fsync") == 0) {
       if (fsync(mfp->mf_fd))
         status = FAIL;
-    } else
+    } else {
 # endif
-    /* OpenNT is strictly POSIX (Benzinger) */
-    /* Tandem/Himalaya NSK-OSS doesn't have sync() */
+    // OpenNT is strictly POSIX (Benzinger).
+    // Tandem/Himalaya NSK-OSS doesn't have sync()
 # if defined(__OPENNT) || defined(__TANDEM)
     fflush(NULL);
 # else
     sync();
 # endif
+# ifdef HAVE_FSYNC
+    }
+# endif
 #endif
 # ifdef SYNC_DUP_CLOSE
-    /*
-     * Win32 is a bit more work: Duplicate the file handle and close it.
-     * This should flush the file to disk.
-     */
+    // Win32 is a bit more work: Duplicate the file handle and close it.
+    // This should flush the file to disk.
+    int fd;
     if ((fd = dup(mfp->mf_fd)) >= 0)
       close(fd);
 # endif
@@ -530,54 +502,42 @@ int mf_sync(memfile_T *mfp, int flags)
   return status;
 }
 
-/*
- * For all blocks in memory file *mfp that have a positive block number set
- * the dirty flag.  These are blocks that need to be written to a newly
- * created swapfile.
- */
+/// Set dirty flag for all blocks in memory file with a positive block number.
+/// These are blocks that need to be written to a newly created swapfile.
 void mf_set_dirty(memfile_T *mfp)
 {
-  bhdr_T      *hp;
-
+  bhdr_T *hp;
   for (hp = mfp->mf_used_last; hp != NULL; hp = hp->bh_prev)
     if (hp->bh_bnum > 0)
       hp->bh_flags |= BH_DIRTY;
-  mfp->mf_dirty = TRUE;
+  mfp->mf_dirty = true;
 }
 
-/*
- * insert block *hp in front of hashlist of memfile *mfp
- */
+/// Insert block in front of memfile's hash list.
 static void mf_ins_hash(memfile_T *mfp, bhdr_T *hp)
 {
   mf_hash_add_item(&mfp->mf_hash, (mf_hashitem_T *)hp);