Delete structs.h by spliting it and moving code to other headers

Here's the list of squashed commits (for more info, see PR #378).

 - Define guicolor_T as a typedef in syntax.h
 - Move a big chunk of code from structs.h to buffer_defs.h
 - Move aco_save_T from structs.h to fileio.h
 - Move option_table_T from structs.h to hardcopy.h

	Aditionally:

	 - Move the printer_opts global to hardcopy.c
	 - Delete structs.h. Include buffer_defs.h where structs.h was included
	   before.
	 - Add header guards to option_defs.h

 - Put mark types and constants in new mark_defs.h
 - Move undo structs to undo_defs.h
 - Move memfile structs to new memfile_defs.h
 - Move expand_T and cmdmod_T to ex_cmds_defs.h
 - Move memline_T to memline_defs.h
 - Move many defs and types to ex_eval.h
 - Move syntax related types to syntax_defs.h
 - Move struct memfile to memfile_defs.h
 - struct buffblock and struct buffheader moved back to buffer_defs.h
 - Move some datatypes to hashtab.h and eval_defs.h
 - Move the buffer_defs.h include and TODOs for remaining unrelated types in buffer_defs.h

21 files changed, 806 insertions, 783 deletions

diff --git a/src/structs.h b/src/buffer_defs.h
index c678727b0a..9d5e75b609 100644
--- a/src/structs.h
+++ b/src/buffer_defs.h
@@ -1,59 +1,42 @@
-/* vi:set ts=8 sts=4 sw=4:
- *
- * 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.
- */
+#ifndef NEOVIM_BUFFER_DEFS_H
+#define NEOVIM_BUFFER_DEFS_H
 
 // for garray_T
 #include "garray.h"
 // for pos_T and lpos_T
 #include "pos.h"
-
-/*
- * This file contains various definitions of structures that are used by Vim
- */
+// for the number window-local and buffer-local options
+#include "option_defs.h"
+// for jump list and tag stack sizes in a buffer and mark types
+#include "mark_defs.h"
+// for u_header_T
+#include "undo_defs.h"
+// for hashtab_T
+#include "hashtab.h"
+// for dict_T
+#include "eval_defs.h"
 
 typedef struct window_S win_T;
 typedef struct wininfo_S wininfo_T;
 typedef struct frame_S frame_T;
-typedef int scid_T;                             /* script ID */
+typedef int scid_T;                     /* script ID */
 typedef struct file_buffer buf_T;       /* forward declaration */
+typedef struct memfile memfile_T;
 
-/*
- * This is here because regexp_defs.h needs win_T and regprog_T is used below.
- */
-#include "regexp_defs.h"
+// for struct memline (it needs memfile_T)
+#include "memline_defs.h"
 
-/*
- * This is here because gui.h needs the pos_T and win_T, and win_T needs gui.h
- * for scrollbar_T.
- */
-# define guicolor_T int         /* avoid error in prototypes */
+// for struct memfile, bhdr_T, blocknr_T... (it needs buf_T)
+#include "memfile_defs.h"
 
 /*
- * marks: positions in a file
- * (a normal mark is a lnum/col pair, the same as a file position)
+ * This is here because regexp_defs.h needs win_T and buf_T. regprog_T is
+ * used below.
  */
+#include "regexp_defs.h"
 
-/* (Note: for EBCDIC there are more than 26, because there are gaps in the
- * alphabet coding.  To minimize changes to the code, I decided to just
- * increase the number of possible marks. */
-#define NMARKS          ('z' - 'a' + 1) /* max. # of named marks */
-#define JUMPLISTSIZE    100             /* max. # of marks in jump list */
-#define TAGSTACKSIZE    20              /* max. # of tags in tag stack */
-
-typedef struct filemark {
-  pos_T mark;                   /* cursor position */
-  int fnum;                     /* file number */
-} fmark_T;
-
-/* Xtended file mark: also has a file name */
-typedef struct xfilemark {
-  fmark_T fmark;
-  char_u      *fname;           /* file name, used when fnum == 0 */
-} xfmark_T;
+// for  synstate_T (needs reg_extmatch_T, win_T and buf_T)
+#include "syntax_defs.h"
 
 /*
  * The taggy struct is used to store the information about a :tag command.
@@ -66,6 +49,24 @@ typedef struct taggy {
 } taggy_T;
 
 /*
+ * structure used to store one block of the stuff/redo/recording buffers
+ */
+struct buffblock {
+  struct buffblock    *b_next;          /* pointer to next buffblock */
+  char_u b_str[1];                      /* contents (actually longer) */
+};
+
+/*
+ * header used for the stuff buffer and the redo buffer
+ */
+struct buffheader {
+  struct buffblock bh_first;            /* first (dummy) block of list */
+  struct buffblock    *bh_curr;         /* buffblock for appending */
+  int bh_index;                         /* index for reading */
+  int bh_space;                         /* space in bh_curr for appending */
+};
+
+/*
  * Structure that contains all options that are local to a window.
  * Used twice in a window: for the current buffer and for all buffers.
  * Also used in wininfo_T.
@@ -179,302 +180,11 @@ struct wininfo_S {
   garray_T wi_folds;            /* clone of w_folds */
 };
 
-/* Structure to store info about the Visual area. */
-typedef struct {
-  pos_T vi_start;               /* start pos of last VIsual */
-  pos_T vi_end;                 /* end position of last VIsual */
-  int vi_mode;                  /* VIsual_mode of last VIsual */
-  colnr_T vi_curswant;          /* MAXCOL from w_curswant */
-} visualinfo_T;
-
-/*
- * structures used for undo
- */
-
-typedef struct u_entry u_entry_T;
-typedef struct u_header u_header_T;
-struct u_entry {
-  u_entry_T   *ue_next;         /* pointer to next entry in list */
-  linenr_T ue_top;              /* number of line above undo block */
-  linenr_T ue_bot;              /* number of line below undo block */
-  linenr_T ue_lcount;           /* linecount when u_save called */
-  char_u      **ue_array;       /* array of lines in undo block */
-  long ue_size;                 /* number of lines in ue_array */
-#ifdef U_DEBUG
-  int ue_magic;                 /* magic number to check allocation */
-#endif
-};
-
-struct u_header {
-  /* The following have a pointer and a number. The number is used when
-   * reading the undo file in u_read_undo() */
-  union {
-    u_header_T *ptr;            /* pointer to next undo header in list */
-    long seq;
-  } uh_next;
-  union {
-    u_header_T *ptr;            /* pointer to previous header in list */
-    long seq;
-  } uh_prev;
-  union {
-    u_header_T *ptr;            /* pointer to next header for alt. redo */
-    long seq;
-  } uh_alt_next;
-  union {
-    u_header_T *ptr;            /* pointer to previous header for alt. redo */
-    long seq;
-  } uh_alt_prev;
-  long uh_seq;                  /* sequence number, higher == newer undo */
-  int uh_walk;                  /* used by undo_time() */
-  u_entry_T   *uh_entry;        /* pointer to first entry */
-  u_entry_T   *uh_getbot_entry;   /* pointer to where ue_bot must be set */
-  pos_T uh_cursor;              /* cursor position before saving */
-  long uh_cursor_vcol;
-  int uh_flags;                 /* see below */
-  pos_T uh_namedm[NMARKS];              /* marks before undo/after redo */
-  visualinfo_T uh_visual;       /* Visual areas before undo/after redo */
-  time_t uh_time;               /* timestamp when the change was made */
-  long uh_save_nr;              /* set when the file was saved after the
-                                   changes in this block */
-#ifdef U_DEBUG
-  int uh_magic;                 /* magic number to check allocation */
-#endif
-};
-
-/* values for uh_flags */
-#define UH_CHANGED  0x01        /* b_changed flag before undo/after redo */
-#define UH_EMPTYBUF 0x02        /* buffer was empty */
-
-/*
- * things used in memfile.c
- */
-
-typedef struct block_hdr bhdr_T;
-typedef struct memfile memfile_T;
-typedef long blocknr_T;
-
-/*
- * mf_hashtab_T is a chained hashtable with blocknr_T key and arbitrary
- * structures as items.  This is an intrusive data structure: we require
- * that items begin with mf_hashitem_T which contains the key and linked
- * list pointers.  List of items in each bucket is doubly-linked.
- */
-
-typedef struct mf_hashitem_S mf_hashitem_T;
-
-struct mf_hashitem_S {
-  mf_hashitem_T   *mhi_next;
-  mf_hashitem_T   *mhi_prev;
-  blocknr_T mhi_key;
-};
-
-#define MHT_INIT_SIZE   64
-
-typedef struct mf_hashtab_S {
-  long_u mht_mask;                  /* mask used for hash value (nr of items
-                                     * in array is "mht_mask" + 1) */
-  long_u mht_count;                 /* nr of items inserted into hashtable */
-  mf_hashitem_T   **mht_buckets;    /* points to mht_small_buckets or
-                                     *dynamically allocated array */
-  mf_hashitem_T   *mht_small_buckets[MHT_INIT_SIZE];     /* initial buckets */
-  char mht_fixed;                   /* non-zero value forbids growth */
-} mf_hashtab_T;
-
-/*
- * for each (previously) used block in the memfile there is one block header.
- *
- * The block may be linked in the used list OR in the free list.
- * The used blocks are also kept in hash lists.
- *
- * The used list is a doubly linked list, most recently used block first.
- *	The blocks in the used list have a block of memory allocated.
- *	mf_used_count is the number of pages in the used list.
- * The hash lists are used to quickly find a block in the used list.
- * The free list is a single linked list, not sorted.
- *	The blocks in the free list have no block of memory allocated and
- *	the contents of the block in the file (if any) is irrelevant.
- */
-
-struct block_hdr {
-  mf_hashitem_T bh_hashitem;        /* header for hash table and key */
-#define bh_bnum bh_hashitem.mhi_key /* block number, part of bh_hashitem */
-
-  bhdr_T      *bh_next;             /* next block_hdr in free or used list */
-  bhdr_T      *bh_prev;             /* previous block_hdr in used list */
-  char_u      *bh_data;             /* pointer to memory (for used block) */
-  int bh_page_count;                /* number of pages in this block */
-
-#define BH_DIRTY    1
-#define BH_LOCKED   2
-  char bh_flags;                    /* BH_DIRTY or BH_LOCKED */
-};
-
-/*
- * when a block with a negative number is flushed to the file, it gets
- * a positive number. Because the reference to the block is still the negative
- * number, we remember the translation to the new positive number in the
- * double linked trans lists. The structure is the same as the hash lists.
- */
-typedef struct nr_trans NR_TRANS;
-
-struct nr_trans {
-  mf_hashitem_T nt_hashitem;            /* header for hash table and key */
-#define nt_old_bnum nt_hashitem.mhi_key /* old, negative, number */
-
-  blocknr_T nt_new_bnum;                /* new, positive, number */
-};
-
-/*
- * structure used to store one block of the stuff/redo/recording buffers
- */
-struct buffblock {
-  struct buffblock    *b_next;          /* pointer to next buffblock */
-  char_u b_str[1];                      /* contents (actually longer) */
-};
-
-/*
- * header used for the stuff buffer and the redo buffer
- */
-struct buffheader {
-  struct buffblock bh_first;            /* first (dummy) block of list */
-  struct buffblock    *bh_curr;         /* buffblock for appending */
-  int bh_index;                         /* index for reading */
-  int bh_space;                         /* space in bh_curr for appending */
-};
-
-/*
- * used for completion on the command line
- */
-typedef struct expand {
-  int xp_context;                       /* type of expansion */
-  char_u      *xp_pattern;              /* start of item to expand */
-  int xp_pattern_len;                   /* bytes in xp_pattern before cursor */
-  char_u      *xp_arg;                  /* completion function */
-  int xp_scriptID;                      /* SID for completion function */
-  int xp_backslash;                     /* one of the XP_BS_ values */
-#ifndef BACKSLASH_IN_FILENAME
-  int xp_shell;                         /* TRUE for a shell command, more
-                                           characters need to be escaped */
-#endif
-  int xp_numfiles;                      /* number of files found by
-                                                    file name completion */
-  char_u      **xp_files;               /* list of files */
-  char_u      *xp_line;                 /* text being completed */
-  int xp_col;                           /* cursor position in line */
-} expand_T;
-
-/* values for xp_backslash */
-#define XP_BS_NONE      0       /* nothing special for backslashes */
-#define XP_BS_ONE       1       /* uses one backslash before a space */
-#define XP_BS_THREE     2       /* uses three backslashes before a space */
-
-/*
- * Command modifiers ":vertical", ":browse", ":confirm" and ":hide" set a flag.
- * This needs to be saved for recursive commands, put them in a structure for
- * easy manipulation.
- */
-typedef struct {
-  int hide;                             /* TRUE when ":hide" was used */
-  int split;                            /* flags for win_split() */
-  int tab;                              /* > 0 when ":tab" was used */
-  int confirm;                          /* TRUE to invoke yes/no dialog */
-  int keepalt;                          /* TRUE when ":keepalt" was used */
-  int keepmarks;                        /* TRUE when ":keepmarks" was used */
-  int keepjumps;                        /* TRUE when ":keepjumps" was used */
-  int lockmarks;                        /* TRUE when ":lockmarks" was used */
-  int keeppatterns;                     /* TRUE when ":keeppatterns" was used */
-  char_u      *save_ei;                 /* saved value of 'eventignore' */
-} cmdmod_T;
-
-#define MF_SEED_LEN     8
-
-struct memfile {
-  char_u      *mf_fname;                /* name of the file */
-  char_u      *mf_ffname;               /* idem, full path */
-  int mf_fd;                            /* file descriptor */
-  bhdr_T      *mf_free_first;           /* first block_hdr in free list */
-  bhdr_T      *mf_used_first;           /* mru block_hdr in used list */
-  bhdr_T      *mf_used_last;            /* lru block_hdr in used list */
-  unsigned mf_used_count;               /* number of pages in used list */
-  unsigned mf_used_count_max;           /* maximum number of pages in memory */
-  mf_hashtab_T mf_hash;                 /* hash lists */
-  mf_hashtab_T mf_trans;                /* trans lists */
-  blocknr_T mf_blocknr_max;             /* highest positive block number + 1*/
-  blocknr_T mf_blocknr_min;             /* lowest negative block number - 1 */
-  blocknr_T mf_neg_count;               /* number of negative blocks numbers */
-  blocknr_T mf_infile_count;            /* number of pages in the file */
-  unsigned mf_page_size;                /* number of bytes in a page */
-  int mf_dirty;                         /* TRUE if there are dirty blocks */
-  buf_T       *mf_buffer;               /* bufer this memfile is for */
-  char_u mf_seed[MF_SEED_LEN];          /* seed for encryption */
-
-  /* Values for key, method and seed used for reading data blocks when
-   * updating for a newly set key or method. Only when mf_old_key != NULL. */
-  char_u      *mf_old_key;
-  int mf_old_cm;
-  char_u mf_old_seed[MF_SEED_LEN];
-};
-
-/*
- * things used in memline.c
- */
-/*
- * When searching for a specific line, we remember what blocks in the tree
- * are the branches leading to that block. This is stored in ml_stack.  Each
- * entry is a pointer to info in a block (may be data block or pointer block)
- */
-typedef struct info_pointer {
-  blocknr_T ip_bnum;            /* block number */
-  linenr_T ip_low;              /* lowest lnum in this block */
-  linenr_T ip_high;             /* highest lnum in this block */
-  int ip_index;                 /* index for block with current lnum */
-} infoptr_T;    /* block/index pair */
-
-typedef struct ml_chunksize {
-  int mlcs_numlines;
-  long mlcs_totalsize;
-} chunksize_T;
-
-/* Flags when calling ml_updatechunk() */
-
-#define ML_CHNK_ADDLINE 1
-#define ML_CHNK_DELLINE 2
-#define ML_CHNK_UPDLINE 3
-
-/*
- * the memline structure holds all the information about a memline
- */
-typedef struct memline {
-  linenr_T ml_line_count;       /* number of lines in the buffer */
-
-  memfile_T   *ml_mfp;          /* pointer to associated memfile */
-
-#define ML_EMPTY        1       /* empty buffer */
-#define ML_LINE_DIRTY   2       /* cached line was changed and allocated */
-#define ML_LOCKED_DIRTY 4       /* ml_locked was changed */
-#define ML_LOCKED_POS   8       /* ml_locked needs positive block number */
-  int ml_flags;
-
-  infoptr_T   *ml_stack;        /* stack of pointer blocks (array of IPTRs) */
-  int ml_stack_top;             /* current top if ml_stack */
-  int ml_stack_size;            /* total number of entries in ml_stack */
-
-  linenr_T ml_line_lnum;        /* line number of cached line, 0 if not valid */
-  char_u      *ml_line_ptr;     /* pointer to cached line */
-
-  bhdr_T      *ml_locked;       /* block used by last ml_get */
-  linenr_T ml_locked_low;       /* first line in ml_locked */
-  linenr_T ml_locked_high;      /* last line in ml_locked */
-  int ml_locked_lineadd;            /* number of lines inserted in ml_locked */
-  chunksize_T *ml_chunksize;
-  int ml_numchunks;
-  int ml_usedchunks;
-} memline_T;
-
-
 /*
  * Argument list: Array of file names.
  * Used for the global argument list and the argument lists local to a window.
+ *
+ * TODO: move struct arglist to another header
  */
 typedef struct arglist {
   garray_T al_ga;               /* growarray with the array of file names */
@@ -485,6 +195,8 @@ typedef struct arglist {
  * For each argument remember the file name as it was given, and the buffer
  * number that contains the expanded file name (required for when ":cd" is
  * used.
+ *
+ * TODO: move aentry_T to another header
  */
 typedef struct argentry {
   char_u      *ae_fname;        /* file name as specified */
@@ -500,195 +212,6 @@ typedef struct argentry {
 #define ARGCOUNT        (ALIST(curwin)->al_ga.ga_len)
 #define WARGCOUNT(wp)   (ALIST(wp)->al_ga.ga_len)
 
-/*
- * A list used for saving values of "emsg_silent".  Used by ex_try() to save the
- * value of "emsg_silent" if it was non-zero.  When this is done, the CSF_SILENT
- * flag below is set.
- */
-
-typedef struct eslist_elem eslist_T;
-struct eslist_elem {
-  int saved_emsg_silent;                /* saved value of "emsg_silent" */
-  eslist_T    *next;                    /* next element on the list */
-};
-
-/*
- * For conditional commands a stack is kept of nested conditionals.
- * When cs_idx < 0, there is no conditional command.
- */
-#define CSTACK_LEN      50
-
-struct condstack {
-  short cs_flags[CSTACK_LEN];           /* CSF_ flags */
-  char cs_pending[CSTACK_LEN];          /* CSTP_: what's pending in ":finally"*/
-  union {
-    void    *csp_rv[CSTACK_LEN];        /* return typeval for pending return */
-    void    *csp_ex[CSTACK_LEN];        /* exception for pending throw */
-  }           cs_pend;
-  void        *cs_forinfo[CSTACK_LEN];   /* info used by ":for" */
-  int cs_line[CSTACK_LEN];              /* line nr of ":while"/":for" line */
-  int cs_idx;                           /* current entry, or -1 if none */
-  int cs_looplevel;                     /* nr of nested ":while"s and ":for"s */
-  int cs_trylevel;                      /* nr of nested ":try"s */
-  eslist_T    *cs_emsg_silent_list;     /* saved values of "emsg_silent" */
-  char cs_lflags;                       /* loop flags: CSL_ flags */
-};
-# define cs_rettv       cs_pend.csp_rv
-# define cs_exception   cs_pend.csp_ex
-
-/* There is no CSF_IF, the lack of CSF_WHILE, CSF_FOR and CSF_TRY means ":if"
- * was used. */
-# define CSF_TRUE       0x0001  /* condition was TRUE */
-# define CSF_ACTIVE     0x0002  /* current state is active */
-# define CSF_ELSE       0x0004  /* ":else" has been passed */
-# define CSF_WHILE      0x0008  /* is a ":while" */
-# define CSF_FOR        0x0010  /* is a ":for" */
-
-# define CSF_TRY        0x0100  /* is a ":try" */
-# define CSF_FINALLY    0x0200  /* ":finally" has been passed */
-# define CSF_THROWN     0x0400  /* exception thrown to this try conditional */
-# define CSF_CAUGHT     0x0800  /* exception caught by this try conditional */
-# define CSF_SILENT     0x1000  /* "emsg_silent" reset by ":try" */
-/* Note that CSF_ELSE is only used when CSF_TRY and CSF_WHILE are unset
- * (an ":if"), and CSF_SILENT is only used when CSF_TRY is set. */
-
-/*
- * What's pending for being reactivated at the ":endtry" of this try
- * conditional:
- */
-# define CSTP_NONE      0       /* nothing pending in ":finally" clause */
-# define CSTP_ERROR     1       /* an error is pending */
-# define CSTP_INTERRUPT 2       /* an interrupt is pending */
-# define CSTP_THROW     4       /* a throw is pending */
-# define CSTP_BREAK     8       /* ":break" is pending */
-# define CSTP_CONTINUE  16      /* ":continue" is pending */
-# define CSTP_RETURN    24      /* ":return" is pending */
-# define CSTP_FINISH    32      /* ":finish" is pending */
-
-/*
- * Flags for the cs_lflags item in struct condstack.
- */
-# define CSL_HAD_LOOP    1      /* just found ":while" or ":for" */
-# define CSL_HAD_ENDLOOP 2      /* just found ":endwhile" or ":endfor" */
-# define CSL_HAD_CONT    4      /* just found ":continue" */
-# define CSL_HAD_FINA    8      /* just found ":finally" */
-
-/*
- * A list of error messages that can be converted to an exception.  "throw_msg"
- * is only set in the first element of the list.  Usually, it points to the
- * original message stored in that element, but sometimes it points to a later
- * message in the list.  See cause_errthrow() below.
- */
-struct msglist {
-  char_u              *msg;             /* original message */
-  char_u              *throw_msg;       /* msg to throw: usually original one */
-  struct msglist      *next;            /* next of several messages in a row */
-};
-
-/*
- * Structure describing an exception.
- * (don't use "struct exception", it's used by the math library).
- */
-typedef struct vim_exception except_T;
-struct vim_exception {
-  int type;                             /* exception type */
-  char_u              *value;           /* exception value */
-  struct msglist      *messages;        /* message(s) causing error exception */
-  char_u              *throw_name;      /* name of the throw point */
-  linenr_T throw_lnum;                  /* line number of the throw point */
-  except_T            *caught;          /* next exception on the caught stack */
-};
-
-/*
- * The exception types.
- */
-#define ET_USER         0       /* exception caused by ":throw" command */
-#define ET_ERROR        1       /* error exception */
-#define ET_INTERRUPT    2       /* interrupt exception triggered by Ctrl-C */
-
-/*
- * Structure to save the error/interrupt/exception state between calls to
- * enter_cleanup() and leave_cleanup().  Must be allocated as an automatic
- * variable by the (common) caller of these functions.
- */
-typedef struct cleanup_stuff cleanup_T;
-struct cleanup_stuff {
-  int pending;                  /* error/interrupt/exception state */
-  except_T *exception;          /* exception value */
-};
-
-/* struct passed to in_id_list() */
-struct sp_syn {
-  int inc_tag;                  /* ":syn include" unique tag */
-  short id;                     /* highlight group ID of item */
-  short       *cont_in_list;    /* cont.in group IDs, if non-zero */
-};
-
-/*
- * Each keyword has one keyentry, which is linked in a hash list.
- */
-typedef struct keyentry keyentry_T;
-
-struct keyentry {
-  keyentry_T  *ke_next;         /* next entry with identical "keyword[]" */
-  struct sp_syn k_syn;          /* struct passed to in_id_list() */
-  short       *next_list;       /* ID list for next match (if non-zero) */
-  int flags;
-  int k_char;                   /* conceal substitute character */
-  char_u keyword[1];            /* actually longer */
-};
-
-/*
- * Struct used to store one state of the state stack.
- */
-typedef struct buf_state {
-  int bs_idx;                    /* index of pattern */
-  int bs_flags;                  /* flags for pattern */
-  int bs_seqnr;                  /* stores si_seqnr */
-  int bs_cchar;                  /* stores si_cchar */
-  reg_extmatch_T *bs_extmatch;   /* external matches from start pattern */
-} bufstate_T;
-
-/*
- * syn_state contains the syntax state stack for the start of one line.
- * Used by b_sst_array[].
- */
-typedef struct syn_state synstate_T;
-
-struct syn_state {
-  synstate_T  *sst_next;        /* next entry in used or free list */
-  linenr_T sst_lnum;            /* line number for this state */
-  union {
-    bufstate_T sst_stack[SST_FIX_STATES];          /* short state stack */
-    garray_T sst_ga;            /* growarray for long state stack */
-  } sst_union;
-  int sst_next_flags;           /* flags for sst_next_list */
-  int sst_stacksize;            /* number of states on the stack */
-  short       *sst_next_list;   /* "nextgroup" list in this state
-                                 * (this is a copy, don't free it! */
-  disptick_T sst_tick;          /* tick when last displayed */
-  linenr_T sst_change_lnum;     /* when non-zero, change in this line
-                                 * may have made the state invalid */
-};
-
-/*
- * Structure shared between syntax.c, screen.c and gui_x11.c.
- */
-typedef struct attr_entry {
-  short ae_attr;                        /* HL_BOLD, etc. */
-  union {
-    struct {
-      char_u          *start;           /* start escape sequence */
-      char_u          *stop;            /* stop escape sequence */
-    } term;
-    struct {
-      /* These colors need to be > 8 bits to hold 256. */
-      short_u fg_color;                 /* foreground color number */
-      short_u bg_color;                 /* background color number */
-    } cterm;
-  } ae_u;
-} attrentry_T;
-
 #ifdef USE_ICONV
 # ifdef HAVE_ICONV_H
 #  include <iconv.h>
@@ -779,163 +302,6 @@ struct stl_hlrec {
   int userhl;                   /* 0: no HL, 1-9: User HL, < 0 for syn ID */
 };
 
-
-/*
- * Syntax items - usually buffer-specific.
- */
-
-/* Item for a hashtable.  "hi_key" can be one of three values:
- * NULL:	   Never been used
- * HI_KEY_REMOVED: Entry was removed
- * Otherwise:	   Used item, pointer to the actual key; this usually is
- *		   inside the item, subtract an offset to locate the item.
- *		   This reduces the size of hashitem by 1/3.
- */
-typedef struct hashitem_S {
-  long_u hi_hash;               /* cached hash number of hi_key */
-  char_u      *hi_key;
-} hashitem_T;
-
-/* The address of "hash_removed" is used as a magic number for hi_key to
- * indicate a removed item. */
-#define HI_KEY_REMOVED &hash_removed
-#define HASHITEM_EMPTY(hi) ((hi)->hi_key == NULL || (hi)->hi_key == \
-                            &hash_removed)
-
-/* Initial size for a hashtable.  Our items are relatively small and growing
- * is expensive, thus use 16 as a start.  Must be a power of 2. */
-#define HT_INIT_SIZE 16
-
-typedef struct hashtable_S {
-  long_u ht_mask;               /* mask used for hash value (nr of items in
-                                 * array is "ht_mask" + 1) */
-  long_u ht_used;               /* number of items used */
-  long_u ht_filled;             /* number of items used + removed */
-  int ht_locked;                /* counter for hash_lock() */
-  int ht_error;                 /* when set growing failed, can't add more
-                                   items before growing works */
-  hashitem_T  *ht_array;        /* points to the array, allocated when it's
-                                   not "ht_smallarray" */
-  hashitem_T ht_smallarray[HT_INIT_SIZE];      /* initial array */
-} hashtab_T;
-
-typedef long_u hash_T;          /* Type for hi_hash */
-
-
-#if SIZEOF_INT <= 3             /* use long if int is smaller than 32 bits */
-typedef long varnumber_T;
-#else
-typedef int varnumber_T;
-#endif
-typedef double float_T;
-
-typedef struct listvar_S list_T;
-typedef struct dictvar_S dict_T;
-
-/*
- * Structure to hold an internal variable without a name.
- */
-typedef struct {
-  char v_type;              /* see below: VAR_NUMBER, VAR_STRING, etc. */
-  char v_lock;              /* see below: VAR_LOCKED, VAR_FIXED */
-  union {
-    varnumber_T v_number;               /* number value */
-    float_T v_float;                    /* floating number value */
-    char_u          *v_string;          /* string value (can be NULL!) */
-    list_T          *v_list;            /* list value (can be NULL!) */
-    dict_T          *v_dict;            /* dict value (can be NULL!) */
-  }           vval;
-} typval_T;
-
-/* Values for "v_type". */
-#define VAR_UNKNOWN 0
-#define VAR_NUMBER  1   /* "v_number" is used */
-#define VAR_STRING  2   /* "v_string" is used */
-#define VAR_FUNC    3   /* "v_string" is function name */
-#define VAR_LIST    4   /* "v_list" is used */
-#define VAR_DICT    5   /* "v_dict" is used */
-#define VAR_FLOAT   6   /* "v_float" is used */
-
-/* Values for "dv_scope". */
-#define VAR_SCOPE     1 /* a:, v:, s:, etc. scope dictionaries */
-#define VAR_DEF_SCOPE 2 /* l:, g: scope dictionaries: here funcrefs are not
-                           allowed to mask existing functions */
-
-/* Values for "v_lock". */
-#define VAR_LOCKED  1   /* locked with lock(), can use unlock() */
-#define VAR_FIXED   2   /* locked forever */
-
-/*
- * Structure to hold an item of a list: an internal variable without a name.
- */
-typedef struct listitem_S listitem_T;
-
-struct listitem_S {
-  listitem_T  *li_next;         /* next item in list */
-  listitem_T  *li_prev;         /* previous item in list */
-  typval_T li_tv;               /* type and value of the variable */
-};
-
-/*
- * Struct used by those that are using an item in a list.
- */
-typedef struct listwatch_S listwatch_T;
-
-struct listwatch_S {
-  listitem_T          *lw_item;         /* item being watched */
-  listwatch_T         *lw_next;         /* next watcher */
-};
-
-/*
- * Structure to hold info about a list.
- */
-struct listvar_S {
-  listitem_T  *lv_first;        /* first item, NULL if none */
-  listitem_T  *lv_last;         /* last item, NULL if none */
-  int lv_refcount;              /* reference count */
-  int lv_len;                   /* number of items */
-  listwatch_T *lv_watch;        /* first watcher, NULL if none */
-  int lv_idx;                   /* cached index of an item */
-  listitem_T  *lv_idx_item;     /* when not NULL item at index "lv_idx" */
-  int lv_copyID;                /* ID used by deepcopy() */
-  list_T      *lv_copylist;     /* copied list used by deepcopy() */
-  char lv_lock;                 /* zero, VAR_LOCKED, VAR_FIXED */
-  list_T      *lv_used_next;    /* next list in used lists list */
-  list_T      *lv_used_prev;    /* previous list in used lists list */
-};
-
-/*
- * Structure to hold an item of a Dictionary.
- * Also used for a variable.
- * The key is copied into "di_key" to avoid an extra alloc/free for it.
- */
-struct dictitem_S {
-  typval_T di_tv;               /* type and value of the variable */
-  char_u di_flags;              /* flags (only used for variable) */
-  char_u di_key[1];             /* key (actually longer!) */
-};
-
-typedef struct dictitem_S dictitem_T;
-
-#define DI_FLAGS_RO     1 /* "di_flags" value: read-only variable */
-#define DI_FLAGS_RO_SBX 2 /* "di_flags" value: read-only in the sandbox */
-#define DI_FLAGS_FIX    4 /* "di_flags" value: fixed variable, not allocated */
-#define DI_FLAGS_LOCK   8 /* "di_flags" value: locked variable */
-
-/*
- * Structure to hold info about a Dictionary.
- */
-struct dictvar_S {
-  char dv_lock;                 /* zero, VAR_LOCKED, VAR_FIXED */
-  char dv_scope;                /* zero, VAR_SCOPE, VAR_DEF_SCOPE */
-  int dv_refcount;              /* reference count */
-  int dv_copyID;                /* ID used by deepcopy() */
-  hashtab_T dv_hashtab;         /* hashtab that refers to the items */
-  dict_T      *dv_copydict;     /* copied dict used by deepcopy() */
-  dict_T      *dv_used_next;    /* next dict in used dicts list */
-  dict_T      *dv_used_prev;    /* previous dict in used dicts list */
-};
-
 /* values for b_syn_spell: what to do with toplevel text */
 #define SYNSPL_DEFAULT  0       /* spell check if @Spell not defined */
 #define SYNSPL_TOP      1       /* spell check toplevel text */
@@ -1331,21 +697,11 @@ struct file_buffer {
   int b_shortname;              /* this file has an 8.3 file name */
 #endif
 
-
-
-
-
-
-
   synblock_T b_s;               /* Info related to syntax highlighting.  w_s
                                  * normally points to this, but some windows
                                  * may use a different synblock_T. */
-
-
-
 };
 
-
 /*
  * Stuff for diff mode.
  */
@@ -1400,8 +756,6 @@ struct tabpage_S {
   frame_T         *(tp_snapshot[SNAP_COUNT]);    /* window layout snapshots */
   dictitem_T tp_winvar;             /* variable for "t:" Dictionary */
   dict_T          *tp_vars;         /* internal variables, local to tab page */
-
-
 };
 
 /*
@@ -1724,27 +1078,4 @@ struct window_S {
   qf_info_T   *w_llist_ref;
 };
 
-/*
- * Struct to save values in before executing autocommands for a buffer that is
- * not the current buffer.  Without FEAT_AUTOCMD only "curbuf" is remembered.
- */
-typedef struct {
-  buf_T       *save_curbuf;     /* saved curbuf */
-  int use_aucmd_win;            /* using aucmd_win */
-  win_T       *save_curwin;     /* saved curwin */
-  win_T       *new_curwin;      /* new curwin */
-  buf_T       *new_curbuf;      /* new curbuf */
-  char_u      *globaldir;       /* saved value of globaldir */
-} aco_save_T;
-
-/*
- * Generic option table item, only used for printer at the moment.
- */
-typedef struct {
-  const char  *name;
-  int hasnum;
-  long number;
-  char_u      *string;          /* points into option string */
-  int strlen;
-  int present;
-} option_table_T;
+#endif // NEOVIM_BUFFER_DEFS_H
diff --git a/src/eval_defs.h b/src/eval_defs.h
new file mode 100644
index 0000000000..c925514597
--- /dev/null
+++ b/src/eval_defs.h
@@ -0,0 +1,120 @@
+#ifndef NEOVIM_EVAL_DEFS_H
+#define NEOVIM_EVAL_DEFS_H
+
+#include "hashtab.h"
+
+#if SIZEOF_INT <= 3             /* use long if int is smaller than 32 bits */
+typedef long varnumber_T;
+#else
+typedef int varnumber_T;
+#endif
+typedef double float_T;
+
+typedef struct listvar_S list_T;
+typedef struct dictvar_S dict_T;
+
+/*
+ * Structure to hold an internal variable without a name.
+ */
+typedef struct {
+  char v_type;              /* see below: VAR_NUMBER, VAR_STRING, etc. */
+  char v_lock;              /* see below: VAR_LOCKED, VAR_FIXED */
+  union {
+    varnumber_T v_number;               /* number value */
+    float_T v_float;                    /* floating number value */
+    char_u          *v_string;          /* string value (can be NULL!) */
+    list_T          *v_list;            /* list value (can be NULL!) */
+    dict_T          *v_dict;            /* dict value (can be NULL!) */
+  }           vval;
+} typval_T;
+
+/* Values for "v_type". */
+#define VAR_UNKNOWN 0
+#define VAR_NUMBER  1   /* "v_number" is used */
+#define VAR_STRING  2   /* "v_string" is used */
+#define VAR_FUNC    3   /* "v_string" is function name */
+#define VAR_LIST    4   /* "v_list" is used */
+#define VAR_DICT    5   /* "v_dict" is used */
+#define VAR_FLOAT   6   /* "v_float" is used */
+
+/* Values for "dv_scope". */
+#define VAR_SCOPE     1 /* a:, v:, s:, etc. scope dictionaries */
+#define VAR_DEF_SCOPE 2 /* l:, g: scope dictionaries: here funcrefs are not
+                           allowed to mask existing functions */
+
+/* Values for "v_lock". */
+#define VAR_LOCKED  1   /* locked with lock(), can use unlock() */
+#define VAR_FIXED   2   /* locked forever */
+
+/*
+ * Structure to hold an item of a list: an internal variable without a name.
+ */
+typedef struct listitem_S listitem_T;
+
+struct listitem_S {
+  listitem_T  *li_next;         /* next item in list */
+  listitem_T  *li_prev;         /* previous item in list */
+  typval_T li_tv;               /* type and value of the variable */
+};
+
+/*
+ * Struct used by those that are using an item in a list.
+ */
+typedef struct listwatch_S listwatch_T;
+
+struct listwatch_S {
+  listitem_T          *lw_item;         /* item being watched */
+  listwatch_T         *lw_next;         /* next watcher */
+};
+
+/*
+ * Structure to hold info about a list.
+ */
+struct listvar_S {
+  listitem_T  *lv_first;        /* first item, NULL if none */
+  listitem_T  *lv_last;         /* last item, NULL if none */
+  int lv_refcount;              /* reference count */
+  int lv_len;                   /* number of items */
+  listwatch_T *lv_watch;        /* first watcher, NULL if none */
+  int lv_idx;                   /* cached index of an item */
+  listitem_T  *lv_idx_item;     /* when not NULL item at index "lv_idx" */
+  int lv_copyID;                /* ID used by deepcopy() */
+  list_T      *lv_copylist;     /* copied list used by deepcopy() */
+  char lv_lock;                 /* zero, VAR_LOCKED, VAR_FIXED */
+  list_T      *lv_used_next;    /* next list in used lists list */
+  list_T      *lv_used_prev;    /* previous list in used lists list */
+};
+
+/*
+ * Structure to hold an item of a Dictionary.
+ * Also used for a variable.
+ * The key is copied into "di_key" to avoid an extra alloc/free for it.
+ */
+struct dictitem_S {
+  typval_T di_tv;               /* type and value of the variable */
+  char_u di_flags;              /* flags (only used for variable) */
+  char_u di_key[1];             /* key (actually longer!) */
+};
+
+typedef struct dictitem_S dictitem_T;
+
+#define DI_FLAGS_RO     1 /* "di_flags" value: read-only variable */
+#define DI_FLAGS_RO_SBX 2 /* "di_flags" value: read-only in the sandbox */
+#define DI_FLAGS_FIX    4 /* "di_flags" value: fixed variable, not allocated */
+#define DI_FLAGS_LOCK   8 /* "di_flags" value: locked variable */
+
+/*
+ * Structure to hold info about a Dictionary.
+ */
+struct dictvar_S {
+  char dv_lock;                 /* zero, VAR_LOCKED, VAR_FIXED */
+  char dv_scope;                /* zero, VAR_SCOPE, VAR_DEF_SCOPE */
+  int dv_refcount;              /* reference count */
+  int dv_copyID;                /* ID used by deepcopy() */
+  hashtab_T dv_hashtab;         /* hashtab that refers to the items */
+  dict_T      *dv_copydict;     /* copied dict used by deepcopy() */
+  dict_T      *dv_used_next;    /* next dict in used dicts list */
+  dict_T      *dv_used_prev;    /* previous dict in used dicts list */
+};
+
+#endif // NEOVIM_EVAL_DEFS_H
diff --git a/src/ex_cmds_defs.h b/src/ex_cmds_defs.h
index 8b6c7c866e..3b173341e1 100644
--- a/src/ex_cmds_defs.h
+++ b/src/ex_cmds_defs.h
@@ -1190,4 +1190,48 @@ struct exarg {
 #define EXFLAG_NR       0x02    /* '#': number */
 #define EXFLAG_PRINT    0x04    /* 'p': print */
 
+/*
+ * used for completion on the command line
+ */
+typedef struct expand {
+  int xp_context;                       /* type of expansion */
+  char_u      *xp_pattern;              /* start of item to expand */
+  int xp_pattern_len;                   /* bytes in xp_pattern before cursor */
+  char_u      *xp_arg;                  /* completion function */
+  int xp_scriptID;                      /* SID for completion function */
+  int xp_backslash;                     /* one of the XP_BS_ values */
+#ifndef BACKSLASH_IN_FILENAME
+  int xp_shell;                         /* TRUE for a shell command, more
+                                           characters need to be escaped */
+#endif
+  int xp_numfiles;                      /* number of files found by
+                                                    file name completion */
+  char_u      **xp_files;               /* list of files */
+  char_u      *xp_line;                 /* text being completed */
+  int xp_col;                           /* cursor position in line */
+} expand_T;
+
+/* values for xp_backslash */
+#define XP_BS_NONE      0       /* nothing special for backslashes */
+#define XP_BS_ONE       1       /* uses one backslash before a space */
+#define XP_BS_THREE     2       /* uses three backslashes before a space */
+
+/*
+ * Command modifiers ":vertical", ":browse", ":confirm" and ":hide" set a flag.
+ * This needs to be saved for recursive commands, put them in a structure for
+ * easy manipulation.
+ */
+typedef struct {
+  int hide;                             /* TRUE when ":hide" was used */
+  int split;                            /* flags for win_split() */
+  int tab;                              /* > 0 when ":tab" was used */
+  int confirm;                          /* TRUE to invoke yes/no dialog */
+  int keepalt;                          /* TRUE when ":keepalt" was used */
+  int keepmarks;                        /* TRUE when ":keepmarks" was used */
+  int keepjumps;                        /* TRUE when ":keepjumps" was used */
+  int lockmarks;                        /* TRUE when ":lockmarks" was used */
+  int keeppatterns;                     /* TRUE when ":keeppatterns" was used */
+  char_u      *save_ei;                 /* saved value of 'eventignore' */
+} cmdmod_T;
+
 #endif
diff --git a/src/ex_eval.h b/src/ex_eval.h
index d16465f644..8690247489 100644
--- a/src/ex_eval.h
+++ b/src/ex_eval.h
@@ -1,5 +1,123 @@
 #ifndef NEOVIM_EX_EVAL_H
 #define NEOVIM_EX_EVAL_H
+
+/*
+ * A list used for saving values of "emsg_silent".  Used by ex_try() to save the
+ * value of "emsg_silent" if it was non-zero.  When this is done, the CSF_SILENT
+ * flag below is set.
+ */
+
+typedef struct eslist_elem eslist_T;
+struct eslist_elem {
+  int saved_emsg_silent;                /* saved value of "emsg_silent" */
+  eslist_T    *next;                    /* next element on the list */
+};
+
+/*
+ * For conditional commands a stack is kept of nested conditionals.
+ * When cs_idx < 0, there is no conditional command.
+ */
+#define CSTACK_LEN      50
+
+struct condstack {
+  short cs_flags[CSTACK_LEN];           /* CSF_ flags */
+  char cs_pending[CSTACK_LEN];          /* CSTP_: what's pending in ":finally"*/
+  union {
+    void    *csp_rv[CSTACK_LEN];        /* return typeval for pending return */
+    void    *csp_ex[CSTACK_LEN];        /* exception for pending throw */
+  }           cs_pend;
+  void        *cs_forinfo[CSTACK_LEN];   /* info used by ":for" */
+  int cs_line[CSTACK_LEN];              /* line nr of ":while"/":for" line */
+  int cs_idx;                           /* current entry, or -1 if none */
+  int cs_looplevel;                     /* nr of nested ":while"s and ":for"s */
+  int cs_trylevel;                      /* nr of nested ":try"s */
+  eslist_T    *cs_emsg_silent_list;     /* saved values of "emsg_silent" */
+  char cs_lflags;                       /* loop flags: CSL_ flags */
+};
+# define cs_rettv       cs_pend.csp_rv
+# define cs_exception   cs_pend.csp_ex
+
+/* There is no CSF_IF, the lack of CSF_WHILE, CSF_FOR and CSF_TRY means ":if"
+ * was used. */
+# define CSF_TRUE       0x0001  /* condition was TRUE */
+# define CSF_ACTIVE     0x0002  /* current state is active */
+# define CSF_ELSE       0x0004  /* ":else" has been passed */
+# define CSF_WHILE      0x0008  /* is a ":while" */
+# define CSF_FOR        0x0010  /* is a ":for" */
+
+# define CSF_TRY        0x0100  /* is a ":try" */
+# define CSF_FINALLY    0x0200  /* ":finally" has been passed */
+# define CSF_THROWN     0x0400  /* exception thrown to this try conditional */
+# define CSF_CAUGHT     0x0800  /* exception caught by this try conditional */
+# define CSF_SILENT     0x1000  /* "emsg_silent" reset by ":try" */
+/* Note that CSF_ELSE is only used when CSF_TRY and CSF_WHILE are unset
+ * (an ":if"), and CSF_SILENT is only used when CSF_TRY is set. */
+
+/*
+ * What's pending for being reactivated at the ":endtry" of this try
+ * conditional:
+ */
+# define CSTP_NONE      0       /* nothing pending in ":finally" clause */
+# define CSTP_ERROR     1       /* an error is pending */
+# define CSTP_INTERRUPT 2       /* an interrupt is pending */
+# define CSTP_THROW     4       /* a throw is pending */
+# define CSTP_BREAK     8       /* ":break" is pending */
+# define CSTP_CONTINUE  16      /* ":continue" is pending */
+# define CSTP_RETURN    24      /* ":return" is pending */
+# define CSTP_FINISH    32      /* ":finish" is pending */
+
+/*
+ * Flags for the cs_lflags item in struct condstack.
+ */
+# define CSL_HAD_LOOP    1      /* just found ":while" or ":for" */
+# define CSL_HAD_ENDLOOP 2      /* just found ":endwhile" or ":endfor" */
+# define CSL_HAD_CONT    4      /* just found ":continue" */
+# define CSL_HAD_FINA    8      /* just found ":finally" */
+
+/*
+ * A list of error messages that can be converted to an exception.  "throw_msg"
+ * is only set in the first element of the list.  Usually, it points to the
+ * original message stored in that element, but sometimes it points to a later
+ * message in the list.  See cause_errthrow() below.
+ */
+struct msglist {
+  char_u              *msg;             /* original message */
+  char_u              *throw_msg;       /* msg to throw: usually original one */
+  struct msglist      *next;            /* next of several messages in a row */
+};
+
+/*
+ * Structure describing an exception.
+ * (don't use "struct exception", it's used by the math library).
+ */
+typedef struct vim_exception except_T;
+struct vim_exception {
+  int type;                             /* exception type */
+  char_u              *value;           /* exception value */
+  struct msglist      *messages;        /* message(s) causing error exception */
+  char_u              *throw_name;      /* name of the throw point */
+  linenr_T throw_lnum;                  /* line number of the throw point */
+  except_T            *caught;          /* next exception on the caught stack */
+};
+
+/*
+ * The exception types.
+ */
+#define ET_USER         0       /* exception caused by ":throw" command */
+#define ET_ERROR        1       /* error exception */
+#define ET_INTERRUPT    2       /* interrupt exception triggered by Ctrl-C */
+
+/*
+ * Structure to save the error/interrupt/exception state between calls to
+ * enter_cleanup() and leave_cleanup().  Must be allocated as an automatic
+ * variable by the (common) caller of these functions.
+ */
+typedef struct cleanup_stuff cleanup_T;
+struct cleanup_stuff {
+  int pending;                  /* error/interrupt/exception state */
+  except_T *exception;          /* exception value */
+};
+
 /* ex_eval.c */
 int aborting(void);
 void update_force_abort(void);
diff --git a/src/fileio.h b/src/fileio.h
index 6ac28d9b82..86bf1614bd 100644
--- a/src/fileio.h
+++ b/src/fileio.h
@@ -1,5 +1,21 @@
 #ifndef NEOVIM_FILEIO_H
 #define NEOVIM_FILEIO_H
+
+#include "buffer_defs.h"
+
+/*
+ * Struct to save values in before executing autocommands for a buffer that is
+ * not the current buffer.  Without FEAT_AUTOCMD only "curbuf" is remembered.
+ */
+typedef struct {
+  buf_T       *save_curbuf;     /* saved curbuf */
+  int use_aucmd_win;            /* using aucmd_win */
+  win_T       *save_curwin;     /* saved curwin */
+  win_T       *new_curwin;      /* new curwin */
+  buf_T       *new_curbuf;      /* new curbuf */
+  char_u      *globaldir;       /* saved value of globaldir */
+} aco_save_T;
+
 /* fileio.c */
 void filemess(buf_T *buf, char_u *name, char_u *s, int attr);
 int readfile(char_u *fname, char_u *sfname, linenr_T from,
diff --git a/src/globals.h b/src/globals.h
index 9d61735c85..f6adf0381c 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -9,6 +9,7 @@
 #ifndef NEOVIM_GLOBALS_H
 #define NEOVIM_GLOBALS_H
 
+#include "ex_eval.h"
 #include "mbyte.h"
 #include "menu.h"
 
@@ -938,58 +939,6 @@ EXTERN int stl_syntax INIT(= 0);
 /* don't use 'hlsearch' temporarily */
 EXTERN int no_hlsearch INIT(= FALSE);
 
-
-/*
- * Printer stuff shared between hardcopy.c and machine-specific printing code.
- */
-# define OPT_PRINT_TOP          0
-# define OPT_PRINT_BOT          1
-# define OPT_PRINT_LEFT         2
-# define OPT_PRINT_RIGHT        3
-# define OPT_PRINT_HEADERHEIGHT 4
-# define OPT_PRINT_SYNTAX       5
-# define OPT_PRINT_NUMBER       6
-# define OPT_PRINT_WRAP         7
-# define OPT_PRINT_DUPLEX       8
-# define OPT_PRINT_PORTRAIT     9
-# define OPT_PRINT_PAPER        10
-# define OPT_PRINT_COLLATE      11
-# define OPT_PRINT_JOBSPLIT     12
-# define OPT_PRINT_FORMFEED     13
-
-# define OPT_PRINT_NUM_OPTIONS  14
-
-EXTERN option_table_T printer_opts[OPT_PRINT_NUM_OPTIONS]
-# ifdef DO_INIT
-  =
-  {
-  {"top",     TRUE, 0, NULL, 0, FALSE},
-  {"bottom",  TRUE, 0, NULL, 0, FALSE},
-  {"left",    TRUE, 0, NULL, 0, FALSE},
-  {"right",   TRUE, 0, NULL, 0, FALSE},
-  {"header",  TRUE, 0, NULL, 0, FALSE},
-  {"syntax",  FALSE, 0, NULL, 0, FALSE},
-  {"number",  FALSE, 0, NULL, 0, FALSE},
-  {"wrap",    FALSE, 0, NULL, 0, FALSE},
-  {"duplex",  FALSE, 0, NULL, 0, FALSE},
-  {"portrait", FALSE, 0, NULL, 0, FALSE},
-  {"paper",   FALSE, 0, NULL, 0, FALSE},
-  {"collate", FALSE, 0, NULL, 0, FALSE},
-  {"jobsplit", FALSE, 0, NULL, 0, FALSE},
-  {"formfeed", FALSE, 0, NULL, 0, FALSE},
-  }
-
-# endif
-;
-
-/* For prt_get_unit(). */
-# define PRT_UNIT_NONE  -1
-# define PRT_UNIT_PERC  0
-# define PRT_UNIT_INCH  1
-# define PRT_UNIT_MM    2
-# define PRT_UNIT_POINT 3
-# define PRT_UNIT_NAMES {"pc", "in", "mm", "pt"}
-
 /* Page number used for %N in 'pageheader' and 'guitablabel'. */
 EXTERN linenr_T printer_page_num;
 
diff --git a/src/hardcopy.c b/src/hardcopy.c
index 1237230f0a..9e637e3032 100644
--- a/src/hardcopy.c
+++ b/src/hardcopy.c
@@ -92,6 +92,29 @@
  * printed in the margin.
  */
 
+static option_table_T printer_opts[OPT_PRINT_NUM_OPTIONS]
+#ifdef DO_INIT
+  =
+  {
+  {"top",     TRUE, 0, NULL, 0, FALSE},
+  {"bottom",  TRUE, 0, NULL, 0, FALSE},
+  {"left",    TRUE, 0, NULL, 0, FALSE},
+  {"right",   TRUE, 0, NULL, 0, FALSE},
+  {"header",  TRUE, 0, NULL, 0, FALSE},
+  {"syntax",  FALSE, 0, NULL, 0, FALSE},
+  {"number",  FALSE, 0, NULL, 0, FALSE},
+  {"wrap",    FALSE, 0, NULL, 0, FALSE},
+  {"duplex",  FALSE, 0, NULL, 0, FALSE},
+  {"portrait", FALSE, 0, NULL, 0, FALSE},
+  {"paper",   FALSE, 0, NULL, 0, FALSE},
+  {"collate", FALSE, 0, NULL, 0, FALSE},
+  {"jobsplit", FALSE, 0, NULL, 0, FALSE},
+  {"formfeed", FALSE, 0, NULL, 0, FALSE},
+  }
+#endif
+;
+
+
 static const long_u cterm_color_8[8] =
 {
   (long_u)0x000000L, (long_u)0xff0000L, (long_u)0x00ff00L, (long_u)0xffff00L,
diff --git a/src/hardcopy.h b/src/hardcopy.h
index fb27ee4344..b1ebe8d0ea 100644
--- a/src/hardcopy.h
+++ b/src/hardcopy.h
@@ -32,6 +32,42 @@ typedef struct {
   char_u      *arguments;
 } prt_settings_T;
 
+/*
+ * Generic option table item, only used for printer at the moment.
+ */
+typedef struct {
+  const char  *name;
+  int hasnum;
+  long number;
+  char_u      *string;          /* points into option string */
+  int strlen;
+  int present;
+} option_table_T;
+
+#define OPT_PRINT_TOP          0
+#define OPT_PRINT_BOT          1
+#define OPT_PRINT_LEFT         2
+#define OPT_PRINT_RIGHT        3
+#define OPT_PRINT_HEADERHEIGHT 4
+#define OPT_PRINT_SYNTAX       5
+#define OPT_PRINT_NUMBER       6
+#define OPT_PRINT_WRAP         7
+#define OPT_PRINT_DUPLEX       8
+#define OPT_PRINT_PORTRAIT     9
+#define OPT_PRINT_PAPER        10
+#define OPT_PRINT_COLLATE      11
+#define OPT_PRINT_JOBSPLIT     12
+#define OPT_PRINT_FORMFEED     13
+#define OPT_PRINT_NUM_OPTIONS  14
+
+/* For prt_get_unit(). */
+#define PRT_UNIT_NONE  -1
+#define PRT_UNIT_PERC  0
+#define PRT_UNIT_INCH  1
+#define PRT_UNIT_MM    2
+#define PRT_UNIT_POINT 3
+#define PRT_UNIT_NAMES {"pc", "in", "mm", "pt"}
+
 #define PRINT_NUMBER_WIDTH 8
 
 char_u *parse_printoptions(void);
diff --git a/src/hashtab.h b/src/hashtab.h
index edc3f0a88f..bdcb5a0a2f 100644
--- a/src/hashtab.h
+++ b/src/hashtab.h
@@ -1,5 +1,43 @@
 #ifndef NEOVIM_HASHTAB_H
 #define NEOVIM_HASHTAB_H
+
+/* Item for a hashtable.  "hi_key" can be one of three values:
+ * NULL:	   Never been used
+ * HI_KEY_REMOVED: Entry was removed
+ * Otherwise:	   Used item, pointer to the actual key; this usually is
+ *		   inside the item, subtract an offset to locate the item.
+ *		   This reduces the size of hashitem by 1/3.
+ */
+typedef struct hashitem_S {
+  long_u hi_hash;               /* cached hash number of hi_key */
+  char_u      *hi_key;
+} hashitem_T;
+
+/* The address of "hash_removed" is used as a magic number for hi_key to
+ * indicate a removed item. */
+#define HI_KEY_REMOVED &hash_removed
+#define HASHITEM_EMPTY(hi) ((hi)->hi_key == NULL || (hi)->hi_key == \
+                            &hash_removed)
+
+/* Initial size for a hashtable.  Our items are relatively small and growing
+ * is expensive, thus use 16 as a start.  Must be a power of 2. */
+#define HT_INIT_SIZE 16
+
+typedef struct hashtable_S {
+  long_u ht_mask;               /* mask used for hash value (nr of items in
+                                 * array is "ht_mask" + 1) */
+  long_u ht_used;               /* number of items used */
+  long_u ht_filled;             /* number of items used + removed */
+  int ht_locked;                /* counter for hash_lock() */
+  int ht_error;                 /* when set growing failed, can't add more
+                                   items before growing works */
+  hashitem_T  *ht_array;        /* points to the array, allocated when it's
+                                   not "ht_smallarray" */
+  hashitem_T ht_smallarray[HT_INIT_SIZE];      /* initial array */
+} hashtab_T;
+
+typedef long_u hash_T;          /* Type for hi_hash */
+
 /* hashtab.c */
 void hash_init(hashtab_T *ht);
 void hash_clear(hashtab_T *ht);
diff --git a/src/mark.h b/src/mark.h
index 8da6aa3565..28620b6620 100644
--- a/src/mark.h
+++ b/src/mark.h
@@ -1,5 +1,10 @@
 #ifndef NEOVIM_MARK_H
 #define NEOVIM_MARK_H
+
+#include "buffer_defs.h"
+#include "mark_defs.h"
+#include "pos.h"
+
 /* mark.c */
 int setmark(int c);
 int setmark_pos(int c, pos_T *pos, int fnum);
diff --git a/src/mark_defs.h b/src/mark_defs.h
new file mode 100644
index 0000000000..eb8d5a9767
--- /dev/null
+++ b/src/mark_defs.h
@@ -0,0 +1,29 @@
+#ifndef NEOVIM_MARK_DEFS_H
+#define NEOVIM_MARK_DEFS_H
+
+#include "pos.h"
+
+/*
+ * marks: positions in a file
+ * (a normal mark is a lnum/col pair, the same as a file position)
+ */
+
+/* (Note: for EBCDIC there are more than 26, because there are gaps in the
+ * alphabet coding.  To minimize changes to the code, I decided to just
+ * increase the number of possible marks. */
+#define NMARKS          ('z' - 'a' + 1) /* max. # of named marks */
+#define JUMPLISTSIZE    100             /* max. # of marks in jump list */
+#define TAGSTACKSIZE    20              /* max. # of tags in tag stack */
+
+typedef struct filemark {
+  pos_T mark;                   /* cursor position */
+  int fnum;                     /* file number */
+} fmark_T;
+
+/* Xtended file mark: also has a file name */
+typedef struct xfilemark {
+  fmark_T fmark;
+  char_u      *fname;           /* file name, used when fnum == 0 */
+} xfmark_T;
+
+#endif // NEOVIM_MARK_DEFS_H
diff --git a/src/memfile.h b/src/memfile.h
index 25ecacdfb5..264c08558f 100644
--- a/src/memfile.h
+++ b/src/memfile.h
@@ -1,5 +1,9 @@
 #ifndef NEOVIM_MEMFILE_H
 #define NEOVIM_MEMFILE_H
+
+#include "buffer_defs.h"
+#include "memfile_defs.h"
+
 /* memfile.c */
 memfile_T *mf_open(char_u *fname, int flags);
 int mf_open_file(memfile_T *mfp, char_u *fname);
diff --git a/src/memfile_defs.h b/src/memfile_defs.h
new file mode 100644
index 0000000000..e614cae7ca
--- /dev/null
+++ b/src/memfile_defs.h
@@ -0,0 +1,107 @@
+#ifndef NEOVIM_MEMFILE_DEFS_H
+#define NEOVIM_MEMFILE_DEFS_H
+
+typedef struct block_hdr bhdr_T;
+typedef long blocknr_T;
+
+/*
+ * mf_hashtab_T is a chained hashtable with blocknr_T key and arbitrary
+ * structures as items.  This is an intrusive data structure: we require
+ * that items begin with mf_hashitem_T which contains the key and linked
+ * list pointers.  List of items in each bucket is doubly-linked.
+ */
+
+typedef struct mf_hashitem_S mf_hashitem_T;
+
+struct mf_hashitem_S {
+  mf_hashitem_T   *mhi_next;
+  mf_hashitem_T   *mhi_prev;
+  blocknr_T mhi_key;
+};
+
+#define MHT_INIT_SIZE   64
+
+typedef struct mf_hashtab_S {
+  long_u mht_mask;                  /* mask used for hash value (nr of items
+                                     * in array is "mht_mask" + 1) */
+  long_u mht_count;                 /* nr of items inserted into hashtable */
+  mf_hashitem_T   **mht_buckets;    /* points to mht_small_buckets or
+                                     *dynamically allocated array */
+  mf_hashitem_T   *mht_small_buckets[MHT_INIT_SIZE];     /* initial buckets */
+  char mht_fixed;                   /* non-zero value forbids growth */
+} mf_hashtab_T;
+
+/*
+ * for each (previously) used block in the memfile there is one block header.
+ *
+ * The block may be linked in the used list OR in the free list.
+ * The used blocks are also kept in hash lists.
+ *
+ * The used list is a doubly linked list, most recently used block first.
+ *	The blocks in the used list have a block of memory allocated.
+ *	mf_used_count is the number of pages in the used list.
+ * The hash lists are used to quickly find a block in the used list.
+ * The free list is a single linked list, not sorted.
+ *	The blocks in the free list have no block of memory allocated and
+ *	the contents of the block in the file (if any) is irrelevant.
+ */
+
+struct block_hdr {
+  mf_hashitem_T bh_hashitem;        /* header for hash table and key */
+#define bh_bnum bh_hashitem.mhi_key /* block number, part of bh_hashitem */
+
+  bhdr_T      *bh_next;             /* next block_hdr in free or used list */
+  bhdr_T      *bh_prev;             /* previous block_hdr in used list */
+  char_u      *bh_data;             /* pointer to memory (for used block) */
+  int bh_page_count;                /* number of pages in this block */
+
+#define BH_DIRTY    1
+#define BH_LOCKED   2
+  char bh_flags;                    /* BH_DIRTY or BH_LOCKED */
+};
+
+/*
+ * when a block with a negative number is flushed to the file, it gets
+ * a positive number. Because the reference to the block is still the negative
+ * number, we remember the translation to the new positive number in the
+ * double linked trans lists. The structure is the same as the hash lists.
+ */
+typedef struct nr_trans NR_TRANS;
+
+struct nr_trans {
+  mf_hashitem_T nt_hashitem;            /* header for hash table and key */
+#define nt_old_bnum nt_hashitem.mhi_key /* old, negative, number */
+
+  blocknr_T nt_new_bnum;                /* new, positive, number */
+};
+
+#define MF_SEED_LEN     8
+
+struct memfile {
+  char_u      *mf_fname;                /* name of the file */
+  char_u      *mf_ffname;               /* idem, full path */
+  int mf_fd;                            /* file descriptor */
+  bhdr_T      *mf_free_first;           /* first block_hdr in free list */
+  bhdr_T      *mf_used_first;           /* mru block_hdr in used list */
+  bhdr_T      *mf_used_last;            /* lru block_hdr in used list */
+  unsigned mf_used_count;               /* number of pages in used list */
+  unsigned mf_used_count_max;           /* maximum number of pages in memory */
+  mf_hashtab_T mf_hash;                 /* hash lists */
+  mf_hashtab_T mf_trans;                /* trans lists */
+  blocknr_T mf_blocknr_max;             /* highest positive block number + 1*/
+  blocknr_T mf_blocknr_min;             /* lowest negative block number - 1 */
+  blocknr_T mf_neg_count;               /* number of negative blocks numbers */
+  blocknr_T mf_infile_count;            /* number of pages in the file */
+  unsigned mf_page_size;                /* number of bytes in a page */
+  int mf_dirty;                         /* TRUE if there are dirty blocks */
+  buf_T       *mf_buffer;               /* bufer this memfile is for */
+  char_u mf_seed[MF_SEED_LEN];          /* seed for encryption */
+
+  /* Values for key, method and seed used for reading data blocks when
+   * updating for a newly set key or method. Only when mf_old_key != NULL. */
+  char_u      *mf_old_key;
+  int mf_old_cm;
+  char_u mf_old_seed[MF_SEED_LEN];
+};
+
+#endif // NEOVIM_MEMFILE_DEFS_H
diff --git a/src/memline_defs.h b/src/memline_defs.h
new file mode 100644
index 0000000000..5878cfd7d9
--- /dev/null
+++ b/src/memline_defs.h
@@ -0,0 +1,59 @@
+#ifndef NEOVIM_MEMLINE_DEFS_H
+#define NEOVIM_MEMLINE_DEFS_H
+
+#include "memfile_defs.h"
+
+/*
+ * When searching for a specific line, we remember what blocks in the tree
+ * are the branches leading to that block. This is stored in ml_stack.  Each
+ * entry is a pointer to info in a block (may be data block or pointer block)
+ */
+typedef struct info_pointer {
+  blocknr_T ip_bnum;            /* block number */
+  linenr_T ip_low;              /* lowest lnum in this block */
+  linenr_T ip_high;             /* highest lnum in this block */
+  int ip_index;                 /* index for block with current lnum */
+} infoptr_T;    /* block/index pair */
+
+typedef struct ml_chunksize {
+  int mlcs_numlines;
+  long mlcs_totalsize;
+} chunksize_T;
+
+/* Flags when calling ml_updatechunk() */
+
+#define ML_CHNK_ADDLINE 1
+#define ML_CHNK_DELLINE 2
+#define ML_CHNK_UPDLINE 3
+
+/*
+ * the memline structure holds all the information about a memline
+ */
+typedef struct memline {
+  linenr_T ml_line_count;       /* number of lines in the buffer */
+
+  memfile_T   *ml_mfp;          /* pointer to associated memfile */
+
+#define ML_EMPTY        1       /* empty buffer */
+#define ML_LINE_DIRTY   2       /* cached line was changed and allocated */
+#define ML_LOCKED_DIRTY 4       /* ml_locked was changed */
+#define ML_LOCKED_POS   8       /* ml_locked needs positive block number */
+  int ml_flags;
+
+  infoptr_T   *ml_stack;        /* stack of pointer blocks (array of IPTRs) */
+  int ml_stack_top;             /* current top if ml_stack */
+  int ml_stack_size;            /* total number of entries in ml_stack */
+
+  linenr_T ml_line_lnum;        /* line number of cached line, 0 if not valid */
+  char_u      *ml_line_ptr;     /* pointer to cached line */
+
+  bhdr_T      *ml_locked;       /* block used by last ml_get */
+  linenr_T ml_locked_low;       /* first line in ml_locked */
+  linenr_T ml_locked_high;      /* last line in ml_locked */
+  int ml_locked_lineadd;            /* number of lines inserted in ml_locked */
+  chunksize_T *ml_chunksize;
+  int ml_numchunks;
+  int ml_usedchunks;
+} memline_T;
+
+#endif // NEOVIM_MEMLINE_DEFS_H
diff --git a/src/option.c b/src/option.c
index 26cedfe760..62d3761cc8 100644
--- a/src/option.c
+++ b/src/option.c
@@ -14,7 +14,7 @@
  * - For a global option: Add a variable for it in option_defs.h.
  * - For a buffer or window local option:
  *   - Add a PV_XX entry to the enum below.
- *   - Add a variable to the window or buffer struct in structs.h.
+ *   - Add a variable to the window or buffer struct in buffer_defs.h.
  *   - For a window option, add some code to copy_winopt().
  *   - For a buffer option, add some code to buf_copy_options().
  *   - For a buffer string option, add code to check_buf_options().
diff --git a/src/option_defs.h b/src/option_defs.h
index 19eb06e337..5179cdf2eb 100644
--- a/src/option_defs.h
+++ b/src/option_defs.h
@@ -1,10 +1,5 @@
-/* vi:set ts=8 sts=4 sw=4:
- *
- * 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.
- */
+#ifndef NEOVIM_OPTION_DEFS_H
+#define NEOVIM_OPTION_DEFS_H
 
 #include "types.h"
 
@@ -766,3 +761,5 @@ enum {
 
 /* Value for b_p_ul indicating the global value must be used. */
 #define NO_LOCAL_UNDOLEVEL -123456
+
+#endif // NEOVIM_OPTION_DEFS_H
diff --git a/src/syntax.h b/src/syntax.h
index e11eeb181c..52dfc775db 100644
--- a/src/syntax.h
+++ b/src/syntax.h
@@ -1,5 +1,10 @@
 #ifndef NEOVIM_SYNTAX_H
 #define NEOVIM_SYNTAX_H
+
+#include "buffer_defs.h"
+
+typedef int guicolor_T;
+
 /* syntax.c */
 void syntax_start(win_T *wp, linenr_T lnum);
 void syn_stack_free_all(synblock_T *block);
diff --git a/src/syntax_defs.h b/src/syntax_defs.h
new file mode 100644
index 0000000000..6b16d64621
--- /dev/null
+++ b/src/syntax_defs.h
@@ -0,0 +1,78 @@
+#ifndef NEOVIM_SYNTAX_DEFS_H
+#define NEOVIM_SYNTAX_DEFS_H
+
+#include "regexp_defs.h"
+
+/* struct passed to in_id_list() */
+struct sp_syn {
+  int inc_tag;                  /* ":syn include" unique tag */
+  short id;                     /* highlight group ID of item */
+  short       *cont_in_list;    /* cont.in group IDs, if non-zero */
+};
+
+/*
+ * Each keyword has one keyentry, which is linked in a hash list.
+ */
+typedef struct keyentry keyentry_T;
+
+struct keyentry {
+  keyentry_T  *ke_next;         /* next entry with identical "keyword[]" */
+  struct sp_syn k_syn;          /* struct passed to in_id_list() */
+  short       *next_list;       /* ID list for next match (if non-zero) */
+  int flags;
+  int k_char;                   /* conceal substitute character */
+  char_u keyword[1];            /* actually longer */
+};
+
+/*
+ * Struct used to store one state of the state stack.
+ */
+typedef struct buf_state {
+  int bs_idx;                    /* index of pattern */
+  int bs_flags;                  /* flags for pattern */
+  int bs_seqnr;                  /* stores si_seqnr */
+  int bs_cchar;                  /* stores si_cchar */
+  reg_extmatch_T *bs_extmatch;   /* external matches from start pattern */
+} bufstate_T;
+
+/*
+ * syn_state contains the syntax state stack for the start of one line.
+ * Used by b_sst_array[].
+ */
+typedef struct syn_state synstate_T;
+
+struct syn_state {
+  synstate_T  *sst_next;        /* next entry in used or free list */
+  linenr_T sst_lnum;            /* line number for this state */
+  union {
+    bufstate_T sst_stack[SST_FIX_STATES];          /* short state stack */
+    garray_T sst_ga;            /* growarray for long state stack */
+  } sst_union;
+  int sst_next_flags;           /* flags for sst_next_list */
+  int sst_stacksize;            /* number of states on the stack */
+  short       *sst_next_list;   /* "nextgroup" list in this state
+                                 * (this is a copy, don't free it! */
+  disptick_T sst_tick;          /* tick when last displayed */
+  linenr_T sst_change_lnum;     /* when non-zero, change in this line
+                                 * may have made the state invalid */
+};
+
+/*
+ * Structure shared between syntax.c, screen.c and gui_x11.c.
+ */
+typedef struct attr_entry {
+  short ae_attr;                        /* HL_BOLD, etc. */
+  union {
+    struct {
+      char_u          *start;           /* start escape sequence */
+      char_u          *stop;            /* stop escape sequence */
+    } term;
+    struct {
+      /* These colors need to be > 8 bits to hold 256. */
+      short_u fg_color;                 /* foreground color number */
+      short_u bg_color;                 /* background color number */
+    } cterm;
+  } ae_u;
+} attrentry_T;
+
+#endif // NEOVIM_SYNTAX_DEFS_H
diff --git a/src/undo.h b/src/undo.h
index 58c8a1fb95..396b05ef94 100644
--- a/src/undo.h
+++ b/src/undo.h
@@ -1,5 +1,8 @@
 #ifndef NEOVIM_UNDO_H
 #define NEOVIM_UNDO_H
+
+#include "undo_defs.h"
+
 /* undo.c */
 int u_save_cursor(void);
 int u_save(linenr_T top, linenr_T bot);
diff --git a/src/undo_defs.h b/src/undo_defs.h
new file mode 100644
index 0000000000..f1e6c83c32
--- /dev/null
+++ b/src/undo_defs.h
@@ -0,0 +1,68 @@
+#ifndef NEOVIM_UNDO_DEFS_H
+#define NEOVIM_UNDO_DEFS_H
+
+#include "pos.h"
+
+/* Structure to store info about the Visual area. */
+typedef struct {
+  pos_T vi_start;               /* start pos of last VIsual */
+  pos_T vi_end;                 /* end position of last VIsual */
+  int vi_mode;                  /* VIsual_mode of last VIsual */
+  colnr_T vi_curswant;          /* MAXCOL from w_curswant */
+} visualinfo_T;
+
+typedef struct u_entry u_entry_T;
+typedef struct u_header u_header_T;
+struct u_entry {
+  u_entry_T   *ue_next;         /* pointer to next entry in list */
+  linenr_T ue_top;              /* number of line above undo block */
+  linenr_T ue_bot;              /* number of line below undo block */
+  linenr_T ue_lcount;           /* linecount when u_save called */
+  char_u      **ue_array;       /* array of lines in undo block */
+  long ue_size;                 /* number of lines in ue_array */
+#ifdef U_DEBUG
+  int ue_magic;                 /* magic number to check allocation */
+#endif
+};
+
+struct u_header {
+  /* The following have a pointer and a number. The number is used when
+   * reading the undo file in u_read_undo() */
+  union {
+    u_header_T *ptr;            /* pointer to next undo header in list */
+    long seq;
+  } uh_next;
+  union {
+    u_header_T *ptr;            /* pointer to previous header in list */
+    long seq;
+  } uh_prev;
+  union {
+    u_header_T *ptr;            /* pointer to next header for alt. redo */
+    long seq;
+  } uh_alt_next;
+  union {
+    u_header_T *ptr;            /* pointer to previous header for alt. redo */
+    long seq;
+  } uh_alt_prev;
+  long uh_seq;                  /* sequence number, higher == newer undo */
+  int uh_walk;                  /* used by undo_time() */
+  u_entry_T   *uh_entry;        /* pointer to first entry */
+  u_entry_T   *uh_getbot_entry;   /* pointer to where ue_bot must be set */
+  pos_T uh_cursor;              /* cursor position before saving */
+  long uh_cursor_vcol;
+  int uh_flags;                 /* see below */
+  pos_T uh_namedm[NMARKS];              /* marks before undo/after redo */
+  visualinfo_T uh_visual;       /* Visual areas before undo/after redo */
+  time_t uh_time;               /* timestamp when the change was made */
+  long uh_save_nr;              /* set when the file was saved after the
+                                   changes in this block */
+#ifdef U_DEBUG
+  int uh_magic;                 /* magic number to check allocation */
+#endif
+};
+
+/* values for uh_flags */
+#define UH_CHANGED  0x01        /* b_changed flag before undo/after redo */
+#define UH_EMPTYBUF 0x02        /* buffer was empty */
+
+#endif // NEOVIM_UNDO_DEFS_H
diff --git a/src/vim.h b/src/vim.h
index a12a7786bd..247984dd2f 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1228,14 +1228,6 @@ int vim_memcmp(void *, void *, size_t);
 
 typedef struct timeval proftime_T;
 
-/* Include option_defs.h before structs.h, because the number of window-local and
- * buffer-local options is used there. */
-#include "option_defs.h"         /* options and default values */
-
-/* Note that gui.h is included by structs.h */
-
-#include "structs.h"        /* file that defines many structures */
-
 /* Values for "do_profiling". */
 #define PROF_NONE       0       /* profiling not started */
 #define PROF_YES        1       /* profiling busy */
@@ -1380,6 +1372,7 @@ typedef struct timeval proftime_T;
 typedef int VimClipboard;       /* This is required for the prototypes. */
 
 
+#include "buffer_defs.h"         /* buffer and windows */
 #include "ex_cmds_defs.h"        /* Ex command defines */
 #include "proto.h"          /* function prototypes */