text: #ifndef VAR_H
  #define VAR_H
  /* $OpenBSD: var.h,v 1.17 2014/01/06 12:08:18 espie Exp $ */
  /*
   * Copyright (c) 2001 Marc Espie.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS
   * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OPENBSD
   * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  extern GNode *current_node;
  extern void Var_Init(void);
  extern void Var_setCheckEnvFirst(bool);
  
  /* Global variable handling. */
  /* value = Var_Valuei(name, end);
   *	Returns value of global variable name/end, or NULL if inexistent. */
  extern char *Var_Valuei(const char *, const char *);
  #define Var_Value(n)	Var_Valuei(n, NULL)
  
  /* isDefined = Var_Definedi(name, end);
   *	Checks whether global variable name/end is defined. */
  extern bool Var_Definedi(const char *, const char *);
  
  /* Var_Seti_with_ctxt(name, end, val, ctxt);
   *	Sets value val of variable name/end.  Copies val.
   *	ctxt can be VAR_CMD (command line) or VAR_GLOBAL (normal variable). */
  extern void Var_Seti_with_ctxt(const char *, const char *, const char *,
  	int);
  #define Var_Set(n, v)	Var_Seti_with_ctxt(n, NULL, v, VAR_GLOBAL)
  #define Var_Seti(n, e, v) Var_Seti_with_ctxt(n, e, v, VAR_GLOBAL)
  /* Var_Appendi_with_ctxt(name, end, val, cxt);
   *	Appends value val to variable name/end in context ctxt, defining it
   *	if it does not already exist, and inserting one space otherwise. */
  extern void Var_Appendi_with_ctxt(const char *, const char *,
  	const char *, int);
  #define Var_Append(n, v)	Var_Appendi_with_ctxt(n, NULL, v, VAR_GLOBAL)
  #define Var_Appendi(n, e, v) 	Var_Appendi_with_ctxt(n, e, v, VAR_GLOBAL)
  
  /* Var_Deletei(name, end);
   *	Deletes a global variable. */
  extern void Var_Deletei(const char *, const char *);
  
  /* Dynamic variable indices */
  #define TARGET_INDEX	0
  #define PREFIX_INDEX	1
  #define ARCHIVE_INDEX	2
  #define MEMBER_INDEX	3
  #define OODATE_INDEX	4
  #define ALLSRC_INDEX	5
  #define IMPSRC_INDEX	6
  
  #define Var(idx, gn)	((gn)->context.locals[idx])
  
  
  /* SymTable_Init(t);
   *	Inits the local symtable in a GNode. */
  extern void SymTable_Init(SymTable *);
  /* SymTable_destroy(t);
   *	Destroys the local symtable in a GNode. */
  extern void SymTable_Destroy(SymTable *);
  
  /* Several ways to parse a variable specification. */
  /* value = Var_Parse(varspec, ctxt, undef_is_bad, &length, &freeit);
   *	Parses a variable specification varspec and evaluates it in context
   *	ctxt.  Returns the resulting value, freeit indicates whether it's
   *	a copy that should be freed when no longer needed.  If it's not a
   *	copy, it's only valid until the next time variables are set.
   *	The length of the spec is returned in length, e.g., varspec begins
   *	at the $ and ends at the closing } or ).  Returns special value
   *	var_Error if a problem occurred. */
  extern char *Var_Parse(const char *, SymTable *, bool, size_t *,
  	bool *);
  /* Note that var_Error is an instance of the empty string "", so that
   * callers who don't care don't need to. */
  extern char	var_Error[];
  
  /* ok = Var_ParseSkip(&varspec, ctxt, &ok);
   *	Parses a variable specification and returns true if the varspec
   *	is correct. Advances pointer past specification.  */
  extern bool Var_ParseSkip(const char **, SymTable *);
  
  /* ok = Var_ParseBuffer(buf, varspec, ctxt, undef_is_bad, &length);
   *	Similar to Var_Parse, except the value is directly appended to
   *	buffer buf. */
  extern bool Var_ParseBuffer(Buffer, const char *, SymTable *,
  	bool, size_t *);
  
  
  /* The substitution itself */
  /* subst = Var_Subst(str, ctxt, undef_is_bad);
   *	Substitutes all variable values in string str under context ctxt.
   *	Emit a PARSE_FATAL error if undef_is_bad and an undef variable is
   *	encountered. The result is always a copy that should be free. */
  extern char *Var_Subst(const char *, SymTable *, bool);
  /* subst = Var_Substi(str, estr, ctxt, undef_if_bad);
   */
  extern char *Var_Substi(const char *, const char *, SymTable *, bool);
  
  /* has_target = Var_Check_for_target(s):
   *	specialized tweak on Var_Subst that reads through a command line
   *	and looks for stuff like $@.
   *	Use to desambiguate a list of targets into a target group.
   */
  extern bool Var_Check_for_target(const char *);
  
  /* For loop handling.
   *	// Create handle for variable name.
   *	handle = Var_NewLoopVar(name, end);
   *	// set up buffer
   *	for (...)
   *		// Substitute val for variable in str, and accumulate in buffer
   *		Var_SubstVar(buffer, str, handle, val);
   *	// Free handle
   *	Var_DeleteLoopVar(handle);
   */
  struct LoopVar;	/* opaque handle */
  struct LoopVar *Var_NewLoopVar(const char *, const char *);
  void Var_DeleteLoopVar(struct LoopVar *);
  extern void Var_SubstVar(Buffer, const char *, struct LoopVar *, const char *);
  char *Var_LoopVarName(struct LoopVar *);
  
  
  /* Var_Dump();
   *	Print out all global variables. */
  extern void Var_Dump(void);
  
  /* Var_AddCmdline(name);
   *	Add all variable values from VAR_CMD to variable name.
   *	Used to propagate variable values to submakes through MAKEFLAGS.  */
  extern void Var_AddCmdline(const char *);
  
  /* stuff common to var.c and varparse.c */
  extern bool	errorIsOkay;
  
  #define		VAR_GLOBAL	0
  	/* Variables defined in a global context, e.g in the Makefile itself */
  #define		VAR_CMD		1
  	/* Variables defined on the command line */
  
  #define POISON_INVALID		0
  #define POISON_DEFINED		1
  #define POISON_NORMAL		64
  #define POISON_EMPTY		128
  #define POISON_NOT_DEFINED	256
  
  extern void Var_MarkPoisoned(const char *, const char *, unsigned int);
  #endif
  