FreeBSD-5.3/sys/boot/ficl/ficl.c
/*******************************************************************
** f i c l . c
** Forth Inspired Command Language - external interface
** Author: John Sadler (john_sadler@alum.mit.edu)
** Created: 19 July 1997
** $Id: ficl.c,v 1.16 2001/12/05 07:21:34 jsadler Exp $
*******************************************************************/
/*
** This is an ANS Forth interpreter written in C.
** Ficl uses Forth syntax for its commands, but turns the Forth
** model on its head in other respects.
** Ficl provides facilities for interoperating
** with programs written in C: C functions can be exported to Ficl,
** and Ficl commands can be executed via a C calling interface. The
** interpreter is re-entrant, so it can be used in multiple instances
** in a multitasking system. Unlike Forth, Ficl's outer interpreter
** expects a text block as input, and returns to the caller after each
** text block, so the data pump is somewhere in external code in the
** style of TCL.
**
** Code is written in ANSI C for portability.
*/
/*
** Copyright (c) 1997-2001 John Sadler (john_sadler@alum.mit.edu)
** All rights reserved.
**
** Get the latest Ficl release at http://ficl.sourceforge.net
**
** I am interested in hearing from anyone who uses ficl. If you have
** a problem, a success story, a defect, an enhancement request, or
** if you would like to contribute to the ficl release, please
** contact me by email at the address above.
**
** L I C E N S E and D I S C L A I M E R
**
** 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 AUTHOR 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 AUTHOR 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.
*/
/* $FreeBSD: src/sys/boot/ficl/ficl.c,v 1.18 2002/04/09 17:45:11 dcs Exp $ */
#ifdef TESTMAIN
#include <stdlib.h>
#else
#include <stand.h>
#endif
#include <string.h>
#include "ficl.h"
/*
** System statics
** Each FICL_SYSTEM builds a global dictionary during its start
** sequence. This is shared by all virtual machines of that system.
** Therefore only one VM can update the dictionary
** at a time. The system imports a locking function that
** you can override in order to control update access to
** the dictionary. The function is stubbed out by default,
** but you can insert one: #define FICL_MULTITHREAD 1
** and supply your own version of ficlLockDictionary.
*/
static int defaultStack = FICL_DEFAULT_STACK;
static void ficlSetVersionEnv(FICL_SYSTEM *pSys);
/**************************************************************************
f i c l I n i t S y s t e m
** Binds a global dictionary to the interpreter system.
** You specify the address and size of the allocated area.
** After that, ficl manages it.
** First step is to set up the static pointers to the area.
** Then write the "precompiled" portion of the dictionary in.
** The dictionary needs to be at least large enough to hold the
** precompiled part. Try 1K cells minimum. Use "words" to find
** out how much of the dictionary is used at any time.
**************************************************************************/
FICL_SYSTEM *ficlInitSystemEx(FICL_SYSTEM_INFO *fsi)
{
int nDictCells;
int nEnvCells;
FICL_SYSTEM *pSys = ficlMalloc(sizeof (FICL_SYSTEM));
assert(pSys);
assert(fsi->size == sizeof (FICL_SYSTEM_INFO));
memset(pSys, 0, sizeof (FICL_SYSTEM));
nDictCells = fsi->nDictCells;
if (nDictCells <= 0)
nDictCells = FICL_DEFAULT_DICT;
nEnvCells = fsi->nEnvCells;
if (nEnvCells <= 0)
nEnvCells = FICL_DEFAULT_DICT;
pSys->dp = dictCreateHashed((unsigned)nDictCells, HASHSIZE);
pSys->dp->pForthWords->name = "forth-wordlist";
pSys->envp = dictCreate((unsigned)nEnvCells);
pSys->envp->pForthWords->name = "environment";
pSys->textOut = fsi->textOut;
pSys->pExtend = fsi->pExtend;
#if FICL_WANT_LOCALS
/*
** The locals dictionary is only searched while compiling,
** but this is where speed is most important. On the other
** hand, the dictionary gets emptied after each use of locals
** The need to balance search speed with the cost of the 'empty'
** operation led me to select a single-threaded list...
*/
pSys->localp = dictCreate((unsigned)FICL_MAX_LOCALS * CELLS_PER_WORD);
#endif
/*
** Build the precompiled dictionary and load softwords. We need a temporary
** VM to do this - ficlNewVM links one to the head of the system VM list.
** ficlCompilePlatform (defined in win32.c, for example) adds platform specific words.
*/
ficlCompileCore(pSys);
ficlCompilePrefix(pSys);
#if FICL_WANT_FLOAT
ficlCompileFloat(pSys);
#endif
#if FICL_PLATFORM_EXTEND
ficlCompilePlatform(pSys);
#endif
ficlSetVersionEnv(pSys);
/*
** Establish the parse order. Note that prefixes precede numbers -
** this allows constructs like "0b101010" which might parse as a
** hex value otherwise.
*/
ficlAddPrecompiledParseStep(pSys, "?prefix", ficlParsePrefix);
ficlAddPrecompiledParseStep(pSys, "?number", ficlParseNumber);
#if FICL_WANT_FLOAT
ficlAddPrecompiledParseStep(pSys, ">float", ficlParseFloatNumber);
#endif
/*
** Now create a temporary VM to compile the softwords. Since all VMs are
** linked into the vmList of FICL_SYSTEM, we don't have to pass the VM
** to ficlCompileSoftCore -- it just hijacks whatever it finds in the VM list.
** ficl 2.05: vmCreate no longer depends on the presence of INTERPRET in the
** dictionary, so a VM can be created before the dictionary is built. It just
** can't do much...
*/
ficlNewVM(pSys);
ficlCompileSoftCore(pSys);
ficlFreeVM(pSys->vmList);
return pSys;
}
FICL_SYSTEM *ficlInitSystem(int nDictCells)
{
FICL_SYSTEM_INFO fsi;
ficlInitInfo(&fsi);
fsi.nDictCells = nDictCells;
return ficlInitSystemEx(&fsi);
}
/**************************************************************************
f i c l A d d P a r s e S t e p
** Appends a parse step function to the end of the parse list (see
** FICL_PARSE_STEP notes in ficl.h for details). Returns 0 if successful,
** nonzero if there's no more room in the list.
**************************************************************************/
int ficlAddParseStep(FICL_SYSTEM *pSys, FICL_WORD *pFW)
{
int i;
for (i = 0; i < FICL_MAX_PARSE_STEPS; i++)
{
if (pSys->parseList[i] == NULL)
{
pSys->parseList[i] = pFW;
return 0;
}
}
return 1;
}
/*
** Compile a word into the dictionary that invokes the specified FICL_PARSE_STEP
** function. It is up to the user (as usual in Forth) to make sure the stack
** preconditions are valid (there needs to be a counted string on top of the stack)
** before using the resulting word.
*/
void ficlAddPrecompiledParseStep(FICL_SYSTEM *pSys, char *name, FICL_PARSE_STEP pStep)
{
FICL_DICT *dp = pSys->dp;
FICL_WORD *pFW = dictAppendWord(dp, name, parseStepParen, FW_DEFAULT);
dictAppendCell(dp, LVALUEtoCELL(pStep));
ficlAddParseStep(pSys, pFW);
}
/*
** This word lists the parse steps in order
*/
void ficlListParseSteps(FICL_VM *pVM)
{
int i;
FICL_SYSTEM *pSys = pVM->pSys;
assert(pSys);
vmTextOut(pVM, "Parse steps:", 1);
vmTextOut(pVM, "lookup", 1);
for (i = 0; i < FICL_MAX_PARSE_STEPS; i++)
{
if (pSys->parseList[i] != NULL)
{
vmTextOut(pVM, pSys->parseList[i]->name, 1);
}
else break;
}
return;
}
/**************************************************************************
f i c l N e w V M
** Create a new virtual machine and link it into the system list
** of VMs for later cleanup by ficlTermSystem.
**************************************************************************/
FICL_VM *ficlNewVM(FICL_SYSTEM *pSys)
{
FICL_VM *pVM = vmCreate(NULL, defaultStack, defaultStack);
pVM->link = pSys->vmList;
pVM->pSys = pSys;
pVM->pExtend = pSys->pExtend;
vmSetTextOut(pVM, pSys->textOut);
pSys->vmList = pVM;
return pVM;
}
/**************************************************************************
f i c l F r e e V M
** Removes the VM in question from the system VM list and deletes the
** memory allocated to it. This is an optional call, since ficlTermSystem
** will do this cleanup for you. This function is handy if you're going to
** do a lot of dynamic creation of VMs.
**************************************************************************/
void ficlFreeVM(FICL_VM *pVM)
{
FICL_SYSTEM *pSys = pVM->pSys;
FICL_VM *pList = pSys->vmList;
assert(pVM != 0);
if (pSys->vmList == pVM)
{
pSys->vmList = pSys->vmList->link;
}
else for (; pList != NULL; pList = pList->link)
{
if (pList->link == pVM)
{
pList->link = pVM->link;
break;
}
}
if (pList)
vmDelete(pVM);
return;
}
/**************************************************************************
f i c l B u i l d
** Builds a word into the dictionary.
** Preconditions: system must be initialized, and there must
** be enough space for the new word's header! Operation is
** controlled by ficlLockDictionary, so any initialization
** required by your version of the function (if you overrode
** it) must be complete at this point.
** Parameters:
** name -- duh, the name of the word
** code -- code to execute when the word is invoked - must take a single param
** pointer to a FICL_VM
** flags -- 0 or more of F_IMMEDIATE, F_COMPILE, use bitwise OR!
**
**************************************************************************/
int ficlBuild(FICL_SYSTEM *pSys, char *name, FICL_CODE code, char flags)
{
#if FICL_MULTITHREAD
int err = ficlLockDictionary(TRUE);
if (err) return err;
#endif /* FICL_MULTITHREAD */
assert(dictCellsAvail(pSys->dp) > sizeof (FICL_WORD) / sizeof (CELL));
dictAppendWord(pSys->dp, name, code, flags);
ficlLockDictionary(FALSE);
return 0;
}
/**************************************************************************
f i c l E v a l u a t e
** Wrapper for ficlExec() which sets SOURCE-ID to -1.
**************************************************************************/
int ficlEvaluate(FICL_VM *pVM, char *pText)
{
int returnValue;
CELL id = pVM->sourceID;
pVM->sourceID.i = -1;
returnValue = ficlExecC(pVM, pText, -1);
pVM->sourceID = id;
return returnValue;
}
/**************************************************************************
f i c l E x e c
** Evaluates a block of input text in the context of the
** specified interpreter. Emits any requested output to the
** interpreter's output function.
**
** Contains the "inner interpreter" code in a tight loop
**
** Returns one of the VM_XXXX codes defined in ficl.h:
** VM_OUTOFTEXT is the normal exit condition
** VM_ERREXIT means that the interp encountered a syntax error
** and the vm has been reset to recover (some or all
** of the text block got ignored
** VM_USEREXIT means that the user executed the "bye" command
** to shut down the interpreter. This would be a good
** time to delete the vm, etc -- or you can ignore this
** signal.
**************************************************************************/
int ficlExec(FICL_VM *pVM, char *pText)
{
return ficlExecC(pVM, pText, -1);
}
int ficlExecC(FICL_VM *pVM, char *pText, FICL_INT size)
{
FICL_SYSTEM *pSys = pVM->pSys;
FICL_DICT *dp = pSys->dp;
int except;
jmp_buf vmState;
jmp_buf *oldState;
TIB saveTib;
assert(pVM);
assert(pSys->pInterp[0]);
if (size < 0)
size = strlen(pText);
vmPushTib(pVM, pText, size, &saveTib);
/*
** Save and restore VM's jmp_buf to enable nested calls to ficlExec
*/
oldState = pVM->pState;
pVM->pState = &vmState; /* This has to come before the setjmp! */
except = setjmp(vmState);
switch (except)
{
case 0:
if (pVM->fRestart)
{
pVM->runningWord->code(pVM);
pVM->fRestart = 0;
}
else
{ /* set VM up to interpret text */
vmPushIP(pVM, &(pSys->pInterp[0]));
}
vmInnerLoop(pVM);
break;
case VM_RESTART:
pVM->fRestart = 1;
except = VM_OUTOFTEXT;
break;
case VM_OUTOFTEXT:
vmPopIP(pVM);
#ifdef TESTMAIN
if ((pVM->state != COMPILE) && (pVM->sourceID.i == 0))
ficlTextOut(pVM, FICL_PROMPT, 0);
#endif
break;
case VM_USEREXIT:
case VM_INNEREXIT:
case VM_BREAK:
break;
case VM_QUIT:
if (pVM->state == COMPILE)
{
dictAbortDefinition(dp);
#if FICL_WANT_LOCALS
dictEmpty(pSys->localp, pSys->localp->pForthWords->size);
#endif
}
vmQuit(pVM);
break;
case VM_ERREXIT:
case VM_ABORT:
case VM_ABORTQ:
default: /* user defined exit code?? */
if (pVM->state == COMPILE)
{
dictAbortDefinition(dp);
#if FICL_WANT_LOCALS
dictEmpty(pSys->localp, pSys->localp->pForthWords->size);
#endif
}
dictResetSearchOrder(dp);
vmReset(pVM);
break;
}
pVM->pState = oldState;
vmPopTib(pVM, &saveTib);
return (except);
}
/**************************************************************************
f i c l E x e c X T
** Given a pointer to a FICL_WORD, push an inner interpreter and
** execute the word to completion. This is in contrast with vmExecute,
** which does not guarantee that the word will have completed when
** the function returns (ie in the case of colon definitions, which
** need an inner interpreter to finish)
**
** Returns one of the VM_XXXX exception codes listed in ficl.h. Normal
** exit condition is VM_INNEREXIT, ficl's private signal to exit the
** inner loop under normal circumstances. If another code is thrown to
** exit the loop, this function will re-throw it if it's nested under
** itself or ficlExec.
**
** NOTE: this function is intended so that C code can execute ficlWords
** given their address in the dictionary (xt).
**************************************************************************/
int ficlExecXT(FICL_VM *pVM, FICL_WORD *pWord)
{
int except;
jmp_buf vmState;
jmp_buf *oldState;
FICL_WORD *oldRunningWord;
assert(pVM);
assert(pVM->pSys->pExitInner);
/*
** Save the runningword so that RESTART behaves correctly
** over nested calls.
*/
oldRunningWord = pVM->runningWord;
/*
** Save and restore VM's jmp_buf to enable nested calls
*/
oldState = pVM->pState;
pVM->pState = &vmState; /* This has to come before the setjmp! */
except = setjmp(vmState);
if (except)
vmPopIP(pVM);
else
vmPushIP(pVM, &(pVM->pSys->pExitInner));
switch (except)
{
case 0:
vmExecute(pVM, pWord);
vmInnerLoop(pVM);
break;
case VM_INNEREXIT:
case VM_BREAK:
break;
case VM_RESTART:
case VM_OUTOFTEXT:
case VM_USEREXIT:
case VM_QUIT:
case VM_ERREXIT:
case VM_ABORT:
case VM_ABORTQ:
default: /* user defined exit code?? */
if (oldState)
{
pVM->pState = oldState;
vmThrow(pVM, except);
}
break;
}
pVM->pState = oldState;
pVM->runningWord = oldRunningWord;
return (except);
}
/**************************************************************************
f i c l L o o k u p
** Look in the system dictionary for a match to the given name. If
** found, return the address of the corresponding FICL_WORD. Otherwise
** return NULL.
**************************************************************************/
FICL_WORD *ficlLookup(FICL_SYSTEM *pSys, char *name)
{
STRINGINFO si;
SI_PSZ(si, name);
return dictLookup(pSys->dp, si);
}
/**************************************************************************
f i c l G e t D i c t
** Returns the address of the system dictionary
**************************************************************************/
FICL_DICT *ficlGetDict(FICL_SYSTEM *pSys)
{
return pSys->dp;
}
/**************************************************************************
f i c l G e t E n v
** Returns the address of the system environment space
**************************************************************************/
FICL_DICT *ficlGetEnv(FICL_SYSTEM *pSys)
{
return pSys->envp;
}
/**************************************************************************
f i c l S e t E n v
** Create an environment variable with a one-CELL payload. ficlSetEnvD
** makes one with a two-CELL payload.
**************************************************************************/
void ficlSetEnv(FICL_SYSTEM *pSys, char *name, FICL_UNS value)
{
STRINGINFO si;
FICL_WORD *pFW;
FICL_DICT *envp = pSys->envp;
SI_PSZ(si, name);
pFW = dictLookup(envp, si);
if (pFW == NULL)
{
dictAppendWord(envp, name, constantParen, FW_DEFAULT);
dictAppendCell(envp, LVALUEtoCELL(value));
}
else
{
pFW->param[0] = LVALUEtoCELL(value);
}
return;
}
void ficlSetEnvD(FICL_SYSTEM *pSys, char *name, FICL_UNS hi, FICL_UNS lo)
{
FICL_WORD *pFW;
STRINGINFO si;
FICL_DICT *envp = pSys->envp;
SI_PSZ(si, name);
pFW = dictLookup(envp, si);
if (pFW == NULL)
{
dictAppendWord(envp, name, twoConstParen, FW_DEFAULT);
dictAppendCell(envp, LVALUEtoCELL(lo));
dictAppendCell(envp, LVALUEtoCELL(hi));
}
else
{
pFW->param[0] = LVALUEtoCELL(lo);
pFW->param[1] = LVALUEtoCELL(hi);
}
return;
}
/**************************************************************************
f i c l G e t L o c
** Returns the address of the system locals dictionary. This dict is
** only used during compilation, and is shared by all VMs.
**************************************************************************/
#if FICL_WANT_LOCALS
FICL_DICT *ficlGetLoc(FICL_SYSTEM *pSys)
{
return pSys->localp;
}
#endif
/**************************************************************************
f i c l S e t S t a c k S i z e
** Set the stack sizes (return and parameter) to be used for all
** subsequently created VMs. Returns actual stack size to be used.
**************************************************************************/
int ficlSetStackSize(int nStackCells)
{
if (nStackCells >= FICL_DEFAULT_STACK)
defaultStack = nStackCells;
else
defaultStack = FICL_DEFAULT_STACK;
return defaultStack;
}
/**************************************************************************
f i c l T e r m S y s t e m
** Tear the system down by deleting the dictionaries and all VMs.
** This saves you from having to keep track of all that stuff.
**************************************************************************/
void ficlTermSystem(FICL_SYSTEM *pSys)
{
if (pSys->dp)
dictDelete(pSys->dp);
pSys->dp = NULL;
if (pSys->envp)
dictDelete(pSys->envp);
pSys->envp = NULL;
#if FICL_WANT_LOCALS
if (pSys->localp)
dictDelete(pSys->localp);
pSys->localp = NULL;
#endif
while (pSys->vmList != NULL)
{
FICL_VM *pVM = pSys->vmList;
pSys->vmList = pSys->vmList->link;
vmDelete(pVM);
}
ficlFree(pSys);
pSys = NULL;
return;
}
/**************************************************************************
f i c l S e t V e r s i o n E n v
** Create a double cell environment constant for the version ID
**************************************************************************/
static void ficlSetVersionEnv(FICL_SYSTEM *pSys)
{
ficlSetEnvD(pSys, "ficl-version", FICL_VER_MAJOR, FICL_VER_MINOR);
ficlSetEnv (pSys, "ficl-robust", FICL_ROBUST);
return;
}