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mirror of https://github.com/cc65/cc65.git synced 2024-06-17 00:29:31 +00:00
cc65/src/ca65/istack.c
cuz 522c7e8c46 Added a more generic way to push sources that deliver a token stream
independent of the actual input from the file. Change macro handling
to use the new input stack.
Fixed an error in FreeIf: If an unexpected .ENDIF was reached, the
assembler started an endless loop printing error messages.


git-svn-id: svn://svn.cc65.org/cc65/trunk@24 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-06-03 11:15:11 +00:00

150 lines
4.8 KiB
C

/*****************************************************************************/
/* */
/* istack.c */
/* */
/* Input stack for the scanner */
/* */
/* */
/* */
/* (C) 2000 Ullrich von Bassewitz */
/* Wacholderweg 14 */
/* D-70597 Stuttgart */
/* EMail: uz@musoftware.de */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
/* warranty. In no event will the authors be held liable for any damages */
/* arising from the use of this software. */
/* */
/* Permission is granted to anyone to use this software for any purpose, */
/* including commercial applications, and to alter it and redistribute it */
/* freely, subject to the following restrictions: */
/* */
/* 1. The origin of this software must not be misrepresented; you must not */
/* claim that you wrote the original software. If you use this software */
/* in a product, an acknowledgment in the product documentation would be */
/* appreciated but is not required. */
/* 2. Altered source versions must be plainly marked as such, and must not */
/* be misrepresented as being the original software. */
/* 3. This notice may not be removed or altered from any source */
/* distribution. */
/* */
/*****************************************************************************/
#include "error.h"
#include "mem.h"
#include "istack.h"
/*****************************************************************************/
/* Data */
/*****************************************************************************/
/* Size of the stack (== maximum nested macro or repeat count) */
#define ISTACK_MAX 256
/* Structure holding a stack element */
typedef struct IElement IElement;
struct IElement {
IElement* Next; /* Next stack element */
int (*Func)(void*); /* Function called for input */
void* Data; /* User data given as argument */
const char* Desc; /* Description */
};
/* The stack */
static IElement* IStack = 0; /* Input stack pointer */
static unsigned ICount = 0; /* Number of items on the stack */
/*****************************************************************************/
/* Code */
/*****************************************************************************/
void PushInput (int (*Func) (void*), void* Data, const char* Desc)
/* Push an input function onto the input stack */
{
IElement* E;
/* Check for a stack overflow */
if (ICount > ISTACK_MAX) {
Fatal (FAT_NESTING);
}
/* Create a new stack element */
E = Xmalloc (sizeof (*E));
/* Initialize it */
E->Func = Func;
E->Data = Data;
E->Desc = Desc;
/* Push it */
E->Next = IStack;
IStack = E;
}
void PopInput (void)
/* Pop the current input function from the input stack */
{
IElement* E;
/* We cannot pop from an empty stack */
PRECONDITION (IStack != 0);
/* Remember the last element */
E = IStack;
/* Pop it */
IStack = IStack->Next;
/* And delete it */
Xfree (E);
}
int InputFromStack (void)
/* Try to get input from the input stack. Return true if we had such input,
* return false otherwise.
*/
{
/* Repeatedly call the TOS routine until we have a token or if run out of
* routines.
*/
while (IStack) {
if (IStack->Func (IStack->Data) != 0) {
/* We have a token */
return 1;
}
}
/* Nothing is on the stack */
return 0;
}
void CheckInputStack (void)
/* Called from the scanner before closing an input file. Will check for any
* stuff on the input stack.
*/
{
if (IStack) {
Error (ERR_OPEN_STMT, IStack->Desc);
}
}