rgbds/src/asm/symbol.c

/*
 * Symboltable and macroargs stuff
 */

#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <time.h>

#include "asm/asm.h"
#include "asm/symbol.h"
#include "asm/main.h"
#include "asm/mymath.h"
#include "asm/output.h"
#include "extern/err.h"

struct sSymbol *tHashedSymbols[HASHSIZE];
struct sSymbol *pScope = NULL;
struct sSymbol *pPCSymbol = NULL;
struct sSymbol *p_NARGSymbol = NULL;
char *currentmacroargs[MAXMACROARGS + 1];
char *newmacroargs[MAXMACROARGS + 1];
char SavedTIME[256];
char SavedDATE[256];
char SavedTIMESTAMP_ISO8601_LOCAL[256];
char SavedTIMESTAMP_ISO8601_UTC[256];
bool exportall;

SLONG
Callback_NARG(struct sSymbol * sym)
{
	ULONG i = 0;

	while (currentmacroargs[i] && i < MAXMACROARGS)
		i += 1;

	return (i);
}

/*
 * Get the nValue field of a symbol
 */
SLONG
getvaluefield(struct sSymbol * sym)
{
	if (sym->Callback) {
		return (sym->Callback(sym));
	} else
		return (sym->nValue);
}

/*
 * Calculate the hash value for a string
 */
ULONG
calchash(char *s)
{
	ULONG hash = 5381;

	while (*s != 0)
		hash = (hash * 33) ^ (*s++);

	return (hash % HASHSIZE);
}

/*
 * Create a new symbol by name
 */
struct sSymbol *
createsymbol(char *s)
{
	struct sSymbol **ppsym;
	ULONG hash;

	hash = calchash(s);
	ppsym = &(tHashedSymbols[hash]);

	while ((*ppsym) != NULL)
		ppsym = &((*ppsym)->pNext);

	if (((*ppsym) = malloc(sizeof(struct sSymbol))) != NULL) {
		strcpy((*ppsym)->tzName, s);
		(*ppsym)->nValue = 0;
		(*ppsym)->nType = 0;
		(*ppsym)->pScope = NULL;
		(*ppsym)->pNext = NULL;
		(*ppsym)->pMacro = NULL;
		(*ppsym)->pSection = NULL;
		(*ppsym)->Callback = NULL;
		return (*ppsym);
	} else {
		fatalerror("No memory for symbol");
		return (NULL);
	}
}
/*
 * Find a symbol by name and scope
 */
struct sSymbol *
findsymbol(char *s, struct sSymbol * scope)
{
	struct sSymbol **ppsym;
	SLONG hash;

	hash = calchash(s);
	ppsym = &(tHashedSymbols[hash]);

	while ((*ppsym) != NULL) {
		if ((strcmp(s, (*ppsym)->tzName) == 0)
		    && ((*ppsym)->pScope == scope)) {
			return (*ppsym);
		} else
			ppsym = &((*ppsym)->pNext);
	}
	return (NULL);
}

/*
 * Find the pointer to a symbol by name and scope
 */
struct sSymbol **
findpsymbol(char *s, struct sSymbol * scope)
{
	struct sSymbol **ppsym;
	SLONG hash;

	hash = calchash(s);
	ppsym = &(tHashedSymbols[hash]);

	while ((*ppsym) != NULL) {
		if ((strcmp(s, (*ppsym)->tzName) == 0)
		    && ((*ppsym)->pScope == scope)) {
			return (ppsym);
		} else
			ppsym = &((*ppsym)->pNext);
	}
	return (NULL);
}

/*
 * Find a symbol by name and scope
 */
struct sSymbol *
sym_FindSymbol(char *tzName)
{
	struct sSymbol *pscope;

	if (*tzName == '.')
		pscope = pScope;
	else
		pscope = NULL;

	return (findsymbol(tzName, pscope));
}

/*
 * Purge a symbol
 */
void
sym_Purge(char *tzName)
{
	struct sSymbol **ppSym;
	struct sSymbol *pscope;

	if (*tzName == '.')
		pscope = pScope;
	else
		pscope = NULL;

	ppSym = findpsymbol(tzName, pscope);

	if (ppSym) {
		struct sSymbol *pSym;

		pSym = *ppSym;
		*ppSym = pSym->pNext;

		if (pSym->pMacro)
			free(pSym->pMacro);

		free(pSym);
	} else {
		yyerror("'%s' not defined", tzName);
	}
}

/*
 * Determine if a symbol has been defined
 */
ULONG
sym_isConstDefined(char *tzName)
{
	struct sSymbol *psym, *pscope;

	if (*tzName == '.')
		pscope = pScope;
	else
		pscope = NULL;

	psym = findsymbol(tzName, pscope);

	if (psym && (psym->nType & SYMF_DEFINED)) {
		if (psym->
		    nType & (SYMF_EQU | SYMF_SET | SYMF_MACRO | SYMF_STRING)) {
			return (1);
		} else {
			fatalerror("'%s' is not allowed as argument to the "
			    "DEF function", tzName);
		}
	}
	return (0);
}

ULONG
sym_isDefined(char *tzName)
{
	struct sSymbol *psym, *pscope;

	if (*tzName == '.')
		pscope = pScope;
	else
		pscope = NULL;

	psym = findsymbol(tzName, pscope);

	if (psym && (psym->nType & SYMF_DEFINED))
		return (1);
	else
		return (0);
}

/*
 * Determine if the symbol is a constant
 */
ULONG
sym_isConstant(char *s)
{
	struct sSymbol *psym, *pscope;

	if (*s == '.')
		pscope = pScope;
	else
		pscope = NULL;

	if ((psym = findsymbol(s, pscope)) != NULL) {
		if (psym->nType & SYMF_CONST)
			return (1);
	}
	return (0);
}

/*
 * Get a string equate's value
 */
char *
sym_GetStringValue(char *tzSym)
{
	struct sSymbol *pSym;

	if ((pSym = sym_FindSymbol(tzSym)) != NULL)
		return (pSym->pMacro);
	else {
		yyerror("Stringsymbol '%s' not defined", tzSym);
	}

	return (NULL);
}

/*
 * Return a constant symbols value
 */
ULONG
sym_GetConstantValue(char *s)
{
	struct sSymbol *psym, *pscope;

	if (*s == '.')
		pscope = pScope;
	else
		pscope = NULL;

	if ((psym = findsymbol(s, pscope)) != NULL) {
		if (psym->nType & SYMF_CONST)
			return (getvaluefield(psym));
		else {
			fatalerror("Expression must have a constant value");
		}
	} else {
		yyerror("'%s' not defined", s);
	}

	return (0);
}

/*
 * Return a symbols value... "estimated" if not defined yet
 */
ULONG
sym_GetValue(char *s)
{
	struct sSymbol *psym, *pscope;

	if (*s == '.')
		pscope = pScope;
	else
		pscope = NULL;

	if ((psym = findsymbol(s, pscope)) != NULL) {
		if (psym->nType & SYMF_DEFINED) {
			if (psym->nType & (SYMF_MACRO | SYMF_STRING)) {
				yyerror("'%s' is a macro or string symbol", s);
			}
			return (getvaluefield(psym));
		} else {
			if (nPass == 2) {
				/* Assume undefined symbols are imported from somewhere else */
				psym->nType |= SYMF_IMPORT;
			}
			/* 0x80 seems like a good default value... */
			return (0x80);
		}
	} else {
		if (nPass == 1) {
			createsymbol(s);
			return (0x80);
		} else {
			yyerror("'%s' not defined", s);
		}
	}

	return (0);
}

/*
 * Return a defined symbols value... aborts if not defined yet
 */
ULONG
sym_GetDefinedValue(char *s)
{
	struct sSymbol *psym, *pscope;

	if (*s == '.')
		pscope = pScope;
	else
		pscope = NULL;

	if ((psym = findsymbol(s, pscope)) != NULL) {
		if ((psym->nType & SYMF_DEFINED)) {
			if (psym->nType & (SYMF_MACRO | SYMF_STRING)) {
				yyerror("'%s' is a macro or string symbol", s);
			}
			return (getvaluefield(psym));
		} else {
			yyerror("'%s' not defined", s);
		}
	} else {
		yyerror("'%s' not defined", s);
	}

	return (0);
}

/*
 * Macro argument stuff
 */
void
sym_ShiftCurrentMacroArgs(void)
{
	SLONG i;

	free(currentmacroargs[0]);
	for (i = 0; i < MAXMACROARGS - 1; i += 1) {
		currentmacroargs[i] = currentmacroargs[i + 1];
	}
	currentmacroargs[MAXMACROARGS - 1] = NULL;
}

char *
sym_FindMacroArg(SLONG i)
{
	if (i == -1)
		i = MAXMACROARGS + 1;

	assert(i-1 >= 0);
	assert((size_t)(i-1) < sizeof(currentmacroargs)/sizeof(*currentmacroargs));

	return (currentmacroargs[i - 1]);
}

void
sym_UseNewMacroArgs(void)
{
	SLONG i;

	for (i = 0; i <= MAXMACROARGS; i += 1) {
		currentmacroargs[i] = newmacroargs[i];
		newmacroargs[i] = NULL;
	}
}

void
sym_SaveCurrentMacroArgs(char *save[])
{
	SLONG i;

	for (i = 0; i <= MAXMACROARGS; i += 1)
		save[i] = currentmacroargs[i];
}

void
sym_RestoreCurrentMacroArgs(char *save[])
{
	SLONG i;

	for (i = 0; i <= MAXMACROARGS; i += 1)
		currentmacroargs[i] = save[i];
}

void
sym_FreeCurrentMacroArgs(void)
{
	SLONG i;

	for (i = 0; i <= MAXMACROARGS; i += 1) {
		free(currentmacroargs[i]);
		currentmacroargs[i] = NULL;
	}
}

void
sym_AddNewMacroArg(char *s)
{
	SLONG i = 0;

	while (i < MAXMACROARGS && newmacroargs[i] != NULL)
		i += 1;

	if (i < MAXMACROARGS) {
		if (s)
			newmacroargs[i] = strdup(s);
		else
			newmacroargs[i] = NULL;
	} else
		yyerror("A maximum of %d arguments allowed", MAXMACROARGS);
}

void
sym_SetMacroArgID(ULONG nMacroCount)
{
	char s[256];

	sprintf(s, "_%ld", nMacroCount);
	newmacroargs[MAXMACROARGS] = strdup(s);
}

void
sym_UseCurrentMacroArgs(void)
{
	SLONG i;

	for (i = 1; i <= MAXMACROARGS; i += 1)
		sym_AddNewMacroArg(sym_FindMacroArg(i));
}

/*
 * Find a macro by name
 */
struct sSymbol *
sym_FindMacro(char *s)
{
	return (findsymbol(s, NULL));
}

/*
 * Add an equated symbol
 */
void
sym_AddEqu(char *tzSym, SLONG value)
{
	if ((nPass == 1)
	    || ((nPass == 2) && (sym_isDefined(tzSym) == 0))) {
		/* only add equated symbols in pass 1 */
		struct sSymbol *nsym;

		if ((nsym = findsymbol(tzSym, NULL)) != NULL) {
			if (nsym->nType & SYMF_DEFINED) {
				yyerror("'%s' already defined", tzSym);
			}
		} else
			nsym = createsymbol(tzSym);

		if (nsym) {
			nsym->nValue = value;
			nsym->nType |= SYMF_EQU | SYMF_DEFINED | SYMF_CONST;
			nsym->pScope = NULL;
		}
	}
}

/*
 * Add a string equated symbol.
 *
 * If the desired symbol is a string it needs to be passed to this function with
 * quotes inside the string, like sym_AddString("name", "\"test\"), or the
 * assembler won't be able to use it with DB and similar. This is equivalent as
 * ``` name EQUS "\"test\"" ```
 *
 * If the desired symbol is a register or a number, just the terminator quotes
 * of the string are enough: sym_AddString("M_PI", "3.1415"). This is the same
 * as ``` M_PI EQUS "3.1415" ```
 */
void
sym_AddString(char *tzSym, char *tzValue)
{
	struct sSymbol *nsym;

	if ((nsym = findsymbol(tzSym, NULL)) != NULL) {
		if (nsym->nType & SYMF_DEFINED) {
			yyerror("'%s' already defined", tzSym);
		}
	} else
		nsym = createsymbol(tzSym);

	if (nsym) {
		if ((nsym->pMacro = malloc(strlen(tzValue) + 1)) != NULL)
			strcpy(nsym->pMacro, tzValue);
		else
			fatalerror("No memory for stringequate");
		nsym->nType |= SYMF_STRING | SYMF_DEFINED;
		nsym->ulMacroSize = strlen(tzValue);
		nsym->pScope = NULL;
	}
}

/*
 * check if symbol is a string equated symbol
 */
ULONG
sym_isString(char *tzSym)
{
	struct sSymbol *pSym;

	if ((pSym = findsymbol(tzSym, NULL)) != NULL) {
		if (pSym->nType & SYMF_STRING)
			return (1);
	}
	return (0);
}

/*
 * Alter a SET symbols value
 */
void
sym_AddSet(char *tzSym, SLONG value)
{
	struct sSymbol *nsym;

	if ((nsym = findsymbol(tzSym, NULL)) != NULL) {
	} else
		nsym = createsymbol(tzSym);

	if (nsym) {
		nsym->nValue = value;
		nsym->nType |= SYMF_SET | SYMF_DEFINED | SYMF_CONST;
		nsym->pScope = NULL;
	}
}

/*
 * Add a local (.name) relocatable symbol
 */
void
sym_AddLocalReloc(char *tzSym)
{
	if ((nPass == 1)
	    || ((nPass == 2) && (sym_isDefined(tzSym) == 0))) {
		/* only add local reloc symbols in pass 1 */
		struct sSymbol *nsym;

		if (pScope) {
			if ((nsym = findsymbol(tzSym, pScope)) != NULL) {
				if (nsym->nType & SYMF_DEFINED) {
					yyerror("'%s' already defined", tzSym);
				}
			} else
				nsym = createsymbol(tzSym);

			if (nsym) {
				nsym->nValue = nPC;
				nsym->nType |=
				    SYMF_RELOC | SYMF_LOCAL | SYMF_DEFINED;
				if (exportall) {
				   nsym->nType |= SYMF_EXPORT;
				}
				nsym->pScope = pScope;
				nsym->pSection = pCurrentSection;
			}
		} else
			fatalerror("Local label in main scope");
	}
}

/*
 * Add a relocatable symbol
 */
void
sym_AddReloc(char *tzSym)
{
	if ((nPass == 1)
	    || ((nPass == 2) && (sym_isDefined(tzSym) == 0))) {
		/* only add reloc symbols in pass 1 */
		struct sSymbol *nsym;

		if ((nsym = findsymbol(tzSym, NULL)) != NULL) {
			if (nsym->nType & SYMF_DEFINED) {
				yyerror("'%s' already defined", tzSym);
			}
		} else
			nsym = createsymbol(tzSym);

		if (nsym) {
			nsym->nValue = nPC;
			nsym->nType |= SYMF_RELOC | SYMF_DEFINED;
			if (exportall) {
			   nsym->nType |= SYMF_EXPORT;
			}
			nsym->pScope = NULL;
			nsym->pSection = pCurrentSection;
		}
	}
	pScope = findsymbol(tzSym, NULL);
}

/*
 * Check if the subtraction of two symbols is defined. That is, either both
 * symbols are defined and the result is a constant, or both symbols are
 * relocatable and belong to the same section.
 *
 * It returns 1 if the difference is defined, 0 if not.
 */
int
sym_IsRelocDiffDefined(char *tzSym1, char *tzSym2)
{
	/* Do nothing the first pass. */
	if (nPass != 2)
		return 1;

	struct sSymbol *nsym1, *nsym2;

	/* Do the symbols exist? */
	if ((nsym1 = sym_FindSymbol(tzSym1)) == NULL)
		fatalerror("Symbol \"%s\" isn't defined.", tzSym1);
	if ((nsym2 = sym_FindSymbol(tzSym2)) == NULL)
		fatalerror("Symbol \"%s\" isn't defined.", tzSym2);

	int s1reloc = (nsym1->nType & SYMF_RELOC) != 0;
	int s2reloc = (nsym2->nType & SYMF_RELOC) != 0;

	/* Both are non-relocatable */
	if (!s1reloc && !s2reloc) return 1;

	/* One of them relocatable, the other one not. */
	if (s1reloc ^ s2reloc) return 0;

	/* Both of them are relocatable. Make sure they are defined (internal
         * coherency with sym_AddReloc and sym_AddLocalReloc). */
	if (!(nsym1->nType & SYMF_DEFINED))
		fatalerror("Relocatable symbol \"%s\" isn't defined.", tzSym1);
	if (!(nsym2->nType & SYMF_DEFINED))
		fatalerror("Relocatable symbol \"%s\" isn't defined.", tzSym2);

	/* Both of them must be in the same section for the difference to be
         * defined. */
	return nsym1->pSection == nsym2->pSection;
}

/*
 * Export a symbol
 */
void
sym_Export(char *tzSym)
{
	if (nPass == 1) {
		/* only export symbols in pass 1 */
		struct sSymbol *nsym;

		if ((nsym = findsymbol(tzSym, 0)) == NULL)
			nsym = createsymbol(tzSym);

		if (nsym)
			nsym->nType |= SYMF_EXPORT;
	} else {
		struct sSymbol *nsym;

		if ((nsym = findsymbol(tzSym, 0)) != NULL) {
			if (nsym->nType & SYMF_DEFINED)
				return;
		}
		yyerror("'%s' not defined", tzSym);
	}

}

/*
 * Globalize a symbol (export if defined, import if not)
 */
void
sym_Global(char *tzSym)
{
	if (nPass == 2) {
		/* only globalize symbols in pass 2 */
		struct sSymbol *nsym;

		nsym = findsymbol(tzSym, 0);

		if ((nsym == NULL) || ((nsym->nType & SYMF_DEFINED) == 0)) {
			if (nsym == NULL)
				nsym = createsymbol(tzSym);

			if (nsym)
				nsym->nType |= SYMF_IMPORT;
		} else {
			if (nsym)
				nsym->nType |= SYMF_EXPORT;
		}
	}
}

/*
 * Add a macro definition
 */
void
sym_AddMacro(char *tzSym)
{
	if ((nPass == 1)
	    || ((nPass == 2) && (sym_isDefined(tzSym) == 0))) {
		/* only add macros in pass 1 */
		struct sSymbol *nsym;

		if ((nsym = findsymbol(tzSym, NULL)) != NULL) {
			if (nsym->nType & SYMF_DEFINED) {
				yyerror("'%s' already defined", tzSym);
			}
		} else
			nsym = createsymbol(tzSym);

		if (nsym) {
			nsym->nValue = nPC;
			nsym->nType |= SYMF_MACRO | SYMF_DEFINED;
			nsym->pScope = NULL;
			nsym->ulMacroSize = ulNewMacroSize;
			nsym->pMacro = tzNewMacro;
		}
	}
}

/*
 * Set whether to export all relocable symbols by default
 */
void sym_SetExportAll(BBOOL set) {
	exportall = set;
}

/*
 * Prepare for pass #1
 */
void
sym_PrepPass1(void)
{
	sym_Init();
}

/*
 * Prepare for pass #2
 */
void
sym_PrepPass2(void)
{
	SLONG i;

	for (i = 0; i < HASHSIZE; i += 1) {
		struct sSymbol **ppSym = &(tHashedSymbols[i]);

		while (*ppSym) {
			if ((*ppSym)->
			    nType & (SYMF_SET | SYMF_STRING | SYMF_EQU)) {
				struct sSymbol *pTemp;

				pTemp = (*ppSym)->pNext;
				free(*ppSym);
				*ppSym = pTemp;
			} else
				ppSym = &((*ppSym)->pNext);
		}
	}
	pScope = NULL;
	pPCSymbol->nValue = 0;

	sym_AddString("__TIME__", SavedTIME);
	sym_AddString("__DATE__", SavedDATE);
	sym_AddString("__ISO_8601_LOCAL__", SavedTIMESTAMP_ISO8601_LOCAL);
	sym_AddString("__ISO_8601_UTC__", SavedTIMESTAMP_ISO8601_UTC);
	sym_AddSet("_RS", 0);

	sym_AddEqu("_NARG", 0);
	p_NARGSymbol = findsymbol("_NARG", NULL);
	p_NARGSymbol->Callback = Callback_NARG;

	math_DefinePI();
}

/*
 * Initialize the symboltable
 */
void
sym_Init(void)
{
	SLONG i;
	time_t now;

	for (i = 0; i < MAXMACROARGS; i += 1) {
		currentmacroargs[i] = NULL;
		newmacroargs[i] = NULL;
	}

	for (i = 0; i < HASHSIZE; i += 1)
		tHashedSymbols[i] = NULL;

	sym_AddReloc("@");
	pPCSymbol = findsymbol("@", NULL);
	sym_AddEqu("_NARG", 0);
	p_NARGSymbol = findsymbol("_NARG", NULL);
	p_NARGSymbol->Callback = Callback_NARG;

	sym_AddSet("_RS", 0);

	if (time(&now) != -1) {
		struct tm *time_local = localtime(&now);

		strftime(SavedTIME, sizeof(SavedTIME), "\"%H:%M:%S\"", time_local);
		strftime(SavedDATE, sizeof(SavedDATE), "\"%d %B %Y\"", time_local);
		strftime(SavedTIMESTAMP_ISO8601_LOCAL,
			sizeof(SavedTIMESTAMP_ISO8601_LOCAL), "\"%FT%T%z\"", time_local);

		struct tm *time_utc = gmtime(&now);
		strftime(SavedTIMESTAMP_ISO8601_UTC,
			sizeof(SavedTIMESTAMP_ISO8601_UTC), "\"%FT%TZ\"", time_utc);
	} else {
		warnx("Couldn't determine current time.");
		/* The '?' have to be escaped or they will be treated as
		 * trigraphs... */
		strcpy(SavedTIME, "\"\?\?:\?\?:\?\?\"");
		strcpy(SavedDATE, "\"\?\? \?\?\? \?\?\?\?\"");
		strcpy(SavedTIMESTAMP_ISO8601_LOCAL, "\"\?\?\?\?-\?\?-\?\?T\?\?:\?\?:\?\?+\?\?\?\?\"");
		strcpy(SavedTIMESTAMP_ISO8601_UTC, "\"\?\?\?\?-\?\?-\?\?T\?\?:\?\?:\?\?Z\"");
	}

	sym_AddString("__TIME__", SavedTIME);
	sym_AddString("__DATE__", SavedDATE);
	sym_AddString("__ISO_8601_LOCAL__", SavedTIMESTAMP_ISO8601_LOCAL);
	sym_AddString("__ISO_8601_UTC__", SavedTIMESTAMP_ISO8601_UTC);

	pScope = NULL;

	math_DefinePI();

}