ref: 21e50eeff1bac67817406cc9df8e5dce5712eb6e
dir: /src/asm/symbol.c/
/*
* This file is part of RGBDS.
*
* Copyright (c) 1997-2018, Carsten Sorensen and RGBDS contributors.
*
* SPDX-License-Identifier: MIT
*/
/*
* Symboltable and macroargs stuff
*/
#include <assert.h>
#include <errno.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include "asm/asm.h"
#include "asm/fstack.h"
#include "asm/macro.h"
#include "asm/main.h"
#include "asm/mymath.h"
#include "asm/output.h"
#include "asm/section.h"
#include "asm/symbol.h"
#include "asm/util.h"
#include "asm/warning.h"
#include "extern/err.h"
#include "hashmap.h"
#include "helpers.h"
#include "version.h"
HashMap symbols;
static char const *labelScope; /* Current section's label scope */
static struct Symbol *PCSymbol;
static char savedTIME[256];
static char savedDATE[256];
static char savedTIMESTAMP_ISO8601_LOCAL[256];
static char savedTIMESTAMP_ISO8601_UTC[256];
static char savedDAY[3];
static char savedMONTH[3];
static char savedYEAR[20];
static char savedHOUR[3];
static char savedMINUTE[3];
static char savedSECOND[3];
static bool exportall;
bool sym_IsPC(struct Symbol const *sym)
{
return sym == PCSymbol;
}
struct ForEachArgs {
void (*func)(struct Symbol *symbol, void *arg);
void *arg;
};
static void forEachWrapper(void *_symbol, void *_argWrapper)
{
struct ForEachArgs *argWrapper = _argWrapper;
struct Symbol *symbol = _symbol;
argWrapper->func(symbol, argWrapper->arg);
}
void sym_ForEach(void (*func)(struct Symbol *, void *), void *arg)
{
struct ForEachArgs argWrapper = { .func = func, .arg = arg };
hash_ForEach(symbols, forEachWrapper, &argWrapper);
}
static int32_t Callback_NARG(void)
{
if (!macro_GetCurrentArgs()) {
error("_NARG does not make sense outside of a macro\n");
return 0;
}
return macro_NbArgs();
}
static int32_t Callback__LINE__(void)
{
return lexer_GetLineNo();
}
static char const *Callback__FILE__(void)
{
/*
* FIXME: this is dangerous, and here's why this is CURRENTLY okay. It's still bad, fix it.
* There are only two call sites for this; one copies the contents directly, the other is
* EQUS expansions, which cannot straddle file boundaries. So this should be fine.
*/
static char *buf = NULL;
static size_t bufsize = 0;
char const *fileName = fstk_GetFileName();
size_t j = 1;
/* TODO: is there a way for a file name to be empty? */
assert(fileName[0]);
/* The assertion above ensures the loop runs at least once */
for (size_t i = 0; fileName[i]; i++, j++) {
/* Account for the extra backslash inserted below */
if (fileName[i] == '"')
j++;
/* Ensure there will be enough room; DO NOT PRINT ANYTHING ABOVE THIS!! */
if (j + 2 >= bufsize) { /* Always keep room for 2 tail chars */
bufsize = bufsize ? bufsize * 2 : 64;
buf = realloc(buf, bufsize);
if (!buf)
fatalerror("Failed to grow buffer for file name: %s\n",
strerror(errno));
}
/* Escape quotes, since we're returning a string */
if (fileName[i] == '"')
buf[j - 1] = '\\';
buf[j] = fileName[i];
}
/* Write everything after the loop, to ensure the buffer has been allocated */
buf[0] = '"';
buf[j++] = '"';
buf[j] = '\0';
return buf;
}
static int32_t CallbackPC(void)
{
struct Section const *section = sect_GetSymbolSection();
return section ? section->org + sect_GetSymbolOffset() : 0;
}
/*
* Get the value field of a symbol
*/
int32_t sym_GetValue(struct Symbol const *sym)
{
if (sym_IsNumeric(sym) && sym->hasCallback)
return sym->numCallback();
if (sym->type == SYM_LABEL)
/* TODO: do not use section's org directly */
return sym->value + sym_GetSection(sym)->org;
return sym->value;
}
static void dumpFilename(struct Symbol const *sym)
{
if (!sym->src)
fputs("<builtin>", stderr);
else
fstk_Dump(sym->src, sym->fileLine);
}
/*
* Set a symbol's definition filename and line
*/
static void setSymbolFilename(struct Symbol *sym)
{
sym->src = fstk_GetFileStack();
sym->fileLine = lexer_GetLineNo();
}
/*
* Update a symbol's definition filename and line
*/
static void updateSymbolFilename(struct Symbol *sym)
{
struct FileStackNode *oldSrc = sym->src;
setSymbolFilename(sym);
/* If the old node was referenced, ensure the new one is */
if (oldSrc->referenced && oldSrc->ID != -1)
out_RegisterNode(sym->src);
/* TODO: unref the old node, and use `out_ReplaceNode` instead if deleting it */
}
/*
* Create a new symbol by name
*/
static struct Symbol *createsymbol(char const *s)
{
struct Symbol *symbol = malloc(sizeof(*symbol));
if (!symbol)
fatalerror("Failed to create symbol '%s': %s\n", s, strerror(errno));
if (snprintf(symbol->name, MAXSYMLEN + 1, "%s", s) > MAXSYMLEN)
warning(WARNING_LONG_STR, "Symbol name is too long: '%s'\n", s);
symbol->isExported = false;
symbol->isBuiltin = false;
symbol->hasCallback = false;
symbol->section = NULL;
setSymbolFilename(symbol);
symbol->ID = -1;
symbol->next = NULL;
hash_AddElement(symbols, symbol->name, symbol);
return symbol;
}
/*
* Creates the full name of a local symbol in a given scope, by prepending
* the name with the parent symbol's name.
*/
static void fullSymbolName(char *output, size_t outputSize,
char const *localName, char const *scopeName)
{
int ret = snprintf(output, outputSize, "%s%s", scopeName, localName);
if (ret < 0)
fatalerror("snprintf error when expanding symbol name: %s", strerror(errno));
else if ((size_t)ret >= outputSize)
fatalerror("Symbol name is too long: '%s%s'\n", scopeName, localName);
}
/*
* Find a symbol by name and scope
*/
static struct Symbol *findsymbol(char const *s, char const *scope)
{
char fullname[MAXSYMLEN + 1];
if (s[0] == '.' && scope) {
fullSymbolName(fullname, sizeof(fullname), s, scope);
s = fullname;
}
char const *separator = strchr(s, '.');
if (separator && strchr(separator + 1, '.'))
fatalerror("'%s' is a nonsensical reference to a nested local symbol\n", s);
return hash_GetElement(symbols, s);
}
/*
* Find a symbol by name, with automatically determined scope
*/
struct Symbol *sym_FindSymbol(char const *symName)
{
return findsymbol(symName, symName[0] == '.' ? labelScope : NULL);
}
static inline bool isReferenced(struct Symbol const *sym)
{
return sym->ID != -1;
}
/*
* Purge a symbol
*/
void sym_Purge(char const *symName)
{
struct Symbol *symbol = sym_FindSymbol(symName);
if (!symbol) {
error("'%s' not defined\n", symName);
} else if (symbol->isBuiltin) {
error("Built-in symbol '%s' cannot be purged\n", symName);
} else if (isReferenced(symbol)) {
error("Symbol \"%s\" is referenced and thus cannot be purged\n", symName);
} else {
/* Do not keep a reference to the label's name after purging it */
if (symbol->name == labelScope)
labelScope = NULL;
hash_RemoveElement(symbols, symbol->name);
/* TODO: ideally, also unref the file stack nodes */
free(symbol);
}
}
uint32_t sym_GetPCValue(void)
{
struct Section const *sect = sect_GetSymbolSection();
if (!sect)
error("PC has no value outside a section\n");
else if (sect->org == -1)
error("Expected constant PC but section is not fixed\n");
else
return CallbackPC();
return 0;
}
/*
* Return a constant symbol's value, assuming it's defined
*/
uint32_t sym_GetConstantSymValue(struct Symbol const *sym)
{
if (sym == PCSymbol)
return sym_GetPCValue();
else if (!sym_IsConstant(sym))
error("\"%s\" does not have a constant value\n", sym->name);
else
return sym_GetValue(sym);
return 0;
}
/*
* Return a constant symbol's value
*/
uint32_t sym_GetConstantValue(char const *s)
{
struct Symbol const *sym = sym_FindSymbol(s);
if (sym == NULL)
error("'%s' not defined\n", s);
else
return sym_GetConstantSymValue(sym);
return 0;
}
/*
* Return a defined symbols value... aborts if not defined yet
*/
uint32_t sym_GetDefinedValue(char const *s)
{
struct Symbol const *sym = sym_FindSymbol(s);
if (sym == NULL || !sym_IsDefined(sym))
error("'%s' not defined\n", s);
else if (!sym_IsNumeric(sym))
error("'%s' is a macro or string symbol\n", s);
else
return sym_GetValue(sym);
return 0;
}
char const *sym_GetCurrentSymbolScope(void)
{
return labelScope;
}
void sym_SetCurrentSymbolScope(char const *newScope)
{
labelScope = newScope;
}
/*
* Create a symbol that will be non-relocatable and ensure that it
* hasn't already been defined or referenced in a context that would
* require that it be relocatable
*/
static struct Symbol *createNonrelocSymbol(char const *symbolName)
{
struct Symbol *symbol = findsymbol(symbolName, NULL);
if (!symbol)
symbol = createsymbol(symbolName);
else if (sym_IsDefined(symbol)) {
error("'%s' already defined at ", symbolName);
dumpFilename(symbol);
putc('\n', stderr);
}
return symbol;
}
/*
* Add an equated symbol
*/
struct Symbol *sym_AddEqu(char const *symName, int32_t value)
{
struct Symbol *sym = createNonrelocSymbol(symName);
sym->type = SYM_EQU;
sym->value = value;
return sym;
}
/*
* 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 to
* ``` 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" ```
*/
struct Symbol *sym_AddString(char const *symName, char const *value)
{
struct Symbol *sym = createNonrelocSymbol(symName);
size_t len = strlen(value);
char *string = malloc(len + 1);
if (string == NULL)
fatalerror("No memory for string equate: %s\n", strerror(errno));
strcpy(string, value);
sym->type = SYM_EQUS;
/* TODO: use other fields */
sym->macroSize = len;
sym->macro = string;
return sym;
}
/*
* Alter a SET symbols value
*/
struct Symbol *sym_AddSet(char const *symName, int32_t value)
{
struct Symbol *sym = findsymbol(symName, NULL);
if (sym == NULL) {
sym = createsymbol(symName);
} else if (sym_IsDefined(sym) && sym->type != SYM_SET) {
error("'%s' already defined as %s at ",
symName, sym->type == SYM_LABEL ? "label" : "constant");
dumpFilename(sym);
putc('\n', stderr);
} else {
/* TODO: can the scope be incorrect when taking over refs? */
updateSymbolFilename(sym);
}
sym->type = SYM_SET;
sym->value = value;
return sym;
}
/*
* Add a label (aka "relocatable symbol")
* @param name The label's full name (so `.name` is invalid)
* @return The created symbol
*/
static struct Symbol *addLabel(char const *name)
{
assert(name[0] != '.'); /* The symbol name must have been expanded prior */
struct Symbol *sym = findsymbol(name, NULL); /* Due to this, don't look for expansions */
if (!sym) {
sym = createsymbol(name);
} else if (sym_IsDefined(sym)) {
error("'%s' already defined at ", name);
dumpFilename(sym);
putc('\n', stderr);
return NULL;
} else {
updateSymbolFilename(sym);
}
/* If the symbol already exists as a ref, just "take over" it */
sym->type = SYM_LABEL;
sym->value = sect_GetSymbolOffset();
if (exportall)
sym->isExported = true;
sym->section = sect_GetSymbolSection();
if (sym && !sym->section)
error("Label \"%s\" created outside of a SECTION\n", name);
return sym;
}
/*
* Add a local (.name or Parent.name) relocatable symbol
*/
struct Symbol *sym_AddLocalLabel(char const *name)
{
if (!labelScope) {
error("Local label '%s' in main scope\n", name);
return NULL;
}
char fullname[MAXSYMLEN + 1];
if (name[0] == '.') {
/* If symbol is of the form `.name`, expand to the full `Parent.name` name */
fullSymbolName(fullname, sizeof(fullname), name, labelScope);
name = fullname; /* Use the expanded name instead */
} else {
size_t i = 0;
/* Otherwise, check that `Parent` is in fact the current scope */
while (labelScope[i] && name[i] == labelScope[i])
i++;
/* Assuming no dots in `labelScope` */
assert(strchr(&name[i], '.')); /* There should be at least one dot, though */
size_t parentLen = i + (strchr(&name[i], '.') - name);
/*
* Check that `labelScope[i]` ended the check, guaranteeing that `name` is at least
* as long, and then that this was the entirety of the `Parent` part of `name`.
*/
if (labelScope[i] != '\0' || name[i] != '.')
error("Not currently in the scope of '%.*s'\n", parentLen, name);
if (strchr(&name[parentLen + 1], '.')) /* There will at least be a terminator */
fatalerror("'%s' is a nonsensical reference to a nested local label\n",
name);
}
return addLabel(name);
}
/*
* Add a relocatable symbol
*/
struct Symbol *sym_AddLabel(char const *name)
{
struct Symbol *sym = addLabel(name);
/* Set the symbol as the new scope */
if (sym)
labelScope = sym->name;
return sym;
}
/*
* Export a symbol
*/
void sym_Export(char const *symName)
{
struct Symbol *sym = sym_FindSymbol(symName);
/* If the symbol doesn't exist, create a ref that can be purged */
if (!sym)
sym = sym_Ref(symName);
sym->isExported = true;
}
/*
* Add a macro definition
*/
struct Symbol *sym_AddMacro(char const *symName, int32_t defLineNo, char *body, size_t size)
{
struct Symbol *sym = createNonrelocSymbol(symName);
sym->type = SYM_MACRO;
sym->macroSize = size;
sym->macro = body;
setSymbolFilename(sym); /* TODO: is this really necessary? */
/*
* The symbol is created at the line after the `endm`,
* override this with the actual definition line
*/
sym->fileLine = defLineNo;
return sym;
}
/*
* Flag that a symbol is referenced in an RPN expression
* and create it if it doesn't exist yet
*/
struct Symbol *sym_Ref(char const *symName)
{
struct Symbol *nsym = sym_FindSymbol(symName);
if (nsym == NULL) {
char fullname[MAXSYMLEN + 1];
if (symName[0] == '.') {
if (!labelScope)
fatalerror("Local label reference '%s' in main scope\n", symName);
fullSymbolName(fullname, sizeof(fullname), symName, labelScope);
symName = fullname;
}
nsym = createsymbol(symName);
nsym->type = SYM_REF;
}
return nsym;
}
/*
* Set whether to export all relocatable symbols by default
*/
void sym_SetExportAll(bool set)
{
exportall = set;
}
/**
* Returns a pointer to the first non-zero character in a string
* Non-'0', not non-'\0'.
*/
static inline char const *removeLeadingZeros(char const *ptr)
{
while (*ptr == '0')
ptr++;
return ptr;
}
static inline struct Symbol *createBuiltinSymbol(char const *name)
{
struct Symbol *sym = createsymbol(name);
sym->isBuiltin = true;
sym->hasCallback = true;
sym->src = NULL;
sym->fileLine = 0;
return sym;
}
/*
* Initialize the symboltable
*/
void sym_Init(void)
{
PCSymbol = createBuiltinSymbol("@");
struct Symbol *_NARGSymbol = createBuiltinSymbol("_NARG");
struct Symbol *__LINE__Symbol = createBuiltinSymbol("__LINE__");
struct Symbol *__FILE__Symbol = createBuiltinSymbol("__FILE__");
PCSymbol->type = SYM_LABEL;
PCSymbol->section = NULL;
PCSymbol->numCallback = CallbackPC;
_NARGSymbol->type = SYM_EQU;
_NARGSymbol->numCallback = Callback_NARG;
__LINE__Symbol->type = SYM_EQU;
__LINE__Symbol->numCallback = Callback__LINE__;
__FILE__Symbol->type = SYM_EQUS;
__FILE__Symbol->strCallback = Callback__FILE__;
sym_AddSet("_RS", 0)->isBuiltin = true;
sym_AddEqu("__RGBDS_MAJOR__", PACKAGE_VERSION_MAJOR)->isBuiltin = true;
sym_AddEqu("__RGBDS_MINOR__", PACKAGE_VERSION_MINOR)->isBuiltin = true;
sym_AddEqu("__RGBDS_PATCH__", PACKAGE_VERSION_PATCH)->isBuiltin = true;
time_t now = time(NULL);
if (now == (time_t)-1) {
warn("Couldn't determine current time");
/* Fall back by pretending we are at the Epoch */
now = 0;
}
const struct tm *time_utc = gmtime(&now);
const 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), "\"%Y-%m-%dT%H:%M:%S%z\"",
time_local);
strftime(savedTIMESTAMP_ISO8601_UTC,
sizeof(savedTIMESTAMP_ISO8601_UTC), "\"%Y-%m-%dT%H:%M:%SZ\"",
time_utc);
strftime(savedYEAR, sizeof(savedYEAR), "%Y", time_utc);
strftime(savedMONTH, sizeof(savedMONTH), "%m", time_utc);
strftime(savedDAY, sizeof(savedDAY), "%d", time_utc);
strftime(savedHOUR, sizeof(savedHOUR), "%H", time_utc);
strftime(savedMINUTE, sizeof(savedMINUTE), "%M", time_utc);
strftime(savedSECOND, sizeof(savedSECOND), "%S", time_utc);
#define addString(name, val) sym_AddString(name, val)->isBuiltin = true
addString("__TIME__", savedTIME);
addString("__DATE__", savedDATE);
addString("__ISO_8601_LOCAL__", savedTIMESTAMP_ISO8601_LOCAL);
addString("__ISO_8601_UTC__", savedTIMESTAMP_ISO8601_UTC);
/* This cannot start with zeros */
addString("__UTC_YEAR__", savedYEAR);
addString("__UTC_MONTH__", removeLeadingZeros(savedMONTH));
addString("__UTC_DAY__", removeLeadingZeros(savedDAY));
addString("__UTC_HOUR__", removeLeadingZeros(savedHOUR));
addString("__UTC_MINUTE__", removeLeadingZeros(savedMINUTE));
addString("__UTC_SECOND__", removeLeadingZeros(savedSECOND));
#undef addString
labelScope = NULL;
math_DefinePI();
}