ref: 459773b3f0b26144e3756d9e510cca10f846ef15
dir: /src/asm/output.c/
/* * This file is part of RGBDS. * * Copyright (c) 1997-2019, Carsten Sorensen and RGBDS contributors. * * SPDX-License-Identifier: MIT */ /* * Outputs an objectfile */ #include <assert.h> #include <errno.h> #include <inttypes.h> #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include "asm/charmap.h" #include "asm/fstack.h" #include "asm/main.h" #include "asm/output.h" #include "asm/rpn.h" #include "asm/section.h" #include "asm/symbol.h" #include "asm/warning.h" #include "extern/err.h" #include "linkdefs.h" #include "platform.h" // strdup struct Patch { struct FileStackNode const *src; uint32_t lineNo; uint32_t offset; struct Section *pcSection; uint32_t pcOffset; uint8_t type; uint32_t rpnSize; uint8_t *rpn; struct Patch *next; }; struct Assertion { struct Patch *patch; struct Section *section; char *message; struct Assertion *next; }; char *objectName; /* TODO: shouldn't `currentSection` be somewhere else? */ struct Section *sectionList, *currentSection; /* Linked list of symbols to put in the object file */ static struct Symbol *objectSymbols = NULL; static struct Symbol **objectSymbolsTail = &objectSymbols; static uint32_t nbSymbols = 0; /* Length of the above list */ static struct Assertion *assertions = NULL; static struct FileStackNode *fileStackNodes = NULL; /* * Count the number of sections used in this object */ static uint32_t countSections(void) { uint32_t count = 0; for (struct Section const *sect = sectionList; sect; sect = sect->next) count++; return count; } /* * Count the number of patches used in this object */ static uint32_t countPatches(struct Section const *sect) { uint32_t r = 0; for (struct Patch const *patch = sect->patches; patch != NULL; patch = patch->next) r++; return r; } /** * Count the number of assertions used in this object */ static uint32_t countAsserts(void) { struct Assertion *assert = assertions; uint32_t count = 0; while (assert) { count++; assert = assert->next; } return count; } /* * Write a long to a file (little-endian) */ static void putlong(uint32_t i, FILE *f) { putc(i, f); putc(i >> 8, f); putc(i >> 16, f); putc(i >> 24, f); } /* * Write a NULL-terminated string to a file */ static void putstring(char const *s, FILE *f) { while (*s) putc(*s++, f); putc(0, f); } static uint32_t getNbFileStackNodes(void) { return fileStackNodes ? fileStackNodes->ID + 1 : 0; } void out_RegisterNode(struct FileStackNode *node) { /* If node is not already registered, register it (and parents), and give it a unique ID */ while (node->ID == (uint32_t)-1) { node->ID = getNbFileStackNodes(); if (node->ID == (uint32_t)-1) fatalerror("Reached too many file stack nodes; try splitting the file up\n"); node->next = fileStackNodes; fileStackNodes = node; /* Also register the node's parents */ node = node->parent; if (!node) break; } } void out_ReplaceNode(struct FileStackNode *node) { (void)node; #if 0 This is code intended to replace a node, which is pretty useless until ref counting is added... struct FileStackNode **ptr = &fileStackNodes; /* * The linked list is supposed to have decrementing IDs, so iterate with less memory reads, * to hopefully hit the cache less. A debug check is added after, in case a change is made * that breaks this assumption. */ for (uint32_t i = fileStackNodes->ID; i != node->ID; i--) ptr = &(*ptr)->next; assert((*ptr)->ID == node->ID); node->next = (*ptr)->next; assert(!node->next || node->next->ID == node->ID - 1); /* Catch inconsistencies early */ /* TODO: unreference the node */ *ptr = node; #endif } /* * Return a section's ID */ static uint32_t getsectid(struct Section const *sect) { struct Section const *sec = sectionList; uint32_t ID = 0; while (sec) { if (sec == sect) return ID; ID++; sec = sec->next; } fatalerror("Unknown section '%s'\n", sect->name); } static uint32_t getSectIDIfAny(struct Section const *sect) { return sect ? getsectid(sect) : -1; } /* * Write a patch to a file */ static void writepatch(struct Patch const *patch, FILE *f) { assert(patch->src->ID != -1); putlong(patch->src->ID, f); putlong(patch->lineNo, f); putlong(patch->offset, f); putlong(getSectIDIfAny(patch->pcSection), f); putlong(patch->pcOffset, f); putc(patch->type, f); putlong(patch->rpnSize, f); fwrite(patch->rpn, 1, patch->rpnSize, f); } /* * Write a section to a file */ static void writesection(struct Section const *sect, FILE *f) { putstring(sect->name, f); putlong(sect->size, f); bool isUnion = sect->modifier == SECTION_UNION; bool isFragment = sect->modifier == SECTION_FRAGMENT; putc(sect->type | isUnion << 7 | isFragment << 6, f); putlong(sect->org, f); putlong(sect->bank, f); putc(sect->align, f); putlong(sect->alignOfs, f); if (sect_HasData(sect->type)) { fwrite(sect->data, 1, sect->size, f); putlong(countPatches(sect), f); for (struct Patch const *patch = sect->patches; patch != NULL; patch = patch->next) writepatch(patch, f); } } /* * Write a symbol to a file */ static void writesymbol(struct Symbol const *sym, FILE *f) { putstring(sym->name, f); if (!sym_IsDefined(sym)) { putc(SYMTYPE_IMPORT, f); } else { assert(sym->src->ID != -1); putc(sym->isExported ? SYMTYPE_EXPORT : SYMTYPE_LOCAL, f); putlong(sym->src->ID, f); putlong(sym->fileLine, f); putlong(getSectIDIfAny(sym_GetSection(sym)), f); putlong(sym->value, f); } } static void registerSymbol(struct Symbol *sym) { *objectSymbolsTail = sym; objectSymbolsTail = &sym->next; out_RegisterNode(sym->src); if (nbSymbols == (uint32_t)-1) fatalerror("Registered too many symbols (%" PRIu32 "); try splitting up your files\n", (uint32_t)-1); sym->ID = nbSymbols++; } /* * Returns a symbol's ID within the object file * If the symbol does not have one, one is assigned by registering the symbol */ static uint32_t getSymbolID(struct Symbol *sym) { if (sym->ID == (uint32_t)-1 && !sym_IsPC(sym)) registerSymbol(sym); return sym->ID; } static void writerpn(uint8_t *rpnexpr, uint32_t *rpnptr, uint8_t *rpn, uint32_t rpnlen) { char symName[512]; for (size_t offset = 0; offset < rpnlen; ) { #define popbyte() rpn[offset++] #define writebyte(byte) rpnexpr[(*rpnptr)++] = byte uint8_t rpndata = popbyte(); switch (rpndata) { struct Symbol *sym; uint32_t value; uint8_t b; size_t i; case RPN_CONST: writebyte(RPN_CONST); writebyte(popbyte()); writebyte(popbyte()); writebyte(popbyte()); writebyte(popbyte()); break; case RPN_SYM: i = 0; do { symName[i] = popbyte(); } while (symName[i++]); // The symbol name is always written expanded sym = sym_FindExactSymbol(symName); if (sym_IsConstant(sym)) { writebyte(RPN_CONST); value = sym_GetConstantValue(symName); } else { writebyte(RPN_SYM); value = getSymbolID(sym); } writebyte(value & 0xFF); writebyte(value >> 8); writebyte(value >> 16); writebyte(value >> 24); break; case RPN_BANK_SYM: i = 0; do { symName[i] = popbyte(); } while (symName[i++]); // The symbol name is always written expanded sym = sym_FindExactSymbol(symName); value = getSymbolID(sym); writebyte(RPN_BANK_SYM); writebyte(value & 0xFF); writebyte(value >> 8); writebyte(value >> 16); writebyte(value >> 24); break; case RPN_BANK_SECT: writebyte(RPN_BANK_SECT); do { b = popbyte(); writebyte(b); } while (b != 0); break; case RPN_SIZEOF_SECT: writebyte(RPN_SIZEOF_SECT); do { b = popbyte(); writebyte(b); } while (b != 0); break; case RPN_STARTOF_SECT: writebyte(RPN_STARTOF_SECT); do { b = popbyte(); writebyte(b); } while (b != 0); break; default: writebyte(rpndata); break; } #undef popbyte #undef writebyte } } /* * Allocate a new patch structure and link it into the list * WARNING: all patches are assumed to eventually be written, so the file stack node is registered */ static struct Patch *allocpatch(uint32_t type, struct Expression const *expr, uint32_t ofs) { struct Patch *patch = malloc(sizeof(struct Patch)); uint32_t rpnSize = expr->isKnown ? 5 : expr->rpnPatchSize; struct FileStackNode *node = fstk_GetFileStack(); if (!patch) fatalerror("No memory for patch: %s\n", strerror(errno)); patch->rpn = malloc(sizeof(*patch->rpn) * rpnSize); if (!patch->rpn) fatalerror("No memory for patch's RPN rpnSize: %s\n", strerror(errno)); patch->type = type; patch->src = node; out_RegisterNode(node); patch->lineNo = lexer_GetLineNo(); patch->offset = ofs; patch->pcSection = sect_GetSymbolSection(); patch->pcOffset = sect_GetSymbolOffset(); /* If the rpnSize's value is known, output a constant RPN rpnSize directly */ if (expr->isKnown) { patch->rpnSize = rpnSize; /* Make sure to update `rpnSize` above if modifying this! */ patch->rpn[0] = RPN_CONST; patch->rpn[1] = (uint32_t)(expr->val) & 0xFF; patch->rpn[2] = (uint32_t)(expr->val) >> 8; patch->rpn[3] = (uint32_t)(expr->val) >> 16; patch->rpn[4] = (uint32_t)(expr->val) >> 24; } else { patch->rpnSize = 0; writerpn(patch->rpn, &patch->rpnSize, expr->rpn, expr->rpnLength); } assert(patch->rpnSize == rpnSize); return patch; } /* * Create a new patch (includes the rpn expr) */ void out_CreatePatch(uint32_t type, struct Expression const *expr, uint32_t ofs, uint32_t pcShift) { struct Patch *patch = allocpatch(type, expr, ofs); // If the patch had a quantity of bytes output before it, // PC is not at the patch's location, but at the location // before those bytes. patch->pcOffset -= pcShift; patch->next = currentSection->patches; currentSection->patches = patch; } /** * Creates an assert that will be written to the object file */ bool out_CreateAssert(enum AssertionType type, struct Expression const *expr, char const *message, uint32_t ofs) { struct Assertion *assertion = malloc(sizeof(*assertion)); if (!assertion) return false; assertion->patch = allocpatch(type, expr, ofs); assertion->message = strdup(message); if (!assertion->message) { free(assertion); return false; } assertion->next = assertions; assertions = assertion; return true; } static void writeassert(struct Assertion *assert, FILE *f) { writepatch(assert->patch, f); putstring(assert->message, f); } static void writeFileStackNode(struct FileStackNode const *node, FILE *f) { putlong(node->parent ? node->parent->ID : -1, f); putlong(node->lineNo, f); putc(node->type, f); if (node->type != NODE_REPT) { putstring(((struct FileStackNamedNode const *)node)->name, f); } else { struct FileStackReptNode const *reptNode = (struct FileStackReptNode const *)node; putlong(reptNode->reptDepth, f); /* Iters are stored by decreasing depth, so reverse the order for output */ for (uint32_t i = reptNode->reptDepth; i--; ) putlong(reptNode->iters[i], f); } } static void registerUnregisteredSymbol(struct Symbol *symbol, void *arg) { (void)arg; // sym_ForEach requires a void* parameter, but we are not using it. // Check for symbol->src, to skip any built-in symbol from rgbasm if (symbol->src && symbol->ID == (uint32_t)-1) { registerSymbol(symbol); } } /* * Write an objectfile */ void out_WriteObject(void) { FILE *f; if (strcmp(objectName, "-") != 0) f = fopen(objectName, "wb"); else f = fdopen(1, "wb"); if (!f) err(1, "Couldn't write file '%s'", objectName); /* Also write symbols that weren't written above */ sym_ForEach(registerUnregisteredSymbol, NULL); fprintf(f, RGBDS_OBJECT_VERSION_STRING, RGBDS_OBJECT_VERSION_NUMBER); putlong(RGBDS_OBJECT_REV, f); putlong(nbSymbols, f); putlong(countSections(), f); putlong(getNbFileStackNodes(), f); for (struct FileStackNode const *node = fileStackNodes; node; node = node->next) { writeFileStackNode(node, f); if (node->next && node->next->ID != node->ID - 1) fatalerror("Internal error: fstack node #%" PRIu32 " follows #%" PRIu32 ". Please report this to the developers!\n", node->next->ID, node->ID); } for (struct Symbol const *sym = objectSymbols; sym; sym = sym->next) writesymbol(sym, f); for (struct Section *sect = sectionList; sect; sect = sect->next) writesection(sect, f); putlong(countAsserts(), f); for (struct Assertion *assert = assertions; assert; assert = assert->next) writeassert(assert, f); fclose(f); } /* * Set the objectfilename */ void out_SetFileName(char *s) { objectName = s; if (verbose) printf("Output filename %s\n", s); }