ref: 599ce757a1f644aba35d692cec68202944f7163f
dir: /src/link/object.c/
/* * This file is part of RGBDS. * * Copyright (c) 2019, Eldred Habert and RGBDS contributors. * * SPDX-License-Identifier: MIT */ #include <errno.h> #include <inttypes.h> #include <limits.h> #include <stdio.h> #include <stdint.h> #include <string.h> #include <stdlib.h> #include "link/assign.h" #include "link/main.h" #include "link/object.h" #include "link/patch.h" #include "link/sdas_obj.h" #include "link/section.h" #include "link/symbol.h" #include "error.h" #include "helpers.h" #include "linkdefs.h" static struct SymbolList { size_t nbSymbols; struct Symbol **symbolList; struct SymbolList *next; } *symbolLists; unsigned int nbObjFiles; static struct { struct FileStackNode *nodes; uint32_t nbNodes; } *nodes; static struct Assertion *assertions; // Helper functions for reading object files // Internal, DO NOT USE. // For helper wrapper macros defined below, such as `tryReadlong` #define tryRead(func, type, errval, var, file, ...) \ do { \ FILE *tmpFile = file; \ type tmpVal = func(tmpFile); \ /* TODO: maybe mark the condition as `unlikely`; how to do that portably? */ \ if (tmpVal == (errval)) { \ errx(__VA_ARGS__, feof(tmpFile) \ ? "Unexpected end of file" \ : strerror(errno)); \ } \ var = tmpVal; \ } while (0) /* * Reads an unsigned long (32-bit) value from a file. * @param file The file to read from. This will read 4 bytes from the file. * @return The value read, cast to a int64_t, or -1 on failure. */ static int64_t readlong(FILE *file) { uint32_t value = 0; // Read the little-endian value byte by byte for (uint8_t shift = 0; shift < sizeof(value) * CHAR_BIT; shift += 8) { int byte = getc(file); if (byte == EOF) return INT64_MAX; // This must be casted to `unsigned`, not `uint8_t`. Rationale: // the type of the shift is the type of `byte` after undergoing // integer promotion, which would be `int` if this was casted to // `uint8_t`, because int is large enough to hold a byte. This // however causes values larger than 127 to be too large when // shifted, potentially triggering undefined behavior. value |= (unsigned int)byte << shift; } return value; } /* * Helper macro for reading longs from a file, and errors out if it fails to. * Not as a function to avoid overhead in the general case. * @param var The variable to stash the number into * @param file The file to read from. Its position will be advanced * @param ... A format string and related arguments; note that an extra string * argument is provided, the reason for failure */ #define tryReadlong(var, file, ...) \ tryRead(readlong, int64_t, INT64_MAX, var, file, __VA_ARGS__) // There is no `readbyte`, just use `fgetc` or `getc`. /* * Helper macro for reading bytes from a file, and errors out if it fails to. * Differs from `tryGetc` in that the backing function is fgetc(1). * Not as a function to avoid overhead in the general case. * @param var The variable to stash the number into * @param file The file to read from. Its position will be advanced * @param ... A format string and related arguments; note that an extra string * argument is provided, the reason for failure */ #define tryFgetc(var, file, ...) \ tryRead(fgetc, int, EOF, var, file, __VA_ARGS__) /* * Helper macro for reading bytes from a file, and errors out if it fails to. * Differs from `tryGetc` in that the backing function is fgetc(1). * Not as a function to avoid overhead in the general case. * @param var The variable to stash the number into * @param file The file to read from. Its position will be advanced * @param ... A format string and related arguments; note that an extra string * argument is provided, the reason for failure */ #define tryGetc(var, file, ...) \ tryRead(getc, int, EOF, var, file, __VA_ARGS__) /* * Reads a '\0'-terminated string from a file. * @param file The file to read from. The file position will be advanced. * @return The string read, or NULL on failure. * If a non-NULL pointer is returned, make sure to `free` it when done! */ static char *readstr(FILE *file) { // Default buffer size, have it close to the average string length size_t capacity = 32 / 2; size_t index = -1; // Force the first iteration to allocate char *str = NULL; do { // Prepare going to next char index++; // If the buffer isn't suitable to write the next char... if (index >= capacity || !str) { capacity *= 2; str = realloc(str, capacity); // End now in case of error if (!str) return NULL; } // Read char int byte = getc(file); if (byte == EOF) { free(str); return NULL; } str[index] = byte; } while (str[index]); return str; } /* * Helper macro for reading bytes from a file, and errors out if it fails to. * Not as a function to avoid overhead in the general case. * @param var The variable to stash the string into * @param file The file to read from. Its position will be advanced * @param ... A format string and related arguments; note that an extra string * argument is provided, the reason for failure */ #define tryReadstr(var, file, ...) \ tryRead(readstr, char*, NULL, var, file, __VA_ARGS__) // Functions to parse object files /* * Reads a file stack node form a file. * @param file The file to read from * @param nodes The file's array of nodes * @param i The ID of the node in the array * @param fileName The filename to report in errors */ static void readFileStackNode(FILE *file, struct FileStackNode fileNodes[], uint32_t i, char const *fileName) { uint32_t parentID; tryReadlong(parentID, file, "%s: Cannot read node #%" PRIu32 "'s parent ID: %s", fileName, i); fileNodes[i].parent = parentID == (uint32_t)-1 ? NULL : &fileNodes[parentID]; tryReadlong(fileNodes[i].lineNo, file, "%s: Cannot read node #%" PRIu32 "'s line number: %s", fileName, i); tryGetc(fileNodes[i].type, file, "%s: Cannot read node #%" PRIu32 "'s type: %s", fileName, i); switch (fileNodes[i].type) { case NODE_FILE: case NODE_MACRO: tryReadstr(fileNodes[i].name, file, "%s: Cannot read node #%" PRIu32 "'s file name: %s", fileName, i); break; case NODE_REPT: tryReadlong(fileNodes[i].reptDepth, file, "%s: Cannot read node #%" PRIu32 "'s rept depth: %s", fileName, i); fileNodes[i].iters = malloc(sizeof(*fileNodes[i].iters) * fileNodes[i].reptDepth); if (!fileNodes[i].iters) fatal(NULL, 0, "%s: Failed to alloc node #%" PRIu32 "'s iters: %s", fileName, i, strerror(errno)); for (uint32_t k = 0; k < fileNodes[i].reptDepth; k++) tryReadlong(fileNodes[i].iters[k], file, "%s: Cannot read node #%" PRIu32 "'s iter #%" PRIu32 ": %s", fileName, i, k); if (!fileNodes[i].parent) fatal(NULL, 0, "%s is not a valid object file: root node (#%" PRIu32 ") may not be REPT", fileName, i); } } /* * Reads a symbol from a file. * @param file The file to read from * @param symbol The struct to fill * @param fileName The filename to report in errors */ static void readSymbol(FILE *file, struct Symbol *symbol, char const *fileName, struct FileStackNode fileNodes[]) { tryReadstr(symbol->name, file, "%s: Cannot read symbol name: %s", fileName); tryGetc(symbol->type, file, "%s: Cannot read \"%s\"'s type: %s", fileName, symbol->name); // If the symbol is defined in this file, read its definition if (symbol->type != SYMTYPE_IMPORT) { symbol->objFileName = fileName; uint32_t nodeID; tryReadlong(nodeID, file, "%s: Cannot read \"%s\"'s node ID: %s", fileName, symbol->name); symbol->src = &fileNodes[nodeID]; tryReadlong(symbol->lineNo, file, "%s: Cannot read \"%s\"'s line number: %s", fileName, symbol->name); tryReadlong(symbol->sectionID, file, "%s: Cannot read \"%s\"'s section ID: %s", fileName, symbol->name); tryReadlong(symbol->offset, file, "%s: Cannot read \"%s\"'s value: %s", fileName, symbol->name); } else { symbol->sectionID = -1; } } /* * Reads a patch from a file. * @param file The file to read from * @param patch The struct to fill * @param fileName The filename to report in errors * @param i The number of the patch to report in errors */ static void readPatch(FILE *file, struct Patch *patch, char const *fileName, char const *sectName, uint32_t i, struct FileStackNode fileNodes[]) { uint32_t nodeID; uint8_t type; tryReadlong(nodeID, file, "%s: Unable to read \"%s\"'s patch #%" PRIu32 "'s node ID: %s", fileName, sectName, i); patch->src = &fileNodes[nodeID]; tryReadlong(patch->lineNo, file, "%s: Unable to read \"%s\"'s patch #%" PRIu32 "'s line number: %s", fileName, sectName, i); tryReadlong(patch->offset, file, "%s: Unable to read \"%s\"'s patch #%" PRIu32 "'s offset: %s", fileName, sectName, i); tryReadlong(patch->pcSectionID, file, "%s: Unable to read \"%s\"'s patch #%" PRIu32 "'s PC offset: %s", fileName, sectName, i); tryReadlong(patch->pcOffset, file, "%s: Unable to read \"%s\"'s patch #%" PRIu32 "'s PC offset: %s", fileName, sectName, i); tryGetc(type, file, "%s: Unable to read \"%s\"'s patch #%" PRIu32 "'s type: %s", fileName, sectName, i); patch->type = type; tryReadlong(patch->rpnSize, file, "%s: Unable to read \"%s\"'s patch #%" PRIu32 "'s RPN size: %s", fileName, sectName, i); patch->rpnExpression = malloc(sizeof(*patch->rpnExpression) * patch->rpnSize); if (!patch->rpnExpression) err("%s: Failed to alloc \"%s\"'s patch #%" PRIu32 "'s RPN expression", fileName, sectName, i); size_t nbElementsRead = fread(patch->rpnExpression, sizeof(*patch->rpnExpression), patch->rpnSize, file); if (nbElementsRead != patch->rpnSize) errx("%s: Cannot read \"%s\"'s patch #%" PRIu32 "'s RPN expression: %s", fileName, sectName, i, feof(file) ? "Unexpected end of file" : strerror(errno)); } /* * Sets a patch's pcSection from its pcSectionID. * @param patch The struct to fix */ static void linkPatchToPCSect(struct Patch *patch, struct Section *fileSections[]) { patch->pcSection = patch->pcSectionID == (uint32_t)-1 ? NULL : fileSections[patch->pcSectionID]; } /* * Reads a section from a file. * @param file The file to read from * @param section The struct to fill * @param fileName The filename to report in errors */ static void readSection(FILE *file, struct Section *section, char const *fileName, struct FileStackNode fileNodes[]) { int32_t tmp; uint8_t byte; tryReadstr(section->name, file, "%s: Cannot read section name: %s", fileName); tryReadlong(tmp, file, "%s: Cannot read \"%s\"'s' size: %s", fileName, section->name); if (tmp < 0 || tmp > UINT16_MAX) errx("\"%s\"'s section size (%" PRId32 ") is invalid", section->name, tmp); section->size = tmp; section->offset = 0; tryGetc(byte, file, "%s: Cannot read \"%s\"'s type: %s", fileName, section->name); section->type = byte & 0x3F; if (byte >> 7) section->modifier = SECTION_UNION; else if (byte >> 6) section->modifier = SECTION_FRAGMENT; else section->modifier = SECTION_NORMAL; tryReadlong(tmp, file, "%s: Cannot read \"%s\"'s org: %s", fileName, section->name); section->isAddressFixed = tmp >= 0; if (tmp > UINT16_MAX) { error(NULL, 0, "\"%s\"'s org is too large (%" PRId32 ")", section->name, tmp); tmp = UINT16_MAX; } section->org = tmp; tryReadlong(tmp, file, "%s: Cannot read \"%s\"'s bank: %s", fileName, section->name); section->isBankFixed = tmp >= 0; section->bank = tmp; tryGetc(byte, file, "%s: Cannot read \"%s\"'s alignment: %s", fileName, section->name); if (byte > 16) byte = 16; section->isAlignFixed = byte != 0; section->alignMask = (1 << byte) - 1; tryReadlong(tmp, file, "%s: Cannot read \"%s\"'s alignment offset: %s", fileName, section->name); if (tmp > UINT16_MAX) { error(NULL, 0, "\"%s\"'s alignment offset is too large (%" PRId32 ")", section->name, tmp); tmp = UINT16_MAX; } section->alignOfs = tmp; if (sect_HasData(section->type)) { // Ensure we never allocate 0 bytes uint8_t *data = malloc(sizeof(*data) * section->size + 1); if (!data) err("%s: Unable to read \"%s\"'s data", fileName, section->name); if (section->size) { size_t nbElementsRead = fread(data, sizeof(*data), section->size, file); if (nbElementsRead != section->size) errx("%s: Cannot read \"%s\"'s data: %s", fileName, section->name, feof(file) ? "Unexpected end of file" : strerror(errno)); } section->data = data; tryReadlong(section->nbPatches, file, "%s: Cannot read \"%s\"'s number of patches: %s", fileName, section->name); struct Patch *patches = malloc(sizeof(*patches) * section->nbPatches + 1); if (!patches) err("%s: Unable to read \"%s\"'s patches", fileName, section->name); for (uint32_t i = 0; i < section->nbPatches; i++) readPatch(file, &patches[i], fileName, section->name, i, fileNodes); section->patches = patches; } else { section->data = NULL; // `mergeSections()` expects to be able to always read the ptr } } /* * Links a symbol to a section, keeping the section's symbol list sorted. * @param symbol The symbol to link * @param section The section to link */ static void linkSymToSect(struct Symbol *symbol, struct Section *section) { uint32_t a = 0, b = section->nbSymbols; while (a != b) { uint32_t c = (a + b) / 2; if (section->symbols[c]->offset > symbol->offset) b = c; else a = c + 1; } struct Symbol *tmp = symbol; for (uint32_t i = a; i <= section->nbSymbols; i++) { symbol = tmp; tmp = section->symbols[i]; section->symbols[i] = symbol; } section->nbSymbols++; } /* * Reads an assertion from a file * @param file The file to read from * @param assert The struct to fill * @param fileName The filename to report in errors */ static void readAssertion(FILE *file, struct Assertion *assert, char const *fileName, uint32_t i, struct FileStackNode fileNodes[]) { char assertName[sizeof("Assertion #4294967295")]; // UINT32_MAX snprintf(assertName, sizeof(assertName), "Assertion #%" PRIu32, i); readPatch(file, &assert->patch, fileName, assertName, 0, fileNodes); tryReadstr(assert->message, file, "%s: Cannot read assertion's message: %s", fileName); } static struct Section *getMainSection(struct Section *section) { if (section->modifier != SECTION_NORMAL) section = sect_GetSection(section->name); return section; } void obj_ReadFile(char const *fileName, unsigned int fileID) { FILE *file; if (strcmp("-", fileName) != 0) file = fopen(fileName, "rb"); else file = fdopen(STDIN_FILENO, "rb"); // `stdin` is in text mode by default if (!file) err("Could not open file %s", fileName); // First, check if the object is a RGBDS object or a SDCC one. If the first byte is 'R', // we'll assume it's a RGBDS object file, and otherwise, that it's a SDCC object file. int c = getc(file); ungetc(c, file); // Guaranteed to work switch (c) { case EOF: fatal(NULL, 0, "File \"%s\" is empty!", fileName); case 'R': break; default: // This is (probably) a SDCC object file, defer the rest of detection to it // Since SDCC does not provide line info, everything will be reported as coming from the // object file. It's better than nothing. nodes[fileID].nbNodes = 1; nodes[fileID].nodes = malloc(sizeof(nodes[fileID].nodes[0]) * nodes[fileID].nbNodes); if (!nodes[fileID].nodes) err("Failed to get memory for %s's nodes", fileName); struct FileStackNode *where = &nodes[fileID].nodes[0]; if (!where) fatal(NULL, 0, "Failed to alloc fstack node for \"%s\": %s", fileName, strerror(errno)); where->parent = NULL; where->type = NODE_FILE; where->name = strdup(fileName); if (!where->name) fatal(NULL, 0, "Failed to duplicate \"%s\"'s name: %s", fileName, strerror(errno)); sdobj_ReadFile(where, file); return; } // Begin by reading the magic bytes int matchedElems; if (fscanf(file, RGBDS_OBJECT_VERSION_STRING "%n", &matchedElems) == 1 && matchedElems != strlen(RGBDS_OBJECT_VERSION_STRING)) errx("\"%s\" is not a RGBDS object file", fileName); verbosePrint("Reading object file %s\n", fileName); uint32_t revNum; tryReadlong(revNum, file, "%s: Cannot read revision number: %s", fileName); if (revNum != RGBDS_OBJECT_REV) errx("%s is a revision 0x%04" PRIx32 " object file; only 0x%04x is supported", fileName, revNum, RGBDS_OBJECT_REV); uint32_t nbSymbols; uint32_t nbSections; tryReadlong(nbSymbols, file, "%s: Cannot read number of symbols: %s", fileName); tryReadlong(nbSections, file, "%s: Cannot read number of sections: %s", fileName); nbSectionsToAssign += nbSections; tryReadlong(nodes[fileID].nbNodes, file, "%s: Cannot read number of nodes: %s", fileName); nodes[fileID].nodes = calloc(nodes[fileID].nbNodes, sizeof(nodes[fileID].nodes[0])); if (!nodes[fileID].nodes) err("Failed to get memory for %s's nodes", fileName); verbosePrint("Reading %u nodes...\n", nodes[fileID].nbNodes); for (uint32_t i = nodes[fileID].nbNodes; i--; ) readFileStackNode(file, nodes[fileID].nodes, i, fileName); // This file's symbols, kept to link sections to them struct Symbol **fileSymbols = malloc(sizeof(*fileSymbols) * nbSymbols + 1); if (!fileSymbols) err("Failed to get memory for %s's symbols", fileName); struct SymbolList *symbolList = malloc(sizeof(*symbolList)); if (!symbolList) err("Failed to register %s's symbol list", fileName); symbolList->symbolList = fileSymbols; symbolList->nbSymbols = nbSymbols; symbolList->next = symbolLists; symbolLists = symbolList; uint32_t *nbSymPerSect = calloc(nbSections ? nbSections : 1, sizeof(*nbSymPerSect)); verbosePrint("Reading %" PRIu32 " symbols...\n", nbSymbols); for (uint32_t i = 0; i < nbSymbols; i++) { // Read symbol struct Symbol *symbol = malloc(sizeof(*symbol)); if (!symbol) err("%s: Couldn't create new symbol", fileName); readSymbol(file, symbol, fileName, nodes[fileID].nodes); fileSymbols[i] = symbol; if (symbol->type == SYMTYPE_EXPORT) sym_AddSymbol(symbol); if (symbol->sectionID != -1) nbSymPerSect[symbol->sectionID]++; } // This file's sections, stored in a table to link symbols to them struct Section **fileSections = malloc(sizeof(*fileSections) * (nbSections ? nbSections : 1)); verbosePrint("Reading %" PRIu32 " sections...\n", nbSections); for (uint32_t i = 0; i < nbSections; i++) { // Read section fileSections[i] = malloc(sizeof(*fileSections[i])); if (!fileSections[i]) err("%s: Couldn't create new section", fileName); fileSections[i]->nextu = NULL; readSection(file, fileSections[i], fileName, nodes[fileID].nodes); fileSections[i]->fileSymbols = fileSymbols; if (nbSymPerSect[i]) { fileSections[i]->symbols = malloc(nbSymPerSect[i] * sizeof(*fileSections[i]->symbols)); if (!fileSections[i]->symbols) err("%s: Couldn't link to symbols", fileName); } else { fileSections[i]->symbols = NULL; } fileSections[i]->nbSymbols = 0; sect_AddSection(fileSections[i]); } free(nbSymPerSect); // Give patches' PC section pointers to their sections for (uint32_t i = 0; i < nbSections; i++) { if (sect_HasData(fileSections[i]->type)) { for (uint32_t j = 0; j < fileSections[i]->nbPatches; j++) linkPatchToPCSect(&fileSections[i]->patches[j], fileSections); } } // Give symbols' section pointers to their sections for (uint32_t i = 0; i < nbSymbols; i++) { int32_t sectionID = fileSymbols[i]->sectionID; if (sectionID == -1) { fileSymbols[i]->section = NULL; } else { struct Section *section = fileSections[sectionID]; // Give the section a pointer to the symbol as well linkSymToSect(fileSymbols[i], section); if (section->modifier != SECTION_NORMAL) { if (section->modifier == SECTION_FRAGMENT) // Add the fragment's offset to the symbol's fileSymbols[i]->offset += section->offset; section = getMainSection(section); } fileSymbols[i]->section = section; } } uint32_t nbAsserts; tryReadlong(nbAsserts, file, "%s: Cannot read number of assertions: %s", fileName); verbosePrint("Reading %" PRIu32 " assertions...\n", nbAsserts); for (uint32_t i = 0; i < nbAsserts; i++) { struct Assertion *assertion = malloc(sizeof(*assertion)); if (!assertion) err("%s: Couldn't create new assertion", fileName); readAssertion(file, assertion, fileName, i, nodes[fileID].nodes); linkPatchToPCSect(&assertion->patch, fileSections); assertion->fileSymbols = fileSymbols; assertion->next = assertions; assertions = assertion; } free(fileSections); fclose(file); } void obj_DoSanityChecks(void) { sect_DoSanityChecks(); } void obj_CheckAssertions(void) { patch_CheckAssertions(assertions); } void obj_Setup(unsigned int nbFiles) { nbObjFiles = nbFiles; if (nbFiles > SIZE_MAX / sizeof(*nodes)) fatal(NULL, 0, "Impossible to link more than %zu files!", SIZE_MAX / sizeof(*nodes)); nodes = malloc(sizeof(*nodes) * nbFiles); } static void freeNode(struct FileStackNode *node) { if (node->type == NODE_REPT) free(node->iters); else free(node->name); } static void freeSection(struct Section *section, void *arg) { (void)arg; do { struct Section *next = section->nextu; free(section->name); if (sect_HasData(section->type)) { free(section->data); for (uint32_t i = 0; i < section->nbPatches; i++) free(section->patches[i].rpnExpression); free(section->patches); } free(section->symbols); free(section); section = next; } while (section); } static void freeSymbol(struct Symbol *symbol) { free(symbol->name); free(symbol); } void obj_Cleanup(void) { for (unsigned int i = 0; i < nbObjFiles; i++) { for (uint32_t j = 0; j < nodes[i].nbNodes; j++) { freeNode(&nodes[i].nodes[j]); } free(nodes[i].nodes); } free(nodes); sym_CleanupSymbols(); sect_ForEach(freeSection, NULL); sect_CleanupSections(); for (struct SymbolList *list = symbolLists, *next; list; list = next) { next = list->next; for (size_t i = 0; i < list->nbSymbols; i++) freeSymbol(list->symbolList[i]); free(list->symbolList); free(list); } }