name : element_declarations.c /* Read an XML document from standard input and print element declarations (if any) to standard output. It must be used with Expat compiled for UTF-8 output. __ __ _ ___\ \/ /_ __ __ _| |_ / _ \\ /| '_ \ / _` | __| | __// \| |_) | (_| | |_ \___/_/\_\ .__/ \__,_|\__| |_| XML parser Copyright (c) 1997-2000 Thai Open Source Software Center Ltd Copyright (c) 2001-2003 Fred L. Drake, Jr. <fdrake@users.sourceforge.net> Copyright (c) 2004-2006 Karl Waclawek <karl@waclawek.net> Copyright (c) 2005-2007 Steven Solie <steven@solie.ca> Copyright (c) 2016-2024 Sebastian Pipping <sebastian@pipping.org> Copyright (c) 2017 Rhodri James <rhodri@wildebeest.org.uk> Copyright (c) 2019 Zhongyuan Zhou <zhouzhongyuan@huawei.com> Licensed under the MIT license: Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #include <stdbool.h> #include <stdio.h> #include <stdlib.h> #include <expat.h> #ifdef XML_LARGE_SIZE # define XML_FMT_INT_MOD "ll" #else # define XML_FMT_INT_MOD "l" #endif #ifdef XML_UNICODE_WCHAR_T # define XML_FMT_STR "ls" #else # define XML_FMT_STR "s" #endif // While traversing the XML_Content tree, we avoid recursion // to not be vulnerable to a denial of service attack. typedef struct StackStruct { const XML_Content *model; unsigned level; struct StackStruct *prev; } Stack; static Stack * stackPushMalloc(Stack *stackTop, const XML_Content *model, unsigned level) { Stack *const newStackTop = malloc(sizeof(Stack)); if (! newStackTop) { return NULL; } newStackTop->model = model; newStackTop->level = level; newStackTop->prev = stackTop; return newStackTop; } static Stack * stackPopFree(Stack *stackTop) { Stack *const newStackTop = stackTop->prev; free(stackTop); return newStackTop; } static char * contentTypeName(enum XML_Content_Type contentType) { switch (contentType) { case XML_CTYPE_EMPTY: return "EMPTY"; case XML_CTYPE_ANY: return "ANY"; case XML_CTYPE_MIXED: return "MIXED"; case XML_CTYPE_NAME: return "NAME"; case XML_CTYPE_CHOICE: return "CHOICE"; case XML_CTYPE_SEQ: return "SEQ"; default: return "???"; } } static char * contentQuantName(enum XML_Content_Quant contentQuant) { switch (contentQuant) { case XML_CQUANT_NONE: return "NONE"; case XML_CQUANT_OPT: return "OPT"; case XML_CQUANT_REP: return "REP"; case XML_CQUANT_PLUS: return "PLUS"; default: return "???"; } } static void dumpContentModelElement(const XML_Content *model, unsigned level, const XML_Content *root) { // Indent unsigned u = 0; for (; u < level; u++) { printf(" "); } // Node printf("[%u] type=%s(%d), quant=%s(%d)", (unsigned)(model - root), contentTypeName(model->type), model->type, contentQuantName(model->quant), model->quant); if (model->name) { printf(", name=\"%" XML_FMT_STR "\"", model->name); } else { printf(", name=NULL"); } printf(", numchildren=%d", model->numchildren); printf("\n"); } static bool dumpContentModel(const XML_Char *name, const XML_Content *root) { printf("Element \"%" XML_FMT_STR "\":\n", name); Stack *stackTop = stackPushMalloc(NULL, root, 1); if (! stackTop) { return false; } while (stackTop) { const XML_Content *const model = stackTop->model; const unsigned level = stackTop->level; dumpContentModelElement(model, level, root); stackTop = stackPopFree(stackTop); for (size_t u = model->numchildren; u >= 1; u--) { Stack *const newStackTop = stackPushMalloc(stackTop, model->children + (u - 1), level + 1); if (! newStackTop) { // We ran out of memory, so let's free all memory allocated // earlier in this function, to be leak-clean: while (stackTop != NULL) { stackTop = stackPopFree(stackTop); } return false; } stackTop = newStackTop; } } printf("\n"); return true; } static void XMLCALL handleElementDeclaration(void *userData, const XML_Char *name, XML_Content *model) { XML_Parser parser = (XML_Parser)userData; const bool success = dumpContentModel(name, model); XML_FreeContentModel(parser, model); if (! success) { XML_StopParser(parser, /* resumable= */ XML_FALSE); } } int main(void) { XML_Parser parser = XML_ParserCreate(NULL); int done; if (! parser) { fprintf(stderr, "Couldn't allocate memory for parser\n"); return 1; } XML_SetUserData(parser, parser); XML_SetElementDeclHandler(parser, handleElementDeclaration); do { void *const buf = XML_GetBuffer(parser, BUFSIZ); if (! buf) { fprintf(stderr, "Couldn't allocate memory for buffer\n"); XML_ParserFree(parser); return 1; } const size_t len = fread(buf, 1, BUFSIZ, stdin); if (ferror(stdin)) { fprintf(stderr, "Read error\n"); XML_ParserFree(parser); return 1; } done = feof(stdin); if (XML_ParseBuffer(parser, (int)len, done) == XML_STATUS_ERROR) { enum XML_Error errorCode = XML_GetErrorCode(parser); if (errorCode == XML_ERROR_ABORTED) { errorCode = XML_ERROR_NO_MEMORY; } fprintf(stderr, "Parse error at line %" XML_FMT_INT_MOD "u:\n%" XML_FMT_STR "\n", XML_GetCurrentLineNumber(parser), XML_ErrorString(errorCode)); XML_ParserFree(parser); return 1; } } while (! done); XML_ParserFree(parser); return 0; }