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+/*
+ * clippy (CLI preparator in python) C pseudo-lexer
+ * Copyright (C) 2016-2017 David Lamparter for NetDEF, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/* This is just enough of a lexer to make rough sense of a C source file.
+ * It handles C preprocessor directives, strings, and looks for FRR-specific
+ * idioms (aka DEFUN).
+ *
+ * There is some preliminary support for documentation comments for DEFUNs.
+ * They would look like this (note the ~): (replace \ by /)
+ *
+ * \*~ documentation for foobar_cmd
+ * * parameter does xyz
+ * *\
+ * DEFUN(foobar_cmd, ...)
+ *
+ * This is intended for user documentation / command reference. Don't put
+ * code documentation in it.
+ */
+
+%top{
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+}
+%{
+/* ignore harmless bugs in old versions of flex */
+#pragma GCC diagnostic ignored "-Wsign-compare"
+#pragma GCC diagnostic ignored "-Wunused-value"
+
+#include "config.h"
+#include <Python.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "command_graph.h"
+#include "clippy.h"
+
+#define ID 258
+#define PREPROC 259
+#define OPERATOR 260
+#define STRING 261
+#define COMMENT 262
+#define SPECIAL 263
+
+#define DEFUNNY 270
+#define INSTALL 271
+#define AUXILIARY 272
+
+int comment_link;
+char string_end;
+
+char *value;
+
+static void extendbuf(char **what, const char *arg)
+{
+ if (!*what)
+ *what = strdup(arg);
+ else {
+ size_t vall = strlen(*what), argl = strlen(arg);
+ *what = realloc(*what, vall + argl + 1);
+ memcpy(*what + vall, arg, argl);
+ (*what)[vall + argl] = '\0';
+ }
+}
+#define extend(x) extendbuf(&value, x)
+
+#ifndef __clang_analyzer__
+
+%}
+
+ID [A-Za-z0-9_]+
+OPERATOR [!%&/\[\]{}=?:^|\*.;><~'\\+-]
+SPECIAL [(),]
+
+%pointer
+%option yylineno
+%option noyywrap
+%option noinput
+%option nounput
+%option outfile="lib/defun_lex.c"
+%option prefix="def_yy"
+%option 8bit
+
+%s linestart
+%x comment
+%x linecomment
+%x preproc
+%x rstring
+%%
+ BEGIN(linestart);
+
+\n BEGIN(linestart);
+
+<INITIAL,linestart,preproc>"/*" comment_link = YY_START; extend(yytext); BEGIN(comment);
+<comment>[^*\n]* extend(yytext);
+<comment>"*"+[^*/\n]* extend(yytext);
+<comment>\n extend(yytext);
+<comment>"*"+"/" extend(yytext); BEGIN(comment_link); return COMMENT;
+
+<INITIAL,linestart,preproc>"//" comment_link = YY_START; extend(yytext); BEGIN(linecomment);
+<linecomment>[^\n]* extend(yytext);
+<linecomment>\n BEGIN((comment_link == INITIAL) ? linestart : comment_link); return COMMENT;
+
+<linestart># BEGIN(preproc);
+<preproc>\n BEGIN(INITIAL); return PREPROC;
+<preproc>[^\n\\]+ extend(yytext);
+<preproc>\\\n extend(yytext);
+<preproc>\\+[^\n] extend(yytext);
+
+[\"\'] string_end = yytext[0]; extend(yytext); BEGIN(rstring);
+<rstring>[\"\'] {
+ extend(yytext);
+ if (yytext[0] == string_end) {
+ BEGIN(INITIAL);
+ return STRING;
+ }
+ }
+<rstring>\\\n /* ignore */
+<rstring>\\. extend(yytext);
+<rstring>[^\\\"\']+ extend(yytext);
+
+"DEFUN" value = strdup(yytext); return DEFUNNY;
+"DEFUN_NOSH" value = strdup(yytext); return DEFUNNY;
+"DEFUN_HIDDEN" value = strdup(yytext); return DEFUNNY;
+"DEFPY" value = strdup(yytext); return DEFUNNY;
+"DEFPY_NOSH" value = strdup(yytext); return DEFUNNY;
+"DEFPY_ATTR" value = strdup(yytext); return DEFUNNY;
+"DEFPY_HIDDEN" value = strdup(yytext); return DEFUNNY;
+"DEFPY_YANG" value = strdup(yytext); return DEFUNNY;
+"DEFPY_YANG_NOSH" value = strdup(yytext); return DEFUNNY;
+"ALIAS" value = strdup(yytext); return DEFUNNY;
+"ALIAS_HIDDEN" value = strdup(yytext); return DEFUNNY;
+"install_element" value = strdup(yytext); return INSTALL;
+"VTYSH_TARGETS" value = strdup(yytext); return AUXILIARY;
+"VTYSH_NODESWITCH" value = strdup(yytext); return AUXILIARY;
+
+[ \t\n]+ /* ignore */
+\\ /* ignore */
+{ID} BEGIN(INITIAL); value = strdup(yytext); return ID;
+{OPERATOR} BEGIN(INITIAL); value = strdup(yytext); return OPERATOR;
+{SPECIAL} BEGIN(INITIAL); value = strdup(yytext); return SPECIAL;
+. /* printf("-- '%s' in init\n", yytext); */ BEGIN(INITIAL); return yytext[0];
+
+%%
+
+#endif /* __clang_analyzer__ */
+
+static int yylex_clr(char **retbuf)
+{
+ int rv = def_yylex();
+ *retbuf = value;
+ value = NULL;
+ return rv;
+}
+
+static PyObject *get_args(const char *filename, int lineno)
+{
+ PyObject *pyObj = PyList_New(0);
+ PyObject *pyArg = NULL;
+
+ char *tval;
+ int depth = 1;
+ int token;
+
+ while ((token = yylex_clr(&tval)) != YY_NULL) {
+ if (token == SPECIAL && tval[0] == '(') {
+ free(tval);
+ break;
+ }
+ if (token == COMMENT) {
+ free(tval);
+ continue;
+ }
+ fprintf(stderr, "invalid input!\n");
+ exit(1);
+ }
+
+ while ((token = yylex_clr(&tval)) != YY_NULL) {
+ if (token == COMMENT) {
+ free(tval);
+ continue;
+ }
+ if (token == PREPROC) {
+ free(tval);
+ Py_DECREF(pyObj);
+ return PyErr_Format(PyExc_ValueError,
+ "%s:%d: cannot process CPP directive within argument list",
+ filename, lineno);
+ }
+ if (token == SPECIAL) {
+ if (depth == 1 && (tval[0] == ',' || tval[0] == ')')) {
+ if (pyArg)
+ PyList_Append(pyObj, pyArg);
+ pyArg = NULL;
+ if (tval[0] == ')') {
+ free(tval);
+ break;
+ }
+ free(tval);
+ continue;
+ }
+ if (tval[0] == '(')
+ depth++;
+ if (tval[0] == ')')
+ depth--;
+ }
+ if (!pyArg)
+ pyArg = PyList_New(0);
+ PyList_Append(pyArg, PyUnicode_FromString(tval));
+ free(tval);
+ }
+ return pyObj;
+}
+
+/* _clippy.parse() -- read a C file, returning a list of interesting bits.
+ * note this ditches most of the actual C code. */
+PyObject *clippy_parse(PyObject *self, PyObject *args)
+{
+ const char *filename;
+ if (!PyArg_ParseTuple(args, "s", &filename))
+ return NULL;
+
+ FILE *fd = fopen(filename, "r");
+ if (!fd)
+ return PyErr_SetFromErrnoWithFilename(PyExc_IOError, filename);
+
+ char *tval;
+ int token;
+ yyin = fd;
+ value = NULL;
+
+ PyObject *pyCont = PyDict_New();
+ PyObject *pyObj = PyList_New(0);
+ PyDict_SetItemString(pyCont, "filename", PyUnicode_FromString(filename));
+ PyDict_SetItemString(pyCont, "data", pyObj);
+
+ while ((token = yylex_clr(&tval)) != YY_NULL) {
+ int lineno = yylineno;
+ PyObject *pyItem = NULL, *pyArgs;
+ switch (token) {
+ case DEFUNNY:
+ case INSTALL:
+ case AUXILIARY:
+ pyArgs = get_args(filename, lineno);
+ if (!pyArgs) {
+ free(tval);
+ Py_DECREF(pyCont);
+ return NULL;
+ }
+ pyItem = PyDict_New();
+ PyDict_SetItemString(pyItem, "type", PyUnicode_FromString(tval));
+ PyDict_SetItemString(pyItem, "args", pyArgs);
+ break;
+ case COMMENT:
+ if (strncmp(tval, "//~", 3) && strncmp(tval, "/*~", 3))
+ break;
+ pyItem = PyDict_New();
+ PyDict_SetItemString(pyItem, "type", PyUnicode_FromString("COMMENT"));
+ PyDict_SetItemString(pyItem, "line", PyUnicode_FromString(tval));
+ break;
+ case PREPROC:
+ pyItem = PyDict_New();
+ PyDict_SetItemString(pyItem, "type", PyUnicode_FromString("PREPROC"));
+ PyDict_SetItemString(pyItem, "line", PyUnicode_FromString(tval));
+ lineno--;
+ break;
+ }
+ if (pyItem) {
+ PyDict_SetItemString(pyItem, "lineno", PyLong_FromLong(lineno));
+ PyList_Append(pyObj, pyItem);
+ }
+ free(tval);
+ }
+ def_yylex_destroy();
+ fclose(fd);
+ return pyCont;
+}
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