1/*
2 *	docproc is a simple preprocessor for the template files
3 *      used as placeholders for the kernel internal documentation.
4 *	docproc is used for documentation-frontend and
5 *      dependency-generator.
6 *	The two usages have in common that they require
7 *	some knowledge of the .tmpl syntax, therefore they
8 *	are kept together.
9 *
10 *	documentation-frontend
11 *		Scans the template file and call kernel-doc for
12 *		all occurrences of ![EIF]file
13 *		Beforehand each referenced file is scanned for
14 *		any symbols that are exported via these macros:
15 *			EXPORT_SYMBOL(), EXPORT_SYMBOL_GPL(), &
16 *			EXPORT_SYMBOL_GPL_FUTURE()
17 *		This is used to create proper -function and
18 *		-nofunction arguments in calls to kernel-doc.
19 *		Usage: docproc doc file.tmpl
20 *
21 *	dependency-generator:
22 *		Scans the template file and list all files
23 *		referenced in a format recognized by make.
24 *		Usage:	docproc depend file.tmpl
25 *		Writes dependency information to stdout
26 *		in the following format:
27 *		file.tmpl src.c	src2.c
28 *		The filenames are obtained from the following constructs:
29 *		!Efilename
30 *		!Ifilename
31 *		!Dfilename
32 *		!Ffilename
33 *		!Pfilename
34 *
35 */
36
37#define _GNU_SOURCE
38#include <stdio.h>
39#include <stdlib.h>
40#include <string.h>
41#include <ctype.h>
42#include <unistd.h>
43#include <limits.h>
44#include <errno.h>
45#include <sys/types.h>
46#include <sys/wait.h>
47
48/* exitstatus is used to keep track of any failing calls to kernel-doc,
49 * but execution continues. */
50int exitstatus = 0;
51
52typedef void DFL(char *);
53DFL *defaultline;
54
55typedef void FILEONLY(char * file);
56FILEONLY *internalfunctions;
57FILEONLY *externalfunctions;
58FILEONLY *symbolsonly;
59FILEONLY *findall;
60
61typedef void FILELINE(char * file, char * line);
62FILELINE * singlefunctions;
63FILELINE * entity_system;
64FILELINE * docsection;
65
66#define MAXLINESZ     2048
67#define MAXFILES      250
68#define KERNELDOCPATH "scripts/"
69#define KERNELDOC     "kernel-doc"
70#define DOCBOOK       "-docbook"
71#define LIST          "-list"
72#define FUNCTION      "-function"
73#define NOFUNCTION    "-nofunction"
74#define NODOCSECTIONS "-no-doc-sections"
75
76static char *srctree, *kernsrctree;
77
78static char **all_list = NULL;
79static int all_list_len = 0;
80
81static void consume_symbol(const char *sym)
82{
83	int i;
84
85	for (i = 0; i < all_list_len; i++) {
86		if (!all_list[i])
87			continue;
88		if (strcmp(sym, all_list[i]))
89			continue;
90		all_list[i] = NULL;
91		break;
92	}
93}
94
95static void usage (void)
96{
97	fprintf(stderr, "Usage: docproc {doc|depend} file\n");
98	fprintf(stderr, "Input is read from file.tmpl. Output is sent to stdout\n");
99	fprintf(stderr, "doc: frontend when generating kernel documentation\n");
100	fprintf(stderr, "depend: generate list of files referenced within file\n");
101	fprintf(stderr, "Environment variable SRCTREE: absolute path to sources.\n");
102	fprintf(stderr, "                     KBUILD_SRC: absolute path to kernel source tree.\n");
103}
104
105/*
106 * Execute kernel-doc with parameters given in svec
107 */
108static void exec_kernel_doc(char **svec)
109{
110	pid_t pid;
111	int ret;
112	char real_filename[PATH_MAX + 1];
113	/* Make sure output generated so far are flushed */
114	fflush(stdout);
115	switch (pid=fork()) {
116		case -1:
117			perror("fork");
118			exit(1);
119		case  0:
120			memset(real_filename, 0, sizeof(real_filename));
121			strncat(real_filename, kernsrctree, PATH_MAX);
122			strncat(real_filename, "/" KERNELDOCPATH KERNELDOC,
123					PATH_MAX - strlen(real_filename));
124			execvp(real_filename, svec);
125			fprintf(stderr, "exec ");
126			perror(real_filename);
127			exit(1);
128		default:
129			waitpid(pid, &ret ,0);
130	}
131	if (WIFEXITED(ret))
132		exitstatus |= WEXITSTATUS(ret);
133	else
134		exitstatus = 0xff;
135}
136
137/* Types used to create list of all exported symbols in a number of files */
138struct symbols
139{
140	char *name;
141};
142
143struct symfile
144{
145	char *filename;
146	struct symbols *symbollist;
147	int symbolcnt;
148};
149
150struct symfile symfilelist[MAXFILES];
151int symfilecnt = 0;
152
153static void add_new_symbol(struct symfile *sym, char * symname)
154{
155	sym->symbollist =
156          realloc(sym->symbollist, (sym->symbolcnt + 1) * sizeof(char *));
157	sym->symbollist[sym->symbolcnt++].name = strdup(symname);
158}
159
160/* Add a filename to the list */
161static struct symfile * add_new_file(char * filename)
162{
163	symfilelist[symfilecnt++].filename = strdup(filename);
164	return &symfilelist[symfilecnt - 1];
165}
166
167/* Check if file already are present in the list */
168static struct symfile * filename_exist(char * filename)
169{
170	int i;
171	for (i=0; i < symfilecnt; i++)
172		if (strcmp(symfilelist[i].filename, filename) == 0)
173			return &symfilelist[i];
174	return NULL;
175}
176
177/*
178 * List all files referenced within the template file.
179 * Files are separated by tabs.
180 */
181static void adddep(char * file)		   { printf("\t%s", file); }
182static void adddep2(char * file, char * line)     { line = line; adddep(file); }
183static void noaction(char * line)		   { line = line; }
184static void noaction2(char * file, char * line)   { file = file; line = line; }
185
186/* Echo the line without further action */
187static void printline(char * line)               { printf("%s", line); }
188
189/*
190 * Find all symbols in filename that are exported with EXPORT_SYMBOL &
191 * EXPORT_SYMBOL_GPL (& EXPORT_SYMBOL_GPL_FUTURE implicitly).
192 * All symbols located are stored in symfilelist.
193 */
194static void find_export_symbols(char * filename)
195{
196	FILE * fp;
197	struct symfile *sym;
198	char line[MAXLINESZ];
199	if (filename_exist(filename) == NULL) {
200		char real_filename[PATH_MAX + 1];
201		memset(real_filename, 0, sizeof(real_filename));
202		strncat(real_filename, srctree, PATH_MAX);
203		strncat(real_filename, "/", PATH_MAX - strlen(real_filename));
204		strncat(real_filename, filename,
205				PATH_MAX - strlen(real_filename));
206		sym = add_new_file(filename);
207		fp = fopen(real_filename, "r");
208		if (fp == NULL)
209		{
210			fprintf(stderr, "docproc: ");
211			perror(real_filename);
212			exit(1);
213		}
214		while (fgets(line, MAXLINESZ, fp)) {
215			char *p;
216			char *e;
217			if (((p = strstr(line, "EXPORT_SYMBOL_GPL")) != NULL) ||
218                            ((p = strstr(line, "EXPORT_SYMBOL")) != NULL)) {
219				/* Skip EXPORT_SYMBOL{_GPL} */
220				while (isalnum(*p) || *p == '_')
221					p++;
222				/* Remove parentheses & additional whitespace */
223				while (isspace(*p))
224					p++;
225				if (*p != '(')
226					continue; /* Syntax error? */
227				else
228					p++;
229				while (isspace(*p))
230					p++;
231				e = p;
232				while (isalnum(*e) || *e == '_')
233					e++;
234				*e = '\0';
235				add_new_symbol(sym, p);
236			}
237		}
238		fclose(fp);
239	}
240}
241
242/*
243 * Document all external or internal functions in a file.
244 * Call kernel-doc with following parameters:
245 * kernel-doc -docbook -nofunction function_name1 filename
246 * Function names are obtained from all the src files
247 * by find_export_symbols.
248 * intfunc uses -nofunction
249 * extfunc uses -function
250 */
251static void docfunctions(char * filename, char * type)
252{
253	int i,j;
254	int symcnt = 0;
255	int idx = 0;
256	char **vec;
257
258	for (i=0; i <= symfilecnt; i++)
259		symcnt += symfilelist[i].symbolcnt;
260	vec = malloc((2 + 2 * symcnt + 3) * sizeof(char *));
261	if (vec == NULL) {
262		perror("docproc: ");
263		exit(1);
264	}
265	vec[idx++] = KERNELDOC;
266	vec[idx++] = DOCBOOK;
267	vec[idx++] = NODOCSECTIONS;
268	for (i=0; i < symfilecnt; i++) {
269		struct symfile * sym = &symfilelist[i];
270		for (j=0; j < sym->symbolcnt; j++) {
271			vec[idx++]     = type;
272			consume_symbol(sym->symbollist[j].name);
273			vec[idx++] = sym->symbollist[j].name;
274		}
275	}
276	vec[idx++]     = filename;
277	vec[idx] = NULL;
278	printf("<!-- %s -->\n", filename);
279	exec_kernel_doc(vec);
280	fflush(stdout);
281	free(vec);
282}
283static void intfunc(char * filename) {	docfunctions(filename, NOFUNCTION); }
284static void extfunc(char * filename) { docfunctions(filename, FUNCTION);   }
285
286/*
287 * Document specific function(s) in a file.
288 * Call kernel-doc with the following parameters:
289 * kernel-doc -docbook -function function1 [-function function2]
290 */
291static void singfunc(char * filename, char * line)
292{
293	char *vec[200]; /* Enough for specific functions */
294        int i, idx = 0;
295        int startofsym = 1;
296	vec[idx++] = KERNELDOC;
297	vec[idx++] = DOCBOOK;
298
299        /* Split line up in individual parameters preceded by FUNCTION */
300        for (i=0; line[i]; i++) {
301                if (isspace(line[i])) {
302                        line[i] = '\0';
303                        startofsym = 1;
304                        continue;
305                }
306                if (startofsym) {
307                        startofsym = 0;
308                        vec[idx++] = FUNCTION;
309                        vec[idx++] = &line[i];
310                }
311        }
312	for (i = 0; i < idx; i++) {
313        	if (strcmp(vec[i], FUNCTION))
314        		continue;
315		consume_symbol(vec[i + 1]);
316	}
317	vec[idx++] = filename;
318	vec[idx] = NULL;
319	exec_kernel_doc(vec);
320}
321
322/*
323 * Insert specific documentation section from a file.
324 * Call kernel-doc with the following parameters:
325 * kernel-doc -docbook -function "doc section" filename
326 */
327static void docsect(char *filename, char *line)
328{
329	char *vec[6]; /* kerneldoc -docbook -function "section" file NULL */
330	char *s;
331
332	for (s = line; *s; s++)
333		if (*s == '\n')
334			*s = '\0';
335
336	if (asprintf(&s, "DOC: %s", line) < 0) {
337		perror("asprintf");
338		exit(1);
339	}
340	consume_symbol(s);
341	free(s);
342
343	vec[0] = KERNELDOC;
344	vec[1] = DOCBOOK;
345	vec[2] = FUNCTION;
346	vec[3] = line;
347	vec[4] = filename;
348	vec[5] = NULL;
349	exec_kernel_doc(vec);
350}
351
352static void find_all_symbols(char *filename)
353{
354	char *vec[4]; /* kerneldoc -list file NULL */
355	pid_t pid;
356	int ret, i, count, start;
357	char real_filename[PATH_MAX + 1];
358	int pipefd[2];
359	char *data, *str;
360	size_t data_len = 0;
361
362	vec[0] = KERNELDOC;
363	vec[1] = LIST;
364	vec[2] = filename;
365	vec[3] = NULL;
366
367	if (pipe(pipefd)) {
368		perror("pipe");
369		exit(1);
370	}
371
372	switch (pid=fork()) {
373		case -1:
374			perror("fork");
375			exit(1);
376		case  0:
377			close(pipefd[0]);
378			dup2(pipefd[1], 1);
379			memset(real_filename, 0, sizeof(real_filename));
380			strncat(real_filename, kernsrctree, PATH_MAX);
381			strncat(real_filename, "/" KERNELDOCPATH KERNELDOC,
382					PATH_MAX - strlen(real_filename));
383			execvp(real_filename, vec);
384			fprintf(stderr, "exec ");
385			perror(real_filename);
386			exit(1);
387		default:
388			close(pipefd[1]);
389			data = malloc(4096);
390			do {
391				while ((ret = read(pipefd[0],
392						   data + data_len,
393						   4096)) > 0) {
394					data_len += ret;
395					data = realloc(data, data_len + 4096);
396				}
397			} while (ret == -EAGAIN);
398			if (ret != 0) {
399				perror("read");
400				exit(1);
401			}
402			waitpid(pid, &ret ,0);
403	}
404	if (WIFEXITED(ret))
405		exitstatus |= WEXITSTATUS(ret);
406	else
407		exitstatus = 0xff;
408
409	count = 0;
410	/* poor man's strtok, but with counting */
411	for (i = 0; i < data_len; i++) {
412		if (data[i] == '\n') {
413			count++;
414			data[i] = '\0';
415		}
416	}
417	start = all_list_len;
418	all_list_len += count;
419	all_list = realloc(all_list, sizeof(char *) * all_list_len);
420	str = data;
421	for (i = 0; i < data_len && start != all_list_len; i++) {
422		if (data[i] == '\0') {
423			all_list[start] = str;
424			str = data + i + 1;
425			start++;
426		}
427	}
428}
429
430/*
431 * Parse file, calling action specific functions for:
432 * 1) Lines containing !E
433 * 2) Lines containing !I
434 * 3) Lines containing !D
435 * 4) Lines containing !F
436 * 5) Lines containing !P
437 * 6) Lines containing !C
438 * 7) Default lines - lines not matching the above
439 */
440static void parse_file(FILE *infile)
441{
442	char line[MAXLINESZ];
443	char * s;
444	while (fgets(line, MAXLINESZ, infile)) {
445		if (line[0] == '!') {
446			s = line + 2;
447			switch (line[1]) {
448				case 'E':
449					while (*s && !isspace(*s)) s++;
450					*s = '\0';
451					externalfunctions(line+2);
452					break;
453				case 'I':
454					while (*s && !isspace(*s)) s++;
455					*s = '\0';
456					internalfunctions(line+2);
457					break;
458				case 'D':
459					while (*s && !isspace(*s)) s++;
460                                        *s = '\0';
461                                        symbolsonly(line+2);
462                                        break;
463				case 'F':
464					/* filename */
465					while (*s && !isspace(*s)) s++;
466					*s++ = '\0';
467                                        /* function names */
468					while (isspace(*s))
469						s++;
470					singlefunctions(line +2, s);
471					break;
472				case 'P':
473					/* filename */
474					while (*s && !isspace(*s)) s++;
475					*s++ = '\0';
476					/* DOC: section name */
477					while (isspace(*s))
478						s++;
479					docsection(line + 2, s);
480					break;
481				case 'C':
482					while (*s && !isspace(*s)) s++;
483					*s = '\0';
484					if (findall)
485						findall(line+2);
486					break;
487				default:
488					defaultline(line);
489			}
490		}
491		else {
492			defaultline(line);
493		}
494	}
495	fflush(stdout);
496}
497
498
499int main(int argc, char *argv[])
500{
501	FILE * infile;
502	int i;
503
504	srctree = getenv("SRCTREE");
505	if (!srctree)
506		srctree = getcwd(NULL, 0);
507	kernsrctree = getenv("KBUILD_SRC");
508	if (!kernsrctree || !*kernsrctree)
509		kernsrctree = srctree;
510	if (argc != 3) {
511		usage();
512		exit(1);
513	}
514	/* Open file, exit on error */
515	infile = fopen(argv[2], "r");
516        if (infile == NULL) {
517                fprintf(stderr, "docproc: ");
518                perror(argv[2]);
519                exit(2);
520        }
521
522	if (strcmp("doc", argv[1]) == 0)
523	{
524		/* Need to do this in two passes.
525		 * First pass is used to collect all symbols exported
526		 * in the various files;
527		 * Second pass generate the documentation.
528		 * This is required because some functions are declared
529		 * and exported in different files :-((
530		 */
531		/* Collect symbols */
532		defaultline       = noaction;
533		internalfunctions = find_export_symbols;
534		externalfunctions = find_export_symbols;
535		symbolsonly       = find_export_symbols;
536		singlefunctions   = noaction2;
537		docsection        = noaction2;
538		findall           = find_all_symbols;
539		parse_file(infile);
540
541		/* Rewind to start from beginning of file again */
542		fseek(infile, 0, SEEK_SET);
543		defaultline       = printline;
544		internalfunctions = intfunc;
545		externalfunctions = extfunc;
546		symbolsonly       = printline;
547		singlefunctions   = singfunc;
548		docsection        = docsect;
549		findall           = NULL;
550
551		parse_file(infile);
552
553		for (i = 0; i < all_list_len; i++) {
554			if (!all_list[i])
555				continue;
556			fprintf(stderr, "Warning: didn't use docs for %s\n",
557				all_list[i]);
558		}
559	}
560	else if (strcmp("depend", argv[1]) == 0)
561	{
562		/* Create first part of dependency chain
563		 * file.tmpl */
564		printf("%s\t", argv[2]);
565		defaultline       = noaction;
566		internalfunctions = adddep;
567		externalfunctions = adddep;
568		symbolsonly       = adddep;
569		singlefunctions   = adddep2;
570		docsection        = adddep2;
571		findall           = adddep;
572		parse_file(infile);
573		printf("\n");
574	}
575	else
576	{
577		fprintf(stderr, "Unknown option: %s\n", argv[1]);
578		exit(1);
579	}
580	fclose(infile);
581	fflush(stdout);
582	return exitstatus;
583}
584