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			fprintf(stderr, "docproc: ");
210			perror(real_filename);
211			exit(1);
212		}
213		while (fgets(line, MAXLINESZ, fp)) {
214			char *p;
215			char *e;
216			if (((p = strstr(line, "EXPORT_SYMBOL_GPL")) != NULL) ||
217                            ((p = strstr(line, "EXPORT_SYMBOL")) != NULL)) {
218				/* Skip EXPORT_SYMBOL{_GPL} */
219				while (isalnum(*p) || *p == '_')
220					p++;
221				/* Remove parentheses & additional whitespace */
222				while (isspace(*p))
223					p++;
224				if (*p != '(')
225					continue; /* Syntax error? */
226				else
227					p++;
228				while (isspace(*p))
229					p++;
230				e = p;
231				while (isalnum(*e) || *e == '_')
232					e++;
233				*e = '\0';
234				add_new_symbol(sym, p);
235			}
236		}
237		fclose(fp);
238	}
239}
240
241/*
242 * Document all external or internal functions in a file.
243 * Call kernel-doc with following parameters:
244 * kernel-doc -docbook -nofunction function_name1 filename
245 * Function names are obtained from all the src files
246 * by find_export_symbols.
247 * intfunc uses -nofunction
248 * extfunc uses -function
249 */
250static void docfunctions(char * filename, char * type)
251{
252	int i,j;
253	int symcnt = 0;
254	int idx = 0;
255	char **vec;
256
257	for (i=0; i <= symfilecnt; i++)
258		symcnt += symfilelist[i].symbolcnt;
259	vec = malloc((2 + 2 * symcnt + 3) * sizeof(char *));
260	if (vec == NULL) {
261		perror("docproc: ");
262		exit(1);
263	}
264	vec[idx++] = KERNELDOC;
265	vec[idx++] = DOCBOOK;
266	vec[idx++] = NODOCSECTIONS;
267	for (i=0; i < symfilecnt; i++) {
268		struct symfile * sym = &symfilelist[i];
269		for (j=0; j < sym->symbolcnt; j++) {
270			vec[idx++]     = type;
271			consume_symbol(sym->symbollist[j].name);
272			vec[idx++] = sym->symbollist[j].name;
273		}
274	}
275	vec[idx++]     = filename;
276	vec[idx] = NULL;
277	printf("<!-- %s -->\n", filename);
278	exec_kernel_doc(vec);
279	fflush(stdout);
280	free(vec);
281}
282static void intfunc(char * filename) {	docfunctions(filename, NOFUNCTION); }
283static void extfunc(char * filename) { docfunctions(filename, FUNCTION);   }
284
285/*
286 * Document specific function(s) in a file.
287 * Call kernel-doc with the following parameters:
288 * kernel-doc -docbook -function function1 [-function function2]
289 */
290static void singfunc(char * filename, char * line)
291{
292	char *vec[200]; /* Enough for specific functions */
293        int i, idx = 0;
294        int startofsym = 1;
295	vec[idx++] = KERNELDOC;
296	vec[idx++] = DOCBOOK;
297
298        /* Split line up in individual parameters preceded by FUNCTION */
299        for (i=0; line[i]; i++) {
300                if (isspace(line[i])) {
301                        line[i] = '\0';
302                        startofsym = 1;
303                        continue;
304                }
305                if (startofsym) {
306                        startofsym = 0;
307                        vec[idx++] = FUNCTION;
308                        vec[idx++] = &line[i];
309                }
310        }
311	for (i = 0; i < idx; i++) {
312        	if (strcmp(vec[i], FUNCTION))
313        		continue;
314		consume_symbol(vec[i + 1]);
315	}
316	vec[idx++] = filename;
317	vec[idx] = NULL;
318	exec_kernel_doc(vec);
319}
320
321/*
322 * Insert specific documentation section from a file.
323 * Call kernel-doc with the following parameters:
324 * kernel-doc -docbook -function "doc section" filename
325 */
326static void docsect(char *filename, char *line)
327{
328	char *vec[6]; /* kerneldoc -docbook -function "section" file NULL */
329	char *s;
330
331	for (s = line; *s; s++)
332		if (*s == '\n')
333			*s = '\0';
334
335	if (asprintf(&s, "DOC: %s", line) < 0) {
336		perror("asprintf");
337		exit(1);
338	}
339	consume_symbol(s);
340	free(s);
341
342	vec[0] = KERNELDOC;
343	vec[1] = DOCBOOK;
344	vec[2] = FUNCTION;
345	vec[3] = line;
346	vec[4] = filename;
347	vec[5] = NULL;
348	exec_kernel_doc(vec);
349}
350
351static void find_all_symbols(char *filename)
352{
353	char *vec[4]; /* kerneldoc -list file NULL */
354	pid_t pid;
355	int ret, i, count, start;
356	char real_filename[PATH_MAX + 1];
357	int pipefd[2];
358	char *data, *str;
359	size_t data_len = 0;
360
361	vec[0] = KERNELDOC;
362	vec[1] = LIST;
363	vec[2] = filename;
364	vec[3] = NULL;
365
366	if (pipe(pipefd)) {
367		perror("pipe");
368		exit(1);
369	}
370
371	switch (pid=fork()) {
372		case -1:
373			perror("fork");
374			exit(1);
375		case  0:
376			close(pipefd[0]);
377			dup2(pipefd[1], 1);
378			memset(real_filename, 0, sizeof(real_filename));
379			strncat(real_filename, kernsrctree, PATH_MAX);
380			strncat(real_filename, "/" KERNELDOCPATH KERNELDOC,
381					PATH_MAX - strlen(real_filename));
382			execvp(real_filename, vec);
383			fprintf(stderr, "exec ");
384			perror(real_filename);
385			exit(1);
386		default:
387			close(pipefd[1]);
388			data = malloc(4096);
389			do {
390				while ((ret = read(pipefd[0],
391						   data + data_len,
392						   4096)) > 0) {
393					data_len += ret;
394					data = realloc(data, data_len + 4096);
395				}
396			} while (ret == -EAGAIN);
397			if (ret != 0) {
398				perror("read");
399				exit(1);
400			}
401			waitpid(pid, &ret ,0);
402	}
403	if (WIFEXITED(ret))
404		exitstatus |= WEXITSTATUS(ret);
405	else
406		exitstatus = 0xff;
407
408	count = 0;
409	/* poor man's strtok, but with counting */
410	for (i = 0; i < data_len; i++) {
411		if (data[i] == '\n') {
412			count++;
413			data[i] = '\0';
414		}
415	}
416	start = all_list_len;
417	all_list_len += count;
418	all_list = realloc(all_list, sizeof(char *) * all_list_len);
419	str = data;
420	for (i = 0; i < data_len && start != all_list_len; i++) {
421		if (data[i] == '\0') {
422			all_list[start] = str;
423			str = data + i + 1;
424			start++;
425		}
426	}
427}
428
429/*
430 * Parse file, calling action specific functions for:
431 * 1) Lines containing !E
432 * 2) Lines containing !I
433 * 3) Lines containing !D
434 * 4) Lines containing !F
435 * 5) Lines containing !P
436 * 6) Lines containing !C
437 * 7) Default lines - lines not matching the above
438 */
439static void parse_file(FILE *infile)
440{
441	char line[MAXLINESZ];
442	char * s;
443	while (fgets(line, MAXLINESZ, infile)) {
444		if (line[0] == '!') {
445			s = line + 2;
446			switch (line[1]) {
447				case 'E':
448					while (*s && !isspace(*s)) s++;
449					*s = '\0';
450					externalfunctions(line+2);
451					break;
452				case 'I':
453					while (*s && !isspace(*s)) s++;
454					*s = '\0';
455					internalfunctions(line+2);
456					break;
457				case 'D':
458					while (*s && !isspace(*s)) s++;
459                                        *s = '\0';
460                                        symbolsonly(line+2);
461                                        break;
462				case 'F':
463					/* filename */
464					while (*s && !isspace(*s)) s++;
465					*s++ = '\0';
466                                        /* function names */
467					while (isspace(*s))
468						s++;
469					singlefunctions(line +2, s);
470					break;
471				case 'P':
472					/* filename */
473					while (*s && !isspace(*s)) s++;
474					*s++ = '\0';
475					/* DOC: section name */
476					while (isspace(*s))
477						s++;
478					docsection(line + 2, s);
479					break;
480				case 'C':
481					while (*s && !isspace(*s)) s++;
482					*s = '\0';
483					if (findall)
484						findall(line+2);
485					break;
486				default:
487					defaultline(line);
488			}
489		} else {
490			defaultline(line);
491		}
492	}
493	fflush(stdout);
494}
495
496
497int main(int argc, char *argv[])
498{
499	FILE * infile;
500	int i;
501
502	srctree = getenv("SRCTREE");
503	if (!srctree)
504		srctree = getcwd(NULL, 0);
505	kernsrctree = getenv("KBUILD_SRC");
506	if (!kernsrctree || !*kernsrctree)
507		kernsrctree = srctree;
508	if (argc != 3) {
509		usage();
510		exit(1);
511	}
512	/* Open file, exit on error */
513	infile = fopen(argv[2], "r");
514        if (infile == NULL) {
515                fprintf(stderr, "docproc: ");
516                perror(argv[2]);
517                exit(2);
518        }
519
520	if (strcmp("doc", argv[1]) == 0) {
521		/* Need to do this in two passes.
522		 * First pass is used to collect all symbols exported
523		 * in the various files;
524		 * Second pass generate the documentation.
525		 * This is required because some functions are declared
526		 * and exported in different files :-((
527		 */
528		/* Collect symbols */
529		defaultline       = noaction;
530		internalfunctions = find_export_symbols;
531		externalfunctions = find_export_symbols;
532		symbolsonly       = find_export_symbols;
533		singlefunctions   = noaction2;
534		docsection        = noaction2;
535		findall           = find_all_symbols;
536		parse_file(infile);
537
538		/* Rewind to start from beginning of file again */
539		fseek(infile, 0, SEEK_SET);
540		defaultline       = printline;
541		internalfunctions = intfunc;
542		externalfunctions = extfunc;
543		symbolsonly       = printline;
544		singlefunctions   = singfunc;
545		docsection        = docsect;
546		findall           = NULL;
547
548		parse_file(infile);
549
550		for (i = 0; i < all_list_len; i++) {
551			if (!all_list[i])
552				continue;
553			fprintf(stderr, "Warning: didn't use docs for %s\n",
554				all_list[i]);
555		}
556	} else if (strcmp("depend", argv[1]) == 0) {
557		/* Create first part of dependency chain
558		 * file.tmpl */
559		printf("%s\t", argv[2]);
560		defaultline       = noaction;
561		internalfunctions = adddep;
562		externalfunctions = adddep;
563		symbolsonly       = adddep;
564		singlefunctions   = adddep2;
565		docsection        = adddep2;
566		findall           = adddep;
567		parse_file(infile);
568		printf("\n");
569	} else {
570		fprintf(stderr, "Unknown option: %s\n", argv[1]);
571		exit(1);
572	}
573	fclose(infile);
574	fflush(stdout);
575	return exitstatus;
576}
577