docbook: warn on unused doc entries

When you don't use !E or !I but only !F, then it's very easy to miss
including some functions, structs etc.  in documentation.  To help
finding which ones were missed, allow printing out the unused ones as
warnings.

For example, using this on mac80211 yields a lot of warnings like this:

  Warning: didn't use docs for DOC: mac80211 workqueue
  Warning: didn't use docs for ieee80211_max_queues
  Warning: didn't use docs for ieee80211_bss_change
  Warning: didn't use docs for ieee80211_bss_conf

when generating the documentation for it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 128 insertions, 1 deletions

diff --git a/scripts/basic/docproc.c b/scripts/basic/docproc.c
index 79ab973fb43..fc3b18d844a 100644
--- a/scripts/basic/docproc.c
+++ b/scripts/basic/docproc.c
@@ -34,12 +34,14 @@
  *
  */
 
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
 #include <unistd.h>
 #include <limits.h>
+#include <errno.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 
@@ -54,6 +56,7 @@ typedef void FILEONLY(char * file);
 FILEONLY *internalfunctions;
 FILEONLY *externalfunctions;
 FILEONLY *symbolsonly;
+FILEONLY *findall;
 
 typedef void FILELINE(char * file, char * line);
 FILELINE * singlefunctions;
@@ -65,12 +68,30 @@ FILELINE * docsection;
 #define KERNELDOCPATH "scripts/"
 #define KERNELDOC     "kernel-doc"
 #define DOCBOOK       "-docbook"
+#define LIST          "-list"
 #define FUNCTION      "-function"
 #define NOFUNCTION    "-nofunction"
 #define NODOCSECTIONS "-no-doc-sections"
 
 static char *srctree, *kernsrctree;
 
+static char **all_list = NULL;
+static int all_list_len = 0;
+
+static void consume_symbol(const char *sym)
+{
+	int i;
+
+	for (i = 0; i < all_list_len; i++) {
+		if (!all_list[i])
+			continue;
+		if (strcmp(sym, all_list[i]))
+			continue;
+		all_list[i] = NULL;
+		break;
+	}
+}
+
 static void usage (void)
 {
 	fprintf(stderr, "Usage: docproc {doc|depend} file\n");
@@ -248,6 +269,7 @@ static void docfunctions(char * filename, char * type)
 		struct symfile * sym = &symfilelist[i];
 		for (j=0; j < sym->symbolcnt; j++) {
 			vec[idx++]     = type;
+			consume_symbol(sym->symbollist[j].name);
 			vec[idx++] = sym->symbollist[j].name;
 		}
 	}
@@ -287,6 +309,11 @@ static void singfunc(char * filename, char * line)
                         vec[idx++] = &line[i];
                 }
         }
+	for (i = 0; i < idx; i++) {
+        	if (strcmp(vec[i], FUNCTION))
+        		continue;
+		consume_symbol(vec[i + 1]);
+	}
 	vec[idx++] = filename;
 	vec[idx] = NULL;
 	exec_kernel_doc(vec);
@@ -306,6 +333,10 @@ static void docsect(char *filename, char *line)
 		if (*s == '\n')
 			*s = '\0';
 
+	asprintf(&s, "DOC: %s", line);
+	consume_symbol(s);
+	free(s);
+
 	vec[0] = KERNELDOC;
 	vec[1] = DOCBOOK;
 	vec[2] = FUNCTION;
@@ -315,6 +346,84 @@ static void docsect(char *filename, char *line)
 	exec_kernel_doc(vec);
 }
 
+static void find_all_symbols(char *filename)
+{
+	char *vec[4]; /* kerneldoc -list file NULL */
+	pid_t pid;
+	int ret, i, count, start;
+	char real_filename[PATH_MAX + 1];
+	int pipefd[2];
+	char *data, *str;
+	size_t data_len = 0;
+
+	vec[0] = KERNELDOC;
+	vec[1] = LIST;
+	vec[2] = filename;
+	vec[3] = NULL;
+
+	if (pipe(pipefd)) {
+		perror("pipe");
+		exit(1);
+	}
+
+	switch (pid=fork()) {
+		case -1:
+			perror("fork");
+			exit(1);
+		case  0:
+			close(pipefd[0]);
+			dup2(pipefd[1], 1);
+			memset(real_filename, 0, sizeof(real_filename));
+			strncat(real_filename, kernsrctree, PATH_MAX);
+			strncat(real_filename, "/" KERNELDOCPATH KERNELDOC,
+					PATH_MAX - strlen(real_filename));
+			execvp(real_filename, vec);
+			fprintf(stderr, "exec ");
+			perror(real_filename);
+			exit(1);
+		default:
+			close(pipefd[1]);
+			data = malloc(4096);
+			do {
+				while ((ret = read(pipefd[0],
+						   data + data_len,
+						   4096)) > 0) {
+					data_len += ret;
+					data = realloc(data, data_len + 4096);
+				}
+			} while (ret == -EAGAIN);
+			if (ret != 0) {
+				perror("read");
+				exit(1);
+			}
+			waitpid(pid, &ret ,0);
+	}
+	if (WIFEXITED(ret))
+		exitstatus |= WEXITSTATUS(ret);
+	else
+		exitstatus = 0xff;
+
+	count = 0;
+	/* poor man's strtok, but with counting */
+	for (i = 0; i < data_len; i++) {
+		if (data[i] == '\n') {
+			count++;
+			data[i] = '\0';
+		}
+	}
+	start = all_list_len;
+	all_list_len += count;
+	all_list = realloc(all_list, sizeof(char *) * all_list_len);
+	str = data;
+	for (i = 0; i < data_len && start != all_list_len; i++) {
+		if (data[i] == '\0') {
+			all_list[start] = str;
+			str = data + i + 1;
+			start++;
+		}
+	}
+}
+
 /*
  * Parse file, calling action specific functions for:
  * 1) Lines containing !E
@@ -322,7 +431,8 @@ static void docsect(char *filename, char *line)
  * 3) Lines containing !D
  * 4) Lines containing !F
  * 5) Lines containing !P
- * 6) Default lines - lines not matching the above
+ * 6) Lines containing !C
+ * 7) Default lines - lines not matching the above
  */
 static void parse_file(FILE *infile)
 {
@@ -365,6 +475,12 @@ static void parse_file(FILE *infile)
 						s++;
 					docsection(line + 2, s);
 					break;
+				case 'C':
+					while (*s && !isspace(*s)) s++;
+					*s = '\0';
+					if (findall)
+						findall(line+2);
+					break;
 				default:
 					defaultline(line);
 			}
@@ -380,6 +496,7 @@ static void parse_file(FILE *infile)
 int main(int argc, char *argv[])
 {
 	FILE * infile;
+	int i;
 
 	srctree = getenv("SRCTREE");
 	if (!srctree)
@@ -415,6 +532,7 @@ int main(int argc, char *argv[])
 		symbolsonly       = find_export_symbols;
 		singlefunctions   = noaction2;
 		docsection        = noaction2;
+		findall           = find_all_symbols;
 		parse_file(infile);
 
 		/* Rewind to start from beginning of file again */
@@ -425,8 +543,16 @@ int main(int argc, char *argv[])
 		symbolsonly       = printline;
 		singlefunctions   = singfunc;
 		docsection        = docsect;
+		findall           = NULL;
 
 		parse_file(infile);
+
+		for (i = 0; i < all_list_len; i++) {
+			if (!all_list[i])
+				continue;
+			fprintf(stderr, "Warning: didn't use docs for %s\n",
+				all_list[i]);
+		}
 	}
 	else if (strcmp("depend", argv[1]) == 0)
 	{
@@ -439,6 +565,7 @@ int main(int argc, char *argv[])
 		symbolsonly       = adddep;
 		singlefunctions   = adddep2;
 		docsection        = adddep2;
+		findall           = adddep;
 		parse_file(infile);
 		printf("\n");
 	}