source: MondoRescue/branches/2.2.9/mindi-busybox/scripts/basic/docproc.c

/*
 *  docproc is a simple preprocessor for the template files
 *      used as placeholders for the kernel internal documentation.
 *  docproc is used for documentation-frontend and
 *      dependency-generator.
 *  The two usages have in common that they require
 *  some knowledge of the .tmpl syntax, therefore they
 *  are kept together.
 *
 *  documentation-frontend
 *      Scans the template file and call kernel-doc for
 *      all occurrences of ![EIF]file
 *      Beforehand each referenced file are scanned for
 *      any exported sympols "EXPORT_SYMBOL()" statements.
 *      This is used to create proper -function and
 *      -nofunction arguments in calls to kernel-doc.
 *      Usage: docproc doc file.tmpl
 *
 *  dependency-generator:
 *      Scans the template file and list all files
 *      referenced in a format recognized by make.
 *      Usage:  docproc depend file.tmpl
 *      Writes dependency information to stdout
 *      in the following format:
 *      file.tmpl src.c src2.c
 *      The filenames are obtained from the following constructs:
 *      !Efilename
 *      !Ifilename
 *      !Dfilename
 *      !Ffilename
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/wait.h>

/* exitstatus is used to keep track of any failing calls to kernel-doc,
 * but execution continues. */
int exitstatus = 0;

typedef void DFL(char *);
DFL *defaultline;

typedef void FILEONLY(char * file);
FILEONLY *internalfunctions;
FILEONLY *externalfunctions;
FILEONLY *symbolsonly;

typedef void FILELINE(char * file, char * line);
FILELINE * singlefunctions;
FILELINE * entity_system;

#define MAXLINESZ     2048
#define MAXFILES      250
#define KERNELDOCPATH "scripts/"
#define KERNELDOC     "kernel-doc"
#define DOCBOOK       "-docbook"
#define FUNCTION      "-function"
#define NOFUNCTION    "-nofunction"

void usage (void)
{
    fprintf(stderr, "Usage: docproc {doc|depend} file\n");
    fprintf(stderr, "Input is read from file.tmpl. Output is sent to stdout\n");
    fprintf(stderr, "doc: frontend when generating kernel documentation\n");
    fprintf(stderr, "depend: generate list of files referenced within file\n");
}

/*
 * Execute kernel-doc with parameters givin in svec
 */
void exec_kernel_doc(char **svec)
{
    pid_t pid;
    int ret;
    char *real_filename;
    int rflen;

    /* Make sure output generated so far are flushed */
    fflush(stdout);
    switch(pid=fork()) {
        case -1:
            perror("vfork"+1);
            exit(1);
        case  0:
            rflen  = strlen(getenv("SRCTREE"));
            rflen += strlen(KERNELDOCPATH KERNELDOC);
            real_filename = alloca(rflen + 1);
            strcpy(real_filename, getenv("SRCTREE"));
            strcat(real_filename, KERNELDOCPATH KERNELDOC);
            execvp(real_filename, svec);
            fprintf(stderr, "exec ");
            perror(real_filename);
            exit(1);
        default:
            waitpid(pid, &ret ,0);
    }
    if (WIFEXITED(ret))
        exitstatus |= WEXITSTATUS(ret);
    else
        exitstatus = 0xff;
}

/* Types used to create list of all exported symbols in a number of files */
struct symbols
{
    char *name;
};

struct symfile
{
    char *filename;
    struct symbols *symbollist;
    int symbolcnt;
};

struct symfile symfilelist[MAXFILES];
int symfilecnt = 0;

void add_new_symbol(struct symfile *sym, char * symname)
{
    sym->symbollist =
      realloc(sym->symbollist, (sym->symbolcnt + 1) * sizeof(char *));
    sym->symbollist[sym->symbolcnt++].name = strdup(symname);
}

/* Add a filename to the list */
struct symfile * add_new_file(char * filename)
{
    symfilelist[symfilecnt++].filename = strdup(filename);
    return &symfilelist[symfilecnt - 1];
}
/* Check if file already are present in the list */
struct symfile * filename_exist(char * filename)
{
    int i;
    for (i=0; i < symfilecnt; i++)
        if (strcmp(symfilelist[i].filename, filename) == 0)
            return &symfilelist[i];
    return NULL;
}

/*
 * List all files referenced within the template file.
 * Files are separated by tabs.
 */
void adddep(char * file)           { printf("\t%s", file); }
void adddep2(char * file, char * line)     { line = line; adddep(file); }
void noaction(char * line)         { line = line; }
void noaction2(char * file, char * line)   { file = file; line = line; }

/* Echo the line without further action */
void printline(char * line)               { printf("%s", line); }

/*
 * Find all symbols exported with EXPORT_SYMBOL and EXPORT_SYMBOL_GPL
 * in filename.
 * All symbols located are stored in symfilelist.
 */
void find_export_symbols(char * filename)
{
    FILE * fp;
    struct symfile *sym;
    char line[MAXLINESZ];
    if (filename_exist(filename) == NULL) {
        int rflen = strlen(getenv("SRCTREE")) + strlen(filename);
        char *real_filename = alloca(rflen + 1);
        strcpy(real_filename, getenv("SRCTREE"));
        strcat(real_filename, filename);
        sym = add_new_file(filename);
        fp = fopen(real_filename, "r");
        if (fp == NULL)
        {
            fprintf(stderr, "docproc: ");
            perror(real_filename);
        }
        while (fgets(line, MAXLINESZ, fp)) {
            char *p;
            char *e;
            if (((p = strstr(line, "EXPORT_SYMBOL_GPL")) != 0) ||
                ((p = strstr(line, "EXPORT_SYMBOL")) != 0)) {
                /* Skip EXPORT_SYMBOL{_GPL} */
                while (isalnum(*p) || *p == '_')
                    p++;
                /* Remove paranteses and additional ws */
                while (isspace(*p))
                    p++;
                if (*p != '(')
                    continue; /* Syntax error? */
                else
                    p++;
                while (isspace(*p))
                    p++;
                e = p;
                while (isalnum(*e) || *e == '_')
                    e++;
                *e = '\0';
                add_new_symbol(sym, p);
            }
        }
        fclose(fp);
    }
}

/*
 * Document all external or internal functions in a file.
 * Call kernel-doc with following parameters:
 * kernel-doc -docbook -nofunction function_name1 filename
 * function names are obtained from all the the src files
 * by find_export_symbols.
 * intfunc uses -nofunction
 * extfunc uses -function
 */
void docfunctions(char * filename, char * type)
{
    int i,j;
    int symcnt = 0;
    int idx = 0;
    char **vec;

    for (i=0; i <= symfilecnt; i++)
        symcnt += symfilelist[i].symbolcnt;
    vec = malloc((2 + 2 * symcnt + 2) * sizeof(char*));
    if (vec == NULL) {
        perror("docproc: ");
        exit(1);
    }
    vec[idx++] = KERNELDOC;
    vec[idx++] = DOCBOOK;
    for (i=0; i < symfilecnt; i++) {
        struct symfile * sym = &symfilelist[i];
        for (j=0; j < sym->symbolcnt; j++) {
            vec[idx++]     = type;
            vec[idx++] = sym->symbollist[j].name;
        }
    }
    vec[idx++]     = filename;
    vec[idx] = NULL;
    printf("<!-- %s -->\n", filename);
    exec_kernel_doc(vec);
    fflush(stdout);
    free(vec);
}
void intfunc(char * filename) { docfunctions(filename, NOFUNCTION); }
void extfunc(char * filename) { docfunctions(filename, FUNCTION);   }

/*
 * Document specific function(s) in a file.
 * Call kernel-doc with the following parameters:
 * kernel-doc -docbook -function function1 [-function function2]
 */
void singfunc(char * filename, char * line)
{
    char *vec[200]; /* Enough for specific functions */
    int i, idx = 0;
    int startofsym = 1;
    vec[idx++] = KERNELDOC;
    vec[idx++] = DOCBOOK;

    /* Split line up in individual parameters preceeded by FUNCTION */
    for (i=0; line[i]; i++) {
        if (isspace(line[i])) {
            line[i] = '\0';
            startofsym = 1;
            continue;
        }
        if (startofsym) {
            startofsym = 0;
            vec[idx++] = FUNCTION;
            vec[idx++] = &line[i];
        }
    }
    vec[idx++] = filename;
    vec[idx] = NULL;
    exec_kernel_doc(vec);
}

/*
 * Parse file, calling action specific functions for:
 * 1) Lines containing !E
 * 2) Lines containing !I
 * 3) Lines containing !D
 * 4) Lines containing !F
 * 5) Default lines - lines not matching the above
 */
void parse_file(FILE *infile)
{
    char line[MAXLINESZ];
    char * s;
    while (fgets(line, MAXLINESZ, infile)) {
        if (line[0] == '!') {
            s = line + 2;
            switch (line[1]) {
                case 'E':
                    while (*s && !isspace(*s)) s++;
                    *s = '\0';
                    externalfunctions(line+2);
                    break;
                case 'I':
                    while (*s && !isspace(*s)) s++;
                    *s = '\0';
                    internalfunctions(line+2);
                    break;
                case 'D':
                    while (*s && !isspace(*s)) s++;
                    *s = '\0';
                    symbolsonly(line+2);
                    break;
                case 'F':
                    /* filename */
                    while (*s && !isspace(*s)) s++;
                    *s++ = '\0';
                    /* function names */
                    while (isspace(*s))
                        s++;
                    singlefunctions(line +2, s);
                    break;
                default:
                    defaultline(line);
            }
        }
        else {
            defaultline(line);
        }
    }
    fflush(stdout);
}


int main(int argc, char **argv)
{
    FILE * infile;
    if (argc != 3) {
        usage();
        exit(1);
    }
    /* Open file, exit on error */
    infile = fopen(argv[2], "r");
    if (infile == NULL) {
        fprintf(stderr, "docproc: ");
        perror(argv[2]);
        exit(2);
    }

    if (strcmp("doc", argv[1]) == 0)
    {
        /* Need to do this in two passes.
         * First pass is used to collect all symbols exported
         * in the various files.
         * Second pass generate the documentation.
         * This is required because function are declared
         * and exported in different files :-((
         */
        /* Collect symbols */
        defaultline       = noaction;
        internalfunctions = find_export_symbols;
        externalfunctions = find_export_symbols;
        symbolsonly       = find_export_symbols;
        singlefunctions   = noaction2;
        parse_file(infile);

        /* Rewind to start from beginning of file again */
        fseek(infile, 0, SEEK_SET);
        defaultline       = printline;
        internalfunctions = intfunc;
        externalfunctions = extfunc;
        symbolsonly       = printline;
        singlefunctions   = singfunc;

        parse_file(infile);
    }
    else if (strcmp("depend", argv[1]) == 0)
    {
        /* Create first part of dependency chain
         * file.tmpl */
        printf("%s\t", argv[2]);
        defaultline       = noaction;
        internalfunctions = adddep;
        externalfunctions = adddep;
        symbolsonly       = adddep;
        singlefunctions   = adddep2;
        parse_file(infile);
        printf("\n");
    }
    else
    {
        fprintf(stderr, "Unknown option: %s\n", argv[1]);
        exit(1);
    }
    fclose(infile);
    fflush(stdout);
    return exitstatus;
}