FreeBSD/Linux Kernel Cross Reference
sys/gnu/gcov/gcc_4_7.c

     // SPDX-License-Identifier: GPL-2.0
     // 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; version 2.
     //
     // 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; if not, write to the Free Software
    // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    // 02110-1301, USA.
    /*
     *  This code provides functions to handle gcc's profiling data format
     *  introduced with gcc 4.7.
     *
     *  This file is based heavily on gcc_3_4.c file.
     *
     *  For a better understanding, refer to gcc source:
     *  gcc/gcov-io.h
     *  libgcc/libgcov.c
     *
     *  Uses gcc-internal data definitions.
     */
    
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/types.h>
    #include <sys/systm.h>
    #include <sys/sbuf.h>
    #include <sys/malloc.h>
    #include <sys/module.h>
    #include <gnu/gcov/gcov.h>
    
    
    #if (__GNUC__ >= 7)
    #define GCOV_COUNTERS                   9
    #elif (__GNUC__ > 5) || (__GNUC__ == 5 && __GNUC_MINOR__ >= 1)
    #define GCOV_COUNTERS                   10
    #elif __GNUC__ == 4 && __GNUC_MINOR__ >= 9
    #define GCOV_COUNTERS                   9
    #else
    #define GCOV_COUNTERS                   8
    #endif
    
    #define GCOV_TAG_FUNCTION_LENGTH        3
    
    static struct gcov_info *gcov_info_head;
    
    /**
     * struct gcov_ctr_info - information about counters for a single function
     * @num: number of counter values for this type
     * @values: array of counter values for this type
     *
     * This data is generated by gcc during compilation and doesn't change
     * at run-time with the exception of the values array.
     */
    struct gcov_ctr_info {
            unsigned int num;
            gcov_type *values;
    };
    
    /**
     * struct gcov_fn_info - profiling meta data per function
     * @key: comdat key
     * @ident: unique ident of function
     * @lineno_checksum: function lineo_checksum
     * @cfg_checksum: function cfg checksum
     * @ctrs: instrumented counters
     *
     * This data is generated by gcc during compilation and doesn't change
     * at run-time.
     *
     * Information about a single function.  This uses the trailing array
     * idiom. The number of counters is determined from the merge pointer
     * array in gcov_info.  The key is used to detect which of a set of
     * comdat functions was selected -- it points to the gcov_info object
     * of the object file containing the selected comdat function.
     */
    struct gcov_fn_info {
            const struct gcov_info *key;
            unsigned int ident;
            unsigned int lineno_checksum;
            unsigned int cfg_checksum;
            struct gcov_ctr_info ctrs[0];
    };
    
    /**
     * struct gcov_info - profiling data per object file
     * @version: gcov version magic indicating the gcc version used for compilation
     * @next: list head for a singly-linked list
     * @stamp: uniquifying time stamp
     * @filename: name of the associated gcov data file
    * @merge: merge functions (null for unused counter type)
    * @n_functions: number of instrumented functions
    * @functions: pointer to pointers to function information
    *
    * This data is generated by gcc during compilation and doesn't change
    * at run-time with the exception of the next pointer.
    */
   struct gcov_info {
           unsigned int version;
           struct gcov_info *next;
           unsigned int stamp;
           const char *filename;
           void (*merge[GCOV_COUNTERS])(gcov_type *, unsigned int);
           unsigned int n_functions;
           struct gcov_fn_info **functions;
   };
   
   /**
    * gcov_info_filename - return info filename
    * @info: profiling data set
    */
   const char *
   gcov_info_filename(struct gcov_info *info)
   {
           return (info->filename);
   }
   
   /**
    * gcov_info_version - return info version
    * @info: profiling data set
    */
   unsigned int
   gcov_info_version(struct gcov_info *info)
   {
           return (info->version);
   }
   
   /**
    * gcov_info_next - return next profiling data set
    * @info: profiling data set
    *
    * Returns next gcov_info following @info or first gcov_info in the chain if
    * @info is %NULL.
    */
   struct gcov_info *
   gcov_info_next(struct gcov_info *info)
   {
           if (!info)
                   return gcov_info_head;
   
           return (info->next);
   }
   
   /**
    * gcov_info_link - link/add profiling data set to the list
    * @info: profiling data set
    */
   void
   gcov_info_link(struct gcov_info *info)
   {
           info->next = gcov_info_head;
           gcov_info_head = info;
   }
   
   /**
    * gcov_info_unlink - unlink/remove profiling data set from the list
    * @prev: previous profiling data set
    * @info: profiling data set
    */
   void
   gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info)
   {
           if (prev)
                   prev->next = info->next;
           else
                   gcov_info_head = info->next;
   }
   
   /* Symbolic links to be created for each profiling data file. */
   const struct gcov_link gcov_link[] = {
           { OBJ_TREE, "gcno" },   /* Link to .gcno file in $(objtree). */
           { 0, NULL},
   };
   
   /*
    * Determine whether a counter is active. Doesn't change at run-time.
    */
   static int
   counter_active(struct gcov_info *info, unsigned int type)
   {
           return (info->merge[type] ? 1 : 0);
   }
   
   /* Determine number of active counters. Based on gcc magic. */
   static unsigned int
   num_counter_active(struct gcov_info *info)
   {
           unsigned int i;
           unsigned int result = 0;
   
           for (i = 0; i < GCOV_COUNTERS; i++) {
                   if (counter_active(info, i))
                           result++;
           }
           return (result);
   }
   
   /**
    * gcov_info_reset - reset profiling data to zero
    * @info: profiling data set
    */
   void
   gcov_info_reset(struct gcov_info *info)
   {
           struct gcov_ctr_info *ci_ptr;
           unsigned int fi_idx;
           unsigned int ct_idx;
   
           for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
                   ci_ptr = info->functions[fi_idx]->ctrs;
   
                   for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) {
                           if (!counter_active(info, ct_idx))
                                   continue;
   
                           memset(ci_ptr->values, 0,
                                           sizeof(gcov_type) * ci_ptr->num);
                           ci_ptr++;
                   }
           }
   }
   
   /**
    * gcov_info_is_compatible - check if profiling data can be added
    * @info1: first profiling data set
    * @info2: second profiling data set
    *
    * Returns non-zero if profiling data can be added, zero otherwise.
    */
   int
   gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2)
   {
           return (info1->stamp == info2->stamp);
   }
   
   /**
    * gcov_info_add - add up profiling data
    * @dest: profiling data set to which data is added
    * @source: profiling data set which is added
    *
    * Adds profiling counts of @source to @dest.
    */
   void
   gcov_info_add(struct gcov_info *dst, struct gcov_info *src)
   {
           struct gcov_ctr_info *dci_ptr;
           struct gcov_ctr_info *sci_ptr;
           unsigned int fi_idx;
           unsigned int ct_idx;
           unsigned int val_idx;
   
           for (fi_idx = 0; fi_idx < src->n_functions; fi_idx++) {
                   dci_ptr = dst->functions[fi_idx]->ctrs;
                   sci_ptr = src->functions[fi_idx]->ctrs;
   
                   for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) {
                           if (!counter_active(src, ct_idx))
                                   continue;
   
                           for (val_idx = 0; val_idx < sci_ptr->num; val_idx++)
                                   dci_ptr->values[val_idx] +=
                                           sci_ptr->values[val_idx];
   
                           dci_ptr++;
                           sci_ptr++;
                   }
           }
   }
   
   /**
    * gcov_info_dup - duplicate profiling data set
    * @info: profiling data set to duplicate
    *
    * Return newly allocated duplicate on success, %NULL on error.
    */
   struct gcov_info *
   gcov_info_dup(struct gcov_info *info)
   {
           struct gcov_info *dup;
           struct gcov_ctr_info *dci_ptr; /* dst counter info */
           struct gcov_ctr_info *sci_ptr; /* src counter info */
           unsigned int active;
           unsigned int fi_idx; /* function info idx */
           unsigned int ct_idx; /* counter type idx */
           size_t fi_size; /* function info size */
           size_t cv_size; /* counter values size */
   
           if ((dup = malloc(sizeof(*dup), M_GCOV, M_NOWAIT|M_ZERO)) == NULL)
                   return (NULL);
           memcpy(dup, info, sizeof(*dup));
   
           dup->next = NULL;
           dup->filename = NULL;
           dup->functions = NULL;
   
           dup->filename = strdup_flags(info->filename, M_GCOV, M_NOWAIT);
           if (dup->filename == NULL)
                   goto err_free;
   
           dup->functions = malloc(info->n_functions * sizeof(struct gcov_fn_info *), M_GCOV, M_NOWAIT|M_ZERO);
           if (dup->functions == NULL)
                   goto err_free;
           active = num_counter_active(info);
           fi_size = sizeof(struct gcov_fn_info);
           fi_size += sizeof(struct gcov_ctr_info) * active;
   
           for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
                   dup->functions[fi_idx] = malloc(fi_size, M_GCOV, M_NOWAIT|M_ZERO);
                   if (!dup->functions[fi_idx])
                           goto err_free;
   
                   *(dup->functions[fi_idx]) = *(info->functions[fi_idx]);
   
                   sci_ptr = info->functions[fi_idx]->ctrs;
                   dci_ptr = dup->functions[fi_idx]->ctrs;
   
                   for (ct_idx = 0; ct_idx < active; ct_idx++) {
   
                           cv_size = sizeof(gcov_type) * sci_ptr->num;
   
                           dci_ptr->values = malloc(cv_size, M_GCOV, M_NOWAIT);
   
                           if (!dci_ptr->values)
                                   goto err_free;
   
                           dci_ptr->num = sci_ptr->num;
                           memcpy(dci_ptr->values, sci_ptr->values, cv_size);
   
                           sci_ptr++;
                           dci_ptr++;
                   }
           }
   
           return (dup);
   err_free:
           gcov_info_free(dup);
           return (NULL);
   }
   
   /**
    * gcov_info_free - release memory for profiling data set duplicate
    * @info: profiling data set duplicate to free
    */
   void
   gcov_info_free(struct gcov_info *info)
   {
           unsigned int active;
           unsigned int fi_idx;
           unsigned int ct_idx;
           struct gcov_ctr_info *ci_ptr;
   
           if (!info->functions)
                   goto free_info;
   
           active = num_counter_active(info);
   
           for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
                   if (!info->functions[fi_idx])
                           continue;
   
                   ci_ptr = info->functions[fi_idx]->ctrs;
   
                   for (ct_idx = 0; ct_idx < active; ct_idx++, ci_ptr++)
                           free(ci_ptr->values, M_GCOV);
   
                   free(info->functions[fi_idx], M_GCOV);
           }
   
   free_info:
           free(info->functions, M_GCOV);
           free(__DECONST(char *, info->filename), M_GCOV);
           free(info, M_GCOV);
    }
   
   #define ITER_STRIDE     PAGE_SIZE
   
   /**
    * struct gcov_iterator - specifies current file position in logical records
    * @info: associated profiling data
    * @buffer: buffer containing file data
    * @size: size of buffer
    * @pos: current position in file
    */
   struct gcov_iterator {
           struct gcov_info *info;
           caddr_t buffer;
           size_t size;
           off_t pos;
   };
   
   /**
    * store_gcov_uint32 - store 32 bit number in gcov format to buffer
    * @buffer: target buffer or NULL
    * @off: offset into the buffer
    * @v: value to be stored
    *
    * Number format defined by gcc: numbers are recorded in the 32 bit
    * unsigned binary form of the endianness of the machine generating the
    * file. Returns the number of bytes stored. If @buffer is %NULL, doesn't
    * store anything.
    */
   static size_t
   store_gcov_uint32(void *buffer, size_t off, uint32_t v)
   {
           uint32_t *data;
   
           if (buffer) {
                   data = (void*)((caddr_t)buffer + off);
                   *data = v;
           }
   
           return sizeof(*data);
   }
   
   /**
    * store_gcov_uint64 - store 64 bit number in gcov format to buffer
    * @buffer: target buffer or NULL
    * @off: offset into the buffer
    * @v: value to be stored
    *
    * Number format defined by gcc: numbers are recorded in the 32 bit
    * unsigned binary form of the endianness of the machine generating the
    * file. 64 bit numbers are stored as two 32 bit numbers, the low part
    * first. Returns the number of bytes stored. If @buffer is %NULL, doesn't store
    * anything.
    */
   
   static size_t
   store_gcov_uint64(void *buffer, size_t off, uint64_t v)
   {
           uint32_t *data;
   
           if (buffer) {
                   data = (void*)((caddr_t)buffer + off);
   
                   data[0] = (v & 0xffffffffUL);
                   data[1] = (v >> 32);
           }
   
           return sizeof(*data) * 2;
   }
   
   /**
    * convert_to_gcda - convert profiling data set to gcda file format
    * @buffer: the buffer to store file data or %NULL if no data should be stored
    * @info: profiling data set to be converted
    *
    * Returns the number of bytes that were/would have been stored into the buffer.
    */
   static size_t
   convert_to_gcda(char *buffer, struct gcov_info *info)
   {
           struct gcov_fn_info *fi_ptr;
           struct gcov_ctr_info *ci_ptr;
           unsigned int fi_idx;
           unsigned int ct_idx;
           unsigned int cv_idx;
           size_t pos = 0;
   
           /* File header. */
           pos += store_gcov_uint32(buffer, pos, GCOV_DATA_MAGIC);
           pos += store_gcov_uint32(buffer, pos, info->version);
           pos += store_gcov_uint32(buffer, pos, info->stamp);
   
           for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) {
                   fi_ptr = info->functions[fi_idx];
   
                   /* Function record. */
                   pos += store_gcov_uint32(buffer, pos, GCOV_TAG_FUNCTION);
                   pos += store_gcov_uint32(buffer, pos, GCOV_TAG_FUNCTION_LENGTH);
                   pos += store_gcov_uint32(buffer, pos, fi_ptr->ident);
                   pos += store_gcov_uint32(buffer, pos, fi_ptr->lineno_checksum);
                   pos += store_gcov_uint32(buffer, pos, fi_ptr->cfg_checksum);
   
                   ci_ptr = fi_ptr->ctrs;
   
                   for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) {
                           if (!counter_active(info, ct_idx))
                                   continue;
   
                           /* Counter record. */
                           pos += store_gcov_uint32(buffer, pos,
                                                 GCOV_TAG_FOR_COUNTER(ct_idx));
                           pos += store_gcov_uint32(buffer, pos, ci_ptr->num * 2);
   
                           for (cv_idx = 0; cv_idx < ci_ptr->num; cv_idx++) {
                                   pos += store_gcov_uint64(buffer, pos,
                                                         ci_ptr->values[cv_idx]);
                           }
   
                           ci_ptr++;
                   }
           }
   
           return (pos);
   }
   
   /**
    * gcov_iter_new - allocate and initialize profiling data iterator
    * @info: profiling data set to be iterated
    *
    * Return file iterator on success, %NULL otherwise.
    */
   struct gcov_iterator *
   gcov_iter_new(struct gcov_info *info)
   {
           struct gcov_iterator *iter;
   
           iter = malloc(sizeof(struct gcov_iterator), M_GCOV, M_NOWAIT|M_ZERO);
           if (iter == NULL)
                   goto err_free;
   
           iter->info = info;
           /* Dry-run to get the actual buffer size. */
           iter->size = convert_to_gcda(NULL, info);
           iter->buffer = malloc(iter->size, M_GCOV, M_NOWAIT);
           if (!iter->buffer)
                   goto err_free;
   
           convert_to_gcda(iter->buffer, info);
   
           return iter;
   
   err_free:
           free(iter, M_GCOV);
           return (NULL);
   }
   
   
   /**
    * gcov_iter_get_info - return profiling data set for given file iterator
    * @iter: file iterator
    */
   void
   gcov_iter_free(struct gcov_iterator *iter)
   {
           free(iter->buffer, M_GCOV);
           free(iter, M_GCOV);
   }
   
   /**
    * gcov_iter_get_info - return profiling data set for given file iterator
    * @iter: file iterator
    */
   struct gcov_info *
   gcov_iter_get_info(struct gcov_iterator *iter)
   {
           return (iter->info);
   }
   
   /**
    * gcov_iter_start - reset file iterator to starting position
    * @iter: file iterator
    */
   void
   gcov_iter_start(struct gcov_iterator *iter)
   {
           iter->pos = 0;
   }
   
   /**
    * gcov_iter_next - advance file iterator to next logical record
    * @iter: file iterator
    *
    * Return zero if new position is valid, non-zero if iterator has reached end.
    */
   int
   gcov_iter_next(struct gcov_iterator *iter)
   {
           if (iter->pos < iter->size)
                   iter->pos += ITER_STRIDE;
   
           if (iter->pos >= iter->size)
                   return (EINVAL);
   
           return 0;
   }
   
   /**
    * gcov_iter_write - write data for current pos to seq_file
    * @iter: file iterator
    * @seq: seq_file handle
    *
    * Return zero on success, non-zero otherwise.
    */
   int
   gcov_iter_write(struct gcov_iterator *iter, struct sbuf *sbuf)
   {
           size_t len;
   
           if (iter->pos >= iter->size)
                   return (EINVAL);
   
           len = ITER_STRIDE;
           if (iter->pos + len > iter->size)
                   len = iter->size - iter->pos;
   
           sbuf_bcat(sbuf, iter->buffer + iter->pos, len);
   
           return (0);
   }

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