[PATCH] Fix objdump -S with unit-at-a-time II
Andi Kleen
ak@suse.de
Fri Jun 1 20:59:00 GMT 2007
On Friday 01 June 2007 20:48, Andi Kleen wrote:
> Hallo,
>
> I finally got tired of objdump -S not working anymore with -funit-at-a-time
> which is default in newer gccs. The problem was that the old code
> can only print source files linearly with increasing line numbers,
> but the unit-at-a-time gcc tends to output the functions in a different
> order. This means typically only the first function was dumped and then
> nothing.
Small improvement to the previous patch. Previously the last line
of a source file wasn't properly indexed.
2007-06-01 Andi Kleen <ak@suse.de>
* objdump.c: Include sys/mman.h
(print_file_list): Remove f, add map, mapsize, linemap, maxline,
last_line, first fields.
(slurp_file): Add.
(index_file): Add
(print_file_open): Call slurp_file and index_file. Initialize new
fields.
(skip_to_line): Rename to print_line and write only single line.
(dump_line): Add.
(show_line): Change to new algorithm.
diff -u src/binutils/objdump.c-o src/binutils/objdump.c
--- src/binutils/objdump.c-o 2007-05-29 13:19:49.000000000 +0200
+++ src/binutils/objdump.c 2007-06-01 22:55:51.000000000 +0200
@@ -61,6 +61,10 @@
#include "debug.h"
#include "budbg.h"
+#ifdef HAVE_MMAP
+#include <sys/mman.h>
+#endif
+
/* Internal headers for the ELF .stab-dump code - sorry. */
#define BYTES_IN_WORD 32
#include "aout/aout64.h"
@@ -927,8 +931,12 @@
struct print_file_list *next;
const char *filename;
const char *modname;
- unsigned int line;
- FILE *f;
+ const char *map;
+ size_t mapsize;
+ const char **linemap;
+ unsigned maxline;
+ unsigned last_line;
+ int first;
};
static struct print_file_list *print_files;
@@ -938,6 +946,95 @@
#define SHOW_PRECEDING_CONTEXT_LINES (5)
+/* Read a complete file into memory. */
+
+static const char *
+slurp_file(const char *fn, size_t *size)
+{
+#ifdef HAVE_MMAP
+ int ps = getpagesize ();
+ size_t msize;
+#endif
+ const char *map;
+ struct stat st;
+ int fd = open (fn, O_RDONLY);
+ if (fd < 0)
+ return NULL;
+ if (fstat (fd, &st) < 0)
+ return NULL;
+ *size = st.st_size;
+#ifdef HAVE_MMAP
+ msize = (*size + ps - 1) & ~(ps - 1);
+ map = mmap (NULL, msize, PROT_READ, MAP_SHARED, fd, 0);
+ if (map != (char*)-1L)
+ {
+ close(fd);
+ return map;
+ }
+#endif
+ map = malloc(*size);
+ if (!map || (size_t)read (fd, (char *)map, *size) != *size)
+ {
+ free((void *)map);
+ map = NULL;
+ }
+ close(fd);
+ return map;
+}
+
+#define line_map_decrease 5
+
+/* Precompute array of lines for a mapped file. */
+
+static const char **
+index_file (const char *map, size_t size, unsigned int *maxline)
+{
+ const char *p, *lstart, *end;
+ int chars_per_line = 45; /* first iteration will use 40 */
+ unsigned int lineno;
+ const char **linemap = NULL;
+ unsigned long line_map_size = 0;
+
+ lineno = 0;
+ lstart = map;
+ end = map + size;
+ for (p = map; p < end; p++)
+ {
+ if (*p == '\n')
+ {
+ if (p + 1 < end && p[1] == '\r')
+ p++;
+ }
+ else if (*p == '\r')
+ {
+ if (p + 1 < end && p[1] == '\n')
+ p++;
+ }
+ else
+ continue;
+
+ /* end of line found */
+
+ if (linemap == NULL || line_map_size < lineno + 1)
+ {
+ unsigned long newsize;
+
+ chars_per_line -= line_map_decrease;
+ if (chars_per_line <= 1)
+ chars_per_line = 1;
+ line_map_size = size / chars_per_line + 1;
+ newsize = line_map_size * sizeof(char *);
+ linemap = xrealloc (linemap, newsize);
+ }
+
+ linemap[lineno++] = lstart;
+ lstart = p + 1;
+ }
+
+ *maxline = lineno;
+ return linemap;
+}
+
/* Tries to open MODNAME, and if successful adds a node to print_files
linked list and returns that node. Returns NULL on failure. */
@@ -945,24 +1042,22 @@
try_print_file_open (const char *origname, const char *modname)
{
struct print_file_list *p;
- FILE *f;
- f = fopen (modname, "r");
- if (f == NULL)
- return NULL;
+ p = xmalloc (sizeof (struct print_file_list));
- if (print_files != NULL && print_files->f != NULL)
+ p->map = slurp_file (modname, &p->mapsize);
+ if (p->map == NULL)
{
- fclose (print_files->f);
- print_files->f = NULL;
+ free(p);
+ return NULL;
}
-
- p = xmalloc (sizeof (struct print_file_list));
+
+ p->linemap = index_file (p->map, p->mapsize, &p->maxline);
+ p->last_line = 0;
p->filename = origname;
p->modname = modname;
- p->line = 0;
- p->f = f;
p->next = print_files;
+ p->first = 1;
print_files = p;
return p;
}
@@ -1021,29 +1116,32 @@
return NULL;
}
-/* Skip ahead to a given line in a file, optionally printing each
- line. */
+/* Print a source file line */
-static void
-skip_to_line (struct print_file_list *p, unsigned int line,
- bfd_boolean show)
+static void
+print_line (struct print_file_list *p, unsigned int line)
{
- while (p->line < line)
- {
- char buf[100];
-
- if (fgets (buf, sizeof buf, p->f) == NULL)
- {
- fclose (p->f);
- p->f = NULL;
- break;
- }
+ const char *l;
+
+ --line;
+ if (line >= p->maxline)
+ return;
+ l = p->linemap [line];
+ fwrite (l, 1, strcspn (l, "\n\r"), stdout);
+ putchar ('\n');
+}
- if (show)
- printf ("%s", buf);
+/* Print a range of source code lines. */
- if (strchr (buf, '\n') != NULL)
- ++p->line;
+static void
+dump_lines (struct print_file_list *p, unsigned int start, unsigned int end)
+{
+ if (p->map == NULL)
+ return;
+ while (start <= end)
+ {
+ print_line (p, start);
+ start++;
}
}
@@ -1084,79 +1182,31 @@
&& line > 0)
{
struct print_file_list **pp, *p;
+ unsigned l;
for (pp = &print_files; *pp != NULL; pp = &(*pp)->next)
if (strcmp ((*pp)->filename, filename) == 0)
break;
p = *pp;
- if (p != NULL)
- {
- if (p != print_files)
- {
- int l;
-
- /* We have reencountered a file name which we saw
- earlier. This implies that either we are dumping out
- code from an included file, or the same file was
- linked in more than once. There are two common cases
- of an included file: inline functions in a header
- file, and a bison or flex skeleton file. In the
- former case we want to just start printing (but we
- back up a few lines to give context); in the latter
- case we want to continue from where we left off. I
- can't think of a good way to distinguish the cases,
- so I used a heuristic based on the file name. */
- if (strcmp (p->filename + strlen (p->filename) - 2, ".h") != 0)
- l = p->line;
- else
- {
- l = line - SHOW_PRECEDING_CONTEXT_LINES;
- if (l < 0)
- l = 0;
- }
-
- if (p->f == NULL)
- {
- p->f = fopen (p->modname, "r");
- p->line = 0;
- }
- if (p->f != NULL)
- skip_to_line (p, l, FALSE);
-
- if (print_files->f != NULL)
- {
- fclose (print_files->f);
- print_files->f = NULL;
- }
- }
-
- if (p->f != NULL)
- {
- skip_to_line (p, line, TRUE);
- *pp = p->next;
- p->next = print_files;
- print_files = p;
- }
- }
- else
- {
+ if (p == NULL)
p = update_source_path (filename);
- if (p != NULL)
- {
- int l;
-
- if (file_start_context)
- l = 0;
- else
- l = line - SHOW_PRECEDING_CONTEXT_LINES;
- if (l < 0)
- l = 0;
- skip_to_line (p, l, FALSE);
- if (p->f != NULL)
- skip_to_line (p, line, TRUE);
- }
+ if (p != NULL && line != p->last_line)
+ {
+ if (file_start_context && p->first)
+ l = 1;
+ else
+ {
+ l = line - SHOW_PRECEDING_CONTEXT_LINES;
+ if (l >= line)
+ l = 1;
+ if (p->last_line >= l && p->last_line <= line)
+ l = p->last_line + 1;
+ }
+ dump_lines (p, l, line);
+ p->last_line = line;
+ p->first = 0;
}
}
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