On 08/15/2016 12:47 PM, Nathan Sidwell wrote:
> On 08/09/16 10:32, Martin Liška wrote:
>> Hello.
>>
>> Following enhancement for gcov solves issues when we cannot create a file
>> due to a filesystem
>> path length limit. Selected approach utilizes existing md5sum functions.
>>
>> Patch survives make check -k RUNTESTFLAGS="gcov.exp" on x86_64-linux-gnu.
>>
>> Ready for trunk?
>> Thanks,
>> Martin
>>
>
> + [@option{-e}|@option{--hash-names}]
> '--hash-filenames' would be better. Let's not confuse the user with thinking
> may be the function names are hashed. (or perhaps '--hash-paths'? The
> world's a little unclear on whether 'filename->last bit of file path, or the
> whole thing')
>
>
> +/* For situations when a long name can potentially hit filesystem path limit,
> + let's calculate md5sum of the patch and create file x.gcov##md5sum.gcov.
> */
> +
> +static int flag_hash_names = 0;
> +
> s/patch/path.
> Which bit of 'x.gcov##md5sum.gcov' is the hash? is it 'x' or sommethihg
> else? Perhaps this more detailed comment should be near where the filename is
> generated. And this flag just labelled as someting like 'hash long pathnames'
>
> + fnotice (file, " -e, --hash-names Use hash of file path in
> "
> .. and ..
> + { "long-file-names", no_argument, NULL, 'e' },
Hi Nathan.
All nits are applied in the second version of patch.
>
> don't seem to match? Why 'e'?
I've renamed it to -x, well, a lot of letters are already occupied.
Martin
>
> nathan
>From b923bc8d838cf1de01a97db8f5ea5c78519a782b Mon Sep 17 00:00:00 2001
From: marxin <mli...@suse.cz>
Date: Tue, 9 Aug 2016 16:27:10 +0200
Subject: [PATCH] gcov: add new option (--hash-filenames) (PR
gcov-profile/36412).
gcc/ChangeLog:
2016-08-09 Martin Liska <mli...@suse.cz>
PR gcov-profile/36412
* doc/gcov.texi: Document --hash-filenames(-x).
* gcov.c (print_usage): Add the option.
(process_args): Process the option.
(md5sum_to_hex): New function.
(make_gcov_file_name): Do the md5sum and append it to a
filename.
---
gcc/doc/gcov.texi | 7 +++++++
gcc/gcov.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 53 insertions(+), 2 deletions(-)
diff --git a/gcc/doc/gcov.texi b/gcc/doc/gcov.texi
index df58df8..1737416 100644
--- a/gcc/doc/gcov.texi
+++ b/gcc/doc/gcov.texi
@@ -133,6 +133,7 @@ gcov [@option{-v}|@option{--version}] [@option{-h}|@option{--help}]
[@option{-r}|@option{--relative-only}]
[@option{-s}|@option{--source-prefix} @var{directory}]
[@option{-u}|@option{--unconditional-branches}]
+ [@option{-x}|@option{--hash-filenames}]
@var{files}
@c man end
@c man begin SEEALSO
@@ -278,6 +279,12 @@ branch:28,nottaken
Display demangled function names in output. The default is to show
mangled function names.
+@item -x
+@itemx --hash-filenames
+For situations when a long name can potentially hit filesystem path limit,
+let's calculate md5sum of the path and create file
+@file{source_file.c##<md5sum>.gcov}.
+
@end table
@command{gcov} should be run with the current directory the same as that
diff --git a/gcc/gcov.c b/gcc/gcov.c
index 30fc167..614f371 100644
--- a/gcc/gcov.c
+++ b/gcc/gcov.c
@@ -43,6 +43,7 @@ along with Gcov; see the file COPYING3. If not see
#include <vector>
#include <algorithm>
+#include "md5.h"
using namespace std;
@@ -359,6 +360,11 @@ static int flag_demangled_names = 0;
static int flag_long_names = 0;
+/* For situations when a long name can potentially hit filesystem path limit,
+ let's calculate md5sum of the path and append it to a file name. */
+
+static int flag_hash_filenames = 0;
+
/* Output count information for every basic block, not merely those
that contain line number information. */
@@ -667,6 +673,7 @@ print_usage (int error_p)
fnotice (file, " -s, --source-prefix DIR Source prefix to elide\n");
fnotice (file, " -u, --unconditional-branches Show unconditional branch counts too\n");
fnotice (file, " -v, --version Print version number, then exit\n");
+ fnotice (file, " -x, --hash-filenames Hash long pathnames\n");
fnotice (file, "\nFor bug reporting instructions, please see:\n%s.\n",
bug_report_url);
exit (status);
@@ -706,6 +713,7 @@ static const struct option options[] =
{ "source-prefix", required_argument, NULL, 's' },
{ "unconditional-branches", no_argument, NULL, 'u' },
{ "display-progress", no_argument, NULL, 'd' },
+ { "hash-filenames", no_argument, NULL, 'x' },
{ 0, 0, 0, 0 }
};
@@ -716,8 +724,8 @@ process_args (int argc, char **argv)
{
int opt;
- while ((opt = getopt_long (argc, argv, "abcdfhilmno:s:pruv", options, NULL)) !=
- -1)
+ const char *opts = "abcdfhilmno:s:pruvx";
+ while ((opt = getopt_long (argc, argv, opts, options, NULL)) != -1)
{
switch (opt)
{
@@ -770,6 +778,9 @@ process_args (int argc, char **argv)
break;
case 'v':
print_version ();
+ case 'x':
+ flag_hash_filenames = 1;
+ break;
/* print_version will exit. */
default:
print_usage (true);
@@ -2147,6 +2158,15 @@ canonicalize_name (const char *name)
return result;
}
+/* Print hex representation of 16 bytes from SUM and write it to BUFFER. */
+
+static void
+md5sum_to_hex (const char *sum, char *buffer)
+{
+ for (unsigned i = 0; i < 16; i++)
+ sprintf (buffer + (2 * i), "%02x", sum[i]);
+}
+
/* Generate an output file name. INPUT_NAME is the canonicalized main
input file and SRC_NAME is the canonicalized file name.
LONG_OUTPUT_NAMES and PRESERVE_PATHS affect name generation. With
@@ -2184,6 +2204,30 @@ make_gcov_file_name (const char *input_name, const char *src_name)
ptr = mangle_name (src_name, ptr);
strcpy (ptr, ".gcov");
+ /* With -x flag, file names will be in format:
+ source_file.c##<md5sum>.gcov. */
+ if (flag_hash_filenames)
+ {
+ md5_ctx ctx;
+ char md5sum[16];
+ char md5sum_hex[33];
+
+ md5_init_ctx (&ctx);
+ md5_process_bytes (result, strlen (result), &ctx);
+ md5_finish_ctx (&ctx, md5sum);
+ md5sum_to_hex (md5sum, md5sum_hex);
+ free (result);
+
+ result = XNEWVEC (char, strlen (src_name) + 50);
+ ptr = result;
+ ptr = mangle_name (src_name, ptr);
+ ptr[0] = ptr[1] = '#';
+ ptr += 2;
+ memcpy (ptr, md5sum_hex, 32);
+ ptr += 32;
+ strcpy (ptr, ".gcov");
+ }
+
return result;
}
--
2.9.2
