Patchwork Add option for dumping to stderr (issue6190057)

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Submitter Sharad Singhai
Date May 10, 2012, 8:18 a.m.
Message ID <CAKxPW64DYUKnKOrc4WHuTatXEcsmFSpC7JqCKFdauy+P2G2Byg@mail.gmail.com>
Download mbox | patch
Permalink /patch/158224/
State New
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Sharad Singhai - May 10, 2012, 8:18 a.m.
Okay, I have restored the original behavior where standard streams
were considered weak. Thus in case of a conflict, the
standard streams have lower precedence. For example,

               gcc -O2 -fdump-tree-pre=stdout -fdump-tree-pre ...

does the PRE dump in auto numbered file since stdout has lower
precedence. Also this works as expected,

               gcc -O2 -fdump-tree-pre=pre.txt -fdump-tree-all=stderr ...

It outputs PRE dump to pre.txt while the remaining tree dumps are
output on to stderr. Does it look okay?

Thanks,
Sharad


2012-05-09   Sharad Singhai  <singhai@google.com>

	* doc/invoke.texi: Add documentation for the new option.
	* tree-dump.c (dump_get_standard_stream): New function.
	(dump_files): Update for new field.
	(dump_switch_p_1): Handle dump filenames.
	(dump_begin): Likewise.
	(get_dump_file_name): Likewise.
	(dump_end): Remove attribute.
	(dump_enable_all): Add new parameter FILENAME.
	All callers updated.
	* tree-pass.h (enum tree_dump_index): Add new constant.
	(struct dump_file_info): Add new field FILENAME.
	* testsuite/g++.dg/other/dump-filename-1.C: New test.


Sharad


On Wed, May 9, 2012 at 5:31 PM, Xinliang David Li <davidxl@google.com> wrote:
> Bummer.  I was thinking to reserve '=' for selective  dumping:
>
> -fdump-tree-pre=<func_list_regexp>
>
> I guess this can be achieved via @
>
> -fdump-tree-pre@<func_list>
>
> -fdump-tree-pre=<file_name>@<func_list>
>
>
> Another issue -- I don't think the current precedence rule is correct.
> Consider that -fopt-info=2 will be mapped to
>
> -fdump-tree-all-transform-verbose2=stderr
> -fdump-rtl-all-transform-verbose2=stderr
>
> then
>
> the current precedence rule will cause surprise when the following is used
>
> -fopt-info -fdump-tree-pre
>
> The PRE dump will be emitted to stderr which is not what user wants.
> In short, special streams should be treated as 'weak' the same way as
> your previous implementation.
>
> thanks,
>
> David
>
>
>
> On Wed, May 9, 2012 at 4:56 PM, Sharad Singhai <singhai@google.com> wrote:
>> Thanks for your suggestions/comments. I have updated the patch and
>> documentation. It supports the following usage:
>>
>> gcc .... -fdump-tree-all=tree.dump -fdump-tree-pre=stdout
>> -fdump-rtl-ira=ira.dump
>>
>> Here all tree dumps except the PRE are output into tree.dump, PRE dump
>> goes to stdout and the IRA dump goes to ira.dump.
>>
>> Thanks,
>> Sharad
>>
>> 2012-05-09   Sharad Singhai  <singhai@google.com>
>>
>>        * doc/invoke.texi: Add documentation for the new option.
>>        * tree-dump.c (dump_get_standard_stream): New function.
>>        (dump_files): Update for new field.
>>        (dump_switch_p_1): Handle dump filenames.
>>        (dump_begin): Likewise.
>>        (get_dump_file_name): Likewise.
>>        (dump_end): Remove attribute.
>>        (dump_enable_all): Add new parameter FILENAME.
>>        All callers updated.
>>        (enable_rtl_dump_file):
>>        * tree-pass.h (enum tree_dump_index): Add new constant.
>>        (struct dump_file_info): Add new field FILENAME.
>>        * testsuite/g++.dg/other/dump-filename-1.C: New test.
>>
>> Index: doc/invoke.texi
>> ===================================================================
>> --- doc/invoke.texi     (revision 187265)
>> +++ doc/invoke.texi     (working copy)
>> @@ -5322,20 +5322,23 @@ Here are some examples showing uses of these optio
>>
>>  @item -d@var{letters}
>>  @itemx -fdump-rtl-@var{pass}
>> +@itemx -fdump-rtl-@var{pass}=@var{filename}
>>  @opindex d
>>  Says to make debugging dumps during compilation at times specified by
>>  @var{letters}.  This is used for debugging the RTL-based passes of the
>>  compiler.  The file names for most of the dumps are made by appending
>>  a pass number and a word to the @var{dumpname}, and the files are
>> -created in the directory of the output file.  Note that the pass
>> -number is computed statically as passes get registered into the pass
>> -manager.  Thus the numbering is not related to the dynamic order of
>> -execution of passes.  In particular, a pass installed by a plugin
>> -could have a number over 200 even if it executed quite early.
>> -@var{dumpname} is generated from the name of the output file, if
>> -explicitly specified and it is not an executable, otherwise it is the
>> -basename of the source file. These switches may have different effects
>> -when @option{-E} is used for preprocessing.
>> +created in the directory of the output file. If the
>> +@option{=@var{filename}} is appended to the longer form of the dump
>> +option then the dump is done on that file instead of numbered
>> +files. Note that the pass number is computed statically as passes get
>> +registered into the pass manager.  Thus the numbering is not related
>> +to the dynamic order of execution of passes.  In particular, a pass
>> +installed by a plugin could have a number over 200 even if it executed
>> +quite early.  @var{dumpname} is generated from the name of the output
>> +file, if explicitly specified and it is not an executable, otherwise
>> +it is the basename of the source file. These switches may have
>> +different effects when @option{-E} is used for preprocessing.
>>
>>  Debug dumps can be enabled with a @option{-fdump-rtl} switch or some
>>  @option{-d} option @var{letters}.  Here are the possible
>> @@ -5719,15 +5722,18 @@ counters for each function compiled.
>>
>>  @item -fdump-tree-@var{switch}
>>  @itemx -fdump-tree-@var{switch}-@var{options}
>> +@itemx -fdump-tree-@var{switch}-@var{options}=@var{filename}
>>  @opindex fdump-tree
>>  Control the dumping at various stages of processing the intermediate
>>  language tree to a file.  The file name is generated by appending a
>>  switch specific suffix to the source file name, and the file is
>> -created in the same directory as the output file.  If the
>> -@samp{-@var{options}} form is used, @var{options} is a list of
>> -@samp{-} separated options which control the details of the dump.  Not
>> -all options are applicable to all dumps; those that are not
>> -meaningful are ignored.  The following options are available
>> +created in the same directory as the output file. In case of
>> +@option{=@var{filename}} option, the dump is output on the given file
>> +name instead.  If the @samp{-@var{options}} form is used,
>> +@var{options} is a list of @samp{-} separated options which control
>> +the details or location of the dump.  Not all options are applicable
>> +to all dumps; those that are not meaningful are ignored.  The
>> +following options are available
>>
>>  @table @samp
>>  @item address
>> @@ -5765,9 +5771,46 @@ Enable showing the tree dump for each statement.
>>  Enable showing the EH region number holding each statement.
>>  @item scev
>>  Enable showing scalar evolution analysis details.
>> +@item slim
>> +Inhibit dumping of members of a scope or body of a function merely
>> +because that scope has been reached.  Only dump such items when they
>> +are directly reachable by some other path.  When dumping pretty-printed
>> +trees, this option inhibits dumping the bodies of control structures.
>> +@item =@var{filename}
>> +Instead of using an auto generated dump file name, use the given file
>> +name. The file names @file{stdout} and @file{stderr} are treated
>> +specially and are considered already open standard streams. For
>> +example:
>> +
>> +@smallexample
>> +gcc -O2 -fdump-tree-pre=stderr -fdump-rtl-ira=ira.txt ...
>> +@end smallexample
>> +
>> +outputs PRE dump on @file{stderr}, while the IRA dump is output in a
>> +file named @file{ira.txt}.
>> +
>> +In case of any conflicts, the command line file name takes precedence
>> +over generated file names. For example:
>> +
>> +@smallexample
>> +gcc -O2 -fdump-tree-pre=stdout -fdump-tree-pre ...
>> +gcc -O2 -fdump-tree-pre -fdump-tree-pre=stdout ...
>> +@end smallexample
>> +
>> +Both of the above output the PRE dump on @file{stdout}. However, if
>> +there are multiple command line file names are applicable then the
>> +last one is used. Thus the command
>> +
>> +@smallexample
>> +gcc -O2 -fdump-tree-pre=stderr -fdump-tree-all=all.txt
>> +@end smallexample
>> +
>> +outputs all the dumps in @file{all.txt} because the stderr option for
>> +PRE dump is overridden by a later option.
>> +
>>  @item all
>> -Turn on all options, except @option{raw}, @option{slim}, @option{verbose}
>> -and @option{lineno}.
>> +Turn on all options, except @option{raw}, @option{slim}, @option{verbose},
>> +@option{lineno}.
>>  @end table
>>
>>  The following tree dumps are possible:
>> @@ -5913,6 +5956,7 @@ is made by appending @file{.vrp} to the source fil
>>  @item all
>>  @opindex fdump-tree-all
>>  Enable all the available tree dumps with the flags provided in this option.
>> +
>>  @end table
>>
>>  @item -ftree-vectorizer-verbose=@var{n}
>> Index: tree-dump.c
>> ===================================================================
>> --- tree-dump.c (revision 187265)
>> +++ tree-dump.c (working copy)
>> @@ -773,20 +773,20 @@ dump_node (const_tree t, int flags, FILE *stream)
>>    tree_dump_index enumeration in tree-pass.h.  */
>>  static struct dump_file_info dump_files[TDI_end] =
>>  {
>> -  {NULL, NULL, NULL, 0, 0, 0},
>> -  {".cgraph", "ipa-cgraph", NULL, TDF_IPA, 0,  0},
>> -  {".tu", "translation-unit", NULL, TDF_TREE, 0, 1},
>> -  {".class", "class-hierarchy", NULL, TDF_TREE, 0, 2},
>> -  {".original", "tree-original", NULL, TDF_TREE, 0, 3},
>> -  {".gimple", "tree-gimple", NULL, TDF_TREE, 0, 4},
>> -  {".nested", "tree-nested", NULL, TDF_TREE, 0, 5},
>> -  {".vcg", "tree-vcg", NULL, TDF_TREE, 0, 6},
>> -  {".ads", "ada-spec", NULL, 0, 0, 7},
>> +  {NULL, NULL, NULL, NULL, 0, 0, 0},
>> +  {".cgraph", "ipa-cgraph", NULL, NULL, TDF_IPA, 0,  0},
>> +  {".tu", "translation-unit", NULL, NULL, TDF_TREE, 0, 1},
>> +  {".class", "class-hierarchy", NULL, NULL, TDF_TREE, 0, 2},
>> +  {".original", "tree-original", NULL, NULL, TDF_TREE, 0, 3},
>> +  {".gimple", "tree-gimple", NULL, NULL, TDF_TREE, 0, 4},
>> +  {".nested", "tree-nested", NULL, NULL, TDF_TREE, 0, 5},
>> +  {".vcg", "tree-vcg", NULL, NULL, TDF_TREE, 0, 6},
>> +  {".ads", "ada-spec", NULL, NULL, 0, 0, 7},
>>  #define FIRST_AUTO_NUMBERED_DUMP 8
>>
>> -  {NULL, "tree-all", NULL, TDF_TREE, 0, 0},
>> -  {NULL, "rtl-all", NULL, TDF_RTL, 0, 0},
>> -  {NULL, "ipa-all", NULL, TDF_IPA, 0, 0},
>> +  {NULL, "tree-all", NULL, NULL, TDF_TREE, 0, 0},
>> +  {NULL, "rtl-all", NULL, NULL, TDF_RTL, 0, 0},
>> +  {NULL, "ipa-all", NULL, NULL, TDF_IPA, 0, 0},
>>  };
>>
>>  /* Dynamically registered tree dump files and switches.  */
>> @@ -802,7 +802,7 @@ struct dump_option_value_info
>>  };
>>
>>  /* Table of dump options. This must be consistent with the TDF_* flags
>> -   in tree.h */
>> +   in tree-pass.h */
>>  static const struct dump_option_value_info dump_options[] =
>>  {
>>   {"address", TDF_ADDRESS},
>> @@ -892,6 +892,9 @@ get_dump_file_name (int phase)
>>   if (dfi->state == 0)
>>     return NULL;
>>
>> +  if (dfi->filename)
>> +    return xstrdup (dfi->filename);
>> +
>>   if (dfi->num < 0)
>>     dump_id[0] = '\0';
>>   else
>> @@ -911,6 +914,22 @@ get_dump_file_name (int phase)
>>   return concat (dump_base_name, dump_id, dfi->suffix, NULL);
>>  }
>>
>> +/* If the DFI dump output corresponds to stdout or stderr stream,
>> +   return that stream, NULL otherwise.  */
>> +
>> +static FILE *
>> +dump_get_standard_stream (struct dump_file_info *dfi)
>> +{
>> +  if (!dfi->filename)
>> +    return NULL;
>> +
>> +  return strcmp("stderr", dfi->filename) == 0
>> +    ? stderr
>> +    : strcmp("stdout", dfi->filename) == 0
>> +    ?  stdout
>> +    : NULL;
>> +}
>> +
>>  /* Begin a tree dump for PHASE. Stores any user supplied flag in
>>    *FLAG_PTR and returns a stream to write to. If the dump is not
>>    enabled, returns NULL.
>> @@ -926,14 +945,20 @@ dump_begin (int phase, int *flag_ptr)
>>   if (phase == TDI_none || !dump_enabled_p (phase))
>>     return NULL;
>>
>> -  name = get_dump_file_name (phase);
>>   dfi = get_dump_file_info (phase);
>> -  stream = fopen (name, dfi->state < 0 ? "w" : "a");
>> -  if (!stream)
>> -    error ("could not open dump file %qs: %m", name);
>> +  stream = dump_get_standard_stream (dfi);
>> +  if (stream)
>> +    dfi->state = 1;
>>   else
>> -    dfi->state = 1;
>> -  free (name);
>> +    {
>> +      name = get_dump_file_name (phase);
>> +      stream = fopen (name, dfi->state < 0 ? "w" : "a");
>> +      if (!stream)
>> +        error ("could not open dump file %qs: %m", name);
>> +      else
>> +        dfi->state = 1;
>> +      free (name);
>> +    }
>>
>>   if (flag_ptr)
>>     *flag_ptr = dfi->flags;
>> @@ -987,35 +1012,46 @@ dump_flag_name (int phase)
>>    dump_begin.  */
>>
>>  void
>> -dump_end (int phase ATTRIBUTE_UNUSED, FILE *stream)
>> +dump_end (int phase, FILE *stream)
>>  {
>> -  fclose (stream);
>> +  struct dump_file_info *dfi = get_dump_file_info (phase);
>> +  if (!dump_get_standard_stream (dfi))
>> +    fclose (stream);
>>  }
>>
>> -/* Enable all tree dumps.  Return number of enabled tree dumps.  */
>> +/* Enable all tree dumps with FLAGS on FILENAME.  Return number of
>> +   enabled tree dumps.  */
>>
>>  static int
>> -dump_enable_all (int flags)
>> +dump_enable_all (int flags, const char *filename)
>>  {
>>   int ir_dump_type = (flags & (TDF_TREE | TDF_RTL | TDF_IPA));
>>   int n = 0;
>>   size_t i;
>>
>>   for (i = TDI_none + 1; i < (size_t) TDI_end; i++)
>> -    if ((dump_files[i].flags & ir_dump_type))
>> -      {
>> -        dump_files[i].state = -1;
>> -        dump_files[i].flags |= flags;
>> -        n++;
>> -      }
>> +    {
>> +      if ((dump_files[i].flags & ir_dump_type))
>> +        {
>> +          dump_files[i].state = -1;
>> +          dump_files[i].flags |= flags;
>> +          n++;
>> +          if (filename)
>> +            dump_files[i].filename = xstrdup (filename);
>> +        }
>> +    }
>>
>>   for (i = 0; i < extra_dump_files_in_use; i++)
>> -    if ((extra_dump_files[i].flags & ir_dump_type))
>> -      {
>> -        extra_dump_files[i].state = -1;
>> -        extra_dump_files[i].flags |= flags;
>> -       n++;
>> -      }
>> +    {
>> +      if ((extra_dump_files[i].flags & ir_dump_type))
>> +        {
>> +          extra_dump_files[i].state = -1;
>> +          extra_dump_files[i].flags |= flags;
>> +          n++;
>> +          if (filename)
>> +            extra_dump_files[i].filename = xstrdup (filename);
>> +        }
>> +    }
>>
>>   return n;
>>  }
>> @@ -1037,7 +1073,7 @@ dump_switch_p_1 (const char *arg, struct dump_file
>>   if (!option_value)
>>     return 0;
>>
>> -  if (*option_value && *option_value != '-')
>> +  if (*option_value && *option_value != '-' && *option_value != '=')
>>     return 0;
>>
>>   ptr = option_value;
>> @@ -1052,17 +1088,30 @@ dump_switch_p_1 (const char *arg, struct dump_file
>>       while (*ptr == '-')
>>        ptr++;
>>       end_ptr = strchr (ptr, '-');
>> +
>>       if (!end_ptr)
>>        end_ptr = ptr + strlen (ptr);
>>       length = end_ptr - ptr;
>>
>> +      if (*ptr == '=')
>> +        {
>> +          /* Interpret rest of the argument as a dump filename.  This
>> +             filename overrides generated dump names as well as other
>> +             command line filenames.  */
>> +          flags |= TDF_FILENAME;
>> +          if (dfi->filename)
>> +            free (dfi->filename);
>> +          dfi->filename = xstrdup (ptr + 1);
>> +          break;
>> +        }
>> +
>>       for (option_ptr = dump_options; option_ptr->name; option_ptr++)
>>        if (strlen (option_ptr->name) == length
>>            && !memcmp (option_ptr->name, ptr, length))
>> -         {
>> -           flags |= option_ptr->value;
>> +          {
>> +            flags |= option_ptr->value;
>>            goto found;
>> -         }
>> +          }
>>       warning (0, "ignoring unknown option %q.*s in %<-fdump-%s%>",
>>               length, ptr, dfi->swtch);
>>     found:;
>> @@ -1075,7 +1124,7 @@ dump_switch_p_1 (const char *arg, struct dump_file
>>   /* Process -fdump-tree-all and -fdump-rtl-all, by enabling all the
>>      known dumps.  */
>>   if (dfi->suffix == NULL)
>> -    dump_enable_all (dfi->flags);
>> +    dump_enable_all (dfi->flags, dfi->filename);
>>
>>   return 1;
>>  }
>> @@ -1124,5 +1173,5 @@ dump_function (int phase, tree fn)
>>  bool
>>  enable_rtl_dump_file (void)
>>  {
>> -  return dump_enable_all (TDF_RTL | TDF_DETAILS | TDF_BLOCKS) > 0;
>> +  return dump_enable_all (TDF_RTL | TDF_DETAILS | TDF_BLOCKS, NULL) > 0;
>>  }
>> Index: tree-pass.h
>> ===================================================================
>> --- tree-pass.h (revision 187265)
>> +++ tree-pass.h (working copy)
>> @@ -84,8 +84,9 @@ enum tree_dump_index
>>  #define TDF_ENUMERATE_LOCALS (1 << 22) /* Enumerate locals by uid.  */
>>  #define TDF_CSELIB     (1 << 23)       /* Dump cselib details.  */
>>  #define TDF_SCEV       (1 << 24)       /* Dump SCEV details.  */
>> +#define TDF_FILENAME    (1 << 25)      /* Dump on provided filename
>> +                                           instead of constructing one. */
>>
>> -
>>  /* In tree-dump.c */
>>
>>  extern char *get_dump_file_name (int);
>> @@ -222,6 +223,8 @@ struct dump_file_info
>>   const char *suffix;           /* suffix to give output file.  */
>>   const char *swtch;            /* command line switch */
>>   const char *glob;             /* command line glob  */
>> +  const char *filename;         /* use this filename instead of making
>> +                                   up one using dump_base_name + suffix.  */
>>   int flags;                    /* user flags */
>>   int state;                    /* state of play */
>>   int num;                      /* dump file number */
>> Index: testsuite/g++.dg/other/dump-filename-1.C
>> ===================================================================
>> --- testsuite/g++.dg/other/dump-filename-1.C    (revision 0)
>> +++ testsuite/g++.dg/other/dump-filename-1.C    (revision 0)
>> @@ -0,0 +1,11 @@
>> +// Test that the dump to a user-defined file works correctly.
>> +/* { dg-options "-O2 -fdump-tree-original=foobar.dump" } */
>> +
>> +void test (int *b, int *e, int stride)
>> +  {
>> +    for (int *p = b; p != e; p += stride)
>> +      *p = 1;
>> +  }
>> +
>> +/* { dg-final { scan-file foobar.dump ";; Function void test" } } */
>> +/* { dg-final { remove-build-file "foobar.dump" } } */
>>
>>
>> On Wed, May 9, 2012 at 12:22 AM, Gabriel Dos Reis
>> <gdr@integrable-solutions.net> wrote:
>>> On Wed, May 9, 2012 at 1:46 AM, Sharad Singhai <singhai@google.com> wrote:
>>> [...]
>>>
>>>> +@item -fdump-rtl-all=stderr
>>>> +@opindex fdump-rtl-all=stderr
>>>
>>> You do not need to have a separate index entry for '=stderr' or '=stdout'.
>>> Rather, expand the description to state this in all the documentation
>>> for -fdump-xxx=yyy.
>>>
>>> [...]
>>>
>>>> +/* Return non-zero iff the USER_FILENAME corresponds to stdout or
>>>> +   stderr stream.  */
>>>> +
>>>> +static int
>>>> +dump_stream_p (const char *user_filename)
>>>> +{
>>>> +  if (user_filename)
>>>> +    return !strncmp ("stderr", user_filename, 6) ||
>>>> +      !strncmp ("stdout", user_filename, 6);
>>>> +  else
>>>> +    return 0;
>>>> +}
>>>
>>> The name is ambiguous.
>>> This function is testing whether its string argument designates one of
>>> the *standard* output streams.  Name it to reflect that..
>>> Have it take the dump state context. Also the coding convention: the binary
>>> operator "||" should be on next line.  In fact the thing could be
>>> simpler.   Instead of
>>> testing over and over again against "stderr" (once in this function, then again
>>> later), just return the corresponding standard FILE* pointer.
>>> Also, this is a case of overuse of strncmp.  If you name the function
>>> dump_get_standard_stream:
>>>
>>>    return strcmp("stderr", dfi->user_filename) == 0
>>>       ? stderr
>>>        : stdcmp("stdout", dfi->use_filename)
>>>        ?  stdout
>>>        : NULL;
>>>
>>> you can simplify:
>>>
>>>> -  name = get_dump_file_name (phase);
>>>>   dfi = get_dump_file_info (phase);
>>>> -  stream = fopen (name, dfi->state < 0 ? "w" : "a");
>>>> -  if (!stream)
>>>> -    error ("could not open dump file %qs: %m", name);
>>>> +  if (dump_stream_p (dfi->user_filename))
>>>> +    {
>>>> +      if (!strncmp ("stderr", dfi->user_filename, 6))
>>>> +        stream = stderr;
>>>> +      else
>>>> +        if (!strncmp ("stdout", dfi->user_filename, 6))
>>>> +          stream = stdout;
>>>> +        else
>>>> +          error ("unknown stream: %qs: %m", dfi->user_filename);
>>>> +      dfi->state = 1;
>>>> +    }
>>>>   else
>>>> -    dfi->state = 1;
>>>> -  free (name);
>>>> +    {
>>>> +      name = get_dump_file_name (phase);
>>>> +      stream = fopen (name, dfi->state < 0 ? "w" : "a");
>>>> +      if (!stream)
>>>> +        error ("could not open dump file %qs: %m", name);
>>>> +      else
>>>> +        dfi->state = 1;
>>>> +      free (name);
>>>> +    }
>>>>
>>>>   if (flag_ptr)
>>>>     *flag_ptr = dfi->flags;
>>>> @@ -987,35 +1017,45 @@ dump_flag_name (int phase)
>>>>    dump_begin.  */
>>>>
>>>>  void
>>>> -dump_end (int phase ATTRIBUTE_UNUSED, FILE *stream)
>>>> +dump_end (int phase, FILE *stream)
>>>>  {
>>>> -  fclose (stream);
>>>> +  struct dump_file_info *dfi = get_dump_file_info (phase);
>>>> +  if (!dump_stream_p (dfi->user_filename))
>>>> +    fclose (stream);
>>>>  }
>>>>
>>>>  /* Enable all tree dumps.  Return number of enabled tree dumps.  */
>>>>
>>>>  static int
>>>> -dump_enable_all (int flags)
>>>> +dump_enable_all (int flags, const char *user_filename)
>>>>  {
>>>>   int ir_dump_type = (flags & (TDF_TREE | TDF_RTL | TDF_IPA));
>>>>   int n = 0;
>>>>   size_t i;
>>>>
>>>>   for (i = TDI_none + 1; i < (size_t) TDI_end; i++)
>>>> -    if ((dump_files[i].flags & ir_dump_type))
>>>> -      {
>>>> -        dump_files[i].state = -1;
>>>> -        dump_files[i].flags |= flags;
>>>> -        n++;
>>>> -      }
>>>> +    {
>>>> +      if ((dump_files[i].flags & ir_dump_type))
>>>> +        {
>>>> +          dump_files[i].state = -1;
>>>> +          dump_files[i].flags |= flags;
>>>> +          n++;
>>>> +        }
>>>> +      if (user_filename)
>>>> +        dump_files[i].user_filename = user_filename;
>>>> +    }
>>>>
>>>>   for (i = 0; i < extra_dump_files_in_use; i++)
>>>> -    if ((extra_dump_files[i].flags & ir_dump_type))
>>>> -      {
>>>> -        extra_dump_files[i].state = -1;
>>>> -        extra_dump_files[i].flags |= flags;
>>>> -       n++;
>>>> -      }
>>>> +    {
>>>> +      if ((extra_dump_files[i].flags & ir_dump_type))
>>>> +        {
>>>> +          extra_dump_files[i].state = -1;
>>>> +          extra_dump_files[i].flags |= flags;
>>>> +          n++;
>>>> +        }
>>>> +      if (user_filename)
>>>> +        extra_dump_files[i].user_filename = user_filename;
>>>> +    }
>>>>
>>>>   return n;
>>>>  }
>>>> @@ -1037,7 +1077,7 @@ dump_switch_p_1 (const char *arg, struct dump_file
>>>>   if (!option_value)
>>>>     return 0;
>>>>
>>>> -  if (*option_value && *option_value != '-')
>>>> +  if (*option_value && *option_value != '-' && *option_value != '=')
>>>>     return 0;
>>>>
>>>>   ptr = option_value;
>>>> @@ -1052,17 +1092,30 @@ dump_switch_p_1 (const char *arg, struct dump_file
>>>>       while (*ptr == '-')
>>>>        ptr++;
>>>>       end_ptr = strchr (ptr, '-');
>>>> +
>>>>       if (!end_ptr)
>>>>        end_ptr = ptr + strlen (ptr);
>>>>       length = end_ptr - ptr;
>>>>
>>>> +      if (*ptr == '=')
>>>> +        {
>>>> +          /* Interpret rest of the argument as a dump filename.  The
>>>> +             user provided filename overrides generated dump names as
>>>> +             well as other command line filenames.  */
>>>> +          flags |= TDF_USER_FILENAME;
>>>> +          if (dfi->user_filename)
>>>> +            free (dfi->user_filename);
>>>> +          dfi->user_filename = xstrdup (ptr + 1);
>>>> +          break;
>>>> +        }
>>>> +
>>>>       for (option_ptr = dump_options; option_ptr->name; option_ptr++)
>>>>        if (strlen (option_ptr->name) == length
>>>>            && !memcmp (option_ptr->name, ptr, length))
>>>> -         {
>>>> -           flags |= option_ptr->value;
>>>> +          {
>>>> +            flags |= option_ptr->value;
>>>>            goto found;
>>>> -         }
>>>> +          }
>>>>       warning (0, "ignoring unknown option %q.*s in %<-fdump-%s%>",
>>>>               length, ptr, dfi->swtch);
>>>>     found:;
>>>> @@ -1075,7 +1128,7 @@ dump_switch_p_1 (const char *arg, struct dump_file
>>>>   /* Process -fdump-tree-all and -fdump-rtl-all, by enabling all the
>>>>      known dumps.  */
>>>>   if (dfi->suffix == NULL)
>>>> -    dump_enable_all (dfi->flags);
>>>> +    dump_enable_all (dfi->flags, dfi->user_filename);
>>>>
>>>>   return 1;
>>>>  }
>>>> @@ -1124,5 +1177,5 @@ dump_function (int phase, tree fn)
>>>>  bool
>>>>  enable_rtl_dump_file (void)
>>>>  {
>>>> -  return dump_enable_all (TDF_RTL | TDF_DETAILS | TDF_BLOCKS) > 0;
>>>> +  return dump_enable_all (TDF_RTL | TDF_DETAILS | TDF_BLOCKS, NULL) > 0;
>>>>  }
>>>> Index: tree-pass.h
>>>> ===================================================================
>>>> --- tree-pass.h (revision 187265)
>>>> +++ tree-pass.h (working copy)
>>>> @@ -84,8 +84,9 @@ enum tree_dump_index
>>>>  #define TDF_ENUMERATE_LOCALS (1 << 22) /* Enumerate locals by uid.  */
>>>>  #define TDF_CSELIB     (1 << 23)       /* Dump cselib details.  */
>>>>  #define TDF_SCEV       (1 << 24)       /* Dump SCEV details.  */
>>>> +#define TDF_USER_FILENAME    (1 << 25) /* Dump on user provided filename,
>>>> +                                           instead of constructing one. */
>>>>
>>>> -
>>>>  /* In tree-dump.c */
>>>>
>>>>  extern char *get_dump_file_name (int);
>>>> @@ -222,6 +223,8 @@ struct dump_file_info
>>>>   const char *suffix;           /* suffix to give output file.  */
>>>>   const char *swtch;            /* command line switch */
>>>>   const char *glob;             /* command line glob  */
>>>> +  const char *user_filename;    /* user provided filename instead of making
>>>> +                                   up one using dump_base_name + suffix.  */
>>>
>>> There is "no user" here: we are the users :-)  Just call it "filename".
>>>
>>> -- Gaby

Patch

Index: doc/invoke.texi
===================================================================
--- doc/invoke.texi	(revision 187265)
+++ doc/invoke.texi	(working copy)
@@ -5322,20 +5322,23 @@  Here are some examples showing uses of these optio

 @item -d@var{letters}
 @itemx -fdump-rtl-@var{pass}
+@itemx -fdump-rtl-@var{pass}=@var{filename}
 @opindex d
 Says to make debugging dumps during compilation at times specified by
 @var{letters}.  This is used for debugging the RTL-based passes of the
 compiler.  The file names for most of the dumps are made by appending
 a pass number and a word to the @var{dumpname}, and the files are
-created in the directory of the output file.  Note that the pass
-number is computed statically as passes get registered into the pass
-manager.  Thus the numbering is not related to the dynamic order of
-execution of passes.  In particular, a pass installed by a plugin
-could have a number over 200 even if it executed quite early.
-@var{dumpname} is generated from the name of the output file, if
-explicitly specified and it is not an executable, otherwise it is the
-basename of the source file. These switches may have different effects
-when @option{-E} is used for preprocessing.
+created in the directory of the output file. If the
+@option{=@var{filename}} is appended to the longer form of the dump
+option then the dump is done on that file instead of numbered
+files. Note that the pass number is computed statically as passes get
+registered into the pass manager.  Thus the numbering is not related
+to the dynamic order of execution of passes.  In particular, a pass
+installed by a plugin could have a number over 200 even if it executed
+quite early.  @var{dumpname} is generated from the name of the output
+file, if explicitly specified and it is not an executable, otherwise
+it is the basename of the source file. These switches may have
+different effects when @option{-E} is used for preprocessing.

 Debug dumps can be enabled with a @option{-fdump-rtl} switch or some
 @option{-d} option @var{letters}.  Here are the possible
@@ -5719,15 +5722,18 @@  counters for each function compiled.

 @item -fdump-tree-@var{switch}
 @itemx -fdump-tree-@var{switch}-@var{options}
+@itemx -fdump-tree-@var{switch}-@var{options}=@var{filename}
 @opindex fdump-tree
 Control the dumping at various stages of processing the intermediate
 language tree to a file.  The file name is generated by appending a
 switch specific suffix to the source file name, and the file is
-created in the same directory as the output file.  If the
-@samp{-@var{options}} form is used, @var{options} is a list of
-@samp{-} separated options which control the details of the dump.  Not
-all options are applicable to all dumps; those that are not
-meaningful are ignored.  The following options are available
+created in the same directory as the output file. In case of
+@option{=@var{filename}} option, the dump is output on the given file
+name instead.  If the @samp{-@var{options}} form is used,
+@var{options} is a list of @samp{-} separated options which control
+the details or location of the dump.  Not all options are applicable
+to all dumps; those that are not meaningful are ignored.  The
+following options are available

 @table @samp
 @item address
@@ -5765,9 +5771,49 @@  Enable showing the tree dump for each statement.
 Enable showing the EH region number holding each statement.
 @item scev
 Enable showing scalar evolution analysis details.
+@item slim
+Inhibit dumping of members of a scope or body of a function merely
+because that scope has been reached.  Only dump such items when they
+are directly reachable by some other path.  When dumping pretty-printed
+trees, this option inhibits dumping the bodies of control structures.
+@item =@var{filename}
+Instead of using an auto generated dump file name, use the given file
+name. The file names @file{stdout} and @file{stderr} are treated
+specially and are considered already open standard streams. In
+addition, the standard streams @file{stdout} and @file{stderr} are
+considered weak, i.e., in case of a conflict, some other applicable
+dump file is used instead. For example:
+
+@smallexample
+gcc -O2 -fdump-tree-pre=stderr -fdump-rtl-ira=ira.txt ...
+@end smallexample
+
+outputs PRE dump on @file{stderr}, while the IRA dump is output in a
+file named @file{ira.txt}.
+
+Usually the command line file names have precedence over automatic
+file names unless the command line file name is a standard stream. For
+example:
+
+@smallexample
+gcc -O2 -fdump-tree-pre=stdout -fdump-tree-pre ...
+gcc -O2 -fdump-tree-pre -fdump-tree-pre=stdout ...
+@end smallexample
+
+Both of the above output the PRE dump into an auto generated file name
+since the @file{stdout} stream has lower precedence. As another
+example,
+
+@smallexample
+gcc -O2 -fdump-tree-pre=pre.txt -fdump-tree-all=stderr ...
+@end smallexample
+
+outputs all the tree dumps on @file{stderr}, except the PRE dump,
+which is output into @file{pre.txt}.
+
 @item all
-Turn on all options, except @option{raw}, @option{slim}, @option{verbose}
-and @option{lineno}.
+Turn on all options, except @option{raw}, @option{slim}, @option{verbose},
+@option{lineno}.
 @end table

 The following tree dumps are possible:
@@ -5913,6 +5959,7 @@  is made by appending @file{.vrp} to the source fil
 @item all
 @opindex fdump-tree-all
 Enable all the available tree dumps with the flags provided in this option.
+
 @end table

 @item -ftree-vectorizer-verbose=@var{n}
Index: tree-dump.c
===================================================================
--- tree-dump.c	(revision 187265)
+++ tree-dump.c	(working copy)
@@ -773,20 +773,20 @@  dump_node (const_tree t, int flags, FILE *stream)
    tree_dump_index enumeration in tree-pass.h.  */
 static struct dump_file_info dump_files[TDI_end] =
 {
-  {NULL, NULL, NULL, 0, 0, 0},
-  {".cgraph", "ipa-cgraph", NULL, TDF_IPA, 0,  0},
-  {".tu", "translation-unit", NULL, TDF_TREE, 0, 1},
-  {".class", "class-hierarchy", NULL, TDF_TREE, 0, 2},
-  {".original", "tree-original", NULL, TDF_TREE, 0, 3},
-  {".gimple", "tree-gimple", NULL, TDF_TREE, 0, 4},
-  {".nested", "tree-nested", NULL, TDF_TREE, 0, 5},
-  {".vcg", "tree-vcg", NULL, TDF_TREE, 0, 6},
-  {".ads", "ada-spec", NULL, 0, 0, 7},
+  {NULL, NULL, NULL, NULL, 0, 0, 0},
+  {".cgraph", "ipa-cgraph", NULL, NULL, TDF_IPA, 0,  0},
+  {".tu", "translation-unit", NULL, NULL, TDF_TREE, 0, 1},
+  {".class", "class-hierarchy", NULL, NULL, TDF_TREE, 0, 2},
+  {".original", "tree-original", NULL, NULL, TDF_TREE, 0, 3},
+  {".gimple", "tree-gimple", NULL, NULL, TDF_TREE, 0, 4},
+  {".nested", "tree-nested", NULL, NULL, TDF_TREE, 0, 5},
+  {".vcg", "tree-vcg", NULL, NULL, TDF_TREE, 0, 6},
+  {".ads", "ada-spec", NULL, NULL, 0, 0, 7},
 #define FIRST_AUTO_NUMBERED_DUMP 8

-  {NULL, "tree-all", NULL, TDF_TREE, 0, 0},
-  {NULL, "rtl-all", NULL, TDF_RTL, 0, 0},
-  {NULL, "ipa-all", NULL, TDF_IPA, 0, 0},
+  {NULL, "tree-all", NULL, NULL, TDF_TREE, 0, 0},
+  {NULL, "rtl-all", NULL, NULL, TDF_RTL, 0, 0},
+  {NULL, "ipa-all", NULL, NULL, TDF_IPA, 0, 0},
 };

 /* Dynamically registered tree dump files and switches.  */
@@ -802,7 +802,7 @@  struct dump_option_value_info
 };

 /* Table of dump options. This must be consistent with the TDF_* flags
-   in tree.h */
+   in tree-pass.h */
 static const struct dump_option_value_info dump_options[] =
 {
   {"address", TDF_ADDRESS},
@@ -892,6 +892,9 @@  get_dump_file_name (int phase)
   if (dfi->state == 0)
     return NULL;

+  if (dfi->filename)
+    return xstrdup (dfi->filename);
+
   if (dfi->num < 0)
     dump_id[0] = '\0';
   else
@@ -911,6 +914,22 @@  get_dump_file_name (int phase)
   return concat (dump_base_name, dump_id, dfi->suffix, NULL);
 }

+/* If FILENAME is a standard stream (stdout or stderr), return that
+   stream, otherwise return NULL.  */
+
+static FILE *
+dump_get_standard_stream (const char *filename)
+{
+  if (!filename)
+    return NULL;
+
+  return strcmp("stderr", filename) == 0
+    ? stderr
+    : strcmp("stdout", filename) == 0
+    ?  stdout
+    : NULL;
+}
+
 /* Begin a tree dump for PHASE. Stores any user supplied flag in
    *FLAG_PTR and returns a stream to write to. If the dump is not
    enabled, returns NULL.
@@ -926,14 +945,20 @@  dump_begin (int phase, int *flag_ptr)
   if (phase == TDI_none || !dump_enabled_p (phase))
     return NULL;

-  name = get_dump_file_name (phase);
   dfi = get_dump_file_info (phase);
-  stream = fopen (name, dfi->state < 0 ? "w" : "a");
-  if (!stream)
-    error ("could not open dump file %qs: %m", name);
+  stream = dump_get_standard_stream (dfi->filename);
+  if (stream)
+    dfi->state = 1;
   else
-    dfi->state = 1;
-  free (name);
+    {
+      name = get_dump_file_name (phase);
+      stream = fopen (name, dfi->state < 0 ? "w" : "a");
+      if (!stream)
+        error ("could not open dump file %qs: %m", name);
+      else
+        dfi->state = 1;
+      free (name);
+    }

   if (flag_ptr)
     *flag_ptr = dfi->flags;
@@ -987,35 +1012,60 @@  dump_flag_name (int phase)
    dump_begin.  */

 void
-dump_end (int phase ATTRIBUTE_UNUSED, FILE *stream)
+dump_end (int phase, FILE *stream)
 {
-  fclose (stream);
+  struct dump_file_info *dfi = get_dump_file_info (phase);
+  if (!dump_get_standard_stream (dfi->filename))
+    fclose (stream);
 }

-/* Enable all tree dumps.  Return number of enabled tree dumps.  */
+/* Enable all tree dumps with FLAGS on FILENAME.  Return number of
+   enabled tree dumps.  */

 static int
-dump_enable_all (int flags)
+dump_enable_all (int flags, const char *filename)
 {
   int ir_dump_type = (flags & (TDF_TREE | TDF_RTL | TDF_IPA));
   int n = 0;
   size_t i;

   for (i = TDI_none + 1; i < (size_t) TDI_end; i++)
-    if ((dump_files[i].flags & ir_dump_type))
-      {
-        dump_files[i].state = -1;
-        dump_files[i].flags |= flags;
-        n++;
-      }
+    {
+      if ((dump_files[i].flags & ir_dump_type))
+        {
+          const char *old_filename = dump_files[i].filename;
+          dump_files[i].state = -1;
+          dump_files[i].flags |= flags;
+          n++;
+          /* Do we need to override an existing filename?  */
+          if (filename && (!old_filename
+                           || dump_get_standard_stream (old_filename)))
+            {
+              dump_files[i].filename = xstrdup (filename);
+              if (filename != old_filename)
+                free ((void *)old_filename);
+            }
+        }
+    }

   for (i = 0; i < extra_dump_files_in_use; i++)
-    if ((extra_dump_files[i].flags & ir_dump_type))
-      {
-        extra_dump_files[i].state = -1;
-        extra_dump_files[i].flags |= flags;
-	n++;
-      }
+    {
+      if ((extra_dump_files[i].flags & ir_dump_type))
+        {
+          const char *old_filename = extra_dump_files[i].filename;
+          extra_dump_files[i].state = -1;
+          extra_dump_files[i].flags |= flags;
+          n++;
+          /* Do we need to override an existing filename?  */
+          if (filename && (!old_filename
+                           || dump_get_standard_stream (old_filename)))
+            {
+              extra_dump_files[i].filename = xstrdup (filename);
+              if (filename != old_filename)
+                free ((void *)old_filename);
+            }
+        }
+    }

   return n;
 }
@@ -1037,7 +1087,7 @@  dump_switch_p_1 (const char *arg, struct dump_file
   if (!option_value)
     return 0;

-  if (*option_value && *option_value != '-')
+  if (*option_value && *option_value != '-' && *option_value != '=')
     return 0;

   ptr = option_value;
@@ -1052,30 +1102,61 @@  dump_switch_p_1 (const char *arg, struct dump_file
       while (*ptr == '-')
 	ptr++;
       end_ptr = strchr (ptr, '-');
+
       if (!end_ptr)
 	end_ptr = ptr + strlen (ptr);
       length = end_ptr - ptr;

+      if (*ptr == '=')
+        {
+          /* Interpret rest of the argument as a dump filename.  This
+             filename overrides generated dump names as well as other
+             command line filenames. However, the standard streams are
+             considered weak, i.e. they do not override other
+             filenames. */
+          const char *filename = ptr + 1;
+
+          if (!dump_get_standard_stream (filename)
+              || !dfi->state
+              || dump_get_standard_stream (dfi->filename))
+            {
+              free ((void *)dfi->filename);
+              dfi->filename = xstrdup (ptr + 1);
+            }
+          flags |= TDF_FILENAME;
+          break;
+        }
+
       for (option_ptr = dump_options; option_ptr->name; option_ptr++)
 	if (strlen (option_ptr->name) == length
 	    && !memcmp (option_ptr->name, ptr, length))
-	  {
-	    flags |= option_ptr->value;
+          {
+            flags |= option_ptr->value;
 	    goto found;
-	  }
+          }
       warning (0, "ignoring unknown option %q.*s in %<-fdump-%s%>",
 	       length, ptr, dfi->swtch);
     found:;
       ptr = end_ptr;
     }

+  /* For the same dump seen again, override the standard stream
+     because it is considered as a weak filename.  */
+  if ((dfi->flags & TDF_FILENAME)
+      && !(flags & TDF_FILENAME)
+      && dump_get_standard_stream (dfi->filename))
+    {
+      dfi->flags &= ~TDF_FILENAME;
+      free ((void *)dfi->filename);
+      dfi->filename = NULL;
+    }
   dfi->state = -1;
   dfi->flags |= flags;

   /* Process -fdump-tree-all and -fdump-rtl-all, by enabling all the
      known dumps.  */
   if (dfi->suffix == NULL)
-    dump_enable_all (dfi->flags);
+    dump_enable_all (dfi->flags, dfi->filename);

   return 1;
 }
@@ -1124,5 +1205,5 @@  dump_function (int phase, tree fn)
 bool
 enable_rtl_dump_file (void)
 {
-  return dump_enable_all (TDF_RTL | TDF_DETAILS | TDF_BLOCKS) > 0;
+  return dump_enable_all (TDF_RTL | TDF_DETAILS | TDF_BLOCKS, NULL) > 0;
 }
Index: tree-pass.h
===================================================================
--- tree-pass.h	(revision 187265)
+++ tree-pass.h	(working copy)
@@ -84,8 +84,9 @@  enum tree_dump_index
 #define TDF_ENUMERATE_LOCALS (1 << 22)	/* Enumerate locals by uid.  */
 #define TDF_CSELIB	(1 << 23)	/* Dump cselib details.  */
 #define TDF_SCEV	(1 << 24)	/* Dump SCEV details.  */
+#define TDF_FILENAME    (1 << 25)	/* Dump on provided filename
+                                           instead of constructing one. */

-
 /* In tree-dump.c */

 extern char *get_dump_file_name (int);
@@ -222,6 +223,8 @@  struct dump_file_info
   const char *suffix;           /* suffix to give output file.  */
   const char *swtch;            /* command line switch */
   const char *glob;             /* command line glob  */
+  const char *filename;         /* use this filename instead of making
+                                   up one using dump_base_name + suffix.  */
   int flags;                    /* user flags */
   int state;                    /* state of play */
   int num;                      /* dump file number */
Index: testsuite/g++.dg/other/dump-filename-1.C
===================================================================
--- testsuite/g++.dg/other/dump-filename-1.C	(revision 0)
+++ testsuite/g++.dg/other/dump-filename-1.C	(revision 0)
@@ -0,0 +1,11 @@ 
+// Test that the dump to a user-defined file works correctly.
+/* { dg-options "-O2 -fdump-tree-original=foobar.dump" } */
+
+void test (int *b, int *e, int stride)
+  {
+    for (int *p = b; p != e; p += stride)
+      *p = 1;
+  }
+
+/* { dg-final { scan-file foobar.dump ";; Function void test" } } */
+/* { dg-final { remove-build-file "foobar.dump" } } */