[v2,1/2] Driver: Add new -truncate option

Message ID 20240418040912.6236-1-peter0x44@disroot.org
State New
Headers
Series [v2,1/2] Driver: Add new -truncate option |

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Commit Message

Peter0x44 April 18, 2024, 4:09 a.m. UTC
  This commit adds a new option to the driver that truncates one file after
linking.

Tested likeso:

$ gcc hello.c -c
$ du -h hello.o
4.0K  hello.o
$ gcc hello.o -truncate hello
$ ./a.out
Hello world
$ du -h hello.o
$ 0   hello.o

$ gcc hello.o -truncate
gcc: error: missing filename after '-truncate'

The motivation for adding this is PR110710. It is used by lto-wrapper to
truncate files in a shell-independent manner.

Signed-off-by: Peter Damianov <peter0x44@disroot.org>
---
v2: moved truncation to driver::final_actions
v2: moved handling of OPT_truncate to be in alphabetic order

 gcc/common.opt |  6 ++++++
 gcc/gcc.cc     | 13 +++++++++++++
 2 files changed, 19 insertions(+)
  

Comments

Richard Biener April 18, 2024, 6:26 a.m. UTC | #1
On Thu, Apr 18, 2024 at 6:12 AM Peter Damianov <peter0x44@disroot.org> wrote:
>
> This commit adds a new option to the driver that truncates one file after
> linking.
>
> Tested likeso:
>
> $ gcc hello.c -c
> $ du -h hello.o
> 4.0K  hello.o
> $ gcc hello.o -truncate hello
> $ ./a.out
> Hello world
> $ du -h hello.o
> $ 0   hello.o

I suppose it should have been

$ gcc hello.o -truncate hello.o

in the example.

> $ gcc hello.o -truncate
> gcc: error: missing filename after '-truncate'
>
> The motivation for adding this is PR110710. It is used by lto-wrapper to
> truncate files in a shell-independent manner.

This looks good to me.

Thanks,
Richard.

> Signed-off-by: Peter Damianov <peter0x44@disroot.org>
> ---
> v2: moved truncation to driver::final_actions
> v2: moved handling of OPT_truncate to be in alphabetic order
>
>  gcc/common.opt |  6 ++++++
>  gcc/gcc.cc     | 13 +++++++++++++
>  2 files changed, 19 insertions(+)
>
> diff --git a/gcc/common.opt b/gcc/common.opt
> index ad348844775..40cab3cb36a 100644
> --- a/gcc/common.opt
> +++ b/gcc/common.opt
> @@ -422,6 +422,12 @@ Display target specific command line options (including assembler and linker opt
>  -time
>  Driver Alias(time)
>
> +;; Truncate the file specified after linking.
> +;; This option is used by lto-wrapper to reduce the peak disk-usage when
> +;; linking with many .LTRANS units.
> +truncate
> +Driver Separate Undocumented MissingArgError(missing filename after %qs)
> +
>  -verbose
>  Driver Alias(v)
>
> diff --git a/gcc/gcc.cc b/gcc/gcc.cc
> index 728332b8153..b4169bbd3be 100644
> --- a/gcc/gcc.cc
> +++ b/gcc/gcc.cc
> @@ -2138,6 +2138,10 @@ static int have_E = 0;
>  /* Pointer to output file name passed in with -o. */
>  static const char *output_file = 0;
>
> +/* Pointer to input file name passed in with -truncate.
> +   This file should be truncated after linking. */
> +static const char *totruncate_file = 0;
> +
>  /* This is the list of suffixes and codes (%g/%u/%U/%j) and the associated
>     temp file.  If the HOST_BIT_BUCKET is used for %j, no entry is made for
>     it here.  */
> @@ -4538,6 +4542,10 @@ driver_handle_option (struct gcc_options *opts,
>        do_save = false;
>        break;
>
> +    case OPT_truncate:
> +      totruncate_file = arg;
> +      break;
> +
>      case OPT____:
>        /* "-###"
>          This is similar to -v except that there is no execution
> @@ -9286,6 +9294,11 @@ driver::final_actions () const
>      delete_failure_queue ();
>    delete_temp_files ();
>
> +  if (totruncate_file != NULL && !seen_error ())
> +    /* Truncate file specified by -truncate.
> +       Used by lto-wrapper to reduce temporary disk-space usage. */
> +    truncate(totruncate_file, 0);
> +
>    if (print_help_list)
>      {
>        printf (("\nFor bug reporting instructions, please see:\n"));
> --
> 2.39.2
>
  
Peter0x44 April 18, 2024, 8:26 a.m. UTC | #2
18 Apr 2024 7:26:27 am Richard Biener <richard.guenther@gmail.com>:

> On Thu, Apr 18, 2024 at 6:12 AM Peter Damianov <peter0x44@disroot.org> 
> wrote:
>>
>> This commit adds a new option to the driver that truncates one file 
>> after
>> linking.
>>
>> Tested likeso:
>>
>> $ gcc hello.c -c
>> $ du -h hello.o
>> 4.0K  hello.o
>> $ gcc hello.o -truncate hello
>> $ ./a.out
>> Hello world
>> $ du -h hello.o
>> $ 0   hello.o
>
> I suppose it should have been
>
> $ gcc hello.o -truncate hello.o
>
> in the example.

Correct.
Sorry about that.

>
>> $ gcc hello.o -truncate
>> gcc: error: missing filename after '-truncate'
>>
>> The motivation for adding this is PR110710. It is used by lto-wrapper 
>> to
>> truncate files in a shell-independent manner.
>
> This looks good to me.
>
> Thanks,
> Richard.
>
>> Signed-off-by: Peter Damianov <peter0x44@disroot.org>
>> ---
>> v2: moved truncation to driver::final_actions
>> v2: moved handling of OPT_truncate to be in alphabetic order
>>
>> gcc/common.opt |  6 ++++++
>> gcc/gcc.cc     | 13 +++++++++++++
>> 2 files changed, 19 insertions(+)
>>
>> diff --git a/gcc/common.opt b/gcc/common.opt
>> index ad348844775..40cab3cb36a 100644
>> --- a/gcc/common.opt
>> +++ b/gcc/common.opt
>> @@ -422,6 +422,12 @@ Display target specific command line options 
>> (including assembler and linker opt
>> -time
>> Driver Alias(time)
>>
>> +;; Truncate the file specified after linking.
>> +;; This option is used by lto-wrapper to reduce the peak disk-usage 
>> when
>> +;; linking with many .LTRANS units.
>> +truncate
>> +Driver Separate Undocumented MissingArgError(missing filename after 
>> %qs)
>> +
>> -verbose
>> Driver Alias(v)
>>
>> diff --git a/gcc/gcc.cc b/gcc/gcc.cc
>> index 728332b8153..b4169bbd3be 100644
>> --- a/gcc/gcc.cc
>> +++ b/gcc/gcc.cc
>> @@ -2138,6 +2138,10 @@ static int have_E = 0;
>> /* Pointer to output file name passed in with -o. */
>> static const char *output_file = 0;
>>
>> +/* Pointer to input file name passed in with -truncate.
>> +   This file should be truncated after linking. */
>> +static const char *totruncate_file = 0;
>> +
>> /* This is the list of suffixes and codes (%g/%u/%U/%j) and the 
>> associated
>>     temp file.  If the HOST_BIT_BUCKET is used for %j, no entry is 
>> made for
>>     it here.  */
>> @@ -4538,6 +4542,10 @@ driver_handle_option (struct gcc_options *opts,
>>        do_save = false;
>>        break;
>>
>> +    case OPT_truncate:
>> +      totruncate_file = arg;
>> +      break;
>> +
>>      case OPT____:
>>        /* "-###"
>>          This is similar to -v except that there is no execution
>> @@ -9286,6 +9294,11 @@ driver::final_actions () const
>>      delete_failure_queue ();
>>    delete_temp_files ();
>>
>> +  if (totruncate_file != NULL && !seen_error ())
>> +    /* Truncate file specified by -truncate.
>> +       Used by lto-wrapper to reduce temporary disk-space usage. */
>> +    truncate(totruncate_file, 0);
>> +
>>    if (print_help_list)
>>      {
>>        printf (("\nFor bug reporting instructions, please see:\n"));
>> --
>> 2.39.2
>>
  

Patch

diff --git a/gcc/common.opt b/gcc/common.opt
index ad348844775..40cab3cb36a 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -422,6 +422,12 @@  Display target specific command line options (including assembler and linker opt
 -time
 Driver Alias(time)
 
+;; Truncate the file specified after linking.
+;; This option is used by lto-wrapper to reduce the peak disk-usage when
+;; linking with many .LTRANS units.
+truncate
+Driver Separate Undocumented MissingArgError(missing filename after %qs)
+
 -verbose
 Driver Alias(v)
 
diff --git a/gcc/gcc.cc b/gcc/gcc.cc
index 728332b8153..b4169bbd3be 100644
--- a/gcc/gcc.cc
+++ b/gcc/gcc.cc
@@ -2138,6 +2138,10 @@  static int have_E = 0;
 /* Pointer to output file name passed in with -o. */
 static const char *output_file = 0;
 
+/* Pointer to input file name passed in with -truncate.
+   This file should be truncated after linking. */
+static const char *totruncate_file = 0;
+
 /* This is the list of suffixes and codes (%g/%u/%U/%j) and the associated
    temp file.  If the HOST_BIT_BUCKET is used for %j, no entry is made for
    it here.  */
@@ -4538,6 +4542,10 @@  driver_handle_option (struct gcc_options *opts,
       do_save = false;
       break;
 
+    case OPT_truncate:
+      totruncate_file = arg;
+      break;
+
     case OPT____:
       /* "-###"
 	 This is similar to -v except that there is no execution
@@ -9286,6 +9294,11 @@  driver::final_actions () const
     delete_failure_queue ();
   delete_temp_files ();
 
+  if (totruncate_file != NULL && !seen_error ())
+    /* Truncate file specified by -truncate.
+       Used by lto-wrapper to reduce temporary disk-space usage. */
+    truncate(totruncate_file, 0);
+
   if (print_help_list)
     {
       printf (("\nFor bug reporting instructions, please see:\n"));