[v3,2/6] gdbsupport: Adapt construct_inferior_arguments

Message ID 20200512154211.1311364-2-m.weghorn@posteo.de
State Superseded
Headers show
Series
  • [v3,1/6] gdb: Move construct_inferior_arguments to gdbsupport
Related show

Commit Message

Kevin Buettner via Gdb-patches May 12, 2020, 3:42 p.m.
Allow construct_inferior_arguments to handle zero args
and have it return a std::string, similar to how
stringify_argv in gdbsupport/common-utils does.

Also, add a const qualifier for the second parameter,
since it is only read, not written to.

The intention is to replace existing uses of
stringify_argv by construct_inferior_arguments
in a subsequent step, since construct_inferior_arguments
properly handles special characters, while stringify_argv
doesn't.

2020-05-12  Michael Weghorn  <m.weghorn@posteo.de>

        * common-inferior.cc, common-inferior.h (construct_inferior_arguments):
        Adapt to handle zero args and return a std::string.
        Adapt call site.
---
 gdb/infcmd.c                  |  9 ++----
 gdbsupport/common-inferior.cc | 55 ++++++++++++-----------------------
 gdbsupport/common-inferior.h  |  2 +-
 3 files changed, 23 insertions(+), 43 deletions(-)

-- 
2.26.2

Comments

Simon Marchi May 12, 2020, 5:53 p.m. | #1
Just some nits.

On 2020-05-12 11:42 a.m., Michael Weghorn via Gdb-patches wrote:
> diff --git a/gdbsupport/common-inferior.cc b/gdbsupport/common-inferior.cc

> index a7d631f357..cadbd50e9c 100644

> --- a/gdbsupport/common-inferior.cc

> +++ b/gdbsupport/common-inferior.cc

> @@ -27,15 +27,12 @@ bool startup_with_shell = true;

>  

>  /* See common-inferior.h.  */

>  

> -char *

> -construct_inferior_arguments (int argc, char **argv)

> +std::string

> +construct_inferior_arguments (int argc, char * const *argv)

>  {

> -  char *result;

> +  gdb_assert (argc >= 0);

>  

> -  /* ARGC should always be at least 1, but we double check this

> -     here.  This is also needed to silence -Werror-stringop

> -     warnings.  */

> -  gdb_assert (argc > 0);

> +  std::string result;

>  

>    if (startup_with_shell)

>      {

> @@ -52,48 +49,39 @@ construct_inferior_arguments (int argc, char **argv)

>        static const char quote = '\'';

>  #endif

>        int i;


Can you inline this in the for loop while at it?

> -      int length = 0;

> -      char *out, *cp;

> -

> -      /* We over-compute the size.  It shouldn't matter.  */

> -      for (i = 0; i < argc; ++i)

> -	length += 3 * strlen (argv[i]) + 1 + 2 * (argv[i][0] == '\0');

> -

> -      result = (char *) xmalloc (length);

> -      out = result;

>  

>        for (i = 0; i < argc; ++i)

>  	{

>  	  if (i > 0)

> -	    *out++ = ' ';

> +	    result += ' ';

>  

>  	  /* Need to handle empty arguments specially.  */

>  	  if (argv[i][0] == '\0')

>  	    {

> -	      *out++ = quote;

> -	      *out++ = quote;

> +	      result += quote;

> +	      result += quote;

>  	    }

>  	  else

>  	    {

>  #ifdef __MINGW32__

> -	      int quoted = 0;

> +	      bool quoted = 0;


Replace 0 with false.

>  

>  	      if (strpbrk (argv[i], special))

>  		{

> -		  quoted = 1;

> -		  *out++ = quote;

> +		  quoted = true;

> +		  result += quote;

>  		}

>  #endif

> -	      for (cp = argv[i]; *cp; ++cp)

> +	      for (char *cp = argv[i]; *cp; ++cp)

>  		{

>  		  if (*cp == '\n')

>  		    {

>  		      /* A newline cannot be quoted with a backslash (it

>  			 just disappears), only by putting it inside

>  			 quotes.  */

> -		      *out++ = quote;

> -		      *out++ = '\n';

> -		      *out++ = quote;

> +		      result += quote;

> +		      result += '\n';

> +		      result += quote;

>  		    }

>  		  else

>  		    {

> @@ -102,24 +90,22 @@ construct_inferior_arguments (int argc, char **argv)

>  #else

>  		      if (strchr (special, *cp) != NULL)

>  #endif

> -			*out++ = '\\';

> -		      *out++ = *cp;

> +			result += '\\';

> +		      result += *cp;

>  		    }

>  		}

>  #ifdef __MINGW32__

>  	      if (quoted)

> -		*out++ = quote;

> +		result += quote;

>  #endif

>  	    }

>  	}

> -      *out = '\0';

>      }

>    else

>      {

>        /* In this case we can't handle arguments that contain spaces,

>  	 tabs, or newlines -- see breakup_args().  */

>        int i;


Can you also inline this one in the for loops?

Simon
Kevin Buettner via Gdb-patches May 13, 2020, 9:56 a.m. | #2
On 12/05/2020 19.53, Simon Marchi wrote:
> Just some nits.

> 

> On 2020-05-12 11:42 a.m., Michael Weghorn via Gdb-patches wrote:

>> diff --git a/gdbsupport/common-inferior.cc b/gdbsupport/common-inferior.cc

>> index a7d631f357..cadbd50e9c 100644

>> --- a/gdbsupport/common-inferior.cc

>> +++ b/gdbsupport/common-inferior.cc

>> @@ -27,15 +27,12 @@ bool startup_with_shell = true;

>>  

>>  /* See common-inferior.h.  */

>>  

>> -char *

>> -construct_inferior_arguments (int argc, char **argv)

>> +std::string

>> +construct_inferior_arguments (int argc, char * const *argv)

>>  {

>> -  char *result;

>> +  gdb_assert (argc >= 0);

>>  

>> -  /* ARGC should always be at least 1, but we double check this

>> -     here.  This is also needed to silence -Werror-stringop

>> -     warnings.  */

>> -  gdb_assert (argc > 0);

>> +  std::string result;

>>  

>>    if (startup_with_shell)

>>      {

>> @@ -52,48 +49,39 @@ construct_inferior_arguments (int argc, char **argv)

>>        static const char quote = '\'';

>>  #endif

>>        int i;

> 

> Can you inline this in the for loop while at it?


Yes, done in v4.

> 

>> -      int length = 0;

>> -      char *out, *cp;

>> -

>> -      /* We over-compute the size.  It shouldn't matter.  */

>> -      for (i = 0; i < argc; ++i)

>> -	length += 3 * strlen (argv[i]) + 1 + 2 * (argv[i][0] == '\0');

>> -

>> -      result = (char *) xmalloc (length);

>> -      out = result;

>>  

>>        for (i = 0; i < argc; ++i)

>>  	{

>>  	  if (i > 0)

>> -	    *out++ = ' ';

>> +	    result += ' ';

>>  

>>  	  /* Need to handle empty arguments specially.  */

>>  	  if (argv[i][0] == '\0')

>>  	    {

>> -	      *out++ = quote;

>> -	      *out++ = quote;

>> +	      result += quote;

>> +	      result += quote;

>>  	    }

>>  	  else

>>  	    {

>>  #ifdef __MINGW32__

>> -	      int quoted = 0;

>> +	      bool quoted = 0;

> 

> Replace 0 with false.


Done in v4.
> 

>>  

>>  	      if (strpbrk (argv[i], special))

>>  		{

>> -		  quoted = 1;

>> -		  *out++ = quote;

>> +		  quoted = true;

>> +		  result += quote;

>>  		}

>>  #endif

>> -	      for (cp = argv[i]; *cp; ++cp)

>> +	      for (char *cp = argv[i]; *cp; ++cp)

>>  		{

>>  		  if (*cp == '\n')

>>  		    {

>>  		      /* A newline cannot be quoted with a backslash (it

>>  			 just disappears), only by putting it inside

>>  			 quotes.  */

>> -		      *out++ = quote;

>> -		      *out++ = '\n';

>> -		      *out++ = quote;

>> +		      result += quote;

>> +		      result += '\n';

>> +		      result += quote;

>>  		    }

>>  		  else

>>  		    {

>> @@ -102,24 +90,22 @@ construct_inferior_arguments (int argc, char **argv)

>>  #else

>>  		      if (strchr (special, *cp) != NULL)

>>  #endif

>> -			*out++ = '\\';

>> -		      *out++ = *cp;

>> +			result += '\\';

>> +		      result += *cp;

>>  		    }

>>  		}

>>  #ifdef __MINGW32__

>>  	      if (quoted)

>> -		*out++ = quote;

>> +		result += quote;

>>  #endif

>>  	    }

>>  	}

>> -      *out = '\0';

>>      }

>>    else

>>      {

>>        /* In this case we can't handle arguments that contain spaces,

>>  	 tabs, or newlines -- see breakup_args().  */

>>        int i;

> 

> Can you also inline this one in the for loops?


Yes done in v4.

Michael

Patch

diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 8f7482347c..a7c037837c 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -151,12 +151,9 @@  get_inferior_args (void)
 {
   if (current_inferior ()->argc != 0)
     {
-      char *n;
-
-      n = construct_inferior_arguments (current_inferior ()->argc,
-					current_inferior ()->argv);
-      set_inferior_args (n);
-      xfree (n);
+      std::string n = construct_inferior_arguments (current_inferior ()->argc,
+					            current_inferior ()->argv);
+      set_inferior_args (n.c_str ());
     }
 
   if (current_inferior ()->args == NULL)
diff --git a/gdbsupport/common-inferior.cc b/gdbsupport/common-inferior.cc
index a7d631f357..cadbd50e9c 100644
--- a/gdbsupport/common-inferior.cc
+++ b/gdbsupport/common-inferior.cc
@@ -27,15 +27,12 @@  bool startup_with_shell = true;
 
 /* See common-inferior.h.  */
 
-char *
-construct_inferior_arguments (int argc, char **argv)
+std::string
+construct_inferior_arguments (int argc, char * const *argv)
 {
-  char *result;
+  gdb_assert (argc >= 0);
 
-  /* ARGC should always be at least 1, but we double check this
-     here.  This is also needed to silence -Werror-stringop
-     warnings.  */
-  gdb_assert (argc > 0);
+  std::string result;
 
   if (startup_with_shell)
     {
@@ -52,48 +49,39 @@  construct_inferior_arguments (int argc, char **argv)
       static const char quote = '\'';
 #endif
       int i;
-      int length = 0;
-      char *out, *cp;
-
-      /* We over-compute the size.  It shouldn't matter.  */
-      for (i = 0; i < argc; ++i)
-	length += 3 * strlen (argv[i]) + 1 + 2 * (argv[i][0] == '\0');
-
-      result = (char *) xmalloc (length);
-      out = result;
 
       for (i = 0; i < argc; ++i)
 	{
 	  if (i > 0)
-	    *out++ = ' ';
+	    result += ' ';
 
 	  /* Need to handle empty arguments specially.  */
 	  if (argv[i][0] == '\0')
 	    {
-	      *out++ = quote;
-	      *out++ = quote;
+	      result += quote;
+	      result += quote;
 	    }
 	  else
 	    {
 #ifdef __MINGW32__
-	      int quoted = 0;
+	      bool quoted = 0;
 
 	      if (strpbrk (argv[i], special))
 		{
-		  quoted = 1;
-		  *out++ = quote;
+		  quoted = true;
+		  result += quote;
 		}
 #endif
-	      for (cp = argv[i]; *cp; ++cp)
+	      for (char *cp = argv[i]; *cp; ++cp)
 		{
 		  if (*cp == '\n')
 		    {
 		      /* A newline cannot be quoted with a backslash (it
 			 just disappears), only by putting it inside
 			 quotes.  */
-		      *out++ = quote;
-		      *out++ = '\n';
-		      *out++ = quote;
+		      result += quote;
+		      result += '\n';
+		      result += quote;
 		    }
 		  else
 		    {
@@ -102,24 +90,22 @@  construct_inferior_arguments (int argc, char **argv)
 #else
 		      if (strchr (special, *cp) != NULL)
 #endif
-			*out++ = '\\';
-		      *out++ = *cp;
+			result += '\\';
+		      result += *cp;
 		    }
 		}
 #ifdef __MINGW32__
 	      if (quoted)
-		*out++ = quote;
+		result += quote;
 #endif
 	    }
 	}
-      *out = '\0';
     }
   else
     {
       /* In this case we can't handle arguments that contain spaces,
 	 tabs, or newlines -- see breakup_args().  */
       int i;
-      int length = 0;
 
       for (i = 0; i < argc; ++i)
 	{
@@ -131,16 +117,13 @@  construct_inferior_arguments (int argc, char **argv)
 	  if (cp != NULL)
 	    error (_("can't handle command-line "
 		     "argument containing whitespace"));
-	  length += strlen (argv[i]) + 1;
 	}
 
-      result = (char *) xmalloc (length);
-      result[0] = '\0';
       for (i = 0; i < argc; ++i)
 	{
 	  if (i > 0)
-	    strcat (result, " ");
-	  strcat (result, argv[i]);
+	    result += " ";
+	  result += argv[i];
 	}
     }
 
diff --git a/gdbsupport/common-inferior.h b/gdbsupport/common-inferior.h
index ee87bc75a3..5e9fc8b0b9 100644
--- a/gdbsupport/common-inferior.h
+++ b/gdbsupport/common-inferior.h
@@ -60,6 +60,6 @@  extern bool startup_with_shell;
 
 /* Compute command-line string given argument vector. This does the
    same shell processing as fork_inferior.  */
-extern char *construct_inferior_arguments (int, char **);
+extern std::string construct_inferior_arguments (int, char * const *);
 
 #endif /* COMMON_COMMON_INFERIOR_H */