Patchwork [v4] Make '{add-,}symbol-file' not care about the position of command line arguments

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Submitter Sergio Durigan Junior
Date Nov. 30, 2017, 7:59 p.m.
Message ID <20171130195950.872-1-sergiodj@redhat.com>
Download mbox | patch
Permalink /patch/24643/
State New
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Comments

Sergio Durigan Junior - Nov. 30, 2017, 7:59 p.m.
Changes from v3:

- 'add-symbol-file -s' now accepts sections whose names start with a
  dash.

- Use a better way to test must-ask questions on the testsuite.


This is a bug that's been detected while doing the readnever work.

If you use 'symbol-file' or 'add-symbol-file', the position of each
argument passed to the command matters.  This means that if you do:

  (gdb) symbol-file -readnow /foo/bar

The symbol file specified will (correctly) have all of its symbols
read by GDB (because of the -readnow flag).  However, if you do:

  (gdb) symbol-file /foo/bar -readnow

GDB will silently ignore the -readnow flag, because it was specified
after the filename.  This is not a good thing to do and may confuse
the user.

To address that, I've modified the argument parsing mechanisms of
symbol_file_command and add_symbol_file_command to be
"position-independent".  I have also added one error call at the end
of add_symbol_file_command's argument parsing logic, which now clearly
complains if no filename has been specified.  Both commands now
support the "--" option to stop argument processing.

This patch provides a testcase for both commands, in order to make
sure that the argument order does not matter.  It has been
regression-tested on BuildBot.

gdb/ChangeLog:

2017-11-30  Sergio Durigan Junior  <sergiodj@redhat.com>

	* symfile.c (symbol_file_command): Call
	'symbol_file_add_main_1' only after processing all command
	line options.
	(add_symbol_file_command): Modify logic to make arguments
	position-independent.

gdb/testsuite/ChangeLog:

2017-11-30  Sergio Durigan Junior  <sergiodj@redhat.com>

	* gdb.base/relocate.exp: Add tests to guarantee that arguments
	to 'symbol-file' and 'add-symbol-file' can be
	position-independent.
---
 gdb/symfile.c                       | 98 +++++++++++++++++++------------------
 gdb/testsuite/gdb.base/relocate.exp | 86 ++++++++++++++++++++++++++++++++
 2 files changed, 137 insertions(+), 47 deletions(-)
Pedro Alves - Dec. 1, 2017, 12:11 p.m.
On 11/30/2017 07:59 PM, Sergio Durigan Junior wrote:
> Changes from v3:
> 
> - 'add-symbol-file -s' now accepts sections whose names start with a
>   dash.
> 
> - Use a better way to test must-ask questions on the testsuite.
> 
> 
> This is a bug that's been detected while doing the readnever work.
> 
> If you use 'symbol-file' or 'add-symbol-file', the position of each
> argument passed to the command matters.  This means that if you do:
> 
>   (gdb) symbol-file -readnow /foo/bar
> 
> The symbol file specified will (correctly) have all of its symbols
> read by GDB (because of the -readnow flag).  However, if you do:
> 
>   (gdb) symbol-file /foo/bar -readnow
> 
> GDB will silently ignore the -readnow flag, because it was specified
> after the filename.  This is not a good thing to do and may confuse
> the user.
> 
> To address that, I've modified the argument parsing mechanisms of
> symbol_file_command and add_symbol_file_command to be
> "position-independent".  I have also added one error call at the end
> of add_symbol_file_command's argument parsing logic, which now clearly
> complains if no filename has been specified.  Both commands now
> support the "--" option to stop argument processing.
> 
> This patch provides a testcase for both commands, in order to make
> sure that the argument order does not matter.  It has been
> regression-tested on BuildBot.
> 
> gdb/ChangeLog:
> 
> 2017-11-30  Sergio Durigan Junior  <sergiodj@redhat.com>
> 
> 	* symfile.c (symbol_file_command): Call
> 	'symbol_file_add_main_1' only after processing all command
> 	line options.
> 	(add_symbol_file_command): Modify logic to make arguments
> 	position-independent.
> 
> gdb/testsuite/ChangeLog:
> 
> 2017-11-30  Sergio Durigan Junior  <sergiodj@redhat.com>
> 
> 	* gdb.base/relocate.exp: Add tests to guarantee that arguments
> 	to 'symbol-file' and 'add-symbol-file' can be
> 	position-independent.

OK.

Thanks,
Pedro Alves
Sergio Durigan Junior - Dec. 1, 2017, 5:41 p.m.
On Friday, December 01 2017, Pedro Alves wrote:

> On 11/30/2017 07:59 PM, Sergio Durigan Junior wrote:
>> Changes from v3:
>> 
>> - 'add-symbol-file -s' now accepts sections whose names start with a
>>   dash.
>> 
>> - Use a better way to test must-ask questions on the testsuite.
>> 
>> 
>> This is a bug that's been detected while doing the readnever work.
>> 
>> If you use 'symbol-file' or 'add-symbol-file', the position of each
>> argument passed to the command matters.  This means that if you do:
>> 
>>   (gdb) symbol-file -readnow /foo/bar
>> 
>> The symbol file specified will (correctly) have all of its symbols
>> read by GDB (because of the -readnow flag).  However, if you do:
>> 
>>   (gdb) symbol-file /foo/bar -readnow
>> 
>> GDB will silently ignore the -readnow flag, because it was specified
>> after the filename.  This is not a good thing to do and may confuse
>> the user.
>> 
>> To address that, I've modified the argument parsing mechanisms of
>> symbol_file_command and add_symbol_file_command to be
>> "position-independent".  I have also added one error call at the end
>> of add_symbol_file_command's argument parsing logic, which now clearly
>> complains if no filename has been specified.  Both commands now
>> support the "--" option to stop argument processing.
>> 
>> This patch provides a testcase for both commands, in order to make
>> sure that the argument order does not matter.  It has been
>> regression-tested on BuildBot.
>> 
>> gdb/ChangeLog:
>> 
>> 2017-11-30  Sergio Durigan Junior  <sergiodj@redhat.com>
>> 
>> 	* symfile.c (symbol_file_command): Call
>> 	'symbol_file_add_main_1' only after processing all command
>> 	line options.
>> 	(add_symbol_file_command): Modify logic to make arguments
>> 	position-independent.
>> 
>> gdb/testsuite/ChangeLog:
>> 
>> 2017-11-30  Sergio Durigan Junior  <sergiodj@redhat.com>
>> 
>> 	* gdb.base/relocate.exp: Add tests to guarantee that arguments
>> 	to 'symbol-file' and 'add-symbol-file' can be
>> 	position-independent.
>
> OK.

Pushed.

e2e321740ce2e36a97be2a410cd56eebaa2304aa

Thanks,
Pedro Alves - Dec. 1, 2017, 9:45 p.m.
On 12/01/2017 05:41 PM, Sergio Durigan Junior wrote:
> On Friday, December 01 2017, Pedro Alves wrote:

> e2e321740ce2e36a97be2a410cd56eebaa2304aa

Looks like you actually pushed some version of the readnever
patch with the old fix for symbol-file instead of this one?

commit e2e321740ce2e36a97be2a410cd56eebaa2304aa
Author:     Sergio Durigan Junior <sergiodj@redhat.com>
AuthorDate: Fri Nov 24 16:56:08 2017 -0500

    Add support for the readnever concept

Thanks,
Pedro Alves
Sergio Durigan Junior - Dec. 1, 2017, 10:02 p.m.
On Friday, December 01 2017, Pedro Alves wrote:

> On 12/01/2017 05:41 PM, Sergio Durigan Junior wrote:
>> On Friday, December 01 2017, Pedro Alves wrote:
>
>> e2e321740ce2e36a97be2a410cd56eebaa2304aa
>
> Looks like you actually pushed some version of the readnever
> patch with the old fix for symbol-file instead of this one?
>
> commit e2e321740ce2e36a97be2a410cd56eebaa2304aa
> Author:     Sergio Durigan Junior <sergiodj@redhat.com>
> AuthorDate: Fri Nov 24 16:56:08 2017 -0500
>
>     Add support for the readnever concept

I was about to revert it.  Sorry about that.

Reverted the readnever commit:

7f0f8ac8b15f5f5327116614b4137e5dd533ada2

And pushed the right one:

40fc416f4e22913ba2a2bafcc8da05f59c677b7d

Thanks,

Patch

diff --git a/gdb/symfile.c b/gdb/symfile.c
index 4bbe0b5a62..1c9f836eb3 100644
--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -1622,26 +1622,35 @@  symbol_file_command (const char *args, int from_tty)
       objfile_flags flags = OBJF_USERLOADED;
       symfile_add_flags add_flags = 0;
       char *name = NULL;
+      bool stop_processing_options = false;
+      int idx;
+      char *arg;
 
       if (from_tty)
 	add_flags |= SYMFILE_VERBOSE;
 
       gdb_argv built_argv (args);
-      for (char *arg : built_argv)
+      for (arg = built_argv[0], idx = 0; arg != NULL; arg = built_argv[++idx])
 	{
-	  if (strcmp (arg, "-readnow") == 0)
-	    flags |= OBJF_READNOW;
-	  else if (*arg == '-')
-	    error (_("unknown option `%s'"), arg);
-	  else
+	  if (stop_processing_options || *arg != '-')
 	    {
-	      symbol_file_add_main_1 (arg, add_flags, flags);
-	      name = arg;
+	      if (name == NULL)
+		name = arg;
+	      else
+		error (_("Unrecognized argument \"%s\""), arg);
 	    }
+	  else if (strcmp (arg, "-readnow") == 0)
+	    flags |= OBJF_READNOW;
+	  else if (strcmp (arg, "--") == 0)
+	    stop_processing_options = true;
+	  else
+	    error (_("Unrecognized argument \"%s\""), arg);
 	}
 
       if (name == NULL)
 	error (_("no symbol file name was specified"));
+
+      symbol_file_add_main_1 (name, add_flags, flags);
     }
 }
 
@@ -2180,8 +2189,6 @@  add_symbol_file_command (const char *args, int from_tty)
   char *arg;
   int argcnt = 0;
   int sec_num = 0;
-  int expecting_sec_name = 0;
-  int expecting_sec_addr = 0;
   struct objfile *objf;
   objfile_flags flags = OBJF_USERLOADED | OBJF_SHARED;
   symfile_add_flags add_flags = 0;
@@ -2196,7 +2203,8 @@  add_symbol_file_command (const char *args, int from_tty)
   };
 
   struct section_addr_info *section_addrs;
-  std::vector<sect_opt> sect_opts;
+  std::vector<sect_opt> sect_opts = { { ".text", NULL } };
+  bool stop_processing_options = false;
   struct cleanup *my_cleanups = make_cleanup (null_cleanup, NULL);
 
   dont_repeat ();
@@ -2204,63 +2212,59 @@  add_symbol_file_command (const char *args, int from_tty)
   if (args == NULL)
     error (_("add-symbol-file takes a file name and an address"));
 
+  bool seen_addr = false;
   gdb_argv argv (args);
 
   for (arg = argv[0], argcnt = 0; arg != NULL; arg = argv[++argcnt])
     {
-      /* Process the argument.  */
-      if (argcnt == 0)
-	{
-	  /* The first argument is the file name.  */
-	  filename.reset (tilde_expand (arg));
-	}
-      else if (argcnt == 1)
-	{
-	  /* The second argument is always the text address at which
-	     to load the program.  */
-	  sect_opt sect = { ".text", arg };
-	  sect_opts.push_back (sect);
-	}
-      else
+      if (stop_processing_options || *arg != '-')
 	{
-	  /* It's an option (starting with '-') or it's an argument
-	     to an option.  */
-	  if (expecting_sec_name)
+	  if (filename == NULL)
 	    {
-	      sect_opt sect = { arg, NULL };
-	      sect_opts.push_back (sect);
-	      expecting_sec_name = 0;
+	      /* First non-option argument is always the filename.  */
+	      filename.reset (tilde_expand (arg));
 	    }
-	  else if (expecting_sec_addr)
+	  else if (!seen_addr)
 	    {
-	      sect_opts.back ().value = arg;
-	      expecting_sec_addr = 0;
-	    }
-	  else if (strcmp (arg, "-readnow") == 0)
-	    flags |= OBJF_READNOW;
-	  else if (strcmp (arg, "-s") == 0)
-	    {
-	      expecting_sec_name = 1;
-	      expecting_sec_addr = 1;
+	      /* The second non-option argument is always the text
+		 address at which to load the program.  */
+	      sect_opts[0].value = arg;
+	      seen_addr = true;
 	    }
 	  else
 	    error (_("Unrecognized argument \"%s\""), arg);
 	}
+      else if (strcmp (arg, "-readnow") == 0)
+	flags |= OBJF_READNOW;
+      else if (strcmp (arg, "-s") == 0)
+	{
+	  if (argv[argcnt + 1] == NULL)
+	    error (_("Missing section name after \"-s\""));
+	  else if (argv[argcnt + 2] == NULL)
+	    error (_("Missing section address after \"-s\""));
+
+	  sect_opt sect = { argv[argcnt + 1], argv[argcnt + 2] };
+
+	  sect_opts.push_back (sect);
+	  argcnt += 2;
+	}
+      else if (strcmp (arg, "--") == 0)
+	stop_processing_options = true;
+      else
+	error (_("Unrecognized argument \"%s\""), arg);
     }
 
+  if (filename == NULL)
+    error (_("You must provide a filename to be loaded."));
+
   /* This command takes at least two arguments.  The first one is a
      filename, and the second is the address where this file has been
      loaded.  Abort now if this address hasn't been provided by the
      user.  */
-  if (sect_opts.empty ())
+  if (!seen_addr)
     error (_("The address where %s has been loaded is missing"),
 	   filename.get ());
 
-  if (expecting_sec_name)
-    error (_("Missing section name after \"-s\""));
-  else if (expecting_sec_addr)
-    error (_("Missing section address after \"-s\""));
-
   /* Print the prompt for the query below.  And save the arguments into
      a sect_addr_info structure to be passed around to other
      functions.  We have to split this up into separate print
diff --git a/gdb/testsuite/gdb.base/relocate.exp b/gdb/testsuite/gdb.base/relocate.exp
index 6eef15fb20..d0a839ae59 100644
--- a/gdb/testsuite/gdb.base/relocate.exp
+++ b/gdb/testsuite/gdb.base/relocate.exp
@@ -37,6 +37,92 @@  foreach x {"-raednow" "readnow" "foo" "-readnow s"} {
 	"add-symbol-file: unknown option $word"
 }
 
+# Check that we can pass parameters using any position in the command
+# line.
+set test "add-symbol-file positionless -readnow"
+gdb_test_multiple "add-symbol-file -readnow $binfile 0x100 -s .bss 0x3" $test {
+    -re "add symbol table from file \"${binfile}\" at\r\n\t\.text_addr = 0x100\r\n\t\.bss_addr = 0x3\r\n\\(y or n\\) " {
+	gdb_test "n" "Not confirmed\." $test
+    }
+}
+# When we use -s as the first argument, the section will be printed
+# first as well.
+set test "add-symbol-file positionless -s"
+gdb_test_multiple "add-symbol-file -s .bss 0x3 -readnow $binfile 0x100" $test {
+    -re "add symbol table from file \"${binfile}\" at\r\n\t\.text_addr = 0x100\r\n\t\.bss_addr = 0x3\r\n\\(y or n\\) " {
+	gdb_test "n" "Not confirmed\." $test
+    }
+}
+set test "add-symbol-file positionless -s, no -readnow"
+gdb_test_multiple "add-symbol-file $binfile 0x100 -s .bss 0x3" $test {
+    -re "add symbol table from file \"${binfile}\" at\r\n\t\.text_addr = 0x100\r\n\t\.bss_addr = 0x3\r\n\\(y or n\\) " {
+	gdb_test "n" "Not confirmed\." $test
+    }
+}
+# Check that passing "-s .text", no matter the position, always has
+# the same result.
+set test "add-symbol-file different -s .text, after file"
+gdb_test_multiple "add-symbol-file $binfile 0x100 -s .text 0x200" $test {
+    -re "add symbol table from file \"${binfile}\" at\r\n\t\.text_addr = 0x100\r\n\t\.text_addr = 0x200\r\n\\(y or n\\) " {
+	gdb_test "n" "Not confirmed\." $test
+    }
+}
+set test "add-symbol-file different -s .text, before file"
+gdb_test_multiple "add-symbol-file -s .text 0x200 $binfile 0x100" $test {
+    -re "add symbol table from file \"${binfile}\" at\r\n\t\.text_addr = 0x100\r\n\t\.text_addr = 0x200\r\n\\(y or n\\) " {
+	gdb_test "n" "Not confirmed\." $test
+    }
+}
+# Test that passing "--" disables option processing.
+gdb_test "add-symbol-file -- $binfile 0x100 -s .bss 0x3" \
+    "Unrecognized argument \"-s\"" \
+    "add-symbol-file with -- disables option processing"
+set test "add-symbol-file with -- disables option processing, non-existent filename"
+gdb_test_multiple "add-symbol-file -- -non-existent-file 0x100" $test {
+    -re "add symbol table from file \"-non-existent-file\" at\r\n\t\.text_addr = 0x100\r\n\\(y or n\\) " {
+	gdb_test "y" "-non-existent-file: No such file or directory\." $test
+    }
+}
+# Test that passing the wrong number of arguments to '-s' leads to an
+# error.
+gdb_test "add-symbol-file $binfile -s" \
+    "Missing section name after \"-s\"" \
+    "add-symbol-file with -s without section name"
+gdb_test "add-symbol-file $binfile -s .bss" \
+    "Missing section address after \"-s\"" \
+    "add-symbol-file with -s without section address"
+# Test that '-s' accepts section names with '-'
+set test "add-symbol-file with -s using section name starting with dash"
+gdb_test_multiple "add-symbol-file -s -section-name 0x200 $binfile 0x100" $test {
+    -re "add symbol table from file \"${binfile}\" at\r\n\t\.text_addr = 0x100\r\n\t\-section-name_addr = 0x200\r\n\\(y or n\\) " {
+	gdb_test "n" "Not confirmed\." $test
+    }
+}
+# Since we're here, might as well test the 'symbol-file' command and
+# if its arguments can also be passed at any position.
+gdb_test "symbol-file -readnow $binfile" \
+    "Reading symbols from ${binfile}\.\.\.expanding to full symbols\.\.\.done\." \
+    "symbol-file with -readnow first"
+clean_restart
+gdb_test "symbol-file $binfile -readnow" \
+    "Reading symbols from ${binfile}\.\.\.expanding to full symbols\.\.\.done\." \
+    "symbol-file with -readnow second"
+gdb_test "symbol-file -readnow" \
+    "no symbol file name was specified" \
+    "symbol-file without filename"
+gdb_test "symbol-file -- -non-existent-file" \
+    "-non-existent-file: No such file or directory\." \
+    "symbol-file with -- disables option processing"
+clean_restart
+gdb_test "symbol-file -readnow -- $binfile" \
+    "Reading symbols from ${binfile}\.\.\.expanding to full symbols\.\.\.done\." \
+    "symbol-file with -- and -readnow"
+gdb_test "symbol-file -- $binfile -readnow" \
+    "Unrecognized argument \"-readnow\"" \
+    "symbol-file with -- and -readnow, invalid option"
+
+clean_restart
+
 gdb_test "add-symbol-file ${binfile} 0 -s" \
     "Missing section name after .-s." \
     "add-symbol-file bare -s"