[PATCH v3] Make '{add-,}symbol-file' not care about the position of command line arguments

Sergio Durigan Junior
2017-11-30T13:33:55Z

Changes from v2:

- Make .text address always be the first set on 'add-symbol-file'
command.

- Add support for "--" on both commands.

- Extend testcases.

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 | 85 ++++++++++++++++++++++---------------
gdb/testsuite/gdb.base/relocate.exp | 60 ++++++++++++++++++++++++++
2 files changed, 110 insertions(+), 35 deletions(-)

diff --git a/gdb/symfile.c b/gdb/symfile.c
index 4bbe0b5a62..28b292e7fa 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 +2189,9 @@ 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;
+ bool expecting_sec_name = false;
+ bool expecting_sec_addr = false;
+ bool seen_addr = false;
struct objfile *objf;
objfile_flags flags = OBJF_USERLOADED | OBJF_SHARED;
symfile_add_flags add_flags = 0;
@@ -2196,7 +2206,8 @@ 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 ();
@@ -2208,51 +2219,55 @@ add_symbol_file_command (const char *args, int from_tty)

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)
{
sect_opt sect = { arg, NULL };
sect_opts.push_back (sect);
- expecting_sec_name = 0;
+ expecting_sec_name = false;
}
else if (expecting_sec_addr)
{
sect_opts.back ().value = arg;
- expecting_sec_addr = 0;
+ expecting_sec_addr = false;
}
- else if (strcmp (arg, "-readnow") == 0)
- flags |= OBJF_READNOW;
- else if (strcmp (arg, "-s") == 0)
+ else if (filename == NULL)
+ {
+ /* First non-option argument is always the filename. */
+ filename.reset (tilde_expand (arg));
+ }
+ else if (!seen_addr)
{
- 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)
+ {
+ expecting_sec_name = true;
+ expecting_sec_addr = true;
+ }
+ 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 ());

diff --git a/gdb/testsuite/gdb.base/relocate.exp b/gdb/testsuite/gdb.base/relocate.exp
index 6eef15fb20..246e4b8282 100644
--- a/gdb/testsuite/gdb.base/relocate.exp
+++ b/gdb/testsuite/gdb.base/relocate.exp
@@ -37,6 +37,66 @@ 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.
+gdb_test "add-symbol-file -readnow $binfile 0x100 -s .bss 0x3" \
+ "Not confirmed\." \
+ "add-symbol-file positionless -readnow" \
+ "add symbol table from file \"${binfile}\" at\r\n\t\.text_addr = 0x100\r\n\t\.bss_addr = 0x3\r\n\\(y or n\\) " \
+ "n"
+# When we use -s as the first argument, the section will be printed
+# first as well.
+gdb_test "add-symbol-file -s .bss 0x3 -readnow $binfile 0x100" \
+ "Not confirmed\." \
+ "add-symbol-file positionless -s" \
+ "add symbol table from file \"${binfile}\" at\r\n\t\.text_addr = 0x100\r\n\t\.bss_addr = 0x3\r\n\\(y or n\\) " \
+ "n"
+gdb_test "add-symbol-file $binfile 0x100 -s .bss 0x3" \
+ "Not confirmed\." \
+ "add-symbol-file positionless -s, no -readnow" \
+ "add symbol table from file \"${binfile}\" at\r\n\t\.text_addr = 0x100\r\n\t\.bss_addr = 0x3\r\n\\(y or n\\) " \
+ "n"
+# Check that passing "-s .text", no matter the position, always has
+# the same result.
+gdb_test "add-symbol-file $binfile 0x100 -s .text 0x200" \
+ "Not confirmed\." \
+ "add-symbol-file different -s .text, after file" \
+ "add symbol table from file \"${binfile}\" at\r\n\t\.text_addr = 0x100\r\n\t\.text_addr = 0x200\r\n\\(y or n\\) " \
+ "n"
+gdb_test "add-symbol-file -s .text 0x200 $binfile 0x100" \
+ "Not confirmed\." \
+ "add-symbol-file different -s .text, before file" \
+ "add symbol table from file \"${binfile}\" at\r\n\t\.text_addr = 0x100\r\n\t\.text_addr = 0x200\r\n\\(y or n\\) " \
+ "n"
+# 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"
+# 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"
--
2.13.3