This patch implements the ability to set/unset environment variables
on the remote target, mimicking what GDB already offers to the user.
There are two features present here: user-set and user-unset
environment variables.
User-set environment variables are only the variables that are
explicitly set by the user, using the 'set environment' command. This
means that variables that were already present in the environment when
starting GDB/GDBserver are not transmitted/considered by this feature.
User-unset environment variables are variables that are explicitly
unset by the user, using the 'unset environment' command.
The idea behind this patch is to store user-set and user-unset
environment variables in two separate sets, both part of gdb_environ.
Then, when extended_remote_create_inferior is preparing to start the
inferior, it will iterate over the two sets and set/unset variables
accordingly. Three new packets are introduced:
- QEnvironmentHexEncoded, which is used to set environment variables,
and contains an hex-encoded string in the format "VAR=VALUE" (VALUE
can be empty if the user set a variable with a null value, by doing
'set environment VAR=').
- QEnvironmentUnset, which is used to unset environment variables, and
contains an hex-encoded string in the format "VAR".
- QEnvironmentReset, which is always the first packet to be
transmitted, and is used to reset the environment, i.e., discard any
changes made by the user on previous runs.
The QEnvironmentHexEncoded packet is inspired on LLDB's extensions to
the RSP. Details about it can be seen here:
<https://raw.githubusercontent.com/llvm-mirror/lldb/master/docs/lldb-gdb-remote.txt>
I decided not to implement the QEnvironment packet because it is
considered deprecated by LLDB. This packet, on LLDB, serves the same
purpose of QEnvironmentHexEncoded, but sends the information using a
plain text, non-hex-encoded string.
The other two packets are new.
This patch also includes updates to the documentation, testsuite, and
unit tests, without introducing regressions.
gdb/ChangeLog:
2017-08-31 Sergio Durigan Junior <sergiodj@redhat.com>
* NEWS (Changes since GDB 8.0): Add entry mentioning new support
for setting/unsetting environment variables on the remote target.
(New remote packets): Add entries for QEnvironmentHexEncoded,
QEnvironmentUnset and QEnvironmentReset.
* common/environ.c (gdb_environ::operator=): Extend method to
handle m_user_set_env_list and m_user_unset_env_list.
(gdb_environ::clear): Likewise.
(match_var_in_string): Change type of first parameter from 'char
*' to 'const char *'.
(gdb_environ::set): Extend method to handle
m_user_set_env_list and m_user_unset_env_list.
(gdb_environ::unset): Likewise.
(gdb_environ::clear_user_set_env): New method.
(gdb_environ::user_set_envp): Likewise.
(gdb_environ::user_unset_envp): Likewise.
* common/environ.h (gdb_environ): Handle m_user_set_env_list and
m_user_unset_env_list on move constructor/assignment.
(unset): Add new default parameter 'update_unset_list = true'.
(clear_user_set_env): New method.
(user_set_envp): Likewise.
(user_unset_envp): Likewise.
(m_user_set_env_list): New std::set.
(m_user_unset_env_list): Likewise.
* common/rsp-low.c (hex2str): New function.
(bin2hex): New overload for bin2hex function.
* common/rsp-low.c (hex2str): New prototype.
(str2hex): New overload prototype.
* remote.c: Include "environ.h". Add QEnvironmentHexEncoded,
QEnvironmentUnset and QEnvironmentReset.
(remote_protocol_features): Add QEnvironmentHexEncoded,
QEnvironmentUnset and QEnvironmentReset packets.
(send_environment_packet): New function.
(extended_remote_environment_support): Likewise.
(extended_remote_create_inferior): Call
extended_remote_environment_support.
(_initialize_remote): Add QEnvironmentHexEncoded,
QEnvironmentUnset and QEnvironmentReset packet configs.
* unittests/environ-selftests.c (gdb_selftest_env_var):
New variable.
(test_vector_initialization): New function.
(test_init_from_host_environ): Likewise.
(test_reinit_from_host_environ): Likewise.
(test_set_A_unset_B_unset_A_cannot_find_A_can_find_B):
Likewise.
(test_unset_set_empty_vector): Likewise.
(test_vector_clear): Likewise.
(test_std_move): Likewise.
(test_move_constructor):
(test_self_move): Likewise.
(test_set_unset_reset): Likewise.
(run_tests): Rewrite in terms of the functions above.
gdb/gdbserver/ChangeLog:
2017-08-31 Sergio Durigan Junior <sergiodj@redhat.com>
* server.c (handle_general_set): Handle QEnvironmentHexEncoded,
QEnvironmentUnset and QEnvironmentReset packets.
(handle_query): Inform remote that QEnvironmentHexEncoded,
QEnvironmentUnset and QEnvironmentReset are supported.
gdb/doc/ChangeLog:
2017-08-31 Sergio Durigan Junior <sergiodj@redhat.com>
* gdb.texinfo (set environment): Add @anchor. Explain that
environment variables set by the user are sent to GDBserver.
(unset environment): Likewise, but for unsetting variables.
(Connecting) <Remote Packet>: Add "environment-hex-encoded",
"QEnvironmentHexEncoded", "environment-unset", "QEnvironmentUnset",
"environment-reset" and "QEnvironmentReset" to the table.
(Remote Protocol) <QEnvironmentHexEncoded, QEnvironmentUnset,
QEnvironmentReset>: New item, explaining the packet.
gdb/testsuite/ChangeLog:
2017-08-31 Sergio Durigan Junior <sergiodj@redhat.com>
* gdb.base/share-env-with-gdbserver.c: New file.
* gdb.base/share-env-with-gdbserver.exp: Likewise.
Even though C++11 supports modifying containers using a const_iterator
(e.g., calling the 'erase' method of a std::vector), early versions of
libstdc++ did not implement that. Some of our buildslaves are using
these versions (e.g., the AArch64 buildslave uses gcc 4.8.8), and my
previous commit causes a breakage on them. The solution is simple:
just use a normal iterator, without const.
gdb/ChangeLog:
2017-06-20 Sergio Durigan Junior <sergiodj@redhat.com>
* common/environ.c (gdb_environ::unset): Use '::iterator' instead
of '::const_iterator'.
As part of the preparation necessary for my upcoming task, I'd like to
propose that we turn gdb_environ into a class. The approach taken
here is simple: the class gdb_environ contains everything that is
needed to manipulate the environment variables. These variables are
stored in an std::vector<char *>, which can be converted to a 'char
**' and passed as argument to functions that need it.
The usage has not changed much. As per Pedro's suggestion, this class
uses a static factory method initialization. This means that when an
instance is created, it is initially empty. When needed, it has to be
initialized using the static method 'from_host_environ'.
As mentioned before, this is a preparation for an upcoming work that I
will be posting in the next few weeks or so. For that work, I'll
probably create another data structure that will contain all the
environment variables that were set by the user using the 'set
environment' command, because I'll need access to them. This will be
much easier with the class-ification of gdb_environ.
As noted, this has been regression-tested with the new version of
environ.exp and no regressions were found.
gdb/ChangeLog:
2017-06-20 Sergio Durigan Junior <sergiodj@redhat.com>
* Makefile.in (SUBDIR_UNITTESTS_SRCS): Add
'unittests/environ-selftests.c'.
(SUBDIR_UNITTESTS_OBS): Add 'environ-selftests.o'.
* charset.c (find_charset_names): Declare object 'iconv_env'.
Update code to use 'iconv_env' object. Remove call to
'free_environ'.
* common/environ.c: Include <utility>.
(make_environ): Delete function.
(free_environ): Delete function.
(gdb_environ::clear): New function.
(gdb_environ::operator=): New function.
(gdb_environ::get): Likewise.
(environ_vector): Delete function.
(set_in_environ): Delete function.
(gdb_environ::set): New function.
(unset_in_environ): Delete function.
(gdb_environ::unset): New function.
(gdb_environ::envp): Likewise.
* common/environ.h: Include <vector>.
(struct gdb_environ): Delete; transform into...
(class gdb_environ): ... this class.
(free_environ): Delete prototype.
(init_environ, get_in_environ, set_in_environ, unset_in_environ,
environ_vector): Likewise.
* infcmd.c (run_command_1): Update code to call
'envp' from 'gdb_environ' class.
(environment_info): Update code to call methods from 'gdb_environ'
class.
(unset_environment_command): Likewise.
(path_info): Likewise.
(path_command): Likewise.
* inferior.c (inferior::~inferior): Delete call to 'free_environ'.
(inferior::inferior): Initialize 'environment' using the host's
information.
* inferior.h: Remove forward declaration of 'struct gdb_environ'.
Include "environ.h".
(class inferior) <environment>: Change type from 'struct
gdb_environ' to 'gdb_environ'.
* mi/mi-cmd-env.c (mi_cmd_env_path): Update code to call
methods from 'gdb_environ' class.
* solib.c (solib_find_1): Likewise
* unittests/environ-selftests.c: New file.
gdb/gdbserver/ChangeLog:
2017-06-20 Sergio Durigan Junior <sergiodj@redhat.com>
* linux-low.c (linux_create_inferior): Adjust code to access the
environment information via 'gdb_environ' class.
* lynx-low.c (lynx_create_inferior): Likewise.
* server.c (our_environ): Make it an instance of 'gdb_environ'.
(get_environ): Return a pointer to 'our_environ'.
(captured_main): Initialize 'our_environ'.
* server.h (get_environ): Adjust prototype.
* spu-low.c (spu_create_inferior): Adjust code to access the
environment information via 'gdb_environ' class.
We will need access to the environment functions when we share
fork_inferior between GDB and gdbserver, therefore we simply make the
API on gdb/environ.[ch] available on common/. No extra adjustments
are needed to make it compile on gdbserver.
gdb/ChangeLog:
2017-03-07 Sergio Durigan Junior <sergiodj@redhat.com>
* Makefile.in (SFILES): Replace "environ.c" with
"common/environ.c".
(HFILES_NO_SRCDIR): Likewise, for "environ.h".
* environ.c: Include "common-defs.h" instead of "defs.h. Moved
to...
* common/environ.c: ... here.
* environ.h: Moved to...
* common/environ.h: ... here.
gdb/gdbserver/ChangeLog:
2017-03-07 Sergio Durigan Junior <sergiodj@redhat.com>
* Makefile.in (SFILES): Add "common/environ.c".
(OBJS): Add "common/environ.h".
