Attach to PID does not process "Initial Commands" before attaching

The current method used to attach to a process on the local machine is to specify the PID on the command line to the debugger. However, by doing this, the debugger will attach to the process prior to executing the initial configuration commands (specified in MI2::initCommands). This is inconsistent with remote attach operations (using target-select remote or target-select extended-remote) which only attach to the remote process after the initial configuration commands have been processed.

The problem with attaching prior to processing the initial configuration commands is that there can be spurious errors that occur because of this. For example, if a source path mapping is needed to resolve the source code, when the debugger attaches to the process, it will attempt to locate the source file, but won’t be able to find it because the source path mappings commands have not yet been processed. Additionally, this can also lead to errors attempting other commands, such as gdb-set target-async on failing with “Cannot change this setting while the inferior is running”.

The below output demonstrates both the source path mapping issue as well as the issue with the failing gdb-set target-async on command. I’d suggest that the current behavior be changed to process the initial configuration commands first, and then issue a “target-attach” command afterwards to attach to the local process.

1-gdb-set target-async on
2-list-features
3-environment-directory "/home/troy/git/hello_world_exe"
4-gdb-set substitute-path "C:\\usr\\src" "/home/troy/git/hello_world_exe/../hello_world_c"
GDB -> App: {"outOfBandRecord":[{"isStream":false,"type":"notify","asyncClass":"thread-group-added","output":[["id","i1"]]}]}
GDB -> App: {"outOfBandRecord":[{"isStream":true,"type":"console","content":"Attaching to process 7801\n"}]}
Attaching to process 7801
GDB -> App: {"outOfBandRecord":[{"isStream":false,"type":"notify","asyncClass":"thread-group-started","output":[["id","i1"],["pid","7801"]]}]}
GDB -> App: {"outOfBandRecord":[{"isStream":false,"type":"notify","asyncClass":"thread-created","output":[["id","1"],["group-id","i1"]]}]}
GDB -> App: {"outOfBandRecord":[{"isStream":true,"type":"console","content":"Reading symbols from /home/troy/git/hello_world_exe/hello_world-gcc..."}]}
Reading symbols from /home/troy/git/hello_world_exe/hello_world-gcc...
GDB -> App: {"outOfBandRecord":[{"isStream":true,"type":"console","content":"done.\n"}]}
done.
GDB -> App: {"outOfBandRecord":[{"isStream":false,"type":"notify","asyncClass":"library-loaded","output":[["id","/lib/x86_64-linux-gnu/libc.so.6"],["target-name","/lib/x86_64-linux-gnu/libc.so.6"],["host-name","/lib/x86_64-linux-gnu/libc.so.6"],["symbols-loaded","0"],["thread-group","i1"],["ranges",[[["from","0x00007f8d2b173360"],["to","0x00007f8d2b2ebafc"]]]]]}]}
GDB -> App: {"outOfBandRecord":[{"isStream":false,"type":"notify","asyncClass":"library-loaded","output":[["id","/lib64/ld-linux-x86-64.so.2"],["target-name","/lib64/ld-linux-x86-64.so.2"],["host-name","/lib64/ld-linux-x86-64.so.2"],["symbols-loaded","0"],["thread-group","i1"],["ranges",[[["from","0x00007f8d2b543f10"],["to","0x00007f8d2b564550"]]]]]}]}
GDB -> App: {"outOfBandRecord":[{"isStream":true,"type":"console","content":"Reading symbols from /lib/x86_64-linux-gnu/libc.so.6..."}]}
Reading symbols from /lib/x86_64-linux-gnu/libc.so.6...
GDB -> App: {"outOfBandRecord":[{"isStream":true,"type":"console","content":"Reading symbols from /usr/lib/debug//lib/x86_64-linux-gnu/libc-2.27.so..."}]}
Reading symbols from /usr/lib/debug//lib/x86_64-linux-gnu/libc-2.27.so...
5-thread-info
GDB -> App: {"outOfBandRecord":[{"isStream":true,"type":"console","content":"done.\n"}]}
done.
GDB -> App: {"outOfBandRecord":[{"isStream":true,"type":"console","content":"done.\n"}]}
done.
GDB -> App: {"outOfBandRecord":[{"isStream":true,"type":"console","content":"Reading symbols from /lib64/ld-linux-x86-64.so.2..."}]}
Reading symbols from /lib64/ld-linux-x86-64.so.2...
GDB -> App: {"outOfBandRecord":[{"isStream":true,"type":"console","content":"Reading symbols from /usr/lib/debug//lib/x86_64-linux-gnu/ld-2.27.so..."}]}
Reading symbols from /usr/lib/debug//lib/x86_64-linux-gnu/ld-2.27.so...
GDB -> App: {"outOfBandRecord":[{"isStream":true,"type":"console","content":"done.\n"}]}
done.
GDB -> App: {"outOfBandRecord":[{"isStream":true,"type":"console","content":"done.\n"}]}
done.
GDB -> App: {"outOfBandRecord":[{"isStream":true,"type":"console","content":"main () at hello_world.c:6\n"}]}
main () at hello_world.c:6
GDB -> App: {"outOfBandRecord":[{"isStream":true,"type":"log","content":"6\thello_world.c: No such file or directory.\n"}]}
6	hello_world.c: No such file or directory.
GDB -> App: {"outOfBandRecord":[{"isStream":false,"type":"exec","asyncClass":"stopped","output":[["frame",[["addr","0x00005615fb5f864a"],["func","main"],["args",[]],["file","hello_world.c"],["fullname","C:\\usr\\src/hello_world.c"],["line","6"]]],["thread-id","1"],["stopped-threads","all"],["core","5"]]}]}
GDB -> App: {"token":1,"outOfBandRecord":[],"resultRecords":{"resultClass":"error","results":[["msg","Cannot change this setting while the inferior is running."]]}}
WARNING: Error executing command 'gdb-set target-async on'
GDB -> App: {"token":2,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["features",["frozen-varobjs","pending-breakpoints","thread-info","data-read-memory-bytes","breakpoint-notifications","ada-task-info","language-option","info-gdb-mi-command","undefined-command-error-code","exec-run-start-option","python"]]]}}
GDB -> App: {"token":3,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["source-path","/home/troy/git/hello_world_exe:$cdir:$cwd"]]}}
GDB -> App: {"token":4,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[]}}
GDB -> App: {"token":5,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["threads",[[["id","1"],["target-id","process 7801"],["name","hello_world-gcc"],["frame",[["level","0"],["addr","0x00005615fb5f864a"],["func","main"],["args",[]],["file","hello_world.c"],["fullname","/home/troy/git/hello_world_c/hello_world.c"],["line","6"]]],["state","stopped"],["core","5"]]]],["current-thread-id","1"]]}}
6-thread-info
GDB -> App: {"token":6,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["threads",[[["id","1"],["target-id","process 7801"],["name","hello_world-gcc"],["frame",[["level","0"],["addr","0x00005615fb5f864a"],["func","main"],["args",[]],["file","hello_world.c"],["fullname","/home/troy/git/hello_world_c/hello_world.c"],["line","6"]]],["state","stopped"],["core","5"]]]],["current-thread-id","1"]]}}
7-stack-info-depth --thread 1
8-stack-info-depth --thread 1
GDB -> App: {"token":7,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["depth","1"]]}}
GDB -> App: {"token":8,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["depth","1"]]}}
9-stack-list-frames --thread 1 0 0
10-stack-list-frames --thread 1 0 0
GDB -> App: {"token":9,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["stack",[["frame",[["level","0"],["addr","0x00005615fb5f864a"],["func","main"],["file","hello_world.c"],["fullname","/home/troy/git/hello_world_c/hello_world.c"],["line","6"]]]]]]}}
GDB -> App: {"token":10,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["stack",[["frame",[["level","0"],["addr","0x00005615fb5f864a"],["func","main"],["file","hello_world.c"],["fullname","/home/troy/git/hello_world_c/hello_world.c"],["line","6"]]]]]]}}
11-thread-info
GDB -> App: {"token":11,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["threads",[[["id","1"],["target-id","process 7801"],["name","hello_world-gcc"],["frame",[["level","0"],["addr","0x00005615fb5f864a"],["func","main"],["args",[]],["file","hello_world.c"],["fullname","/home/troy/git/hello_world_c/hello_world.c"],["line","6"]]],["state","stopped"],["core","5"]]]],["current-thread-id","1"]]}}
12-thread-info
GDB -> App: {"token":12,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["threads",[[["id","1"],["target-id","process 7801"],["name","hello_world-gcc"],["frame",[["level","0"],["addr","0x00005615fb5f864a"],["func","main"],["args",[]],["file","hello_world.c"],["fullname","/home/troy/git/hello_world_c/hello_world.c"],["line","6"]]],["state","stopped"],["core","5"]]]],["current-thread-id","1"]]}}
13-stack-info-depth --thread 1
GDB -> App: {"token":13,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["depth","1"]]}}
14-stack-list-frames --thread 1 0 0
GDB -> App: {"token":14,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["stack",[["frame",[["level","0"],["addr","0x00005615fb5f864a"],["func","main"],["file","hello_world.c"],["fullname","/home/troy/git/hello_world_c/hello_world.c"],["line","6"]]]]]]}}
15-stack-info-depth --thread 1
GDB -> App: {"token":15,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["depth","1"]]}}
16-stack-list-frames --thread 1 0 0
GDB -> App: {"token":16,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["stack",[["frame",[["level","0"],["addr","0x00005615fb5f864a"],["func","main"],["file","hello_world.c"],["fullname","/home/troy/git/hello_world_c/hello_world.c"],["line","6"]]]]]]}}
17-stack-list-variables --thread 1 --frame 0 --simple-values
GDB -> App: {"token":17,"outOfBandRecord":[],"resultRecords":{"resultClass":"done","results":[["variables",[]]]}}

[GitMensch]

Thanks for your work on this extension, it helps a lot!

[WebFreak001]

@brownts would you also like to have collaborator access?

Also we might want to move the repository to a GitHub team eventually, so there can be more than one owner on it.