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[lldb] [client] Implement follow-fork-mode
ClosedPublic

Authored by mgorny on Apr 14 2021, 12:43 PM.

Details

Summary

Implement a new target.process.follow-fork-mode setting to control
LLDB's behavior on fork. If set to 'parent', the forked child is
detached and parent continues being traced. If set to 'child',
the parent is detached and child becomes traced instead.

Diff Detail

Event Timeline

mgorny requested review of this revision.Apr 14 2021, 12:43 PM
mgorny created this revision.

This is it! The fruit of my labor! It feels like it's... kinda small. But I guess this is because all the groundwork has been done well, and now it's just a matter of plugging it in.

mgorny updated this revision to Diff 356440.Jul 4 2021, 11:58 PM

Rebase. Do not run tests on NetBSD yet.

JDevlieghere added inline comments.Jul 14 2021, 9:59 AM
lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
5465–5474

Should we lock the WatchpointList while iterating over it? If so I think that class could benefit from an Iterable (like D105914) that will lock during iteration, which would also simplify this code a bit.

mgorny added inline comments.Jul 19 2021, 4:21 AM
lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
5465–5474

Indeed that sounds like a good idea. Opened D106263 for it. I'll update this one once that one is merged.

mgorny updated this revision to Diff 360049.Jul 20 2021, 1:20 AM

Rebased. Switched to watchpoint iterator API.

mgorny marked an inline comment as done.Jul 20 2021, 1:20 AM

@mgorny Do your changes allow debugging both the parent and child processes after a fork?

@mgorny Do your changes allow debugging both the parent and child processes after a fork?

No. This patch supports choosing either the parent or the child but it's a step in that direction. Further work is necessary to support debugging multiple processes simultaneously.

mgorny updated this revision to Diff 369949.Sep 1 2021, 9:02 AM

Rebased. Changed hw breakpoint sizes to match the normal sending code.

krytarowski accepted this revision.Sep 2 2021, 2:00 AM

Looks good

This revision is now accepted and ready to land.Sep 2 2021, 2:00 AM
This revision was landed with ongoing or failed builds.Sep 2 2021, 3:17 AM
This revision was automatically updated to reflect the committed changes.
Herald added a project: Restricted Project. · View Herald TranscriptSep 2 2021, 3:17 AM
thakis added a subscriber: thakis.Sep 2 2021, 6:04 PM

The new tests here fall for me on macOS:

[4303/4304] Running lldb shell test suite
llvm-lit: /Users/thakis/src/llvm-project/lldb/test/Shell/helper/toolchain.py:126: note: using SDKROOT: '/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk'
llvm-lit: /Users/thakis/src/llvm-project/llvm/utils/lit/lit/llvm/config.py:436: note: using clang: /Users/thakis/src/llvm-build-project/bin/clang
llvm-lit: /Users/thakis/src/llvm-project/llvm/utils/lit/lit/llvm/config.py:436: note: using ld.lld: /Users/thakis/src/llvm-build-project/bin/ld.lld
llvm-lit: /Users/thakis/src/llvm-project/llvm/utils/lit/lit/llvm/config.py:436: note: using lld-link: /Users/thakis/src/llvm-build-project/bin/lld-link
llvm-lit: /Users/thakis/src/llvm-project/llvm/utils/lit/lit/llvm/config.py:436: note: using ld64.lld: /Users/thakis/src/llvm-build-project/bin/ld64.lld
llvm-lit: /Users/thakis/src/llvm-project/llvm/utils/lit/lit/llvm/config.py:436: note: using wasm-ld: /Users/thakis/src/llvm-build-project/bin/wasm-ld
llvm-lit: /Users/thakis/src/llvm-project/lldb/test/Shell/lit.cfg.py:98: warning: Could not set a default per-test timeout. Requires the Python psutil module but it could not be found. Try installing it via pip or via your operating system's package manager.
FAIL: lldb-shell :: Subprocess/fork-follow-child.test (433 of 437)
******************** TEST 'lldb-shell :: Subprocess/fork-follow-child.test' FAILED ********************
Script:
--
: 'RUN: at line 3';   /Users/thakis/src/llvm-build-project/bin/clang --driver-mode=g++ --target=specify-a-target-or-use-a-_host-substitution --target=x86_64-apple-darwin19.6.0 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk -fmodules-cache-path=/Users/thakis/src/llvm-build-project/lldb-test-build.noindex/module-cache-clang/lldb-shell /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/Inputs/fork.cpp -DTEST_FORK=fork -o /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/fork-follow-child.test.tmp
: 'RUN: at line 4';   /Users/thakis/src/llvm-build-project/bin/lldb --no-lldbinit -S /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/lit-lldb-init -b -s /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/fork-follow-child.test /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/fork-follow-child.test.tmp | /Users/thakis/src/llvm-build-project/bin/FileCheck /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/fork-follow-child.test
--
Exit Code: 1

Command Output (stderr):
--
clang-13: warning: argument unused during compilation: '-fmodules-cache-path=/Users/thakis/src/llvm-build-project/lldb-test-build.noindex/module-cache-clang/lldb-shell' [-Wunused-command-line-argument]
/Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/fork-follow-child.test:9:10: error: CHECK: expected string not found in input
# CHECK: child exited: 0
         ^
<stdin>:26:69: note: scanning from here
 0x100003cee <+14>: leaq 0x21b(%rip), %rdi ; "function run in parent\n"
                                                                    ^
<stdin>:27:115: note: possible intended match here
Process 39485 launched: '/Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/fork-follow-child.test.tmp' (x86_64)
                                                                                                                  ^

Input file: <stdin>
Check file: /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/fork-follow-child.test

-dump-input=help explains the following input dump.

Input was:
<<<<<<
           .
           .
           .
          21:  frame #0: 0x0000000100003ce0 fork-follow-child.test.tmp`parent_func()
          22: fork-follow-child.test.tmp`parent_func:
          23: -> 0x100003ce0 <+0>: pushq %rbp
          24:  0x100003ce1 <+1>: movq %rsp, %rbp
          25:  0x100003ce4 <+4>: movl $0x1, 0x434a(%rip) ; _dyld_private + 4
          26:  0x100003cee <+14>: leaq 0x21b(%rip), %rdi ; "function run in parent\n"
check:9'0                                                                         X~~~ error: no match found
          27: Process 39485 launched: '/Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/fork-follow-child.test.tmp' (x86_64)
check:9'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
check:9'1                                                                                                                       ?                         possible intended match
>>>>>>

--

********************
FAIL: lldb-shell :: Subprocess/vfork-follow-child.test (434 of 437)
******************** TEST 'lldb-shell :: Subprocess/vfork-follow-child.test' FAILED ********************
Script:
--
: 'RUN: at line 3';   /Users/thakis/src/llvm-build-project/bin/clang --driver-mode=g++ --target=specify-a-target-or-use-a-_host-substitution --target=x86_64-apple-darwin19.6.0 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk -fmodules-cache-path=/Users/thakis/src/llvm-build-project/lldb-test-build.noindex/module-cache-clang/lldb-shell /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/Inputs/fork.cpp -DTEST_FORK=vfork -o /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/vfork-follow-child.test.tmp
: 'RUN: at line 4';   /Users/thakis/src/llvm-build-project/bin/lldb --no-lldbinit -S /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/lit-lldb-init -b -s /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/vfork-follow-child.test /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/vfork-follow-child.test.tmp | /Users/thakis/src/llvm-build-project/bin/FileCheck /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/vfork-follow-child.test
--
Exit Code: 1

Command Output (stderr):
--
clang-13: warning: argument unused during compilation: '-fmodules-cache-path=/Users/thakis/src/llvm-build-project/lldb-test-build.noindex/module-cache-clang/lldb-shell' [-Wunused-command-line-argument]
/Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/vfork-follow-child.test:9:10: error: CHECK: expected string not found in input
# CHECK: child exited: 0
         ^
<stdin>:26:69: note: scanning from here
 0x100003cee <+14>: leaq 0x21b(%rip), %rdi ; "function run in parent\n"
                                                                    ^
<stdin>:27:116: note: possible intended match here
Process 39484 launched: '/Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/vfork-follow-child.test.tmp' (x86_64)
                                                                                                                   ^

Input file: <stdin>
Check file: /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/vfork-follow-child.test

-dump-input=help explains the following input dump.

Input was:
<<<<<<
           .
           .
           .
          21:  frame #0: 0x0000000100003ce0 vfork-follow-child.test.tmp`parent_func()
          22: vfork-follow-child.test.tmp`parent_func:
          23: -> 0x100003ce0 <+0>: pushq %rbp
          24:  0x100003ce1 <+1>: movq %rsp, %rbp
          25:  0x100003ce4 <+4>: movl $0x1, 0x434a(%rip) ; _dyld_private + 4
          26:  0x100003cee <+14>: leaq 0x21b(%rip), %rdi ; "function run in parent\n"
check:9'0                                                                         X~~~ error: no match found
          27: Process 39484 launched: '/Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/vfork-follow-child.test.tmp' (x86_64)
check:9'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
check:9'1                                                                                                                        ?                         possible intended match
>>>>>>

--

********************
FAIL: lldb-shell :: Subprocess/fork-follow-child-softbp.test (435 of 437)
******************** TEST 'lldb-shell :: Subprocess/fork-follow-child-softbp.test' FAILED ********************
Script:
--
: 'RUN: at line 3';   /Users/thakis/src/llvm-build-project/bin/clang --driver-mode=g++ --target=specify-a-target-or-use-a-_host-substitution --target=x86_64-apple-darwin19.6.0 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk -fmodules-cache-path=/Users/thakis/src/llvm-build-project/lldb-test-build.noindex/module-cache-clang/lldb-shell /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/Inputs/fork.cpp -DTEST_FORK=fork -o /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/fork-follow-child-softbp.test.tmp
: 'RUN: at line 4';   /Users/thakis/src/llvm-build-project/bin/lldb --no-lldbinit -S /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/lit-lldb-init -b -s /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/fork-follow-child-softbp.test /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/fork-follow-child-softbp.test.tmp | /Users/thakis/src/llvm-build-project/bin/FileCheck /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/fork-follow-child-softbp.test
--
Exit Code: 1

Command Output (stderr):
--
clang-13: warning: argument unused during compilation: '-fmodules-cache-path=/Users/thakis/src/llvm-build-project/lldb-test-build.noindex/module-cache-clang/lldb-shell' [-Wunused-command-line-argument]
/Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/fork-follow-child-softbp.test:10:15: error: CHECK-NEXT: expected string not found in input
# CHECK-NEXT: child_func
              ^
<stdin>:22:71: note: scanning from here
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 2.1
                                                                      ^
<stdin>:23:43: note: possible intended match here
 frame #0: 0x0000000100003ce0 fork-follow-child-softbp.test.tmp`parent_func()
                                          ^

Input file: <stdin>
Check file: /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/fork-follow-child-softbp.test

-dump-input=help explains the following input dump.

Input was:
<<<<<<
           .
           .
           .
          17: Breakpoint 1: where = fork-follow-child-softbp.test.tmp`child_func(void*), address = 0x0000000100003d00
          18: (lldb) b parent_func
          19: Breakpoint 2: where = fork-follow-child-softbp.test.tmp`parent_func(), address = 0x0000000100003ce0
          20: (lldb) process launch
          21: Process 39486 stopped
          22: * thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 2.1
next:10'0                                                                           X~~~~ error: no match found
          23:  frame #0: 0x0000000100003ce0 fork-follow-child-softbp.test.tmp`parent_func()
next:10'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
next:10'1                                               ?                                    possible intended match
          24: fork-follow-child-softbp.test.tmp`parent_func:
next:10'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          25: -> 0x100003ce0 <+0>: pushq %rbp
next:10'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          26:  0x100003ce1 <+1>: movq %rsp, %rbp
next:10'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          27:  0x100003ce4 <+4>: movl $0x1, 0x434a(%rip) ; _dyld_private + 4
next:10'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          28:  0x100003cee <+14>: leaq 0x21b(%rip), %rdi ; "function run in parent\n"
next:10'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           .
           .
           .
>>>>>>

--

********************
FAIL: lldb-shell :: Subprocess/fork-follow-child-wp.test (436 of 437)
******************** TEST 'lldb-shell :: Subprocess/fork-follow-child-wp.test' FAILED ********************
Script:
--
: 'RUN: at line 3';   /Users/thakis/src/llvm-build-project/bin/clang --driver-mode=g++ --target=specify-a-target-or-use-a-_host-substitution --target=x86_64-apple-darwin19.6.0 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk -fmodules-cache-path=/Users/thakis/src/llvm-build-project/lldb-test-build.noindex/module-cache-clang/lldb-shell -g /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/Inputs/fork.cpp -DTEST_FORK=fork -o /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/fork-follow-child-wp.test.tmp
: 'RUN: at line 4';   /Users/thakis/src/llvm-build-project/bin/lldb --no-lldbinit -S /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/lit-lldb-init -b -s /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/fork-follow-child-wp.test /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/fork-follow-child-wp.test.tmp | /Users/thakis/src/llvm-build-project/bin/FileCheck /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/fork-follow-child-wp.test
--
Exit Code: 1

Command Output (stderr):
--
clang-13: warning: argument unused during compilation: '-fmodules-cache-path=/Users/thakis/src/llvm-build-project/lldb-test-build.noindex/module-cache-clang/lldb-shell' [-Wunused-command-line-argument]
error: Process must be launched.
/Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/fork-follow-child-wp.test:12:10: error: CHECK: expected string not found in input
# CHECK: stop reason = watchpoint
         ^
<stdin>:29:71: note: scanning from here
* thread #1, queue = 'com.apple.main-thread', stop reason = watchpoint 1
                                                                      ^
<stdin>:40:4: note: possible intended match here
function run in parent
   ^

Input file: <stdin>
Check file: /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/fork-follow-child-wp.test

-dump-input=help explains the following input dump.

Input was:
<<<<<<
            .
            .
            .
           24: Watchpoint 1 hit:
           25: old value: 0
           26: new value: 1
           27: Process 39492 resuming
           28: Process 39492 stopped
           29: * thread #1, queue = 'com.apple.main-thread', stop reason = watchpoint 1
check:12'0                                                                           X~~ error: no match found
           30:  frame #0: 0x0000000100003cee fork-follow-child-wp.test.tmp`parent_func() at fork.cpp:15:3
check:12'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           31:  12
check:12'0     ~~~~~
           32:  13 void parent_func() {
check:12'0     ~~~~~~~~~~~~~~~~~~~~~~~~~
           33:  14 g_val = 1;
check:12'0     ~~~~~~~~~~~~~~~
           34: -> 15 printf("function run in parent\n");
check:12'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           35:  ^
check:12'0     ~~~
           36:  16 }
check:12'0     ~~~~~~
           37:  17
check:12'0     ~~~~~
           38:  18 int child_func(void *unused) {
check:12'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           39: (lldb) continue
check:12'0     ~~~~~~~~~~~~~~~~
           40: function run in parent
check:12'0     ~~~~~~~~~~~~~~~~~~~~~~~
check:12'1        ?                    possible intended match
           41: child exited: 0
check:12'0     ~~~~~~~~~~~~~~~~
           42: Process 39492 resuming
check:12'0     ~~~~~~~~~~~~~~~~~~~~~~~
           43: Process 39492 exited with status = 0 (0x00000000)
check:12'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           44: (lldb) continue
check:12'0     ~~~~~~~~~~~~~~~~
>>>>>>

--

********************
FAIL: lldb-shell :: Subprocess/vfork-follow-child-softbp.test (437 of 437)
******************** TEST 'lldb-shell :: Subprocess/vfork-follow-child-softbp.test' FAILED ********************
Script:
--
: 'RUN: at line 3';   /Users/thakis/src/llvm-build-project/bin/clang --driver-mode=g++ --target=specify-a-target-or-use-a-_host-substitution --target=x86_64-apple-darwin19.6.0 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk -fmodules-cache-path=/Users/thakis/src/llvm-build-project/lldb-test-build.noindex/module-cache-clang/lldb-shell /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/Inputs/fork.cpp -DTEST_FORK=vfork -o /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/vfork-follow-child-softbp.test.tmp
: 'RUN: at line 4';   /Users/thakis/src/llvm-build-project/bin/lldb --no-lldbinit -S /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/lit-lldb-init -b -s /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/vfork-follow-child-softbp.test /Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/vfork-follow-child-softbp.test.tmp | /Users/thakis/src/llvm-build-project/bin/FileCheck /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/vfork-follow-child-softbp.test
--
Exit Code: 1

Command Output (stderr):
--
clang-13: warning: argument unused during compilation: '-fmodules-cache-path=/Users/thakis/src/llvm-build-project/lldb-test-build.noindex/module-cache-clang/lldb-shell' [-Wunused-command-line-argument]
/Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/vfork-follow-child-softbp.test:9:10: error: CHECK: expected string not found in input
# CHECK: function run in parent
         ^
<stdin>:1:1: note: scanning from here
(lldb) command source -s 0 '/Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/lit-lldb-init'
^
<stdin>:6:8: note: possible intended match here
(lldb) settings set interpreter.echo-comment-commands false
       ^

Input file: <stdin>
Check file: /Users/thakis/src/llvm-project/lldb/test/Shell/Subprocess/vfork-follow-child-softbp.test

-dump-input=help explains the following input dump.

Input was:
<<<<<<
           1: (lldb) command source -s 0 '/Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/lit-lldb-init'
check:9'0     X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found
           2: Executing commands in '/Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/lit-lldb-init'.
check:9'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           3: (lldb) # LLDB init file for the LIT tests.
check:9'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           4: (lldb) settings set symbols.enable-external-lookup false
check:9'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           5: (lldb) settings set plugin.process.gdb-remote.packet-timeout 60
check:9'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           6: (lldb) settings set interpreter.echo-comment-commands false
check:9'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
check:9'1            ?                                                     possible intended match
           7: (lldb) settings set symbols.clang-modules-cache-path "/Users/thakis/src/llvm-build-project/lldb-test-build.noindex/module-cache-lldb"
check:9'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           8: (lldb) settings set target.auto-apply-fixits false
check:9'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           9: (lldb) settings set target.inherit-tcc true
check:9'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          10: (lldb) settings set target.detach-on-error false
check:9'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          11: (lldb) target create "/Users/thakis/src/llvm-build-project/tools/lldb/test/Shell/Subprocess/Output/vfork-follow-child-softbp.test.tmp"
check:9'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           .
           .
           .
>>>>>>

--

********************
********************
Failed Tests (5):
  lldb-shell :: Subprocess/fork-follow-child-softbp.test
  lldb-shell :: Subprocess/fork-follow-child-wp.test
  lldb-shell :: Subprocess/fork-follow-child.test
  lldb-shell :: Subprocess/vfork-follow-child-softbp.test
  lldb-shell :: Subprocess/vfork-follow-child.test

I'm sorry about looking into it this late. I've just marked them all unsupported on Darwin.