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Merged
juj merged 8 commits into from
Oct 6, 2021
Merged

Avoid sharing the parent process's stdin handle to python on Windows + other Windows bat script fixes #15146

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b9d67ea
Avoid sharing the parent process's stdin handle to python when invoki…
juj Sep 27, 2021
1efc051
Fix Windows .bat scripts from leaking set env. vars.
juj Oct 6, 2021
28e26eb
Do not let anything come between python subprocess spawn and the exit…
juj Oct 6, 2021
556c793
Fix bad automerge
juj Oct 6, 2021
b0e1935
Avoid dispatching emcc from within an if() block in .bat file
juj Oct 6, 2021
8285143
Always use exit in .bat scripts to avoid goto tainting ERRORLEVEL
juj Oct 6, 2021
5367f94
Fix bad merge in Changelog
juj Oct 6, 2021
dbb87eb
Move :NORMAL last in the batch scripts
juj Oct 6, 2021
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4 changes: 4 additions & 0 deletions ChangeLog.md
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Expand Up @@ -36,6 +36,10 @@ See docs/process.md for more on how version tagging works.
`__syscall22`) to name-based (e.g. `__syscall_open`). This should not be
a visible change except for folks trying to intercept/implement syscalls
in native code (#15202).
- Fixed launcher batch script issues on Windows, and added two env. vars
EM_WORKAROUND_PYTHON_BUG_34780 and EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG that
can be enabled to work around a Windows Python issue
https://bugs.python.org/issue34780 , and a Windows 7 exit code issue (#15146)

2.0.31 - 10/01/2021
-------------------
Expand Down
51 changes: 49 additions & 2 deletions em++.bat
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Expand Up @@ -5,18 +5,65 @@
:: To make modifications to this file, edit `tools/run_python_compiler.bat` and
:: then run `tools/create_entry_points.py`

:: All env. vars specified in this file are to be local only to this script.
@setlocal

@set EM_PY=%EMSDK_PYTHON%
@if "%EM_PY%"=="" (
set EM_PY=python
)

:: If _EMCC_CCACHE is not set, do a regular invocation of the python compiler driver.
:: Otherwise remove the ccache env. var, and then reinvoke this script with ccache enabled.
@if "%_EMCC_CCACHE%"=="" (
:: Do regular invocation of the python compiler driver
set CMD="%EM_PY%" "%~dp0\%~n0.py"
) else (
:: Remove the ccache env. var, invoke ccache and re-enter this script to take the above branch.
set _EMCC_CCACHE=
set CMD=ccache "%~dp0\%~n0.bat"
)

:: Python Windows bug https://bugs.python.org/issue34780: If this script was invoked via a
:: shared stdin handle from the parent process, and that parent process stdin handle is in
:: a certain state, running python.exe might hang here. To work around this, if
:: EM_WORKAROUND_PYTHON_BUG_34780 is defined, invoke python with '< NUL' stdin to avoid
:: sharing the parent's stdin handle to it, avoiding the hang.

:: On Windows 7, the compiler batch scripts are observed to exit with a non-zero errorlevel,
:: even when the python executable above did succeed and quit with errorlevel 0 above.
:: On Windows 8 and newer, this issue has not been observed. It is possible that this
:: issue is related to the above python bug, but this has not been conclusively confirmed,
:: so using a separate env. var EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG to enable the known
:: workaround this issue, which is to explicitly quit the calling process with the previous
:: errorlevel from the above command.

:: Also must use goto to jump to the command dispatch, since we cannot invoke emcc from
:: inside a if() block, because if a cmdline param would contain a char '(' or ')', that
:: would throw off the parsing of the cmdline arg.
@if "%EM_WORKAROUND_PYTHON_BUG_34780%"=="" (
@if "%EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG%"=="" (
goto NORMAL
) else (
goto NORMAL_EXIT
)
) else (
@if "%EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG%"=="" (
goto MUTE_STDIN
) else (
goto MUTE_STDIN_EXIT
)
)

:NORMAL_EXIT
@%CMD% %*
@exit %ERRORLEVEL%

@sbc100 sbc100 Oct 6, 2021

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Without the /b does this not exit the entire cmd.exe shell?

@juj juj Oct 6, 2021

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That's right, though unfortunately with the /b flag that will not fix the Windows 7 issue. The /b flag is used in the other part to avoid a goto, which would reset the %errorlevel% variable to zero.

@sbc100 sbc100 Oct 6, 2021

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So users of EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG are opting into not being able to use these tools in a command shell, is that the idea? Maybe it would never make sense there?

@sbc100 sbc100 Oct 6, 2021

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(Sorry I should have read all of your above comments.. I see it mentions this there).

@juj juj Oct 6, 2021

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Yeah, that is the case - when one enables EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG, that will cause the shell to quit. For command line uses that would be quite undesirable, hence placing it under a separate workaround env. var.


:MUTE_STDIN
@%CMD% %* < NUL
@exit /b %ERRORLEVEL%

:MUTE_STDIN_EXIT
@%CMD% %* < NUL
@exit %ERRORLEVEL%

:NORMAL
@%CMD% %*
46 changes: 46 additions & 0 deletions em-config.bat
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Original file line number Diff line number Diff line change
Expand Up @@ -5,10 +5,56 @@
:: To make modifications to this file, edit `tools/run_python.bat` and then run
:: `tools/create_entry_points.py`

:: All env. vars specified in this file are to be local only to this script.
@setlocal

@set EM_PY=%EMSDK_PYTHON%
@if "%EM_PY%"=="" (
set EM_PY=python
)

:: Python Windows bug https://bugs.python.org/issue34780: If this script was invoked via a
:: shared stdin handle from the parent process, and that parent process stdin handle is in
:: a certain state, running python.exe might hang here. To work around this, if
:: EM_WORKAROUND_PYTHON_BUG_34780 is defined, invoke python with '< NUL' stdin to avoid
:: sharing the parent's stdin handle to it, avoiding the hang.

:: On Windows 7, the compiler batch scripts are observed to exit with a non-zero errorlevel,
:: even when the python executable above did succeed and quit with errorlevel 0 above.
:: On Windows 8 and newer, this issue has not been observed. It is possible that this
:: issue is related to the above python bug, but this has not been conclusively confirmed,
:: so using a separate env. var EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG to enable the known
:: workaround this issue, which is to explicitly quit the calling process with the previous
:: errorlevel from the above command.

:: Also must use goto to jump to the command dispatch, since we cannot invoke emcc from
:: inside a if() block, because if a cmdline param would contain a char '(' or ')', that
:: would throw off the parsing of the cmdline arg.
@if "%EM_WORKAROUND_PYTHON_BUG_34780%"=="" (
@if "%EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG%"=="" (
goto NORMAL
) else (
goto NORMAL_EXIT
)
) else (
@if "%EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG%"=="" (
goto MUTE_STDIN
) else (
goto MUTE_STDIN_EXIT
)
)

:NORMAL_EXIT
@"%EM_PY%" "%~dp0\%~n0.py" %*
@exit %ERRORLEVEL%

:MUTE_STDIN
@"%EM_PY%" "%~dp0\%~n0.py" %* < NUL
@exit /b %ERRORLEVEL%

:MUTE_STDIN_EXIT
@"%EM_PY%" "%~dp0\%~n0.py" %* < NUL
@exit %ERRORLEVEL%

:NORMAL
@"%EM_PY%" "%~dp0\%~n0.py" %*
46 changes: 46 additions & 0 deletions emar.bat
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Original file line number Diff line number Diff line change
Expand Up @@ -5,10 +5,56 @@
:: To make modifications to this file, edit `tools/run_python.bat` and then run
:: `tools/create_entry_points.py`

:: All env. vars specified in this file are to be local only to this script.
@setlocal

@set EM_PY=%EMSDK_PYTHON%
@if "%EM_PY%"=="" (
set EM_PY=python
)

:: Python Windows bug https://bugs.python.org/issue34780: If this script was invoked via a
:: shared stdin handle from the parent process, and that parent process stdin handle is in
:: a certain state, running python.exe might hang here. To work around this, if
:: EM_WORKAROUND_PYTHON_BUG_34780 is defined, invoke python with '< NUL' stdin to avoid
:: sharing the parent's stdin handle to it, avoiding the hang.

:: On Windows 7, the compiler batch scripts are observed to exit with a non-zero errorlevel,
:: even when the python executable above did succeed and quit with errorlevel 0 above.
:: On Windows 8 and newer, this issue has not been observed. It is possible that this
:: issue is related to the above python bug, but this has not been conclusively confirmed,
:: so using a separate env. var EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG to enable the known
:: workaround this issue, which is to explicitly quit the calling process with the previous
:: errorlevel from the above command.

:: Also must use goto to jump to the command dispatch, since we cannot invoke emcc from
:: inside a if() block, because if a cmdline param would contain a char '(' or ')', that
:: would throw off the parsing of the cmdline arg.
@if "%EM_WORKAROUND_PYTHON_BUG_34780%"=="" (
@if "%EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG%"=="" (
goto NORMAL
) else (
goto NORMAL_EXIT
)
) else (
@if "%EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG%"=="" (
goto MUTE_STDIN
) else (
goto MUTE_STDIN_EXIT
)
)

:NORMAL_EXIT
@"%EM_PY%" "%~dp0\%~n0.py" %*
@exit %ERRORLEVEL%

:MUTE_STDIN
@"%EM_PY%" "%~dp0\%~n0.py" %* < NUL
@exit /b %ERRORLEVEL%

:MUTE_STDIN_EXIT
@"%EM_PY%" "%~dp0\%~n0.py" %* < NUL
@exit %ERRORLEVEL%

:NORMAL
@"%EM_PY%" "%~dp0\%~n0.py" %*
46 changes: 46 additions & 0 deletions embuilder.bat
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Original file line number Diff line number Diff line change
Expand Up @@ -5,10 +5,56 @@
:: To make modifications to this file, edit `tools/run_python.bat` and then run
:: `tools/create_entry_points.py`

:: All env. vars specified in this file are to be local only to this script.
@setlocal

@set EM_PY=%EMSDK_PYTHON%
@if "%EM_PY%"=="" (
set EM_PY=python
)

:: Python Windows bug https://bugs.python.org/issue34780: If this script was invoked via a
:: shared stdin handle from the parent process, and that parent process stdin handle is in
:: a certain state, running python.exe might hang here. To work around this, if
:: EM_WORKAROUND_PYTHON_BUG_34780 is defined, invoke python with '< NUL' stdin to avoid
:: sharing the parent's stdin handle to it, avoiding the hang.

:: On Windows 7, the compiler batch scripts are observed to exit with a non-zero errorlevel,
:: even when the python executable above did succeed and quit with errorlevel 0 above.
:: On Windows 8 and newer, this issue has not been observed. It is possible that this
:: issue is related to the above python bug, but this has not been conclusively confirmed,
:: so using a separate env. var EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG to enable the known
:: workaround this issue, which is to explicitly quit the calling process with the previous
:: errorlevel from the above command.

:: Also must use goto to jump to the command dispatch, since we cannot invoke emcc from
:: inside a if() block, because if a cmdline param would contain a char '(' or ')', that
:: would throw off the parsing of the cmdline arg.
@if "%EM_WORKAROUND_PYTHON_BUG_34780%"=="" (
@if "%EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG%"=="" (
goto NORMAL
) else (
goto NORMAL_EXIT
)
) else (
@if "%EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG%"=="" (
goto MUTE_STDIN
) else (
goto MUTE_STDIN_EXIT
)
)

:NORMAL_EXIT
@"%EM_PY%" "%~dp0\%~n0.py" %*
@exit %ERRORLEVEL%

:MUTE_STDIN
@"%EM_PY%" "%~dp0\%~n0.py" %* < NUL
@exit /b %ERRORLEVEL%

:MUTE_STDIN_EXIT
@"%EM_PY%" "%~dp0\%~n0.py" %* < NUL
@exit %ERRORLEVEL%

:NORMAL
@"%EM_PY%" "%~dp0\%~n0.py" %*
51 changes: 49 additions & 2 deletions emcc.bat
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -5,18 +5,65 @@
:: To make modifications to this file, edit `tools/run_python_compiler.bat` and
:: then run `tools/create_entry_points.py`

:: All env. vars specified in this file are to be local only to this script.
@setlocal

@set EM_PY=%EMSDK_PYTHON%
@if "%EM_PY%"=="" (
set EM_PY=python
)

:: If _EMCC_CCACHE is not set, do a regular invocation of the python compiler driver.
:: Otherwise remove the ccache env. var, and then reinvoke this script with ccache enabled.
@if "%_EMCC_CCACHE%"=="" (
:: Do regular invocation of the python compiler driver
set CMD="%EM_PY%" "%~dp0\%~n0.py"
) else (
:: Remove the ccache env. var, invoke ccache and re-enter this script to take the above branch.
set _EMCC_CCACHE=
set CMD=ccache "%~dp0\%~n0.bat"
)

:: Python Windows bug https://bugs.python.org/issue34780: If this script was invoked via a
:: shared stdin handle from the parent process, and that parent process stdin handle is in
:: a certain state, running python.exe might hang here. To work around this, if
:: EM_WORKAROUND_PYTHON_BUG_34780 is defined, invoke python with '< NUL' stdin to avoid
:: sharing the parent's stdin handle to it, avoiding the hang.

:: On Windows 7, the compiler batch scripts are observed to exit with a non-zero errorlevel,
:: even when the python executable above did succeed and quit with errorlevel 0 above.
:: On Windows 8 and newer, this issue has not been observed. It is possible that this
:: issue is related to the above python bug, but this has not been conclusively confirmed,
:: so using a separate env. var EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG to enable the known
:: workaround this issue, which is to explicitly quit the calling process with the previous
:: errorlevel from the above command.

:: Also must use goto to jump to the command dispatch, since we cannot invoke emcc from
:: inside a if() block, because if a cmdline param would contain a char '(' or ')', that
:: would throw off the parsing of the cmdline arg.
@if "%EM_WORKAROUND_PYTHON_BUG_34780%"=="" (
@if "%EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG%"=="" (
goto NORMAL
) else (
goto NORMAL_EXIT
)
) else (
@if "%EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG%"=="" (
goto MUTE_STDIN
) else (
goto MUTE_STDIN_EXIT
)
)

:NORMAL_EXIT
@%CMD% %*
@exit %ERRORLEVEL%

:MUTE_STDIN
@%CMD% %* < NUL
@exit /b %ERRORLEVEL%

:MUTE_STDIN_EXIT
@%CMD% %* < NUL
@exit %ERRORLEVEL%

:NORMAL
@%CMD% %*
46 changes: 46 additions & 0 deletions emcmake.bat
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Original file line number Diff line number Diff line change
Expand Up @@ -5,10 +5,56 @@
:: To make modifications to this file, edit `tools/run_python.bat` and then run
:: `tools/create_entry_points.py`

:: All env. vars specified in this file are to be local only to this script.
@setlocal

@set EM_PY=%EMSDK_PYTHON%
@if "%EM_PY%"=="" (
set EM_PY=python
)

:: Python Windows bug https://bugs.python.org/issue34780: If this script was invoked via a
:: shared stdin handle from the parent process, and that parent process stdin handle is in
:: a certain state, running python.exe might hang here. To work around this, if
:: EM_WORKAROUND_PYTHON_BUG_34780 is defined, invoke python with '< NUL' stdin to avoid
:: sharing the parent's stdin handle to it, avoiding the hang.

:: On Windows 7, the compiler batch scripts are observed to exit with a non-zero errorlevel,
:: even when the python executable above did succeed and quit with errorlevel 0 above.
:: On Windows 8 and newer, this issue has not been observed. It is possible that this
:: issue is related to the above python bug, but this has not been conclusively confirmed,
:: so using a separate env. var EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG to enable the known
:: workaround this issue, which is to explicitly quit the calling process with the previous
:: errorlevel from the above command.

:: Also must use goto to jump to the command dispatch, since we cannot invoke emcc from
:: inside a if() block, because if a cmdline param would contain a char '(' or ')', that
:: would throw off the parsing of the cmdline arg.
@if "%EM_WORKAROUND_PYTHON_BUG_34780%"=="" (
@if "%EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG%"=="" (
goto NORMAL
) else (
goto NORMAL_EXIT
)
) else (
@if "%EM_WORKAROUND_WIN7_BAD_ERRORLEVEL_BUG%"=="" (
goto MUTE_STDIN
) else (
goto MUTE_STDIN_EXIT
)
)

:NORMAL_EXIT
@"%EM_PY%" "%~dp0\%~n0.py" %*
@exit %ERRORLEVEL%

:MUTE_STDIN
@"%EM_PY%" "%~dp0\%~n0.py" %* < NUL
@exit /b %ERRORLEVEL%

:MUTE_STDIN_EXIT
@"%EM_PY%" "%~dp0\%~n0.py" %* < NUL
@exit %ERRORLEVEL%

:NORMAL
@"%EM_PY%" "%~dp0\%~n0.py" %*
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