[pylauncher] Use standard main() entry point with hybrid CRT linking - #27618
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Switch to standard `int main()` entry point in `pylauncher.c` and use `/MT` with `/NODEFAULTLIB:libucrt.lib ucrt.lib` in `build.bat`. The goal of this change is to make the binaries less likely to trigger false positive detections from malware scanners and antivirus tools, which often flag tiny executables compiled with custom entry points and without buffer security checks (`/GS-`). This links CRT startup code and compiler runtime support statically (so buffer security checks `/GS` and cookie initialization are handled automatically by `mainCRTStartup` without custom entrypoint stubs or `vcruntime140.dll` dependencies) while dynamically linking against the OS-provided `ucrtbase.dll`. This increases binary size by ~16-17 KB (total size ~23 KB) compared to the previous `/NODEFAULTLIB /GS-` setup, while avoiding the ~100-300 KB overhead of statically linking the full Universal CRT.
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Switch to standard
int main()entry point inpylauncher.cand use/MTwith/NODEFAULTLIB:libucrt.lib ucrt.libinbuild.bat.The goal of this change is to make the binaries less likely to trigger
false positive detections from malware scanners and antivirus tools,
which often flag tiny executables compiled with custom entry points
and without buffer security checks (
/GS-).This links CRT startup code and compiler runtime support statically
(so buffer security checks
/GSand cookie initialization are handledautomatically by
mainCRTStartupwithout custom entrypoint stubs orvcruntime140.dlldependencies) while dynamically linking against theOS-provided
ucrtbase.dll.This increases binary size by ~16-17 KB (total size ~23 KB) compared
to the previous
/NODEFAULTLIB /GS-setup, while avoiding the~100-300 KB overhead of statically linking the full Universal CRT.