From b644e5750e9a590e7ea64cc0c4dbda9afaf5643f Mon Sep 17 00:00:00 2001
From: Brian McKenna <brian@brianmckenna.org>
Date: Fri, 15 Nov 2024 10:45:29 +1100
Subject: [PATCH 1/2] Remove broken stack size logic from Windows

The API only changes the stack size once there's already a stack
overflow exception. Pretty useless.
---
 src/libutil/current-process.cc | 27 ---------------------------
 1 file changed, 27 deletions(-)

diff --git a/src/libutil/current-process.cc b/src/libutil/current-process.cc
index ac01f441e..46e72b63a 100644
--- a/src/libutil/current-process.cc
+++ b/src/libutil/current-process.cc
@@ -19,10 +19,6 @@
 # include "namespaces.hh"
 #endif
 
-#ifndef _WIN32
-# include <sys/resource.h>
-#endif
-
 namespace nix {
 
 unsigned int getMaxCPU()
@@ -77,29 +73,6 @@ void setStackSize(size_t stackSize)
             );
         }
     }
-    #else
-    ULONG_PTR stackLow, stackHigh;
-    GetCurrentThreadStackLimits(&stackLow, &stackHigh);
-    ULONG maxStackSize = stackHigh - stackLow;
-    ULONG currStackSize = 0;
-    // This retrieves the current promised stack size
-    SetThreadStackGuarantee(&currStackSize);
-    if (currStackSize < stackSize) {
-        savedStackSize = currStackSize;
-        ULONG newStackSize = std::min(static_cast<ULONG>(stackSize), maxStackSize);
-        if (SetThreadStackGuarantee(&newStackSize) == 0) {
-            logger->log(
-                lvlError,
-                HintFmt(
-                    "Failed to increase stack size from %1% to %2% (maximum allowed stack size: %3%): %4%",
-                    savedStackSize,
-                    stackSize,
-                    maxStackSize,
-                    std::to_string(GetLastError())
-                ).str()
-            );
-        }
-    }
     #endif
 }
 

From 7c8c71f8e9319b17e85c0f510bfd0d0558361ac2 Mon Sep 17 00:00:00 2001
From: Brian McKenna <brian@brianmckenna.org>
Date: Fri, 31 Jan 2025 21:11:45 +1100
Subject: [PATCH 2/2] Totally exclude nix::setStackSize on Windows

---
 src/libutil/current-process.cc | 4 ++--
 src/libutil/current-process.hh | 3 +++
 src/nix/main.cc                | 2 ++
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/libutil/current-process.cc b/src/libutil/current-process.cc
index 46e72b63a..255ae2cf5 100644
--- a/src/libutil/current-process.cc
+++ b/src/libutil/current-process.cc
@@ -51,11 +51,11 @@ unsigned int getMaxCPU()
 //////////////////////////////////////////////////////////////////////
 
 
+#ifndef _WIN32
 size_t savedStackSize = 0;
 
 void setStackSize(size_t stackSize)
 {
-    #ifndef _WIN32
     struct rlimit limit;
     if (getrlimit(RLIMIT_STACK, &limit) == 0 && limit.rlim_cur < stackSize) {
         savedStackSize = limit.rlim_cur;
@@ -73,8 +73,8 @@ void setStackSize(size_t stackSize)
             );
         }
     }
-    #endif
 }
+#endif
 
 void restoreProcessContext(bool restoreMounts)
 {
diff --git a/src/libutil/current-process.hh b/src/libutil/current-process.hh
index 8286bf89d..660dcfe0b 100644
--- a/src/libutil/current-process.hh
+++ b/src/libutil/current-process.hh
@@ -17,10 +17,13 @@ namespace nix {
  */
 unsigned int getMaxCPU();
 
+// It does not seem possible to dynamically change stack size on Windows.
+#ifndef _WIN32
 /**
  * Change the stack size.
  */
 void setStackSize(size_t stackSize);
+#endif
 
 /**
  * Restore the original inherited Unix process context (such as signal
diff --git a/src/nix/main.cc b/src/nix/main.cc
index b0e26e093..80ef53084 100644
--- a/src/nix/main.cc
+++ b/src/nix/main.cc
@@ -557,9 +557,11 @@ void mainWrapped(int argc, char * * argv)
 
 int main(int argc, char * * argv)
 {
+#ifndef _WIN32
     // Increase the default stack size for the evaluator and for
     // libstdc++'s std::regex.
     nix::setStackSize(64 * 1024 * 1024);
+#endif
 
     return nix::handleExceptions(argv[0], [&]() {
         nix::mainWrapped(argc, argv);