From b7df0732ea73389d975040a9b715b74a8c1ab8be Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Sat, 6 Nov 2021 20:50:18 +0000
Subject: [PATCH] RTS configure: Move over mem management checks

These are for heap allocation, a strictly RTS concern.

All of this should boil down to `AC_DEFINE` not `AC_SUBST`, so it
belongs in the RTS configure and should be safe to move without
modification.

The RTS configure one has a new
```
AC_CHECK_SIZEOF([void *])
```
that the top-level configure version didn't have, so that
`ac_cv_sizeof_void_p` is defined. Once more code is moved over in latter
commits, that can go away.

Progress towards #17191
---
 configure.ac     | 55 -----------------------------------------------
 rts/configure.ac | 56 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 55 deletions(-)

diff --git a/configure.ac b/configure.ac
index f3c7c773d9eb..df17cbe5d98c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1059,61 +1059,6 @@ AC_COMPILE_IFELSE(
    AC_DEFINE([CC_SUPPORTS_TLS],[0],[Define to 1 if __thread is supported])
   ])
 
-dnl large address space support (see rts/include/rts/storage/MBlock.h)
-dnl
-dnl Darwin has vm_allocate/vm_protect
-dnl Linux has mmap(MAP_NORESERVE)/madv(MADV_DONTNEED)
-dnl FreeBSD, Solaris and maybe other have MAP_NORESERVE/MADV_FREE
-dnl (They also have MADV_DONTNEED, but it means something else!)
-dnl
-dnl Windows has VirtualAlloc MEM_RESERVE/MEM_COMMIT, however
-dnl it counts page-table space as committed memory, and so quickly
-dnl runs out of paging file when we have multiple processes reserving
-dnl 1TB of address space, we get the following error:
-dnl    VirtualAlloc MEM_RESERVE 1099512676352 bytes failed: The paging file is too small for this operation to complete.
-dnl
-
-AC_ARG_ENABLE(large-address-space,
-    [AS_HELP_STRING([--enable-large-address-space],
-        [Use a single large address space on 64 bit systems (enabled by default on 64 bit platforms)])],
-    EnableLargeAddressSpace=$enableval,
-    EnableLargeAddressSpace=yes
-)
-
-use_large_address_space=no
-if test "$ac_cv_sizeof_void_p" -eq 8 ; then
-    if test "x$EnableLargeAddressSpace" = "xyes" ; then
-        if test "$ghc_host_os" = "darwin" ; then
-            use_large_address_space=yes
-        elif test "$ghc_host_os" = "openbsd" ; then
-            # as of OpenBSD 5.8 (2015), OpenBSD does not support mmap with MAP_NORESERVE.
-            # The flag MAP_NORESERVE is supported for source compatibility reasons,
-            # but is completely ignored by OS mmap
-                  use_large_address_space=no
-        elif test "$ghc_host_os" = "mingw32" ; then
-            # as of Windows 8.1/Server 2012 windows does no longer allocate the page
-            # tabe for reserved memory eagerly. So we are now free to use LAS there too.
-                  use_large_address_space=yes
-        else
-            AC_CHECK_DECLS([MAP_NORESERVE, MADV_FREE, MADV_DONTNEED],[],[],
-                [
-                #include <unistd.h>
-                #include <sys/types.h>
-                #include <sys/mman.h>
-                #include <fcntl.h>
-            ])
-            if test "$ac_cv_have_decl_MAP_NORESERVE" = "yes" &&
-                test "$ac_cv_have_decl_MADV_FREE" = "yes" ||
-                test "$ac_cv_have_decl_MADV_DONTNEED" = "yes" ; then
-                    use_large_address_space=yes
-            fi
-        fi
-    fi
-fi
-if test "$use_large_address_space" = "yes" ; then
-   AC_DEFINE([USE_LARGE_ADDRESS_SPACE], [1], [Enable single heap address space support])
-fi
-
 GHC_ADJUSTORS_METHOD([Target])
 AC_SUBST([UseLibffiForAdjustors])
 
diff --git a/rts/configure.ac b/rts/configure.ac
index 5ccf7c6df05f..54bc0630e93a 100644
--- a/rts/configure.ac
+++ b/rts/configure.ac
@@ -33,6 +33,62 @@ GHC_CONVERT_PLATFORM_PARTS([host], [Host])
 FPTOOLS_SET_PLATFORM_VARS([host], [Host])
 FPTOOLS_SET_HASKELL_PLATFORM_VARS([Host])
 
+dnl large address space support (see rts/include/rts/storage/MBlock.h)
+dnl
+dnl Darwin has vm_allocate/vm_protect
+dnl Linux has mmap(MAP_NORESERVE)/madv(MADV_DONTNEED)
+dnl FreeBSD, Solaris and maybe other have MAP_NORESERVE/MADV_FREE
+dnl (They also have MADV_DONTNEED, but it means something else!)
+dnl
+dnl Windows has VirtualAlloc MEM_RESERVE/MEM_COMMIT, however
+dnl it counts page-table space as committed memory, and so quickly
+dnl runs out of paging file when we have multiple processes reserving
+dnl 1TB of address space, we get the following error:
+dnl    VirtualAlloc MEM_RESERVE 1099512676352 bytes failed: The paging file is too small for this operation to complete.
+dnl
+
+AC_ARG_ENABLE(large-address-space,
+    [AS_HELP_STRING([--enable-large-address-space],
+        [Use a single large address space on 64 bit systems (enabled by default on 64 bit platforms)])],
+    EnableLargeAddressSpace=$enableval,
+    EnableLargeAddressSpace=yes
+)
+
+use_large_address_space=no
+AC_CHECK_SIZEOF([void *])
+if test "$ac_cv_sizeof_void_p" -eq 8 ; then
+    if test "x$EnableLargeAddressSpace" = "xyes" ; then
+        if test "$ghc_host_os" = "darwin" ; then
+            use_large_address_space=yes
+        elif test "$ghc_host_os" = "openbsd" ; then
+            # as of OpenBSD 5.8 (2015), OpenBSD does not support mmap with MAP_NORESERVE.
+            # The flag MAP_NORESERVE is supported for source compatibility reasons,
+            # but is completely ignored by OS mmap
+                  use_large_address_space=no
+        elif test "$ghc_host_os" = "mingw32" ; then
+            # as of Windows 8.1/Server 2012 windows does no longer allocate the page
+            # tabe for reserved memory eagerly. So we are now free to use LAS there too.
+                  use_large_address_space=yes
+        else
+            AC_CHECK_DECLS([MAP_NORESERVE, MADV_FREE, MADV_DONTNEED],[],[],
+                [
+                #include <unistd.h>
+                #include <sys/types.h>
+                #include <sys/mman.h>
+                #include <fcntl.h>
+            ])
+            if test "$ac_cv_have_decl_MAP_NORESERVE" = "yes" &&
+                test "$ac_cv_have_decl_MADV_FREE" = "yes" ||
+                test "$ac_cv_have_decl_MADV_DONTNEED" = "yes" ; then
+                    use_large_address_space=yes
+            fi
+        fi
+    fi
+fi
+if test "$use_large_address_space" = "yes" ; then
+   AC_DEFINE([USE_LARGE_ADDRESS_SPACE], [1], [Enable single heap address space support])
+fi
+
 dnl ** Use MMAP in the runtime linker?
 dnl --------------------------------------------------------------
 
-- 
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