I noticed that when you want to define EXEC_BACKEND, perhaps to do some
non-Windows testing of that option, it's not clear how to do that. I
would have expected it in pg_config_manual.h, but it's actually in
configure.in and in MSBuildProject.pm. So if you want to define it
yourself, you kind of have to make up your own way to do it.
I don't see why this should be like that. I propose the attached patch
to move the thing to pg_config_manual.h.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
From c7d574d3b9f363cc44daf45c543ab4addfa25afd Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Thu, 19 Mar 2020 16:32:02 +0100
Subject: [PATCH] Define EXEC_BACKEND in pg_config_manual.h
It was for unclear reasons defined in a separate location, which makes
it more cumbersome to override for testing, and it also did not have
any prominent documentation. Move to pg_config_manual.h, where
similar things are already collected.
---
configure | 2 +-
configure.in | 2 +-
src/include/pg_config_manual.h | 13 +++++++++++++
src/tools/msvc/MSBuildProject.pm | 2 +-
4 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/configure b/configure
index a7cf71b3f1..899116517c 100755
--- a/configure
+++ b/configure
@@ -6906,7 +6906,7 @@ fi
# We already have this in Makefile.win32, but configure needs it too
if test "$PORTNAME" = "win32"; then
- CPPFLAGS="$CPPFLAGS -I$srcdir/src/include/port/win32 -DEXEC_BACKEND"
+ CPPFLAGS="$CPPFLAGS -I$srcdir/src/include/port/win32"
fi
# Now that we're done automatically adding stuff to C[XX]FLAGS, put back the
diff --git a/configure.in b/configure.in
index d36a7e94b3..ecdf172396 100644
--- a/configure.in
+++ b/configure.in
@@ -600,7 +600,7 @@ fi
# We already have this in Makefile.win32, but configure needs it too
if test "$PORTNAME" = "win32"; then
- CPPFLAGS="$CPPFLAGS -I$srcdir/src/include/port/win32 -DEXEC_BACKEND"
+ CPPFLAGS="$CPPFLAGS -I$srcdir/src/include/port/win32"
fi
# Now that we're done automatically adding stuff to C[XX]FLAGS, put back the
diff --git a/src/include/pg_config_manual.h b/src/include/pg_config_manual.h
index d74a8dd808..b7410ff51e 100644
--- a/src/include/pg_config_manual.h
+++ b/src/include/pg_config_manual.h
@@ -122,6 +122,19 @@
*/
#define ALIGNOF_BUFFER 32
+/*
+ * If EXEC_BACKEND is defined, the postmaster uses an alternative method for
+ * starting subprocesses: Instead of simply using fork(), as is standard on
+ * Unix platforms, it uses fork()+exec() or something equivalent on Windows,
+ * as well as lots of extra code to bring the required global state to those
+ * new processes. This must be enabled on Windows (because there is no
+ * fork()). On other platforms, it's only useful for verifying those
+ * otherwise Windows-specific code paths.
+ */
+#if defined(WIN32) && !defined(__CYGWIN__)
+#define EXEC_BACKEND
+#endif
+
/*
* Disable UNIX sockets for certain operating systems.
*/
diff --git a/src/tools/msvc/MSBuildProject.pm b/src/tools/msvc/MSBuildProject.pm
index 823357c023..ebb169e201 100644
--- a/src/tools/msvc/MSBuildProject.pm
+++ b/src/tools/msvc/MSBuildProject.pm
@@ -320,7 +320,7 @@ sub WriteItemDefinitionGroup
<ClCompile>
<Optimization>$p->{opt}</Optimization>
<AdditionalIncludeDirectories>$self->{prefixincludes}src/include;src/include/port/win32;src/include/port/win32_msvc;$includes\%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-
<PreprocessorDefinitions>WIN32;_WINDOWS;__WINDOWS__;__WIN32__;EXEC_BACKEND;WIN32_STACK_RLIMIT=4194304;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_DEPRECATE$self->{defines}$p->{defs}\%(PreprocessorDefinitions)</PreprocessorDefinitions>
+
<PreprocessorDefinitions>WIN32;_WINDOWS;__WINDOWS__;__WIN32__;WIN32_STACK_RLIMIT=4194304;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_DEPRECATE$self->{defines}$p->{defs}\%(PreprocessorDefinitions)</PreprocessorDefinitions>
<StringPooling>$p->{strpool}</StringPooling>
<RuntimeLibrary>$p->{runtime}</RuntimeLibrary>
<DisableSpecificWarnings>$self->{disablewarnings};\%(DisableSpecificWarnings)</DisableSpecificWarnings>
--
2.25.0
