Don't define DEBUG on non VS actions

DEBUG is unused by pyrogenesis and unconditionally adding it to defines
prevents building against a non debug version of spidermonkey. This will
allow building only one copy of spidermonkey, which can be trivially be
replaced with the other depending on needs independent of pyrogenesis
debug or release build.

This also allows to build either build configuration against system
spidermonkey, which obviously is either one build type or the other.
Requires a compilecheck until the pc file gets fixed upstream.

A comment in the spidermonkey build.sh says on FreeBSD spidermonkey
debug configuration doesn't even build and so pyrogenesis debug build
wasn't possible either.

Signed-off-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>

build/premake/premake5.lua

@@ -117,6 +117,16 @@ elseif os.istarget("linux") then
 	end
 end
 
+-- Test whether system mozjs is built with --enable-debug
+-- The pc file doesn't specify the required -DDEBUG needed in that case
+local mozjs_is_debug_build = false
+if _OPTIONS["with-system-mozjs"] then
+	local _, errorCode = os.outputof(cc .. " $(pkg-config mozjs-91 --cflags) ./tests/mozdebug.c -o /dev/null")
+	if errorCode ~= 0 then
+		mozjs_is_debug_build = true
+	end
+end
+
 -- Set up the Workspace
 workspace "pyrogenesis"
 targetdir(rootdir.."/binaries/system")
@@ -175,7 +185,7 @@ function project_set_build_flags()
 		debugenvs { "_NO_DEBUG_HEAP=1" }
 	end
 
-	filter "Debug"
+	filter { "Debug", "action:vs*" }
 		defines { "DEBUG" }
 
 	filter "Release"
@@ -189,6 +199,10 @@ function project_set_build_flags()
 
 	filter { }
 
+	if mozjs_is_debug_build then
+		defines "DEBUG"
+	end
+
 	if _OPTIONS["gles"] then
 		defines { "CONFIG2_GLES=1" }
 	end

build/premake/tests/mozdebug.c

@@ -0,0 +1,5 @@
+#include <js-config.h>
+
+int main() {
+	return 0;
+}