Fixes 64 bit MSVC builds, disables bits parameter

Also Enables automatic detection of architecture for the MSVC compilers.
Builds without assembly optimisations for x64
Closes issue #3098

Signed-off-by: Aleksandar Danilovic <[email protected]>

platform/windows/detect.py

@@ -262,7 +262,33 @@ def configure(env):
 		env.Append(CCFLAGS=["/I"+DIRECTX_PATH+"/Include"])
 		env.Append(LIBPATH=[DIRECTX_PATH+"/Lib/x86"])
 		env['ENV'] = os.environ;
+
+		# This detection function needs the tools env (that is env['ENV'], not SCons's env), and that is why it's this far bellow in the code
+		compiler_version_str = detect_visual_c_compiler_version(env['ENV'])
+
+		# Note: this detection/override code from here onward should be here instead of in SConstruct because it's platform and compiler specific (MSVC/Windows)
+		if(env["bits"] != "default"):
+                        print "Error: bits argument is disabled for MSVC"
+                        print ("Bits argument is not supported for MSVC compilation. Architecture depends on the Native/Cross Compile Tools Prompt/Developer Console (or Visual Studio settings)"
+                               +" that is being used to run SCons. As a consequence, bits argument is disabled. Run scons again without bits argument (example: scons p=windows) and SCons will attempt to detect what MSVC compiler"
+                               +" will be executed and inform you.")
+                        sys.exit()
+
+		# Forcing bits argument because MSVC does not have a flag to set this through SCons... it's different compilers (cl.exe's) called from the propper command prompt
+                # that decide the architecture that is build for. Scons can only detect the os.getenviron (because vsvarsall.bat sets a lot of stuff for cl.exe to work with)
+                env["bits"]="32"
 		env["x86_opt_vc"]=True
+		
+		print "Detected MSVC compiler: "+compiler_version_str
+		# If building for 64bit architecture, disable assembly optimisations for 32 bit builds (theora as of writting)... vc compiler for 64bit can not compile _asm
+		if(compiler_version_str == "amd64" or compiler_version_str == "x86_amd64"):
+                        env["bits"]="64"
+                        env["x86_opt_vc"]=False
+                        print "Compiled program architecture will be a 64 bit executable (forcing bits=64)."
+                elif (compiler_version_str=="x86" or compiler_version_str == "amd64_x86"):
+                        print "Compiled program architecture will be a 32 bit executable. (forcing bits=32)."
+                else:
+                        print "Failed to detect MSVC compiler architecture version... Defaulting to 32bit executable settings (forcing bits=32). Compilation attempt will continue, but SCons can not detect for what architecture this build is compiled for. You should check your settings/compilation setup."                        
 	else:
 
 		# Workaround for MinGW. See:
@@ -366,4 +392,67 @@ def configure(env):
 	env.Append( BUILDERS = { 'HLSL9' : env.Builder(action = methods.build_hlsl_dx9_headers, suffix = 'hlsl.h',src_suffix = '.hlsl') } )
 	env.Append( BUILDERS = { 'GLSL120GLES' : env.Builder(action = methods.build_gles2_headers, suffix = 'glsl.h',src_suffix = '.glsl') } )
 
-
+def detect_visual_c_compiler_version(tools_env):
+        # tools_env is the variable scons uses to call tools that execute tasks, SCons's env['ENV'] that executes tasks...
+        # (see the SCons documentation for more information on what it does)...
+        # in order for this function to be well encapsulated i choose to force it to recieve SCons's TOOLS env (env['ENV']
+        # and not scons setup environment (env)... so make sure you call the right environment on it or it will fail to detect
+        # the propper vc version that will be called
+        
+        # These is no flag to give to visual c compilers to set the architecture, ie scons bits argument (32,64,ARM etc)
+        # There are many different cl.exe files that are run, and each one compiles & links to a different architecture
+        # As far as I know, the only way to figure out what compiler will be run when Scons calls cl.exe via Program()
+        # is to check the PATH varaible and figure out which one will be called first. Code bellow does that and returns:
+        # the following string values:
+
+        # ""              Compiler not detected
+        # "amd64"         Native 64 bit compiler
+        # "amd64_x86"     64 bit Cross Compiler for 32 bit
+        # "x86"           Native 32 bit compiler
+        # "x86_amd64"     32 bit Cross Compiler for 64 bit
+
+        # There are other architectures, but Godot does not support them currently, so this function does not detect arm/amd64_arm
+        # and similar architectures/compilers
+
+        # Set chosen compiler to "not detected"
+        vc_chosen_compiler_index = -1
+        vc_chosen_compiler_str = ""
+        
+        # find() works with -1 so big ifs bellow are needed... the simplest solution, in fact
+        # First test if amd64 and amd64_x86 compilers are present in the path
+        vc_amd64_compiler_detection_index =  tools_env["PATH"].find(tools_env["VCINSTALLDIR"]+"BIN\\amd64;")
+        if(vc_amd64_compiler_detection_index > -1):
+                vc_chosen_compiler_index = vc_amd64_compiler_detection_index
+                vc_chosen_compiler_str = "amd64"
+        
+        vc_amd64_x86_compiler_detection_index = tools_env["PATH"].find(tools_env["VCINSTALLDIR"]+"BIN\\amd64_x86;")
+        if(vc_amd64_x86_compiler_detection_index > -1
+           and (vc_chosen_compiler_index == -1
+                or vc_chosen_compiler_index > vc_amd64_x86_compiler_detection_index)):
+                vc_chosen_compiler_index = vc_amd64_x86_compiler_detection_index
+                vc_chosen_compiler_str = "amd64_x86"
+
+
+        # Now check the 32 bit compilers
+        vc_x86_compiler_detection_index =  tools_env["PATH"].find(tools_env["VCINSTALLDIR"]+"BIN;")
+        if(vc_x86_compiler_detection_index > -1
+           and (vc_chosen_compiler_index == -1
+                or vc_chosen_compiler_index > vc_x86_compiler_detection_index)):
+                vc_chosen_compiler_index = vc_x86_compiler_detection_index
+                vc_chosen_compiler_str = "x86"
+                
+        vc_x86_amd64_compiler_detection_index = tools_env["PATH"].find(tools_env['VCINSTALLDIR']+"BIN\\x86_amd64;")
+        if(vc_x86_amd64_compiler_detection_index > -1
+           and (vc_chosen_compiler_index == -1
+                or vc_chosen_compiler_index > vc_x86_amd64_compiler_detection_index)):
+                vc_chosen_compiler_index = vc_x86_amd64_compiler_detection_index
+                vc_chosen_compiler_str = "x86_amd64"
+
+        # debug help
+        #print vc_amd64_compiler_detection_index
+        #print vc_amd64_x86_compiler_detection_index
+        #print vc_x86_compiler_detection_index
+        #print vc_x86_amd64_compiler_detection_index
+        #print "chosen "+str(vc_chosen_compiler_index)+ " | "+str(vc_chosen_compiler_str)
+
+        return vc_chosen_compiler_str