Better midl (Visual Studio MIDL compiler) Tool detection. (Anthony Roach)

4 files changed, 25 insertions, 17 deletions

diff --git a/src/engine/SCons/Tool/midl.py b/src/engine/SCons/Tool/midl.py
index 2efabcc..d02f23a 100644
--- a/src/engine/SCons/Tool/midl.py
+++ b/src/engine/SCons/Tool/midl.py
@@ -38,6 +38,7 @@ import os.path
 import SCons.Defaults
 import SCons.Scanner.IDL
 import SCons.Util
+import SCons.Tool.msvs
 
 def midl_emitter(target, source, env):
     """Produces a list of outputs from the MIDL compiler"""
@@ -69,4 +70,10 @@ def generate(env):
     env['BUILDERS']['TypeLibrary'] = midl_builder
 
 def exists(env):
-    return env.Detect('midl')
+    if SCons.Tool.msvs.is_msvs_installed():
+        # there's at least one version of MSVS installed, which comes with midl:
+        return 1
+    else:
+        return env.Detect('midl')
+
+
diff --git a/src/engine/SCons/Tool/mslink.py b/src/engine/SCons/Tool/mslink.py
index 7e32e60..5ff8a01 100644
--- a/src/engine/SCons/Tool/mslink.py
+++ b/src/engine/SCons/Tool/mslink.py
@@ -180,13 +180,8 @@ def generate(env):
         pass
 
 def exists(env):
-    try:
-        v = SCons.Tool.msvs.get_visualstudio_versions()
-    except (SCons.Util.RegError, SCons.Errors.InternalError):
-        pass
-    
-    if not v:
-        return env.Detect('link')
-    else:
+    if SCons.Tool.msvs.is_msvs_installed():
         # there's at least one version of MSVS installed.
         return 1
+    else:
+        return env.Detect('link')
diff --git a/src/engine/SCons/Tool/msvc.py b/src/engine/SCons/Tool/msvc.py
index 1caa4db..3d49802 100644
--- a/src/engine/SCons/Tool/msvc.py
+++ b/src/engine/SCons/Tool/msvc.py
@@ -478,13 +478,9 @@ def generate(env):
     env['BUILDERS']['PCH'] = pch_builder
 
 def exists(env):
-    try:
-        v = SCons.Tool.msvs.get_visualstudio_versions()
-    except (SCons.Util.RegError, SCons.Errors.InternalError):
-        pass
-
-    if not v:
-        return env.Detect('cl')
-    else:
+    if SCons.Tool.msvs.is_msvs_installed():
         # there's at least one version of MSVS installed.
         return 1
+    else:
+        return env.Detect('cl')
+
diff --git a/src/engine/SCons/Tool/msvs.py b/src/engine/SCons/Tool/msvs.py
index 10ab42a..06f850e 100644
--- a/src/engine/SCons/Tool/msvs.py
+++ b/src/engine/SCons/Tool/msvs.py
@@ -846,6 +846,16 @@ def get_visualstudio_versions():
 
     return L
 
+def is_msvs_installed():
+    """
+    Check the registry for an installed visual studio.
+    """
+    try:
+        v = SCons.Tool.msvs.get_visualstudio_versions()
+        return v
+    except (SCons.Util.RegError, SCons.Errors.InternalError):
+        return 0
+
 def get_msvs_install_dirs(version = None):
     """
     Get installed locations for various msvc-related products, like the .NET SDK