only use no-unistd option with MSVC environment

3 files changed, 13 insertions, 5 deletions

diff --git a/src/CHANGES.txt b/src/CHANGES.txt
index bfea66175..73936642e 100755
--- a/src/CHANGES.txt
+++ b/src/CHANGES.txt
@@ -21,7 +21,9 @@ RELEASE  VERSION/DATE TO BE FILLED IN LATER
     - Fixed bug which threw error when running SCons on windows system with no MSVC installed.
     - Update link tool to convert target to node before accessing node member
     - Update mingw tool to remove MSVC like nologo CCFLAG
-    - Update lex tool to work in mingw environments
+    - Add default paths for lex tool on windows
+    - Add lex construction variable LEXUNISTD for turning off unix headers on windows
+    - Update lex tool to use win_flex on windows if available
 
   From Mats Wichmann:
     - Quiet open file ResourceWarnings on Python >= 3.6 caused by
diff --git a/src/engine/SCons/Tool/lex.py b/src/engine/SCons/Tool/lex.py
index 3506f7c12..a63ddc9f2 100644
--- a/src/engine/SCons/Tool/lex.py
+++ b/src/engine/SCons/Tool/lex.py
@@ -75,7 +75,7 @@ def get_lex_path(env, append_paths=False):
     """
     # save existing path to reset if we don't want to append any paths
     envPath = env['ENV']['PATH']
-    bins = ['win_flex', 'lex', 'flex']
+    bins = ['flex', 'lex', 'win_flex']
 
     for prog in bins:
         bin_path = SCons.Tool.find_program_path(
@@ -110,14 +110,16 @@ def generate(env):
     cxx_file.add_action(".ll", LexAction)
     cxx_file.add_emitter(".ll", lexEmitter)
 
+    env["LEXFLAGS"] = SCons.Util.CLVar("")
+
     if sys.platform == 'win32':
         get_lex_path(env, append_paths=True)
-        env["LEX"] = env.Detect(['win_flex', 'lex', 'flex'])
-        env["LEXUNISTD"] = SCons.Util.CLVar("--nounistd")
+        env["LEX"] = env.Detect(['flex', 'lex', 'win_flex'])
+        if not env.get("LEXUNISTD"):
+            env["LEXUNISTD"] = SCons.Util.CLVar("")
         env["LEXCOM"] = "$LEX $LEXUNISTD $LEXFLAGS -t $SOURCES > $TARGET"
     else:
         env["LEX"] = env.Detect(["flex", "lex"])
-        env["LEXFLAGS"] = SCons.Util.CLVar("")
         env["LEXCOM"] = "$LEX $LEXFLAGS -t $SOURCES > $TARGET"
 
 def exists(env):
diff --git a/src/engine/SCons/Tool/msvc.py b/src/engine/SCons/Tool/msvc.py
index 9f3c1fa19..23520885b 100644
--- a/src/engine/SCons/Tool/msvc.py
+++ b/src/engine/SCons/Tool/msvc.py
@@ -271,6 +271,10 @@ def generate(env):
     env['SHOBJPREFIX']    = '$OBJPREFIX'
     env['SHOBJSUFFIX']    = '$OBJSUFFIX'
 
+    # MSVC probably wont support unistd.h so default
+    # without it for lex generation
+    env["LEXUNISTD"] = SCons.Util.CLVar("--nounistd")
+
     # Set-up ms tools paths
     msvc_setup_env_once(env)