Allow for simpler environmental variable creation (#333)

edalize/utils.py

@@ -1,22 +1,39 @@
 class EdaCommands(object):
     class Command(object):
-        def __init__(self, command, targets, depends, order_only_deps=[]):
+        def __init__(self, command, targets, depends, order_only_deps=[], variables=[]):
             self.command = command
             self.targets = targets
             self.depends = depends
             self.order_only_deps = order_only_deps
+            self.variables = variables
 
     def __init__(self):
         self.commands = []
         self.vars = []
         self.header = "#Auto generated by Edalize\n\n"
 
-    def add(self, command, targets, depends, order_only_deps=[]):
-        self.commands.append(self.Command(command, targets, depends, order_only_deps))
+    def add(self, command, targets, depends, order_only_deps=[], variables=[]):
+        self.commands.append(
+            self.Command(command, targets, depends, order_only_deps, variables)
+        )
 
     def add_var(self, var):
         self.vars.append(var)
 
+    # Allow for portability between the main platforms
+    def find_env_var_command(self):
+        from sys import platform
+
+        if platform == "linux" or platform == "linux2" or platform == "darwin":
+            return "export"
+        elif platform == "win32":
+            return "set"
+        return ""
+
+    # Simplify the creation of flow environmental variables in the Makefile
+    def add_env_var(self, key, value):
+        self.vars.append(f"{self.find_env_var_command()} {key}={value}")
+
     def set_default_target(self, target):
         self.default_target = target
 
@@ -43,5 +60,14 @@ def write(self, outfile):
 
                 f.write("\n")
 
+                env_prefix = ""
+                if c.variables:
+                    var_list = []
+                    for key in c.variables.keys():
+                        var_list += f"{key}={c.variables.get(key)}"
+                    env_prefix = f"env {' '.join(var_list)}"
+
                 if c.command:
-                    f.write(f"\t$(EDALIZE_LAUNCHER) {' '.join(c.command)}\n")
+                    f.write(
+                        f"\t$(EDALIZE_LAUNCHER) {env_prefix}{' '.join(c.command)}\n"
+                    )