Relax the duplicate-environment restriction for targets so that it's okay if the two environments would build the target with the same command or function call. (Scott Fritchie)

4 files changed, 21 insertions, 1 deletions

diff --git a/src/CHANGES.txt b/src/CHANGES.txt
index a4e4c60..391d11b 100644
--- a/src/CHANGES.txt
+++ b/src/CHANGES.txt
@@ -61,6 +61,12 @@ RELEASE 0.95 - XXX
   - Make the message about ignoring a missing SConscript file into a
     suppressable Warning, not a hard-coded sys.stderr.write().
 
+  - If a builder can be called multiple times for a target (because
+    the sources and overrides are identical, or it's a builder with the
+    "multi" flag set), allow the builder to be called through multiple
+    environments so long as the builders have the same signature for
+    the environments in questions (that is, they're the same action).
+
   From Steven Knight:
 
   - Fix EnsureSConsVersion() so it checks against the SCons version,
diff --git a/src/engine/SCons/Builder.py b/src/engine/SCons/Builder.py
index 17d661c..8372292 100644
--- a/src/engine/SCons/Builder.py
+++ b/src/engine/SCons/Builder.py
@@ -164,9 +164,19 @@ def _init_nodes(builder, env, overrides, tlist, slist):
             raise UserError, "Multiple ways to build the same target were specified for: %s" % str(t)
         if t.has_builder():
             if t.env != env:
-                raise UserError, "Two different environments were specified for the same target: %s"%str(t)
+                t_contents = t.builder.action.get_contents(tlist, slist, t.env)
+                contents = t.builder.action.get_contents(tlist, slist, env)
+
+                if t_contents == contents:
+                    SCons.Warnings.warn(SCons.Warnings.DuplicateEnvironmentWarning,
+                                        "Two different environments were specified for target %s,\n\tbut they appear to have the same action: %s"%(str(t), t.builder.action.strfunction(tlist, slist, t.env)))
+
+                else:
+                    raise UserError, "Two environments with different actions were specified for the same target: %s"%str(t)
+
             elif t.overrides != overrides:
                 raise UserError, "Two different sets of overrides were specified for the same target: %s"%str(t)
+
             elif builder.scanner and t.target_scanner and builder.scanner != t.target_scanner:
                 raise UserError, "Two different scanners were specified for the same target: %s"%str(t)
 
diff --git a/src/engine/SCons/Script/__init__.py b/src/engine/SCons/Script/__init__.py
index 0e56214..ac05f3c 100644
--- a/src/engine/SCons/Script/__init__.py
+++ b/src/engine/SCons/Script/__init__.py
@@ -709,6 +709,7 @@ def _main(args, parser):
     SCons.Warnings._warningOut = _scons_internal_warning
     SCons.Warnings.enableWarningClass(SCons.Warnings.CorruptSConsignWarning)
     SCons.Warnings.enableWarningClass(SCons.Warnings.DeprecatedWarning)
+    SCons.Warnings.enableWarningClass(SCons.Warnings.DuplicateEnvironmentWarning)
     SCons.Warnings.enableWarningClass(SCons.Warnings.MissingSConscriptWarning)
     SCons.Warnings.enableWarningClass(SCons.Warnings.NoParallelSupportWarning)
 
diff --git a/src/engine/SCons/Warnings.py b/src/engine/SCons/Warnings.py
index 6426830..2e2e525 100644
--- a/src/engine/SCons/Warnings.py
+++ b/src/engine/SCons/Warnings.py
@@ -48,6 +48,9 @@ class DependencyWarning(Warning):
 class DeprecatedWarning(Warning):
     pass
 
+class DuplicateEnvironmentWarning(Warning):
+    pass
+
 class MissingSConscriptWarning(Warning):
     pass