Provide graceful failures when a source file doesn't exist and can't be build, and when a nonexistent drive letter is used on Win32.

4 files changed, 25 insertions, 6 deletions

diff --git a/src/engine/SCons/Errors.py b/src/engine/SCons/Errors.py
index 2640220..112a4c9 100644
--- a/src/engine/SCons/Errors.py
+++ b/src/engine/SCons/Errors.py
@@ -45,3 +45,7 @@ class InternalError(Exception):
 class UserError(Exception):
     def __init__(self, args=None):
         self.args = args
+
+class StopError(Exception):
+    def __init__(self, args=None):
+        self.args = args
diff --git a/src/engine/SCons/Node/FS.py b/src/engine/SCons/Node/FS.py
index 59b8e63..d5247f7 100644
--- a/src/engine/SCons/Node/FS.py
+++ b/src/engine/SCons/Node/FS.py
@@ -43,7 +43,7 @@ import types
 import SCons.Node
 from UserDict import UserDict
 import sys
-from SCons.Errors import UserError
+import SCons.Errors
 import SCons.Warnings
 
 try:
@@ -296,7 +296,7 @@ class FS:
                 directory = self.Root[drive]
             except KeyError:
                 if not create:
-                    raise UserError
+                    raise SCons.Errors.UserError
                 dir = Dir(drive, ParentOfRoot(), self)
                 dir.path = dir.path + os.sep
                 dir.abspath = dir.abspath + os.sep
@@ -314,7 +314,7 @@ class FS:
                                               Dir)
             except KeyError:
                 if not create:
-                    raise UserError
+                    raise SCons.Errors.UserError
 
                 # look at the actual filesystem and make sure there isn't
                 # a file already there
@@ -332,7 +332,7 @@ class FS:
             ret = self.__checkClass(directory.entries[file_name], fsclass)
         except KeyError:
             if not create:
-                raise UserError
+                raise SCons.Errors.UserError
 
             # make sure we don't create File nodes when there is actually
             # a directory at that path on the disk, and vice versa
@@ -436,9 +436,9 @@ class FS:
         if not isinstance(build_dir, SCons.Node.Node):
             build_dir = self.Dir(build_dir)
         if not src_dir.is_under(self.Top):
-            raise UserError, "Source directory must be under top of build tree."
+            raise SCons.Errors.UserError, "Source directory must be under top of build tree."
         if src_dir.is_under(build_dir):
-            raise UserError, "Source directory cannot be under build directory."
+            raise SCons.Errors.UserError, "Source directory cannot be under build directory."
         build_dir.link(src_dir, duplicate)
 
     def Repository(self, *dirs):
@@ -848,6 +848,14 @@ class File(Entry):
 
     def prepare(self):
         """Prepare for this file to be created."""
+
+        def missing(node):
+            return not node.builder and not node.rexists()
+        missing_sources = filter(missing, self.children())
+        if missing_sources:
+            desc = "No Builder for target `%s', needed by `%s'." % (missing_sources[0], self)
+            raise SCons.Errors.StopError, desc
+
         if self.exists():
             if self.builder and not self.precious:
                 os.unlink(self.path)
diff --git a/src/engine/SCons/Node/FSTests.py b/src/engine/SCons/Node/FSTests.py
index c817408..5d32873 100644
--- a/src/engine/SCons/Node/FSTests.py
+++ b/src/engine/SCons/Node/FSTests.py
@@ -628,6 +628,7 @@ class FSTestCase(unittest.TestCase):
         assert os.path.exists(test.workpath("remove_me"))
         f1 = fs.File(test.workpath("remove_me"))
         f1.builder = 1
+        f1.env_set(Environment())
         f1.prepare()
         assert not os.path.exists(test.workpath("remove_me"))
 
diff --git a/src/engine/SCons/Script/__init__.py b/src/engine/SCons/Script/__init__.py
index 814d147..dd44621 100644
--- a/src/engine/SCons/Script/__init__.py
+++ b/src/engine/SCons/Script/__init__.py
@@ -99,6 +99,12 @@ class BuildTask(SCons.Taskmaster.Task):
                 # don't try to walk the stack, just print the error.
                 sys.stderr.write("\nSCons error: %s\n" % e)
                 raise
+            except StopError, e:
+                s = str(e)
+                if not keep_going_on_error:
+                    s = s + '  Stop.'
+                sys.stderr.write("scons: *** %s\n" % s)
+                raise
             except:
                 sys.stderr.write("scons: *** %s\n" % sys.exc_value)
                 raise