Work on BB43 (hang on loop in main target references).

* new/targets.jam
  (start-building, end-building): New rules.
  (main-target.generate): Call the above rules.

* test/loop.py: New test.


[SVN r19241]

new/targets.jam

@@ -298,6 +298,32 @@ rule project-target ( name : project : requirements * : default-build * )
 }
 class project-target : abstract-target ;
 
+
+
+# Helper rules to detect cycles in main target references
+local rule start-building ( main-target-instance )
+{
+    if $(main-target-instance) in $(.targets-being-built)
+    {
+        local names ;
+        for local t in $(.targets-being-built) $(main-target-instance)
+        {
+            names += [ $(t).full-name ] ;
+        }
+        
+        errors.error "Recursion in main target references" 
+          : "the following target are being built currently:"
+          : $(names) ;
+    }
+    .targets-being-built += $(main-target-instance) ;    
+}
+
+local rule end-building ( main-target-instance )
+{
+    .targets-being-built = $(.targets-being-built[1--2]) ;
+}
+
+
 # A named top-level target in Jamfile
 rule main-target ( name : project )
 {
@@ -309,6 +335,7 @@ rule main-target ( name : project )
     import sequence ;
     import print ;
     import build-request feature property-set ;
+    import targets : start-building end-building ;
         
     # Add a new alternative for this target
     rule add-alternative ( target )
@@ -407,6 +434,7 @@ rule main-target ( name : project )
     # Returns the result of calling 'generate' on that alternative.
     rule generate ( property-set )
     {
+        start-building $(__name__) ;
         local all-property-sets = [ apply-default-build $(property-set) ] ;
         local usage-requirements = [ property-set.empty ] ;
         local result ;
@@ -418,6 +446,7 @@ rule main-target ( name : project )
             usage-requirements = [ $(usage-requirements).add $(r[1]) ] ;
             result += $(r[2-]) ;
         }
+        end-building $(__name__) ;
         return $(usage-requirements) $(result) ;                
     }
         

test/loop.py

@@ -0,0 +1,28 @@
+#!/usr/bin/python
+
+#  Copyright (C) Vladimir Prus 2003. Permission to copy, use, modify, sell and
+#  distribute this software is granted provided this copyright notice appears in
+#  all copies. This software is provided "as is" without express or implied
+#  warranty, and with no claim as to its suitability for any purpose.
+
+from BoostBuild import Tester, List
+from string import find
+
+t = Tester()
+
+
+t.write("project-root.jam", "")
+t.write("Jamfile", """ 
+
+lib main : main.cpp l ;
+lib l : l.cpp main ; 
+""")
+
+t.write("main.cpp", "")
+t.write("l.cpp", "")
+
+t.run_build_system("--no-error-backtrace", status=1)
+t.fail_test(find(t.stdout(), "error: Recursion in main target references") == -1)
+t.fail_test(find(t.stdout(), "./main ./l ./main") == -1)
+
+t.cleanup()

test/test_all.py

@@ -100,6 +100,7 @@ tests = [ "project_test1",
           "inline",
           "conditionals2",
           "property_expansion",
+          "loop",
 	  ]
 
 if os.name == 'posix':

v2/build/targets.jam

@@ -298,6 +298,32 @@ rule project-target ( name : project : requirements * : default-build * )
 }
 class project-target : abstract-target ;
 
+
+
+# Helper rules to detect cycles in main target references
+local rule start-building ( main-target-instance )
+{
+    if $(main-target-instance) in $(.targets-being-built)
+    {
+        local names ;
+        for local t in $(.targets-being-built) $(main-target-instance)
+        {
+            names += [ $(t).full-name ] ;
+        }
+        
+        errors.error "Recursion in main target references" 
+          : "the following target are being built currently:"
+          : $(names) ;
+    }
+    .targets-being-built += $(main-target-instance) ;    
+}
+
+local rule end-building ( main-target-instance )
+{
+    .targets-being-built = $(.targets-being-built[1--2]) ;
+}
+
+
 # A named top-level target in Jamfile
 rule main-target ( name : project )
 {
@@ -309,6 +335,7 @@ rule main-target ( name : project )
     import sequence ;
     import print ;
     import build-request feature property-set ;
+    import targets : start-building end-building ;
         
     # Add a new alternative for this target
     rule add-alternative ( target )
@@ -407,6 +434,7 @@ rule main-target ( name : project )
     # Returns the result of calling 'generate' on that alternative.
     rule generate ( property-set )
     {
+        start-building $(__name__) ;
         local all-property-sets = [ apply-default-build $(property-set) ] ;
         local usage-requirements = [ property-set.empty ] ;
         local result ;
@@ -418,6 +446,7 @@ rule main-target ( name : project )
             usage-requirements = [ $(usage-requirements).add $(r[1]) ] ;
             result += $(r[2-]) ;
         }
+        end-building $(__name__) ;
         return $(usage-requirements) $(result) ;                
     }
         

v2/test/loop.py

@@ -0,0 +1,28 @@
+#!/usr/bin/python
+
+#  Copyright (C) Vladimir Prus 2003. Permission to copy, use, modify, sell and
+#  distribute this software is granted provided this copyright notice appears in
+#  all copies. This software is provided "as is" without express or implied
+#  warranty, and with no claim as to its suitability for any purpose.
+
+from BoostBuild import Tester, List
+from string import find
+
+t = Tester()
+
+
+t.write("project-root.jam", "")
+t.write("Jamfile", """ 
+
+lib main : main.cpp l ;
+lib l : l.cpp main ; 
+""")
+
+t.write("main.cpp", "")
+t.write("l.cpp", "")
+
+t.run_build_system("--no-error-backtrace", status=1)
+t.fail_test(find(t.stdout(), "error: Recursion in main target references") == -1)
+t.fail_test(find(t.stdout(), "./main ./l ./main") == -1)
+
+t.cleanup()

v2/test/test_all.py

@@ -100,6 +100,7 @@ tests = [ "project_test1",
           "inline",
           "conditionals2",
           "property_expansion",
+          "loop",
 	  ]
 
 if os.name == 'posix':