Merged revisions 56154-56264 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/branches/p3yk

................
  r56155 | neal.norwitz | 2007-07-03 08:59:08 +0300 (Tue, 03 Jul 2007) | 1 line

  Get this test working after converting map to return an iterator
................
  r56202 | neal.norwitz | 2007-07-09 04:30:09 +0300 (Mon, 09 Jul 2007) | 37 lines

  Merged revisions 56124-56201 via svnmerge from
  svn+ssh://pythondev@svn.python.org/python/trunk

  ........
    r56129 | georg.brandl | 2007-06-30 04:01:01 -0700 (Sat, 30 Jun 2007) | 2 lines

    Document smtp.SMTPAuthenticationError.
  ........
    r56137 | georg.brandl | 2007-07-01 01:11:35 -0700 (Sun, 01 Jul 2007) | 2 lines

    Fix a few webbrowser.py problems.
  ........
    r56143 | georg.brandl | 2007-07-02 04:54:28 -0700 (Mon, 02 Jul 2007) | 2 lines

    Remove duplicate sentence from alarm() doc.
  ........
    r56170 | mark.hammond | 2007-07-03 19:03:10 -0700 (Tue, 03 Jul 2007) | 3 lines

    copy built files to the PCBuild directory, where tools like
    distutils or external build processes can find them.
  ........
    r56176 | kurt.kaiser | 2007-07-05 15:03:39 -0700 (Thu, 05 Jul 2007) | 10 lines

    Many calls to tk.call involve an arglist containing a single tuple.
    Calls using METH_OLDARGS unpack this tuple; calls using METH_VARARG
    don't.  Tcl's concatenation of args was affected; IDLE doesn't start.

    Modify Tkapp_Call() to unpack single tuple arglists.

    Bug 1733943
    Ref http://mail.python.org/pipermail/python-checkins/2007-May/060454.html
  ........
    r56177 | neal.norwitz | 2007-07-05 21:13:39 -0700 (Thu, 05 Jul 2007) | 1 line

    Fix typo in comment
  ........
................
  r56251 | neal.norwitz | 2007-07-11 10:01:01 +0300 (Wed, 11 Jul 2007) | 1 line

  Get working with map returning an iterator (had to fix whitespace too)
................
  r56255 | thomas.wouters | 2007-07-11 13:41:37 +0300 (Wed, 11 Jul 2007) | 6 lines


  Clean up merge glitch or copy-paste error (the entire module was duplicated,
  except the first half even had some more copy-paste errors, referring to
  listcomps and genexps instead of setcomps)
................
  r56256 | thomas.wouters | 2007-07-11 15:16:01 +0300 (Wed, 11 Jul 2007) | 14 lines


  Dict comprehensions. Still needs doc changes (like many python-3000 features
  ;-). It generates bytecode similar to:

  x = {}
  for k, v in (generator here):
    x[k] = v

  except there is no tuple-packing and -unpacking involved. Trivial
  measurement suggests it's significantly faster than dict(generator here) (in
  the order of 2 to 3 times as fast) but I have not done extensive
  measurements.
................
  r56263 | guido.van.rossum | 2007-07-11 15:36:26 +0300 (Wed, 11 Jul 2007) | 3 lines

  Patch 1724999 by Ali Gholami Rudi -- avoid complaints about dict size
  change during iter in destroy call.
................

5 files changed, 230 insertions, 64 deletions

diff --git a/Python/Python-ast.c b/Python/Python-ast.c
index 18c2eb5..d5250a4 100644
--- a/Python/Python-ast.c
+++ b/Python/Python-ast.c
@@ -198,6 +198,12 @@ static char *SetComp_fields[]={
         "elt",
         "generators",
 };
+static PyTypeObject *DictComp_type;
+static char *DictComp_fields[]={
+        "key",
+        "value",
+        "generators",
+};
 static PyTypeObject *GeneratorExp_type;
 static char *GeneratorExp_fields[]={
         "elt",
@@ -551,6 +557,8 @@ static int init_types(void)
         if (!ListComp_type) return 0;
         SetComp_type = make_type("SetComp", expr_type, SetComp_fields, 2);
         if (!SetComp_type) return 0;
+        DictComp_type = make_type("DictComp", expr_type, DictComp_fields, 3);
+        if (!DictComp_type) return 0;
         GeneratorExp_type = make_type("GeneratorExp", expr_type,
                                       GeneratorExp_fields, 2);
         if (!GeneratorExp_type) return 0;
@@ -1445,6 +1453,33 @@ SetComp(expr_ty elt, asdl_seq * generators, int lineno, int col_offset, PyArena
 }
 
 expr_ty
+DictComp(expr_ty key, expr_ty value, asdl_seq * generators, int lineno, int
+         col_offset, PyArena *arena)
+{
+        expr_ty p;
+        if (!key) {
+                PyErr_SetString(PyExc_ValueError,
+                                "field key is required for DictComp");
+                return NULL;
+        }
+        if (!value) {
+                PyErr_SetString(PyExc_ValueError,
+                                "field value is required for DictComp");
+                return NULL;
+        }
+        p = (expr_ty)PyArena_Malloc(arena, sizeof(*p));
+        if (!p)
+                return NULL;
+        p->kind = DictComp_kind;
+        p->v.DictComp.key = key;
+        p->v.DictComp.value = value;
+        p->v.DictComp.generators = generators;
+        p->lineno = lineno;
+        p->col_offset = col_offset;
+        return p;
+}
+
+expr_ty
 GeneratorExp(expr_ty elt, asdl_seq * generators, int lineno, int col_offset,
              PyArena *arena)
 {
@@ -2479,6 +2514,26 @@ ast2obj_expr(void* _o)
                         goto failed;
                 Py_DECREF(value);
                 break;
+        case DictComp_kind:
+                result = PyType_GenericNew(DictComp_type, NULL, NULL);
+                if (!result) goto failed;
+                value = ast2obj_expr(o->v.DictComp.key);
+                if (!value) goto failed;
+                if (PyObject_SetAttrString(result, "key", value) == -1)
+                        goto failed;
+                Py_DECREF(value);
+                value = ast2obj_expr(o->v.DictComp.value);
+                if (!value) goto failed;
+                if (PyObject_SetAttrString(result, "value", value) == -1)
+                        goto failed;
+                Py_DECREF(value);
+                value = ast2obj_list(o->v.DictComp.generators,
+                                     ast2obj_comprehension);
+                if (!value) goto failed;
+                if (PyObject_SetAttrString(result, "generators", value) == -1)
+                        goto failed;
+                Py_DECREF(value);
+                break;
         case GeneratorExp_kind:
                 result = PyType_GenericNew(GeneratorExp_type, NULL, NULL);
                 if (!result) goto failed;
@@ -3186,6 +3241,8 @@ init_ast(void)
             return;
         if (PyDict_SetItemString(d, "SetComp", (PyObject*)SetComp_type) < 0)
             return;
+        if (PyDict_SetItemString(d, "DictComp", (PyObject*)DictComp_type) < 0)
+            return;
         if (PyDict_SetItemString(d, "GeneratorExp",
             (PyObject*)GeneratorExp_type) < 0) return;
         if (PyDict_SetItemString(d, "Yield", (PyObject*)Yield_type) < 0) return;
diff --git a/Python/ast.c b/Python/ast.c
index c611436..23df29f 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -426,6 +426,9 @@ set_context(expr_ty e, expr_context_ty ctx, const node *n)
         case SetComp_kind:
             expr_name = "set comprehension";
             break;
+        case DictComp_kind:
+            expr_name = "dict comprehension";
+            break;
         case Dict_kind:
         case Set_kind:
         case Num_kind:
@@ -1047,23 +1050,22 @@ static int
 count_comp_fors(const node *n)
 {
     int n_fors = 0;
-    node *ch = CHILD(n, 1);
 
   count_comp_for:
     n_fors++;
-    REQ(ch, comp_for);
-    if (NCH(ch) == 5)
-        ch = CHILD(ch, 4);
+    REQ(n, comp_for);
+    if (NCH(n) == 5)
+        n = CHILD(n, 4);
     else
         return n_fors;
   count_comp_iter:
-    REQ(ch, comp_iter);
-    ch = CHILD(ch, 0);
-    if (TYPE(ch) == comp_for)
+    REQ(n, comp_iter);
+    n = CHILD(n, 0);
+    if (TYPE(n) == comp_for)
         goto count_comp_for;
-    else if (TYPE(ch) == comp_if) {
-        if (NCH(ch) == 3) {
-            ch = CHILD(ch, 2);
+    else if (TYPE(n) == comp_if) {
+        if (NCH(n) == 3) {
+            n = CHILD(n, 2);
             goto count_comp_iter;
         }
         else
@@ -1099,22 +1101,12 @@ count_comp_ifs(const node *n)
     }
 }
 
-static expr_ty
-ast_for_comprehension(struct compiling *c, const node *n, int type)
+static asdl_seq *
+ast_for_comprehension(struct compiling *c, const node *n)
 {
-    /* testlist_comp: test ( comp_for | (',' test)* [','] )
-       argument: [test '='] test [comp_for]       # Really [keyword '='] test */
-    expr_ty elt;
-    asdl_seq *comps;
     int i, n_fors;
-    node *ch;
-    
-    assert(NCH(n) > 1);
-    
-    elt = ast_for_expr(c, CHILD(n, 0));
-    if (!elt)
-        return NULL;
-    
+    asdl_seq *comps;
+
     n_fors = count_comp_fors(n);
     if (n_fors == -1)
         return NULL;
@@ -1123,20 +1115,19 @@ ast_for_comprehension(struct compiling *c, const node *n, int type)
     if (!comps)
         return NULL;
 
-    ch = CHILD(n, 1);
     for (i = 0; i < n_fors; i++) {
         comprehension_ty comp;
         asdl_seq *t;
         expr_ty expression;
         node *for_ch;
         
-        REQ(ch, comp_for);
+        REQ(n, comp_for);
         
-        for_ch = CHILD(ch, 1);
+        for_ch = CHILD(n, 1);
         t = ast_for_exprlist(c, for_ch, Store);
         if (!t)
             return NULL;
-        expression = ast_for_expr(c, CHILD(ch, 3));
+        expression = ast_for_expr(c, CHILD(n, 3));
         if (!expression)
             return NULL;
 
@@ -1146,19 +1137,19 @@ ast_for_comprehension(struct compiling *c, const node *n, int type)
             comp = comprehension((expr_ty)asdl_seq_GET(t, 0), expression,
                                  NULL, c->c_arena);
         else
-            comp = comprehension(Tuple(t, Store, LINENO(ch), ch->n_col_offset,
+            comp = comprehension(Tuple(t, Store, LINENO(n), n->n_col_offset,
                                        c->c_arena),
                                  expression, NULL, c->c_arena);
 
         if (!comp)
             return NULL;
 
-        if (NCH(ch) == 5) {
+        if (NCH(n) == 5) {
             int j, n_ifs;
             asdl_seq *ifs;
             
-            ch = CHILD(ch, 4);
-            n_ifs = count_comp_ifs(ch);
+            n = CHILD(n, 4);
+            n_ifs = count_comp_ifs(n);
             if (n_ifs == -1)
                 return NULL;
 
@@ -1167,24 +1158,44 @@ ast_for_comprehension(struct compiling *c, const node *n, int type)
                 return NULL;
 
             for (j = 0; j < n_ifs; j++) {
-                REQ(ch, comp_iter);
-                ch = CHILD(ch, 0);
-                REQ(ch, comp_if);
+                REQ(n, comp_iter);
+                n = CHILD(n, 0);
+                REQ(n, comp_if);
                 
-                expression = ast_for_expr(c, CHILD(ch, 1));
+                expression = ast_for_expr(c, CHILD(n, 1));
                 if (!expression)
                     return NULL;
                 asdl_seq_SET(ifs, j, expression);
-                if (NCH(ch) == 3)
-                    ch = CHILD(ch, 2);
+                if (NCH(n) == 3)
+                    n = CHILD(n, 2);
             }
-            /* on exit, must guarantee that ch is a comp_for */
-            if (TYPE(ch) == comp_iter)
-                ch = CHILD(ch, 0);
+            /* on exit, must guarantee that n is a comp_for */
+            if (TYPE(n) == comp_iter)
+                n = CHILD(n, 0);
             comp->ifs = ifs;
         }
         asdl_seq_SET(comps, i, comp);
     }
+    return comps;
+}
+
+static expr_ty
+ast_for_itercomp(struct compiling *c, const node *n, int type)
+{
+    /* testlist_comp: test ( comp_for | (',' test)* [','] )
+       argument: [test '='] test [comp_for]       # Really [keyword '='] test */
+    expr_ty elt;
+    asdl_seq *comps;
+    
+    assert(NCH(n) > 1);
+    
+    elt = ast_for_expr(c, CHILD(n, 0));
+    if (!elt)
+        return NULL;
+    
+    comps = ast_for_comprehension(c, CHILD(n, 1));
+    if (!comps)
+        return NULL;
 
     if (type == COMP_GENEXP)
         return GeneratorExp(elt, comps, LINENO(n), n->n_col_offset, c->c_arena);
@@ -1198,24 +1209,48 @@ ast_for_comprehension(struct compiling *c, const node *n, int type)
 }
 
 static expr_ty
+ast_for_dictcomp(struct compiling *c, const node *n)
+{
+    expr_ty key, value;
+    asdl_seq *comps;
+    
+    assert(NCH(n) > 3);
+    REQ(CHILD(n, 1), COLON);
+    
+    key = ast_for_expr(c, CHILD(n, 0));
+    if (!key)
+        return NULL;
+
+    value = ast_for_expr(c, CHILD(n, 2));
+    if (!value)
+        return NULL;
+    
+    comps = ast_for_comprehension(c, CHILD(n, 3));
+    if (!comps)
+        return NULL;
+    
+    return DictComp(key, value, comps, LINENO(n), n->n_col_offset, c->c_arena);
+}
+
+static expr_ty
 ast_for_genexp(struct compiling *c, const node *n)
 {
     assert(TYPE(n) == (testlist_comp) || TYPE(n) == (argument));
-    return ast_for_comprehension(c, n, COMP_GENEXP);
+    return ast_for_itercomp(c, n, COMP_GENEXP);
 }
 
 static expr_ty
 ast_for_listcomp(struct compiling *c, const node *n)
 {
     assert(TYPE(n) == (testlist_comp));
-    return ast_for_comprehension(c, n, COMP_LISTCOMP);
+    return ast_for_itercomp(c, n, COMP_LISTCOMP);
 }
 
 static expr_ty
 ast_for_setcomp(struct compiling *c, const node *n)
 {
     assert(TYPE(n) == (dictorsetmaker));
-    return ast_for_comprehension(c, n, COMP_SETCOMP);
+    return ast_for_itercomp(c, n, COMP_SETCOMP);
 }
 
 
@@ -1313,6 +1348,8 @@ ast_for_atom(struct compiling *c, const node *n)
         } else if (TYPE(CHILD(ch, 1)) == comp_for) {
             /* it's a set comprehension */
             return ast_for_setcomp(c, ch);
+        } else if (NCH(ch) > 3 && TYPE(CHILD(ch, 3)) == comp_for) {
+            return ast_for_dictcomp(c, ch);
         } else {
             /* it's a dict */
             size = (NCH(ch) + 1) / 4; /* +1 in case no trailing comma */
diff --git a/Python/compile.c b/Python/compile.c
index cbb6b4d..77c6a77 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -42,6 +42,7 @@ int Py_OptimizeFlag = 0;
 #define COMP_GENEXP   0
 #define COMP_LISTCOMP 1
 #define COMP_SETCOMP  2
+#define COMP_DICTCOMP 3
 
 struct instr {
 	unsigned i_jabs : 1;
@@ -2753,7 +2754,7 @@ compiler_call_helper(struct compiler *c,
 static int
 compiler_comprehension_generator(struct compiler *c, PyObject *tmpname,
 				 asdl_seq *generators, int gen_index, 
-				 expr_ty elt, int type)
+				 expr_ty elt, expr_ty val, int type)
 {
 	/* generate code for the iterator, then each of the ifs,
 	   and then write to the element */
@@ -2801,7 +2802,7 @@ compiler_comprehension_generator(struct compiler *c, PyObject *tmpname,
 	if (++gen_index < asdl_seq_LEN(generators))
 		if (!compiler_comprehension_generator(c, tmpname, 
 						      generators, gen_index,
-						      elt, type))
+						      elt, val, type))
 		return 0;
 
 	/* only append after the last for generator */
@@ -2825,6 +2826,17 @@ compiler_comprehension_generator(struct compiler *c, PyObject *tmpname,
 			VISIT(c, expr, elt);
 			ADDOP(c, SET_ADD);
 			break;
+		case COMP_DICTCOMP:
+			if (!compiler_nameop(c, tmpname, Load))
+				return 0;
+			/* With 'd[k] = v', v is evaluated before k, so we do
+			   the same. STORE_SUBSCR requires (item, map, key),
+			   so we still end up ROTing once. */
+			VISIT(c, expr, val);
+			ADDOP(c, ROT_TWO);
+			VISIT(c, expr, elt);
+			ADDOP(c, STORE_SUBSCR);
+			break;
 		default:
 			return 0;
 		}
@@ -2846,7 +2858,7 @@ compiler_comprehension_generator(struct compiler *c, PyObject *tmpname,
 
 static int
 compiler_comprehension(struct compiler *c, expr_ty e, int type, identifier name,
-		       asdl_seq *generators, expr_ty elt)
+		       asdl_seq *generators, expr_ty elt, expr_ty val)
 {
 	PyCodeObject *co = NULL;
 	identifier tmp = NULL;
@@ -2859,18 +2871,34 @@ compiler_comprehension(struct compiler *c, expr_ty e, int type, identifier name,
 		goto error;
 	
 	if (type != COMP_GENEXP) {
+		int op;
 		tmp = compiler_new_tmpname(c);
 		if (!tmp)
 			goto error_in_scope;
+		switch (type) {
+		case COMP_LISTCOMP:
+			op = BUILD_LIST;
+			break;
+		case COMP_SETCOMP:
+			op = BUILD_SET;
+			break;
+		case COMP_DICTCOMP:
+			op = BUILD_MAP;
+			break;
+		default:
+			PyErr_Format(PyExc_SystemError,
+				     "unknown comprehension type %d", type);
+			goto error_in_scope;
+		}
 
-		ADDOP_I(c, (type == COMP_LISTCOMP ?
-			    BUILD_LIST : BUILD_SET), 0);
+		ADDOP_I(c, op, 0);
 		ADDOP(c, DUP_TOP);
 		if (!compiler_nameop(c, tmp, Store))
 			goto error_in_scope;
 	}
 	
-	if (!compiler_comprehension_generator(c, tmp, generators, 0, elt, type))
+	if (!compiler_comprehension_generator(c, tmp, generators, 0, elt,
+					      val, type))
 		goto error_in_scope;
 	
 	if (type != COMP_GENEXP) {
@@ -2911,7 +2939,7 @@ compiler_genexp(struct compiler *c, expr_ty e)
 	assert(e->kind == GeneratorExp_kind);
 	return compiler_comprehension(c, e, COMP_GENEXP, name,
 				      e->v.GeneratorExp.generators,
-				      e->v.GeneratorExp.elt);
+				      e->v.GeneratorExp.elt, NULL);
 }
 
 static int
@@ -2926,7 +2954,7 @@ compiler_listcomp(struct compiler *c, expr_ty e)
 	assert(e->kind == ListComp_kind);
 	return compiler_comprehension(c, e, COMP_LISTCOMP, name,
 				      e->v.ListComp.generators,
-				      e->v.ListComp.elt);
+				      e->v.ListComp.elt, NULL);
 }
 
 static int
@@ -2941,7 +2969,23 @@ compiler_setcomp(struct compiler *c, expr_ty e)
 	assert(e->kind == SetComp_kind);
 	return compiler_comprehension(c, e, COMP_SETCOMP, name,
 				      e->v.SetComp.generators,
-				      e->v.SetComp.elt);
+				      e->v.SetComp.elt, NULL);
+}
+
+
+static int
+compiler_dictcomp(struct compiler *c, expr_ty e)
+{
+	static identifier name;
+	if (!name) {
+		name = PyString_FromString("<dictcomp>");
+		if (!name)
+			return 0;
+	}
+	assert(e->kind == DictComp_kind);
+	return compiler_comprehension(c, e, COMP_DICTCOMP, name,
+				      e->v.DictComp.generators,
+				      e->v.DictComp.key, e->v.DictComp.value);
 }
 
 
@@ -3173,6 +3217,8 @@ compiler_visit_expr(struct compiler *c, expr_ty e)
 		return compiler_listcomp(c, e);
 	case SetComp_kind:
 		return compiler_setcomp(c, e);
+	case DictComp_kind:
+		return compiler_dictcomp(c, e);
 	case Yield_kind:
 		if (c->u->u_ste->ste_type != FunctionBlock)
 			return compiler_error(c, "'yield' outside function");
diff --git a/Python/graminit.c b/Python/graminit.c
index c1c070b..95905d7 100644
--- a/Python/graminit.c
+++ b/Python/graminit.c
@@ -1505,7 +1505,8 @@ static arc arcs_71_4[2] = {
 	{24, 6},
 	{0, 4},
 };
-static arc arcs_71_5[2] = {
+static arc arcs_71_5[3] = {
+	{156, 3},
 	{30, 7},
 	{0, 5},
 };
@@ -1518,18 +1519,27 @@ static arc arcs_71_7[2] = {
 	{0, 7},
 };
 static arc arcs_71_8[1] = {
-	{25, 2},
+	{25, 9},
+};
+static arc arcs_71_9[1] = {
+	{24, 10},
+};
+static arc arcs_71_10[2] = {
+	{30, 7},
+	{0, 10},
 };
-static state states_71[9] = {
+static state states_71[11] = {
 	{1, arcs_71_0},
 	{4, arcs_71_1},
 	{1, arcs_71_2},
 	{1, arcs_71_3},
 	{2, arcs_71_4},
-	{2, arcs_71_5},
+	{3, arcs_71_5},
 	{2, arcs_71_6},
 	{2, arcs_71_7},
 	{1, arcs_71_8},
+	{1, arcs_71_9},
+	{2, arcs_71_10},
 };
 static arc arcs_72_0[1] = {
 	{160, 1},
@@ -1864,7 +1874,7 @@ static dfa dfas[81] = {
 	 "\000\040\040\200\000\000\000\000\000\040\000\000\000\000\000\000\200\041\224\017\000"},
 	{326, "testlist", 0, 3, states_70,
 	 "\000\040\040\200\000\000\000\000\000\040\000\000\000\040\004\000\200\041\224\017\000"},
-	{327, "dictorsetmaker", 0, 9, states_71,
+	{327, "dictorsetmaker", 0, 11, states_71,
 	 "\000\040\040\200\000\000\000\000\000\040\000\000\000\040\004\000\200\041\224\017\000"},
 	{328, "classdef", 0, 8, states_72,
 	 "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\001"},
diff --git a/Python/symtable.c b/Python/symtable.c
index 30e97d6..121f3ee 100644
--- a/Python/symtable.c
+++ b/Python/symtable.c
@@ -170,6 +170,7 @@ static int symtable_visit_expr(struct symtable *st, expr_ty s);
 static int symtable_visit_genexp(struct symtable *st, expr_ty s);
 static int symtable_visit_listcomp(struct symtable *st, expr_ty s);
 static int symtable_visit_setcomp(struct symtable *st, expr_ty s);
+static int symtable_visit_dictcomp(struct symtable *st, expr_ty s);
 static int symtable_visit_arguments(struct symtable *st, arguments_ty);
 static int symtable_visit_excepthandler(struct symtable *st, excepthandler_ty);
 static int symtable_visit_alias(struct symtable *st, alias_ty);
@@ -183,7 +184,7 @@ static int symtable_visit_annotations(struct symtable *st, stmt_ty s);
 
 
 static identifier top = NULL, lambda = NULL, genexpr = NULL,
-    listcomp = NULL, setcomp = NULL, __class__ = NULL;
+    listcomp = NULL, setcomp = NULL, dictcomp = NULL, __class__ = NULL;
 
 #define GET_IDENTIFIER(VAR) \
 	((VAR) ? (VAR) : ((VAR) = PyUnicode_InternFromString(# VAR)))
@@ -1270,6 +1271,10 @@ symtable_visit_expr(struct symtable *st, expr_ty e)
 		if (!symtable_visit_setcomp(st, e))
 			return 0;
 		break;
+	case DictComp_kind:
+		if (!symtable_visit_dictcomp(st, e))
+			return 0;
+		break;
         case Yield_kind:
 		if (e->v.Yield.value)
 			VISIT(st, expr, e->v.Yield.value);
@@ -1521,8 +1526,8 @@ symtable_visit_slice(struct symtable *st, slice_ty s)
 
 static int 
 symtable_handle_comprehension(struct symtable *st, expr_ty e,
-                              identifier scope_name,
-                              asdl_seq *generators, expr_ty elt)
+                              identifier scope_name, asdl_seq *generators,
+                              expr_ty elt, expr_ty value)
 {
 	int is_generator = (e->kind == GeneratorExp_kind);
 	int needs_tmp = !is_generator;
@@ -1550,6 +1555,8 @@ symtable_handle_comprehension(struct symtable *st, expr_ty e,
 	VISIT_SEQ_IN_BLOCK(st, expr, outermost->ifs, (void*)e);
 	VISIT_SEQ_TAIL_IN_BLOCK(st, comprehension,
 				generators, 1, (void*)e);
+	if (value)
+		VISIT_IN_BLOCK(st, expr, value, (void*)e);
 	VISIT_IN_BLOCK(st, expr, elt, (void*)e);
 	return symtable_exit_block(st, (void *)e);
 }
@@ -1559,7 +1566,7 @@ symtable_visit_genexp(struct symtable *st, expr_ty e)
 {
 	return symtable_handle_comprehension(st, e, GET_IDENTIFIER(genexpr),
                                              e->v.GeneratorExp.generators,
-                                             e->v.GeneratorExp.elt);
+                                             e->v.GeneratorExp.elt, NULL);
 }
 
 static int 
@@ -1567,7 +1574,7 @@ symtable_visit_listcomp(struct symtable *st, expr_ty e)
 {
 	return symtable_handle_comprehension(st, e, GET_IDENTIFIER(listcomp),
                                              e->v.ListComp.generators,
-                                             e->v.ListComp.elt);
+                                             e->v.ListComp.elt, NULL);
 }
 
 static int
@@ -1575,5 +1582,14 @@ symtable_visit_setcomp(struct symtable *st, expr_ty e)
 {
 	return symtable_handle_comprehension(st, e, GET_IDENTIFIER(setcomp),
 					     e->v.SetComp.generators,
-					     e->v.SetComp.elt);
+					     e->v.SetComp.elt, NULL);
+}
+
+static int
+symtable_visit_dictcomp(struct symtable *st, expr_ty e)
+{
+	return symtable_handle_comprehension(st, e, GET_IDENTIFIER(dictcomp),
+					     e->v.DictComp.generators,
+					     e->v.DictComp.key,
+					     e->v.DictComp.value);
 }