[vala/wip/transform: 7/99] Move DoStatement transformation into the code transformer

[Luca Bruno <lucabru src gnome org>]

commit de619533969df56baffee5ccc3168ec37c53b0c9
Author: Luca Bruno <lucabru src gnome org>
Date:   Tue Aug 30 13:42:39 2011 +0200

    Move DoStatement transformation into the code transformer
    
    Fixes bug 574352.

 vala/valacodetransformer.vala |   39 ++++++++++++++++++++++++++++-
 vala/valadostatement.vala     |   54 ++++++++++++++++++----------------------
 vala/valaflowanalyzer.vala    |   48 ++++++++++++++++++++++++++++++++++++
 3 files changed, 110 insertions(+), 31 deletions(-)
---
diff --git a/vala/valacodetransformer.vala b/vala/valacodetransformer.vala
index aa0c028..8264033 100644
--- a/vala/valacodetransformer.vala
+++ b/vala/valacodetransformer.vala
@@ -203,7 +203,44 @@ public class Vala.CodeTransformer : CodeVisitor {
        }
 
        public override void visit_do_statement (DoStatement stmt) {
-               stmt.accept_children (this);
+               // convert to simple loop
+
+               // do not generate variable and if block if condition is always true
+               if (always_true (stmt.condition)) {
+                       var loop = new Loop (stmt.body, stmt.source_reference);
+
+                       var parent_block = (Block) stmt.parent_node;
+                       parent_block.replace_statement (stmt, loop);
+
+                       check (loop);
+                       return;
+               }
+
+               var block = new Block (stmt.source_reference);
+
+               var first_local = new LocalVariable (context.analyzer.bool_type.copy (), stmt.get_temp_name 
(), new BooleanLiteral (true, stmt.source_reference), stmt.source_reference);
+               block.add_statement (new DeclarationStatement (first_local, stmt.source_reference));
+
+               var if_condition = new UnaryExpression (UnaryOperator.LOGICAL_NEGATION, stmt.condition, 
stmt.condition.source_reference);
+               var true_block = new Block (stmt.condition.source_reference);
+               true_block.add_statement (new BreakStatement (stmt.condition.source_reference));
+               var if_stmt = new IfStatement (if_condition, true_block, null, 
stmt.condition.source_reference);
+
+               var condition_block = new Block (stmt.condition.source_reference);
+               condition_block.add_statement (if_stmt);
+
+               var first_if = new IfStatement (new UnaryExpression (UnaryOperator.LOGICAL_NEGATION, new 
MemberAccess.simple (first_local.name, stmt.source_reference), stmt.source_reference), condition_block, null, 
stmt.source_reference);
+               stmt.body.insert_statement (0, first_if);
+               var first_assign = new ExpressionStatement (new Assignment (new MemberAccess.simple 
(first_local.name, stmt.source_reference), new BooleanLiteral (false, stmt.source_reference), 
AssignmentOperator.SIMPLE, stmt.source_reference), stmt.source_reference);
+               stmt.body.insert_statement (1, first_assign);
+
+               block.add_statement (new Loop (stmt.body, stmt.source_reference));
+
+               var parent_block = (Block) stmt.parent_node;
+               parent_block.replace_statement (stmt, block);
+
+               stmt.body.checked = false;
+               check (block);
        }
 
        public override void visit_for_statement (ForStatement stmt) {
diff --git a/vala/valadostatement.vala b/vala/valadostatement.vala
index 6bf72c0..940e61f 100644
--- a/vala/valadostatement.vala
+++ b/vala/valadostatement.vala
@@ -81,46 +81,40 @@ public class Vala.DoStatement : CodeNode, Statement {
                visitor.visit_end_full_expression (condition);
        }
 
-       bool always_true (Expression condition) {
-               var literal = condition as BooleanLiteral;
-               return (literal != null && literal.value);
+       public override void replace_expression (Expression old_node, Expression new_node) {
+               if (condition == old_node) {
+                       condition = new_node;
+               }
        }
 
        public override bool check (CodeContext context) {
-               // convert to simple loop
-
-               // do not generate variable and if block if condition is always true
-               if (always_true (condition)) {
-                       var loop = new Loop (body, source_reference);
-
-                       var parent_block = (Block) parent_node;
-                       parent_block.replace_statement (this, loop);
-
-                       return loop.check (context);
+               if (checked) {
+                       return !error;
                }
 
-               var block = new Block (source_reference);
+               checked = true;
 
-               var first_local = new LocalVariable (context.analyzer.bool_type.copy (), get_temp_name (), 
new BooleanLiteral (true, source_reference), source_reference);
-               block.add_statement (new DeclarationStatement (first_local, source_reference));
+               condition.target_type = context.analyzer.bool_type.copy ();
 
-               var if_condition = new UnaryExpression (UnaryOperator.LOGICAL_NEGATION, condition, 
condition.source_reference);
-               var true_block = new Block (condition.source_reference);
-               true_block.add_statement (new BreakStatement (condition.source_reference));
-               var if_stmt = new IfStatement (if_condition, true_block, null, condition.source_reference);
+               condition.check (context);
 
-               var condition_block = new Block (condition.source_reference);
-               condition_block.add_statement (if_stmt);
-
-               var first_if = new IfStatement (new UnaryExpression (UnaryOperator.LOGICAL_NEGATION, new 
MemberAccess.simple (first_local.name, source_reference), source_reference), condition_block, null, 
source_reference);
-               body.insert_statement (0, first_if);
-               body.insert_statement (1, new ExpressionStatement (new Assignment (new MemberAccess.simple 
(first_local.name, source_reference), new BooleanLiteral (false, source_reference), 
AssignmentOperator.SIMPLE, source_reference), source_reference));
+               if (condition.error) {
+                       /* if there was an error in the condition, skip this check */
+                       error = true;
+                       return false;
+               }
 
-               block.add_statement (new Loop (body, source_reference));
+               if (condition.value_type == null || !condition.value_type.compatible 
(context.analyzer.bool_type)) {
+                       error = true;
+                       Report.error (condition.source_reference, "Condition must be boolean");
+                       return false;
+               }
 
-               var parent_block = (Block) parent_node;
-               parent_block.replace_statement (this, block);
+               if (!body.check (context)) {
+                       error = true;
+                       return false;
+               }
 
-               return block.check (context);
+               return !error;
        }
 }
diff --git a/vala/valaflowanalyzer.vala b/vala/valaflowanalyzer.vala
index d726e59..047f201 100644
--- a/vala/valaflowanalyzer.vala
+++ b/vala/valaflowanalyzer.vala
@@ -778,6 +778,54 @@ public class Vala.FlowAnalyzer : CodeVisitor {
                jump_stack.remove_at (jump_stack.size - 1);
        }
 
+       public override void visit_do_statement (DoStatement stmt) {
+               if (unreachable (stmt)) {
+                       return;
+               }
+
+               var body_block = new BasicBlock ();
+               current_block.connect (body_block);
+               current_block = body_block;
+
+               var loop_block = new BasicBlock ();
+               jump_stack.add (new JumpTarget.continue_target (loop_block));
+               var after_loop_block = new BasicBlock ();
+               jump_stack.add (new JumpTarget.break_target (after_loop_block));
+
+               // body
+               stmt.body.accept (this);
+
+               // end of loop block reachable?
+               if (current_block != null) {
+                       current_block.connect (loop_block);
+               }
+
+               // condition
+               current_block = loop_block;
+               loop_block.add_node (stmt.condition);
+               handle_errors (stmt.condition);
+
+               if (!always_false (stmt.condition)) {
+                       loop_block.connect (body_block);
+               }
+
+               if (!always_true (stmt.condition)) {
+                       loop_block.connect (after_loop_block);
+               }
+
+               // after loop block reachable?
+               if (after_loop_block.get_predecessors ().size == 0) {
+                       // after loop block not reachable
+                       mark_unreachable ();
+               } else {
+                       // after loop block reachable
+                       current_block = after_loop_block;
+               }
+
+               jump_stack.remove_at (jump_stack.size - 1);
+               jump_stack.remove_at (jump_stack.size - 1);
+       }
+
        public override void visit_foreach_statement (ForeachStatement stmt) {
                if (unreachable (stmt)) {
                        return;