[vala/wip/transform: 86/99] Factorize some common code with convenient api. Fix do-while loops

[Rico Tzschichholz <ricotz src gnome org>]

commit 2a9a0f0832aea3f99017a5ac9b46829dd03d8626
Author: Luca Bruno <lucabru src gnome org>
Date:   Sun Feb 2 23:14:28 2014 +0100

    Factorize some common code with convenient api. Fix do-while loops

 codegen/valaccodetransformer.vala |  111 ++++++++++---------------------------
 vala/valacodebuilder.vala         |    2 +
 vala/valacodetransformer.vala     |   52 +++++++++++++++++
 3 files changed, 83 insertions(+), 82 deletions(-)
---
diff --git a/codegen/valaccodetransformer.vala b/codegen/valaccodetransformer.vala
index cf514bb..2f09208 100644
--- a/codegen/valaccodetransformer.vala
+++ b/codegen/valaccodetransformer.vala
@@ -165,12 +165,12 @@ public class Vala.CCodeTransformer : CodeTransformer {
 
        public override void visit_while_statement (WhileStatement stmt) {
                // convert to simple loop
-               push_builder (new CodeBuilder (context, stmt, stmt.source_reference));
-               Expression cond = null;
+               begin_replace_statement (stmt);
+               
                if (!always_false (stmt.condition)) {
                        b.open_loop ();
                        if (!always_true (stmt.condition)) {
-                               cond = expression (@"!$(stmt.condition)");
+                               var cond = expression (@"!$(stmt.condition)");
                                b.open_if (cond);
                                b.add_break ();
                                b.close ();
@@ -179,18 +179,13 @@ public class Vala.CCodeTransformer : CodeTransformer {
                        b.close ();
                }
 
-               var parent_block = context.analyzer.get_current_block (stmt);
-               context.analyzer.replaced_nodes.add (stmt);
-               parent_block.replace_statement (stmt, new EmptyStatement (stmt.source_reference));
-
                stmt.body.checked = false;
-               b.check (this);
-               pop_builder ();
+               end_replace_statement ();
        }
 
        public override void visit_do_statement (DoStatement stmt) {
                // convert to simple loop
-               push_builder (new CodeBuilder (context, stmt, stmt.source_reference));
+               begin_replace_statement (stmt);
 
                b.open_loop ();
                // do not generate variable and if block if condition is always true
@@ -204,21 +199,16 @@ public class Vala.CCodeTransformer : CodeTransformer {
                        b.add_assignment (expression (notfirst), expression ("true"));
                        b.close ();
                }
+               stmt.body.checked = false;
                b.add_statement (stmt.body);
                b.close ();
 
-               var parent_block = context.analyzer.get_current_block (stmt);
-               context.analyzer.replaced_nodes.add (stmt);
-               parent_block.replace_statement (stmt, new EmptyStatement (stmt.source_reference));
-
-               stmt.body.checked = false;
-               b.check (this);
-               pop_builder ();
+               end_replace_statement ();
        }
 
        public override void visit_for_statement (ForStatement stmt) {
                // convert to simple loop
-               push_builder (new CodeBuilder (context, stmt, stmt.source_reference));
+               begin_replace_statement (stmt);
 
                // initializer
                foreach (var init_expr in stmt.get_initializer ()) {
@@ -246,17 +236,13 @@ public class Vala.CCodeTransformer : CodeTransformer {
                        b.close ();
                }
 
-               var parent_block = context.analyzer.get_current_block (stmt);
-               context.analyzer.replaced_nodes.add (stmt);
-               parent_block.replace_statement (stmt, new EmptyStatement (stmt.source_reference));
-
                stmt.body.checked = false;
-               b.check (this);
-               pop_builder ();
+               end_replace_statement ();
        }
 
        public override void visit_foreach_statement (ForeachStatement stmt) {
-               push_builder (new CodeBuilder (context, stmt, stmt.source_reference));
+               begin_replace_statement (stmt);
+               
                var collection = b.add_temp_declaration (stmt.collection.value_type, stmt.collection);
 
                stmt.body.remove_local_variable (stmt.element_variable);
@@ -311,13 +297,8 @@ public class Vala.CCodeTransformer : CodeTransformer {
                b.add_statement (stmt.body);
                b.close ();
 
-               var parent_block = context.analyzer.get_current_block (stmt);
-               context.analyzer.replaced_nodes.add (stmt);
-               parent_block.replace_statement (stmt, new EmptyStatement (stmt.source_reference));
-
                stmt.body.checked = false;
-               b.check (this);
-               pop_builder ();
+               end_replace_statement ();
        }
 
        public override void visit_break_statement (BreakStatement stmt) {
@@ -372,20 +353,14 @@ public class Vala.CCodeTransformer : CodeTransformer {
                                // can't handle errors in field initializers
                                Report.error (expr.source_reference, "Field initializers must not throw 
errors");
                        } else {
-                               // store parent_node as we need to replace the expression in the old parent 
node later on
-                               var old_parent_node = expr.parent_node;
                                var formal_target_type = copy_type (expr.target_type);
                                var target_type = copy_type (expr.target_type);
-                               push_builder (new CodeBuilder (context, expr.parent_statement, 
expr.source_reference));
+                               begin_replace_expression (expr);
 
                                var local = b.add_temp_declaration (copy_type (expr.value_type), expr);
                                var replacement = return_temp_access (local, expr.value_type, target_type, 
formal_target_type);
 
-                               context.analyzer.replaced_nodes.add (expr);
-                               old_parent_node.replace_expression (expr, replacement);
-                               b.check (this);
-                               pop_builder ();
-                               check (replacement);
+                               end_replace_expression (replacement);
                        }
                }
        }
@@ -393,10 +368,9 @@ public class Vala.CCodeTransformer : CodeTransformer {
        public override void visit_conditional_expression (ConditionalExpression expr) {
                // convert to if statement
                Expression replacement = null;
-               var old_parent_node = expr.parent_node;
                var formal_target_type = copy_type (expr.target_type);
                var target_type = copy_type (expr.target_type);
-               push_builder (new CodeBuilder (context, expr.parent_statement, expr.source_reference));
+               begin_replace_expression (expr);
 
                var result = b.add_temp_declaration (expr.value_type);
                b.open_if (expr.condition);
@@ -406,11 +380,7 @@ public class Vala.CCodeTransformer : CodeTransformer {
                b.close ();
 
                replacement = return_temp_access (result, expr.value_type, target_type, formal_target_type);
-               context.analyzer.replaced_nodes.add (expr);
-               old_parent_node.replace_expression (expr, replacement);
-               b.check (this);
-               pop_builder ();
-               check (replacement);
+               end_replace_expression (replacement);
        }
 
        public override void visit_binary_expression (BinaryExpression expr) {
@@ -421,9 +391,8 @@ public class Vala.CCodeTransformer : CodeTransformer {
                }
 
                Expression replacement = null;
-               var old_parent_node = expr.parent_node;
                var target_type = copy_type (expr.target_type);
-               push_builder (new CodeBuilder (context, parent_statement, expr.source_reference));
+               begin_replace_expression (expr);
 
                if (context.analyzer.get_current_non_local_symbol (expr) is Block
                    && (expr.operator == BinaryOperator.AND || expr.operator == BinaryOperator.OR)) {
@@ -460,13 +429,9 @@ public class Vala.CCodeTransformer : CodeTransformer {
 
                if (replacement != null) {
                        replacement.target_type = target_type;
-                       context.analyzer.replaced_nodes.add (expr);
-                       old_parent_node.replace_expression (expr, replacement);
-                       b.check (this);
-                       pop_builder ();
-                       check (replacement);
+                       end_replace_expression (replacement);
                } else {
-                       pop_builder ();
+                       end_replace_expression (null);
                        base.visit_binary_expression (expr);
                }
        }
@@ -479,10 +444,9 @@ public class Vala.CCodeTransformer : CodeTransformer {
                }
 
                if (expr.operator == UnaryOperator.INCREMENT || expr.operator == UnaryOperator.DECREMENT) {
-                       var old_parent_node = expr.parent_node;
-                       var target_type = expr.target_type != null ? expr.target_type.copy () : null;
-
-                       push_builder (new CodeBuilder (context, parent_statement, expr.source_reference));
+                       var target_type = copy_type (expr.target_type);
+                       begin_replace_expression (expr);
+                       
                        Expression replacement;
                        if (expr.operator == UnaryOperator.INCREMENT) {
                                replacement = expression (@"$(expr.inner) = $(expr.inner) + 1");
@@ -490,12 +454,8 @@ public class Vala.CCodeTransformer : CodeTransformer {
                                replacement = expression (@"$(expr.inner) = $(expr.inner) - 1");
                        }
                        replacement.target_type = target_type;
-                       context.analyzer.replaced_nodes.add (expr);
-                       old_parent_node.replace_expression (expr, replacement);
-                       b.check (this);
 
-                       pop_builder ();
-                       check (replacement);
+                       end_replace_expression (replacement);
                        return;
                }
 
@@ -510,19 +470,14 @@ public class Vala.CCodeTransformer : CodeTransformer {
                                // can't handle errors in field initializers
                                Report.error (expr.source_reference, "Field initializers must not throw 
errors");
                        } else {
-                               var old_parent_node = expr.parent_node;
                                var target_type = copy_type (expr.target_type);
                                var formal_target_type = copy_type (expr.formal_target_type);
-                               push_builder (new CodeBuilder (context, expr.parent_statement, 
expr.source_reference));
+                               begin_replace_expression (expr);
 
                                var local = b.add_temp_declaration (expr.value_type, expr);
                                var replacement = return_temp_access (local, expr.value_type, target_type, 
formal_target_type);
 
-                               context.analyzer.replaced_nodes.add (expr);
-                               old_parent_node.replace_expression (expr, replacement);
-                               b.check (this);
-                               pop_builder ();
-                               check (replacement);
+                               end_replace_expression (replacement);
                        }
                }
        }
@@ -536,7 +491,7 @@ public class Vala.CCodeTransformer : CodeTransformer {
        }
 
        public override void visit_template (Template expr) {
-               push_builder (new CodeBuilder (context, expr.parent_statement, expr.source_reference));
+               begin_replace_expression (expr);
                
                Expression replacement;
 
@@ -555,15 +510,11 @@ public class Vala.CCodeTransformer : CodeTransformer {
                }
                replacement.target_type = expr.target_type;
 
-               context.analyzer.replaced_nodes.add (expr);
-               expr.parent_node.replace_expression (expr, replacement);
-               b.check (this);
-               pop_builder ();
-               check (replacement);
+               end_replace_expression (replacement);
        }
 
        public override void visit_postfix_expression (PostfixExpression expr) {
-               push_builder (new CodeBuilder (context, expr.parent_statement, expr.source_reference));
+               begin_replace_expression (expr);
                
                var result = b.add_temp_declaration (copy_type (expr.value_type), expr.inner);
                var op = expr.increment ? "+ 1" : "- 1";
@@ -571,11 +522,7 @@ public class Vala.CCodeTransformer : CodeTransformer {
                
                var replacement = return_temp_access (result, expr.value_type, expr.target_type);
 
-               context.analyzer.replaced_nodes.add (expr);
-               expr.parent_node.replace_expression (expr, replacement);
-               b.check (this);
-               pop_builder ();
-               check (replacement);
+               end_replace_expression (replacement);
                
        }
        
diff --git a/vala/valacodebuilder.vala b/vala/valacodebuilder.vala
index 866556e..1e041ef 100644
--- a/vala/valacodebuilder.vala
+++ b/vala/valacodebuilder.vala
@@ -30,6 +30,8 @@ public class Vala.CodeBuilder {
        public ArrayList<CodeNode> decl_nodes = new ArrayList<CodeNode> ();
        public SourceReference source_reference;
 
+       public void* replaced = null;
+
        public CodeBuilder (CodeContext context, Statement insert_statement, SourceReference 
source_reference) {
                this.source_reference = source_reference;
 
diff --git a/vala/valacodetransformer.vala b/vala/valacodetransformer.vala
index b236f6e..f02ae38 100644
--- a/vala/valacodetransformer.vala
+++ b/vala/valacodetransformer.vala
@@ -46,6 +46,58 @@ public class Vala.CodeTransformer : CodeVisitor {
                builder_stack.remove_at (builder_stack.size - 1);
        }
 
+       class ReplaceStatementData {
+               internal Statement stmt;
+               internal Block parent_block;
+       }
+
+       public void begin_replace_statement (Statement stmt) {
+               push_builder (new CodeBuilder (context, stmt, stmt.source_reference));
+               
+               var data = new ReplaceStatementData ();
+               data.stmt = stmt;
+               data.parent_block = context.analyzer.get_current_block (stmt);
+               b.replaced = (owned) data;
+       }
+
+       public void end_replace_statement () {
+               var data = (ReplaceStatementData) (owned) b.replaced;
+               
+               context.analyzer.replaced_nodes.add (data.stmt);
+               data.parent_block.replace_statement (data.stmt, new EmptyStatement 
(data.stmt.source_reference));
+
+               b.check (this);
+               pop_builder ();
+       }
+
+       class ReplaceExpressionData {
+               internal Expression expr;
+               internal CodeNode parent_node;
+       }
+
+       public void begin_replace_expression (owned Expression expr) {
+               push_builder (new CodeBuilder (context, expr.parent_statement, expr.source_reference));
+               
+               var data = new ReplaceExpressionData ();
+               data.expr = expr;
+               data.parent_node = expr.parent_node;
+               b.replaced = (owned) data;
+       }
+
+       public void end_replace_expression (Expression? replacement) {
+               var data = (ReplaceExpressionData) (owned) b.replaced;
+
+               if (replacement != null) {
+                       context.analyzer.replaced_nodes.add (data.expr);
+                       data.parent_node.replace_expression (data.expr, replacement);
+                       b.check (this);
+               }
+               pop_builder ();
+               if (replacement != null) {
+                       check (replacement);
+               }
+       }
+
        /**
         * Transform the code tree for the specified code context.
         *