Viewing file:  Goto_uppering.cpp (4.02 KB) -rw-rw-r--
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/*
* phc -- the open source PHP compiler
* See doc/license/README.license for licensing information
*
* Convert goto statements, branches and labels into a FSM, which will consist
* of a while loop, a switch statement, a state variable, and a lot of
* continues.
*/
#include "Goto_uppering.h"
#include "MIR_to_AST.h"
#include "process_ir/General.h"
using namespace MIR;
Goto_uppering::Goto_uppering ()
{
ast_next = new AST::Variable (new AST::VARIABLE_NAME (s("__next")));
next = new MIR::VARIABLE_NAME (s("__next"));
}
/* We dont want to run this on all statement bodies in the traversal order. So
* we call it manually at the right times. */
Statement_list*
Goto_uppering::convert_statement_list (Statement_list *in)
{
// The prelude contains all class and function declarations
Statement_list *prelude = new Statement_list;
// OUT only contains the while, and the "start" statement.
Statement_list *out = new Statement_list;
// $next = "start";
(*out
<< "$__next = \"start\";"
).finish (next);
// switch ($next)
AST::Switch_case_list *cases = new AST::Switch_case_list;
AST::Switch *switches =
new AST::Switch (
ast_next->clone (),
cases);
// while (true) { switch ($next) { } }
out->push_back (new FOREIGN (
new AST::While (
new AST::BOOL (true),
new AST::Statement_list (
switches))));
// case "start";
AST::Switch_case* current =
new AST::Switch_case (
new AST::STRING (s("start")),
new AST::Statement_list);
cases->push_back (current);
// set up patterns
Wildcard<VARIABLE_NAME> *var_name = new Wildcard<VARIABLE_NAME> ();
Wildcard<LABEL_NAME> *l1 = new Wildcard<LABEL_NAME> ();
Wildcard<LABEL_NAME> *l2 = new Wildcard<LABEL_NAME> ();
Goto *goto_pattern = new Goto (l1);
Branch *branch_pattern = new Branch (var_name, l1, l2);
Label *label_pattern = new Label (l1);;
// Convert all the patterns
foreach (Statement* s, *in)
{
// add statements to the current case statement
if (s->match (goto_pattern))
{
// add the gotos to the current case statement
(*current->statements
<< ast_next << " = \"" << l1->value->value << "\";"
<< "continue;"
).finish (ast_next); // we dont care about attributes
}
else if (s->match (branch_pattern))
{
// add the if and gotos to the current case statement
(*current->statements
<< "if ($" << *var_name->value->value << ")"
<< "{"
<< ast_next << " = \"" << l1->value->value << "\";"
<< " continue;"
<< "}"
<< "else"
<< "{"
<< ast_next << " = \"" << l2->value->value << "\";"
<< " continue;"
<< "}"
).finish (ast_next); // we dont care about attributes
}
else if (s->match (label_pattern))
{
// case "l1":
current = new AST::Switch_case (
new AST::STRING (l1->value->value),
new AST::Statement_list);
cases->push_back (current);
}
else
{
if ((s->attrs->is_true ("phc.lower_control_flow.top_level_declaration")))
prelude->push_back(s);
else
current->statements->push_back((new MIR_to_AST ())->fold_statement (s));
}
}
// add '$next = "end";' after the final statement
(*current->statements
<< ast_next << " = \"end\";"
).finish (ast_next);
// add the breaking statement
current = new AST::Switch_case (
new AST::STRING (s("end")),
new AST::Statement_list);
cases->push_back (current);
(*current->statements
<< "break 2;"
).finish (ast_next);
// combine the two lists, and output all statements
prelude->push_back_all (out);
return prelude;
}
void
Goto_uppering::pre_php_script (PHP_script *in)
{
bool add_call_to_main = false;
if (in->statements->size() > 0 && isa<Method> (in->statements->front()))
{
Method* m = dyc<Method> (in->statements->front());
if (*m->signature->method_name->value == "__MAIN__")
add_call_to_main = true;
}
in->statements = convert_statement_list (in->statements);
if (add_call_to_main)
(*in->statements
<< "__MAIN__();"
).finish (in);
}
void
Goto_uppering::pre_method (Method *in)
{
if(in->statements != NULL) // abstract method
in->statements = convert_statement_list (in->statements);
}
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