Viewing file:  reduce_statements.cpp (8.47 KB) -rw-rw-r--
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/*
* phc -- the open source PHP compiler
* See doc/license/README.license for licensing information
*
* Remove a given number of statements, from a given offset, to help reduce the problem size.
*/
#include "AST_transform.h"
#include "HIR_transform.h"
#include "MIR_transform.h"
#include "pass_manager/Plugin_pass.h"
#include "lib/List.h"
using namespace std;
/* After removing statements, we may be left with gotos and branches to
* statements which dont exist, which will cause compiler errors. Labels will
* leave warnings for unused labels, which also trip us up. Unfortunately,
* those errors are percieved to be the sort of thing we want to isolate, which
* they arent. So if we remove something that involves a label, we want to
* remove other stuff with that label in them. (this is the sort of thing you
* do if you dont have data-flow :().
*/
class Strip_labels : public MIR::Transform
{
public:
Map<string, bool>* labels;
Strip_labels (Map<string, bool>* labels)
{
this->labels = labels;
}
void post_branch (MIR::Branch* in, List<MIR::Statement*>* out)
{
if (!remove_label (in->iftrue) && !remove_label (in->iffalse))
{
out->push_back (in);
}
}
void post_goto (MIR::Goto* in, List<MIR::Statement*>* out)
{
if (!remove_label (in->label_name))
{
out->push_back (in);
}
}
void post_label (MIR::Label* in, List<MIR::Statement*>* out)
{
if (!remove_label (in->label_name))
{
out->push_back (in);
}
}
// return true if the label should be removed
bool remove_label (MIR::LABEL_NAME* in)
{
return (labels->find (*in->value) != labels->end ());
}
};
#define REMOVABLE(TYPE,type) \
void post_##type (TYPE* in, List<Statement*>* out) \
{ \
}
#define REMOVABLE_CONTENTS(TYPE,type,CONTENT_NAME) \
void post_##type (TYPE* in, List<Statement*>* out) \
{ \
if (in->CONTENT_NAME->size() != 0) \
out->push_back (in); \
}
template <class Transform, class Statement>
class Reduce : public Transform
{
// Common base - anything in the AST, HIR and MIR.
protected:
int start;
int length;
int index;
public:
Reduce (int start, int length)
{
this->start = start;
this->length = length;
this->index = 0;
}
// Things which can be removed
void post_statement (Statement *in, List<Statement*>* out)
{
if (index >= start && index < (start + length))
Transform::post_statement(in, out);
else
out->push_back (in);
this->index++;
}
};
class AST_reduce : public Reduce<AST::Transform, AST::Statement>
{
public:
AST_reduce (int start, int length)
: Reduce<AST::Transform, AST::Statement>(start, length)
{
}
// Control-flow with sub-statements
void pre_if (AST::If* in, AST::Statement_list* out)
{
if (in->iftrue->size () > 0 || in->iffalse->size () > 0)
out->push_back (in);
}
void pre_switch_cases (AST::Switch_case* in, AST::Switch_case_list* cases)
{
if (in->statements->size () > 0)
cases->push_back (in);
}
typedef AST::Statement Statement;
REMOVABLE_CONTENTS (AST::Class_def, class_def, members);
REMOVABLE_CONTENTS (AST::Declare, declare, statements);
REMOVABLE_CONTENTS (AST::Do, do, statements);
REMOVABLE_CONTENTS (AST::For, for, statements);
REMOVABLE_CONTENTS (AST::Foreach, foreach, statements);
REMOVABLE_CONTENTS (AST::Interface_def, interface_def, members);
REMOVABLE_CONTENTS (AST::Method, method, statements);
REMOVABLE_CONTENTS (AST::Switch, switch, switch_cases);
REMOVABLE_CONTENTS (AST::Try, try, statements);
REMOVABLE_CONTENTS (AST::While, while, statements);
REMOVABLE (AST::Break, break);
REMOVABLE (AST::Continue, continue);
REMOVABLE (AST::Eval_expr, eval_expr);
REMOVABLE (AST::Global, global);
REMOVABLE (AST::Nop, nop);
REMOVABLE (AST::Return, return);
REMOVABLE (AST::Static_declaration, static_declaration);
REMOVABLE (AST::Throw, throw);
};
class HIR_reduce : public Reduce <HIR::Transform, HIR::Statement>
{
public:
HIR_reduce (int start, int length)
: Reduce <HIR::Transform, HIR::Statement> (start, length)
{
}
void pre_if (HIR::If* in, HIR::Statement_list* out)
{
if (in->iftrue->size () > 0 || in->iffalse->size () > 0)
out->push_back (in);
}
typedef HIR::Statement Statement;
REMOVABLE_CONTENTS (HIR::Class_def, class_def, members);
REMOVABLE_CONTENTS (HIR::Foreach, foreach, statements);
REMOVABLE_CONTENTS (HIR::Interface_def, interface_def, members);
REMOVABLE_CONTENTS (HIR::Loop, loop, statements);
REMOVABLE_CONTENTS (HIR::Method, method, statements);
REMOVABLE_CONTENTS (HIR::Try, try, statements);
REMOVABLE (HIR::Assign_array, assign_array);
REMOVABLE (HIR::Assign_field, assign_field);
REMOVABLE (HIR::Assign_next, assign_next);
REMOVABLE (HIR::Assign_var, assign_var);
REMOVABLE (HIR::Assign_var_var, assign_var_var);
REMOVABLE (HIR::Break, break);
REMOVABLE (HIR::Continue, continue);
REMOVABLE (HIR::Eval_expr, eval_expr);
REMOVABLE (HIR::Global, global);
REMOVABLE (HIR::Pre_op, pre_op);
REMOVABLE (HIR::Return, return);
REMOVABLE (HIR::Static_declaration, static_declaration);
REMOVABLE (HIR::Throw, throw);
};
class MIR_reduce : public Reduce<MIR::Transform, MIR::Statement>
{
public:
MIR_reduce (int start, int length)
: Reduce <MIR::Transform, MIR::Statement> (start, length)
{
labels = new Map<string, bool>;
}
public:
Map<string, bool>* labels;
// Things which can be removed
void post_statement (MIR::Statement *in, List<MIR::Statement*>* out)
{
Reduce<MIR::Transform, MIR::Statement>::post_statement (in, out);
if (out->size() == 0 || out->back () != in)
{
// If we remove a label, remove everything associated with that label.
// Otherwise we'll get compiler warnings and errors.
if (MIR::Goto* go = dynamic_cast <MIR::Goto*> (in))
{
mark_label (go->label_name);
}
else if (MIR::Branch* branch = dynamic_cast <MIR::Branch*> (in))
{
mark_label (branch->iftrue);
mark_label (branch->iffalse);
}
else if (MIR::Label* label = dynamic_cast <MIR::Label*> (in))
{
mark_label (label->label_name);
}
}
}
void mark_label (MIR::LABEL_NAME* name)
{
(*labels)[*name->value] = true;
}
typedef MIR::Statement Statement;
REMOVABLE_CONTENTS (MIR::Class_def, class_def, members);
REMOVABLE_CONTENTS (MIR::Interface_def, interface_def, members);
REMOVABLE_CONTENTS (MIR::Method, method, statements);
REMOVABLE_CONTENTS (MIR::Try, try, statements);
REMOVABLE (MIR::Assign_array, assign_array);
REMOVABLE (MIR::Assign_field, assign_field);
REMOVABLE (MIR::Assign_next, assign_next);
REMOVABLE (MIR::Assign_var, assign_var);
REMOVABLE (MIR::Assign_var_var, assign_var_var);
REMOVABLE (MIR::Eval_expr, eval_expr);
// Leave in foreach_reset, foreach_next and foreach_end
// TODO: remove them all if you remove one.
REMOVABLE (MIR::Global, global);
REMOVABLE (MIR::Pre_op, pre_op);
REMOVABLE (MIR::Return, return);
REMOVABLE (MIR::Static_declaration, static_declaration);
REMOVABLE (MIR::Throw, throw);
REMOVABLE (MIR::Unset, unset);
};
extern "C" void load (Pass_manager* pm, Plugin_pass* pass)
{
// We want to run this immediately after the XML is read in, so we add it after every pass.
pm->add_after_each_pass (pass);
}
void get_options (String* option, int* start, int* length)
{
// Read START and LENGTH from the option string (\d+:\d+)
int colon_index = -1;
for (unsigned int i = 0; i < option->size (); i++)
{
if (option->at (i) == ':')
{
colon_index = i;
break;
}
}
assert (colon_index != -1);
string start_string = option->substr (0, colon_index);
string length_string = option->substr (
colon_index+1,
option->size () - colon_index);
stringstream sss (start_string);
sss >> *start;
stringstream lss (length_string);
lss >> *length;
}
static bool already = false;
extern "C" void run_ast (AST::PHP_script* in, Pass_manager* pm, String* option)
{
if (already)
exit (0); // just retuning means the pass is dumped many times.
already = true;
int start;
int length;
get_options (option, &start, &length);
in->transform_children (new AST_reduce (start, length));
}
extern "C" void run_hir (HIR::PHP_script* in, Pass_manager* pm, String* option)
{
if (already)
exit (0);
already = true;
int start;
int length;
get_options (option, &start, &length);
in->transform_children (new HIR_reduce (start, length));
}
extern "C" void run_mir (MIR::PHP_script* in, Pass_manager* pm, String* option)
{
if (already)
exit (0);
already = true;
int start;
int length;
get_options (option, &start, &length);
MIR_reduce* red = new MIR_reduce (start, length);
in->transform_children (red);
in->transform_children (new Strip_labels (red->labels));
}
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