lxsh/src/debashify.cpp

365 lines
9.8 KiB
C++

#include "debashify.hpp"
#include "recursive.hpp"
#include "util.hpp"
#include "parse.hpp"
#include "struc_helper.hpp"
/*
[[ ]] debashifying:
[[ EXPRESSION && EXPRESSION ]] separated into two parts
EXPRESSION : gen_bashtest_cmd
&& , || : debashify_bashtest
*/
// [[ $a = b ]] : quote vars
// [[ a == b ]] : replace == with =
// [[ a = b* ]] : case a in b*) true;; *) false;; esac
// [[ a =~ b ]] : expr a : "b" >/dev/null
block* gen_bashtest_cmd(std::vector<arg*> args)
{
block* ret = nullptr;
std::string arg1replace;
if(args.size() == 3)
{
if(args[1]->string() == "==")
arg1replace="=";
else if(args[1]->string() == "<")
arg1replace="-lt";
else if(args[1]->string() == "<=")
arg1replace="-le";
else if(args[1]->string() == ">")
arg1replace="-gt";
else if(args[1]->string() == ">=")
arg1replace="-ge";
}
if(arg1replace != "")
{
delete args[1];
args[1] = new arg(arg1replace);
}
if(args.size() == 3 && args[1]->string() == "=" && arg_has_char('*', args[2]))
{
delete args[1];
args[1]=nullptr;
case_block* tc = new case_block(args[0]);
tc->cases.push_back( std::make_pair(std::vector<arg*>({args[2]}), make_list("true")) );
tc->cases.push_back( std::make_pair(std::vector<arg*>({new arg("*")}), make_list("false")) );
ret = tc;
}
else if(args.size() == 3 && args[1]->string() == "=~")
{
delete args[1];
args[1]=nullptr;
add_quotes(args[2]);
ret = make_cmd( std::vector<arg*>({ new arg("expr"), args[0], new arg(":"), args[2] }) );
ret->redirs.push_back(new redirect(">", new arg("/dev/null") ));
}
else // regular [ ]
{
cmd* t = make_cmd(args);
t->args->insert(0, new arg("["));
t->add(new arg("]"));
ret = t;
}
// arg oblivious replacements:
// quote variables
for(auto it: args)
{
if(it!=nullptr)
force_quotes(it);
}
return ret;
}
// [[ a && b ]] : [ a ] && [ b ]
bool debashify_bashtest(pipeline* pl)
{
if(pl->cmds.size()<=0)
return false;
if(pl->cmds[0]->type != _obj::block_cmd)
return false;
cmd* in = dynamic_cast<cmd*>(pl->cmds[0]);
if(in->firstarg_string() == "[[")
{
brace* br = new brace(new list);
condlist* cl = new condlist;
br->lst->add(cl);
arg *a=nullptr;
uint32_t j=1;
bool or_op=false;
for(uint32_t i=1 ; i<in->args->size() ; i++)
{
a = in->args->args[i];
if(i >= in->args->size()-1 || a->string() == "&&" || a->string() == "||")
{
block* tbl = gen_bashtest_cmd(std::vector<arg*>(in->args->args.begin()+j, in->args->args.begin()+i));
cl->add(new pipeline(tbl), or_op);
or_op = a->string() == "||";
j=i+1;
}
}
delete in->args->args[0];
delete in->args->args[in->args->args.size()-1];
in->args->args.resize(0);
delete in;
pl->cmds[0] = br;
return true;
}
return false;
}
bool debashify_declare(cmd* in)
{
if(in->firstarg_string() == "declare")
throw std::runtime_error("Cannot debashify 'declare'");
return false;
}
bool debashify_array_def(cmd* in)
{
for(auto it: in->var_assigns)
{
if(it.second->size()>0 && it.second->sa[0]->type == _obj::subarg_string && it.second->sa[0]->generate(0) == "(")
throw std::runtime_error("Cannot debashify 'VAR=()' arrays");
}
return false;
}
bool debashify_array_call(variable* in)
{
if(in->index != nullptr)
throw std::runtime_error("Cannot debashify 'VAR[I]' arrays");
return false;
}
bool debashify_herestring(pipeline* pl)
{
if(pl->cmds.size()>0)
{
block* c=pl->cmds[0];
for(uint32_t i=0; i<c->redirs.size() ; i++)
{
if(c->redirs[i]->op == "<<<")
{
force_quotes(c->redirs[i]->target);
cmd* printcmd = make_cmd("printf '%s\\n'");
printcmd->add(c->redirs[i]->target);
pl->cmds.insert(pl->cmds.begin(), printcmd);
// cleanup
c->redirs[i]->target=nullptr;
delete c->redirs[i];
c->redirs.erase(pl->cmds[1]->redirs.begin()+i);
return true;
}
}
}
return false;
}
// replace &>, &>> and >&:
// add 2>&1 as redirect
bool debashify_combined_redirects(block* in)
{
bool has_replaced=false;
for(uint32_t i=0; i<in->redirs.size() ; i++)
{
if(in->redirs[i]->op == "&>" || in->redirs[i]->op == "&>>" || in->redirs[i]->op == ">&")
{
// resolve new operator
std::string newop = ">";
if( in->redirs[i]->op == "&>>" )
newop = ">>";
// create new redir with target
redirect* newredir = new redirect(newop, in->redirs[i]->target);
in->redirs[i]->target=nullptr;
// replace old redir
delete in->redirs[i];
in->redirs[i] = newredir;
// insert merge redir
i++;
in->redirs.insert(in->redirs.begin()+i, new redirect("2>&1"));
has_replaced=true;
}
}
return has_replaced;
}
// replace <() and >()
/*
REPLACE TO:
fifoN=${TMPDIR-/tmp}/lxshfifo_$(__lxsh_random 10)
mkfifo "$fifoN"
( {PSUB;} [>|<] "$fifoN" ; rm "$fifoN") &
CMD "$fifoN"
*/
bool debashify_procsub(list* lst)
{
bool has_replaced=false;
for(uint32_t li=0; li<lst->cls.size(); li++)
{
std::vector<std::pair<arg*,bool>> affected_args;
// iterate all applicable args of the cl
for(auto plit: lst->cls[li]->pls)
{
for(auto cmit: plit->cmds)
{
if(cmit->type == _obj::block_cmd)
{
cmd* t = dynamic_cast<cmd*>(cmit);
if(t->args != nullptr)
{
for(auto ait: t->args->args)
{
if(ait->size() == 1 && ait->sa[0]->type == _obj::subarg_procsub)
{
procsub_subarg* st = dynamic_cast<procsub_subarg*>(ait->sa[0]);
affected_args.push_back( std::make_pair(ait, st->is_output) );
}
}
}
}
}
}
// perform the replace
if(affected_args.size()>0)
{
has_replaced=true;
list* lst_insert = new list;
std::string mkfifocmd="mkfifo";
for(uint32_t i=0; i<affected_args.size(); i++)
{
// fifoN=${TMPDIR-/tmp}/lxshfifo_$(__lxsh_random 10)
lst_insert->add( make_condlist( strf("__lxshfifo%u=${TMPDIR-/tmp}/lxshfifo_$(__lxsh_random 10)", i) ) );
mkfifocmd += strf(" \"$__lxshfifo%u\"", i);
}
// mkfifo "$fifoN"
lst_insert->add( make_condlist(mkfifocmd) );
for(uint32_t i=0; i<affected_args.size(); i++)
{
// create ( {PSUB;} > "$fifoN" ; rm "$fifoN") &
subshell* psub = new subshell(new list);
procsub_subarg* st = dynamic_cast<procsub_subarg*>(affected_args[i].first->sa[0]);
// {PSUB;}
brace* cbr = new brace(st->sbsh->lst);
// deindex list
st->sbsh->lst=nullptr;
// {PSUB;} > "$__lxshfifoN"
cbr->redirs.push_back( new redirect( affected_args[i].second ? "<" : ">", make_arg(strf("\"$__lxshfifo%u\"", i)) ) );
// ( {PSUB;} > "$__lxshfifoN" )
psub->lst->add( new condlist(cbr) );
// ( {PSUB;} > "$__lxshfifoN" ; rm "$__lxshfifoN" )
psub->lst->add( make_condlist(strf("rm \"$__lxshfifo%u\"", i)) );
// ( {PSUB;} > "$__lxshfifoN" ; rm "$__lxshfifoN" ) &
condlist* pscl = new condlist(psub);
pscl->parallel=true;
lst_insert->add( pscl );
// replace the arg
delete affected_args[i].first->sa[0];
affected_args[i].first->sa[0] = new string_subarg("\"");
affected_args[i].first->add( new variable_subarg( new variable(strf("__lxshfifo%u", i)) ) );
affected_args[i].first->add( new string_subarg("\"") );
}
lst->insert(li, *lst_insert );
li+= lst_insert->size();
//cleanup
lst_insert->cls.resize(0);
delete lst_insert;
}
}
return has_replaced;
}
function* create_random_func()
{
std::string code="{ tr -cd '[:alnum:]' </dev/urandom | head -c $1; }";
function* fct=parse_function(code.c_str(), code.size(), 0).first;
fct->name="__lxsh_random";
return fct;
}
bool r_debashify(_obj* o, bool* need_random_func)
{
switch(o->type)
{
case _obj::_variable: {
variable* t = dynamic_cast<variable*>(o);
debashify_array_call(t);
} break;
case _obj::_list: {
list* t = dynamic_cast<list*>(o);
if(debashify_procsub(t))
*need_random_func = true;
} break;
case _obj::_pipeline: {
pipeline* t = dynamic_cast<pipeline*>(o);
debashify_herestring(t);
debashify_bashtest(t);
} break;
case _obj::block_cmd: {
cmd* t = dynamic_cast<cmd*>(o);
debashify_combined_redirects(t);
debashify_declare(t);
debashify_array_def(t);
} break;
case _obj::block_subshell: {
subshell* t = dynamic_cast<subshell*>(o);
debashify_combined_redirects(t);
} break;
case _obj::block_brace: {
brace* t = dynamic_cast<brace*>(o);
debashify_combined_redirects(t);
} break;
case _obj::block_main: {
shmain* t = dynamic_cast<shmain*>(o);
debashify_combined_redirects(t);
} break;
case _obj::block_function: {
function* t = dynamic_cast<function*>(o);
debashify_combined_redirects(t);
} break;
case _obj::block_case: {
case_block* t = dynamic_cast<case_block*>(o);
debashify_combined_redirects(t);
} break;
case _obj::block_if: {
if_block* t = dynamic_cast<if_block*>(o);
debashify_combined_redirects(t);
} break;
case _obj::block_while: {
while_block* t = dynamic_cast<while_block*>(o);
debashify_combined_redirects(t);
} break;
case _obj::block_for: {
for_block* t = dynamic_cast<for_block*>(o);
debashify_combined_redirects(t);
} break;
default: break;
}
return true;
}
void debashify(shmain* sh)
{
bool need_random_func=false;
sh->shebang = "#!/bin/sh";
recurse(r_debashify, sh, &need_random_func);
if(need_random_func)
sh->lst->insert(0, new condlist(create_random_func()));
}