overlay[local]

module;

/**

* A predicate that contains RA.

*/

signature class RApredicate {

string getLineOfRA(int n);

}

/**

* Parses strings of RA provided by an RA predicate, and represented the

*/

module RAParser<RApredicate Predicate> {

private string parseRaExpr(Predicate p, int line, int arity, int lhs) {

exists(string str | str = p.getLineOfRA(line).trim() |

arity = str.regexpCapture("\\{([0-9]+)\\} r([0-9]+) = (.+)", 1).toInt() and

lhs = str.regexpCapture("\\{([0-9]+)\\} r([0-9]+) = (.+)", 2).toInt() and

result = str.regexpCapture("\\{([0-9]+)\\} r([0-9]+) = (.+)", 3)

)

}

bindingset[str]

private int parseReturn(string str) {

result = str.trim().regexpCapture("return r([0-9]+)", 1).toInt()

}

bindingset[str]

private predicate parseScan(string str, int arity, int lhs, string rhs) {

exists(string r, string trimmed |

r = "\\{(\\d+)\\}\\s+r(\\d+)\\s+=\\s+SCAN\\s+([0-9a-zA-Z:#_]+)\\s.*" and

trimmed = str.trim()

|

arity = trimmed.regexpCapture(r, 1).toInt() and

lhs = trimmed.regexpCapture(r, 2).toInt() and

rhs = trimmed.regexpCapture(r, 3)

)

}

bindingset[str]

private predicate parseJoin(string str, int arity, int lhs, string left, string right) {

exists(string r, string trimmed |

r =

"\\{(\\d+)\\}\\s+r(\\d+)\\s+=\\s+JOIN\\s+([0-9a-zA-Z:#_]+)\\s+WITH\\s+([0-9a-zA-Z:#_]+)\\s.*" and

trimmed = str.trim()

|

arity = trimmed.regexpCapture(r, 1).toInt() and

lhs = trimmed.regexpCapture(r, 2).toInt() and

left = trimmed.regexpCapture(r, 3) and

right = trimmed.regexpCapture(r, 4)

)

}

bindingset[str]

private predicate parseSelect(string str, int arity, int lhs, string rhs) {

exists(string r, string trimmed |

r = "\\{(\\d+)\\}\\s+r(\\d+)\\s+=\\s+SELECT\\s+([0-9a-zA-Z:#_]+).*" and

trimmed = str.trim()

|

arity = trimmed.regexpCapture(r, 1).toInt() and

lhs = trimmed.regexpCapture(r, 2).toInt() and

rhs = trimmed.regexpCapture(r, 3)

)

}

bindingset[str]

private predicate parseAntiJoin(string str, int arity, int lhs, string left, string right) {

exists(string r, string trimmed |

r = "\\{(\\d+)\\}\\s+r(\\d+)\\s+=\\s+([0-9a-zA-Z:#_]+)\\s+AND\\s+NOT\\s+([0-9a-zA-Z:#_]+).*" and

trimmed = str.trim()

|

arity = trimmed.regexpCapture(r, 1).toInt() and

lhs = trimmed.regexpCapture(r, 2).toInt() and

left = trimmed.regexpCapture(r, 3) and

right = trimmed.regexpCapture(r, 4)

)

}

private newtype TRA =

TReturn(Predicate p, int line, int v) { v = parseReturn(p.getLineOfRA(line)) } or

TScan(Predicate p, int line, int arity, int lhs, string rhs) {

parseScan(p.getLineOfRA(line), arity, lhs, rhs)

} or

TJoin(Predicate p, int line, int arity, int lhs, string left, string right) {

parseJoin(p.getLineOfRA(line), arity, lhs, left, right)

} or

TSelect(Predicate p, int line, int arity, int lhs, string rhs) {

parseSelect(p.getLineOfRA(line), arity, lhs, rhs)

} or

TAntiJoin(Predicate p, int line, int arity, int lhs, string left, string right) {

parseAntiJoin(p.getLineOfRA(line), arity, lhs, left, right)

} or

TUnknown(Predicate p, int line, int lhs, int arity, string rhs) {

rhs = parseRaExpr(p, line, arity, lhs)

}

/** An RA Expression. */

abstract class RAExpr extends TRA {

/** Gets the predicate this RA expression belongs to. */

abstract Predicate getPredicate();

/** Gets the line index of this RA expression. */

abstract int getLine();

/** Gets the LHS of the expression of the form `rNN = ...` */

abstract int getLhs();

/** Gets a variable of the form `rNN` in the RHS of the RA expression. */

abstract int getARhsVariable();

/** Gets the given arity of the RA expression. */

abstract int getArity();

/** Gets a predicate name referenced in the RHS of an RA expression. */

abstract string getARhsPredicate();

final string toString() { result = this.getPredicate().getLineOfRA(this.getLine()) }

/** Gets a child of this RA expression - not by index yet. */

RAExpr getAChild() {

result.getPredicate() = this.getPredicate() and result.getLhs() = this.getARhsVariable()

}

}

/**

* A generic RA expression - where we haven't precisely parsed the RA expression type.

* For Hackathon purposes, we probably don't need more than this.

*/

class RAUnknownExpr extends RAExpr, TUnknown {

Predicate p;

int line;

string rhs;

int arity;

int lhs;

RAUnknownExpr() { this = TUnknown(p, line, lhs, arity, rhs) }

override int getLine() { result = line }

override Predicate getPredicate() { result = p }

override int getLhs() { result = lhs }

override int getARhsVariable() {

result = rhs.splitAt(" ").regexpCapture("r([0-9]+)", 1).toInt()

}

// This is a dumb regex to find a predicate name - they always contain a `#` (TODO...)

override string getARhsPredicate() { result = rhs.splitAt(" ") and result.indexOf("#") > 0 }

override int getArity() { result = arity }

}

class RAReturnExpr extends RAExpr, TReturn {

Predicate p;

int line;

int res;

RAReturnExpr() { this = TReturn(p, line, res) }

override Predicate getPredicate() { result = p }

override int getLine() { result = line }

override int getLhs() { none() }

override int getARhsVariable() { result = res }

override int getArity() { none() }

override string getARhsPredicate() { none() }

}

class RAScanExpr extends RAExpr, TScan {

Predicate p;

int line;

int arity;

int lhs;

string rhs;

RAScanExpr() { this = TScan(p, line, arity, lhs, rhs) }

override Predicate getPredicate() { result = p }

override int getLine() { result = line }

override int getLhs() { result = lhs }

override int getArity() { result = arity }

override int getARhsVariable() { isVariable(rhs, result) }

override string getARhsPredicate() {

result = rhs and

not isVariable(result, _)

}

}

bindingset[s]

private predicate isVariable(string s, int n) { n = s.regexpCapture("r(\\d+)", 1).toInt() }

class RAJoinExpr extends RAExpr, TJoin {

Predicate p;

int line;

int arity;

int lhs;

string left;

string right;

RAJoinExpr() { this = TJoin(p, line, arity, lhs, left, right) }

override Predicate getPredicate() { result = p }

override int getLine() { result = line }

override int getLhs() { result = lhs }

override int getArity() { result = arity }

// Note: We could return reasonable values here sometimes.

override int getARhsVariable() { isVariable([left, right], result) }

// Note: We could return reasonable values here sometimes.

override string getARhsPredicate() {

result = [left, right] and

not isVariable(result, _)

}

}

class RaSelectExpr extends RAExpr, TSelect {

Predicate p;

int line;

int arity;

int lhs;

string rhs;

RaSelectExpr() { this = TSelect(p, line, arity, lhs, rhs) }

override Predicate getPredicate() { result = p }

override int getLine() { result = line }

override int getLhs() { result = lhs }

override int getArity() { result = arity }

// Note: We could return reasonable values here sometimes.

override int getARhsVariable() { isVariable(rhs, result) }

// Note: We could return reasonable values here sometimes.

override string getARhsPredicate() {

result = rhs and

not isVariable(result, _)

}

}

class RaAntiJoinExpr extends RAExpr, TAntiJoin {

Predicate p;

int line;

int arity;

int lhs;

string left;

string right;

RaAntiJoinExpr() { this = TAntiJoin(p, line, arity, lhs, left, right) }

override Predicate getPredicate() { result = p }

override int getLine() { result = line }

override int getLhs() { result = lhs }

override int getArity() { result = arity }

// Note: We could return reasonable values here sometimes.

override int getARhsVariable() { isVariable([left, right], result) }

// Note: We could return reasonable values here sometimes.

override string getARhsPredicate() {

result = [left, right] and

not isVariable(result, _)

}

}

}