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java: inline range test #17997

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158 changes: 158 additions & 0 deletions java/ql/test/library-tests/dataflow/range-analysis-inline/B.java
Original file line number Diff line number Diff line change
@@ -0,0 +1,158 @@
public class B {

// Use this method to mark non-integer bounds
// that should also be annotated.
static void bound(int b) { }

public int forLoop() {
int result = 0;
for (int i = 0;
i < 10; // $ bound="i in [0..10]"
i++) { // $ bound="i in [0..9]"
result = i; // $ bound="i in [0..9]"
}
return result; // $ bound="result in [0..9]"
}

public int forLoopExit() {
int result = 0;
for (; result < 10;) { // $ bound="result in [0..10]"
result += 1; // $ bound="result in [0..9]"
}
return result; // $ bound="result = 10"
}

public int forLoopExitStep() {
int result = 0;
for (; result < 10;) { // $ bound="result in [0..12]"
result += 3; // $ bound="result in [0..9]"
}
return result; // $ bound="result = 12"
}

public int forLoopExitUpd() {
int result = 0;
for (; result < 10; // $ bound="result in [0..10]"
result++) { // $ bound="result in [0..9]"
}
return result; // $ bound="result = 10"
}

public int forLoopExitNested() {
int result = 0;
for (; result < 10;) {
int i = 0;
for (; i < 3;) { // $ bound="i in [0..3]"
i += 1; // $ bound="i in [0..2]"
}
result += i; // $ bound="result in [0..9]" bound="i = 3"
}
return result; // $ MISSING:bound="result = 12"
}

public int emptyForLoop() {
int result = 0;
for (int i = 0; i < 0; // $ bound="i = 0"
i++) { // $ bound="i in [0..-1]"
result = i; // $ bound="i in [0..-1]"
}
return result; // $ bound="result = 0"
}

public int noLoop() {
int result = 0;
result += 1; // $ bound="result = 0"
return result; // $ bound="result = 1"
}

public int foreachLoop() {
int result = 0;
for (int i : new int[] {1, 2, 3, 4, 5}) {
result = i;
}
return result;
}

public int emptyForeachLoop() {
int result = 0;
for (int i : new int[] {}) {
result = i;
}
return result;
}

public int whileLoop() {
int result = 100;
while (result > 5) { // $ bound="result in [4..100]"
result = result - 2; // $ bound="result in [6..100]"
}
return result; // $ bound="result = 4"
}

public int oddWhileLoop() {
int result = 101;
while (result > 5) { // $ bound="result in [5..101]"
result = result - 2; // $ bound="result in [7..101]"
}
return result; // $ bound="result = 5"
}

static void arrayLength(int[] arr) {
bound(arr.length);
for (int i = 0;
i < arr.length;
i++) { // $ bound="i <= arr.length - 1"
arr[i]++; // $ bound="i <= arr.length - 1"
}
}

static int varBound(int b) {
bound(b);
int result = 0;
for (int i = 0;
i < b;
i++) { // $ bound="i <= b - 1"
result = i; // $ bound="i <= b - 1"
}
return result; // We cannot conclude anything here, since we do not know that b > 0
}

static int varBoundPositiveGuard(int b) {
bound(b);
if (b > 0) {
int result = 0;
for (int i = 0;
i < b;
i++) { // $ bound="i <= b - 1"
result = i; // $ bound="i <= b - 1"
}
return result; // $ MISSING: bound="result <= b - 1"
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Btw. this is actually a case that potentially could be improved by some sort of "loop executes at least once" analysis.

} else {
return 0;
}
}

static int varBoundPositiveGuardEarlyReturn(int b) {
bound(b);
if (b <= 0) return 0;
int result = 0;
for (int i = 0;
i < b;
i++) { // $ bound="i <= b - 1"
result = i; // $ bound="i <= b - 1"
}
return result; // $ MISSING: bound="result <= b - 1"
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@aschackmull aschackmull Nov 25, 2024

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That's not MISSING - such a bound would be wrong if b is negative or zero, and thus the range analysis won't infer it.

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Ah, nice. So if I add a guard for b being positive, it might appear. Having both versions would be a good illustration of this.

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I could not get the bound to appear, so now there are just a bunch of negative tests..

}

static int varBoundPositiveAssert(int b) {
bound(b);
assert b > 0;
int result = 0;
for (int i = 0;
i < b;
i++) { // $ bound="i <= b - 1"
result = i; // $ bound="i <= b - 1"
}
return result; // $ MISSING: bound="result <= b - 1"
}
}
Original file line number Diff line number Diff line change
@@ -0,0 +1,71 @@
/**
* Inline range analysis tests for Java.
* See `shared/util/codeql/dataflow/test/InlineFlowTest.qll`
*/

import java
import semmle.code.java.dataflow.RangeAnalysis
private import TestUtilities.InlineExpectationsTest as IET

module RangeTest implements IET::TestSig {
string getARelevantTag() { result = "bound" }

predicate hasActualResult(Location location, string element, string tag, string value) {
tag = "bound" and
(
// simple integer bounds (`ZeroBound`s)
exists(Expr e, int lower, int upper |
constrained(e, lower, upper) and
e instanceof VarRead and
e.getCompilationUnit().fromSource()
|
location = e.getLocation() and
element = e.toString() and
if lower = upper
then value = "\"" + e.toString() + " = " + lower.toString() + "\""
else
value = "\"" + e.toString() + " in [" + lower.toString() + ".." + upper.toString() + "]\""
)
or
// advanced bounds
exists(Expr e, int delta, string deltaStr, boolean upper, string cmp, Expr boundExpr |
annotatedBound(e, _, boundExpr, delta, upper) and
e instanceof VarRead and
e.getCompilationUnit().fromSource() and
(
if delta = 0
then deltaStr = ""
else
if delta > 0
then deltaStr = " + " + delta.toString()
else deltaStr = " - " + delta.abs().toString()
) and
if upper = true then cmp = "<=" else cmp = ">="
|
location = e.getLocation() and
element = e.toString() and
value = "\"" + e.toString() + " " + cmp + " " + boundExpr.toString() + deltaStr + "\""
)
)
}

private predicate constrained(Expr e, int lower, int upper) {
bounded(e, any(ZeroBound z), lower, false, _) and
bounded(e, any(ZeroBound z), upper, true, _)
}

private predicate annotatedBound(Expr e, Bound b, Expr boundExpr, int delta, boolean upper) {
bounded(e, b, delta, upper, _) and
// the expression for the bound is explicitly requested as being annotated
// via a call such as
// ```java
// bound(expr);
// ```
boundExpr = b.getExpr() and
exists(Call c | c.getCallee().getName() = "bound" and c.getArgument(0) = boundExpr) and
// non-trivial bound
not e = b.getExpr()
}
}

import IET::MakeTest<RangeTest>