hohn/codeql
1
0
Fork 0
mirror of https://github.com/github/codeql.git synced 2025-12-17 17:23:36 +01:00
Code Issues Packages Projects Releases Wiki Activity

Python: ObjectAPI to ValueAPI: ReturnValueIgnored: Autoformats

Browse Source
This commit is contained in:
Rebecca Valentine
2020-04-01 12:54:42 -07:00
parent 838e37ca98
commit 09349f1957
1 changed files with 34 additions and 26 deletions
Download Patch File Download Diff File Expand all files Collapse all files

60
python/ql/src/Functions/ReturnValueIgnored.ql
View File

@@ -22,7 +22,9 @@ predicate meaningful_return_value(Expr val) {
or
val instanceof BooleanLiteral
or
exists(FunctionValue callee | val = callee.getACall().getNode() and returns_meaningful_value(callee))
exists(FunctionValue callee |
val = callee.getACall().getNode() and returns_meaningful_value(callee)
)
or
not exists(FunctionValue callee | val = callee.getACall().getNode()) and not val instanceof Name
}
@@ -34,18 +36,22 @@ predicate used_value(Expr val) {
)
}
predicate returns_meaningful_value(FunctionValue f) {
not exists(f.getScope().getFallthroughNode())
and
predicate returns_meaningful_value(FunctionValue f) {
not exists(f.getScope().getFallthroughNode()) and
(
exists(Return ret, Expr val | ret.getScope() = f.getScope() and val = ret.getValue() |
meaningful_return_value(val) and
not used_value(val)
)
or
/* Is f a builtin function that returns something other than None?
* Ignore __import__ as it is often called purely for side effects */
f.isBuiltin() and f.(CallableObjectInternal).getAnInferredReturnType() != ClassValue::nonetype() and not f.getName() = "__import__"
exists(Return ret, Expr val | ret.getScope() = f.getScope() and val = ret.getValue() |
meaningful_return_value(val) and
not used_value(val)
)
or
/*
* Is f a builtin function that returns something other than None?
* Ignore __import__ as it is often called purely for side effects
*/
f.isBuiltin() and
f.(CallableObjectInternal).getAnInferredReturnType() != ClassValue::nonetype() and
not f.getName() = "__import__"
)
}
@@ -59,17 +65,19 @@ predicate wrapped_in_try_except(ExprStmt call) {
}
from ExprStmt call, FunctionValue callee, float percentage_used, int total
where call.getValue() = callee.getACall().getNode() and returns_meaningful_value(callee) and
not wrapped_in_try_except(call) and
exists(int unused |
unused = count(ExprStmt e | e.getValue().getAFlowNode() = callee.getACall()) and
total = count(callee.getACall()) |
percentage_used = (100.0*(total-unused)/total).floor()
) and
/* Report an alert if we see at least 5 calls and the return value is used in at least 3/4 of those calls. */
percentage_used >= 75 and
total >= 5
select call, "Call discards return value of function $@. The result is used in " + percentage_used.toString() + "% of calls.",
callee, callee.getName()
where
call.getValue() = callee.getACall().getNode() and
returns_meaningful_value(callee) and
not wrapped_in_try_except(call) and
exists(int unused |
unused = count(ExprStmt e | e.getValue().getAFlowNode() = callee.getACall()) and
total = count(callee.getACall())
|
percentage_used = (100.0 * (total - unused) / total).floor()
) and
/* Report an alert if we see at least 5 calls and the return value is used in at least 3/4 of those calls. */
percentage_used >= 75 and
total >= 5
select call,
"Call discards return value of function $@. The result is used in " + percentage_used.toString() +
"% of calls.", callee, callee.getName()