`SEMMLE_TYPESCRIPT_NODE_RUNTIME` can be used to provide the path to the Node.js runtime executable.
If this is omitted, the extractor defaults to the current behaviour of looking for `node` on the PATH.
`SEMMLE_TYPESCRIPT_NODE_RUNTIME_EXTRA_ARGS` can be used to provide additional arguments to the
Node.js runtime. These are passed first, before the arguments supplied by the extractor.
These changes are designed to allow TypeScript extraction in controlled customer environments where
we cannot control the PATH, or must use custom Node.js executables with certain arguments set.
This query uses data flow for nullness analysis, which is always going
to be a large overapproximation. The overapproximation became too big
for one of the test cases after the recent change to make data flow go
across assignment by reference.
To make this query more conservative, it will now only report that the
`pDacl` argument can be null if there isn't also evidence that it can be
non-null.
This commit changes how data flow works in the following code.
MyType x = source();
defineByReference(&x);
sink(x);
The question here is whether there should be flow from `source` to
`sink`. Such flow is desirable if `defineByReference` doesn't write to
all of `x`, but it's undesirable if `defineByReference` is a typical
init function in `C` that writes to every field or if
`defineByReference` is `memcpy` or `memset` on the full range.
Before 1.20.0, there would be flow from `source` to `sink` in case `x`
happened to be modeled with `BlockVar` but not in case `x` happened to
be modelled with SSA. The choice of modelling depends on an analysis of
how `x` is used elsewhere in the function, and it's supposed to be an
internal implementation detail that there are two ways to model
variables. In 1.20.0, I changed the `BlockVar` behavior so it worked the
same as SSA, never allowing that flow. It turns out that this change
broke a customer's query.
This commit reverts `BlockVar` to its old behavior of letting flow
propagate past the `defineByReference` call and then regains consistency
by changing all variables that are ever defined by reference to be
modelled with `BlockVar` instead of SSA. This means we now get too much
flow in certain cases, but that appears to be better overall than
getting too little flow. See also the discussion in CPP-336.
Previously, `AllConfigurations.qll` would pull in (almost) all taint
tracking configurations, which has started causing OOMEs during
compilation.
I've pruned it down to only the most interesting configurations. Since
flow summaries are experimental at this point and require a bit of manual
configuration anyway, this shouldn't be much of an issue in practice.
My recent changes to suppress FPs in `ReturnStackAllocatedMemory.ql`
caused us to lose all results where there was a `Conversion` at the
initial address escape. We cannot handle conversions in general, but
this commit restores the good results for the trivial types of
conversion that we can handle.
