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codeql/cpp/ql/lib/semmle/code/cpp/dataflow/ExternalFlow.qll
Anders Schack-Mulligen 7f8d0771df MaD: Rename file.
2025-12-12 13:50:58 +01:00

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/**
* INTERNAL use only. This is an experimental API subject to change without notice.
*
* Provides classes and predicates for dealing with flow models specified in CSV format.
*
* The CSV specification has the following columns:
* - Sources:
* `namespace; type; subtypes; name; signature; ext; output; kind`
* - Sinks:
* `namespace; type; subtypes; name; signature; ext; input; kind`
* - Summaries:
* `namespace; type; subtypes; name; signature; ext; input; output; kind`
*
* The interpretation of a row is similar to API-graphs with a left-to-right
* reading.
* 1. The `namespace` column selects a namespace.
* 2. The `type` column selects a type within that namespace. This column can
* introduce template type names that can be mentioned in the `signature` column.
* For example, `vector<T,Allocator>` introduces the template names `T` and
* `Allocator`. Non-type template parameters cannot be specified.
* 3. The `subtypes` is a boolean that indicates whether to jump to an
* arbitrary subtype of that type. Set this to `false` if leaving the `type`
* blank (for example, a free function).
* 4. The `name` column optionally selects a specific named member of the type.
* Like the `type` column, this column can introduce template type names
* that can be mentioned in the `signature` column. For example,
* `insert<InputIt>` introduces the template name `InputIt`. Non-type
* template parameters cannot be specified.
* 5. The `signature` column optionally restricts the named member. If
* `signature` is blank then no such filtering is done. The format of the
* signature is a comma-separated list of types enclosed in parentheses. The
* types must be stripped of template names. That is, write `const vector &`
* instead of `const vector<T> &`.
* 6. The `ext` column specifies additional API-graph-like edges. Currently
* there is only one valid value: "".
* 7. The `input` column specifies how data enters the element selected by the
* first 6 columns, and the `output` column specifies how data leaves the
* element selected by the first 6 columns. An `input` can be either:
* - "": Selects a write to the selected element in case this is a field.
* - "Argument[n]": Selects an argument in a call to the selected element.
* The arguments are zero-indexed, and `-1` specifies the qualifier object,
* that is, `*this`.
* - one or more "*" can be added in front of the argument index to indicate
* indirection, for example, `Argument[*0]` indicates the first indirection
* of the 0th argument.
* - `n1..n2` syntax can be used to indicate a range of arguments, inclusive
* at both ends. One or more "*"s can be added in front of the whole range
* to indicate that every argument in the range is indirect, for example
* `*0..1` is the first indirection of both arguments 0 and 1.
* - "ReturnValue": Selects a value being returned by the selected element.
* One or more "*" can be added as an argument to indicate indirection, for
* example, "ReturnValue[*]" indicates the first indirection of the return
* value.
* The special symbol `@` can be used to specify an arbitrary (but fixed)
* number of indirections. For example, the `input` column `Argument[*@0]`
* indicates one or more indirections of the 0th argument.
*
* An `output` can be either:
* - "": Selects a read of a selected field.
* - "Argument[n]": Selects the post-update value of an argument in a call to
* the selected element. That is, the value of the argument after the call
* returns. The arguments are zero-indexed, and `-1` specifies the qualifier
* object, that is, `*this`.
* - one or more "*" can be added in front of the argument index to indicate
* indirection, for example, `Argument[*0]` indicates the first indirection
* of the 0th argument.
* - `n1..n2` syntax can be used to indicate a range of arguments, inclusive
* at both ends. One or more "*"s can be added in front of the whole range
* to indicate that every argument in the range is indirect, for example
* `*0..1` is the first indirection of both arguments 0 and 1.
* - "Parameter[n]": Selects the value of a parameter of the selected element.
* The syntax is the same as for "Argument", for example "Parameter[0]",
* "Parameter[*0]", "Parameter[0..2]" etc.
* - "ReturnValue": Selects a value being returned by the selected element.
* One or more "*" can be added as an argument to indicate indirection, for
* example, "ReturnValue[*]" indicates the first indirection of the return
* value.
* The special symbol `@` can be used to specify an arbitrary (but fixed)
* number of indirections. For example, the `output` column
* `ReturnValue[*@0]` indicates one or more indirections of the return
* value.
* Note: The symbol `@` only ever takes a single value across a row. Thus,
* the (`input`, `output`) pair `("Argument[*@0]", "ReturnValue[@]")`
* represents:
* - flow from the _first_ indirection of the 0th argument to the return
* value, and
* - flow from the _second_ indirection of the 0th argument to the first
* indirection of the return value, etc.
* 8. The `kind` column is a tag that can be referenced from QL to determine to
* which classes the interpreted elements should be added. For example, for
* sources "remote" indicates a default remote flow source, and for summaries
* "taint" indicates a default additional taint step and "value" indicates a
* globally applicable value-preserving step.
*/
import cpp
private import new.DataFlow
private import semmle.code.cpp.ir.dataflow.internal.DataFlowPrivate as Private
private import semmle.code.cpp.ir.dataflow.internal.DataFlowUtil
private import internal.FlowSummaryImpl
private import internal.FlowSummaryImpl::Public
private import internal.FlowSummaryImpl::Private
private import internal.FlowSummaryImpl::Private::External
private import internal.ExternalFlowExtensions::Extensions as Extensions
private import codeql.mad.ModelValidation as SharedModelVal
private import codeql.util.Unit
private import codeql.mad.static.ModelsAsData as SharedMaD
/**
* A unit class for adding additional source model rows.
*
* Extend this class to add additional source definitions.
*/
class SourceModelCsv extends Unit {
/** Holds if `row` specifies a source definition. */
abstract predicate row(string row);
}
/**
* A unit class for adding additional sink model rows.
*
* Extend this class to add additional sink definitions.
*/
class SinkModelCsv extends Unit {
/** Holds if `row` specifies a sink definition. */
abstract predicate row(string row);
}
/**
* A unit class for adding additional summary model rows.
*
* Extend this class to add additional flow summary definitions.
*/
class SummaryModelCsv extends Unit {
/** Holds if `row` specifies a summary definition. */
abstract predicate row(string row);
}
/** Holds if `row` is a source model. */
predicate sourceModel(string row) { any(SourceModelCsv s).row(row) }
/** Holds if `row` is a sink model. */
predicate sinkModel(string row) { any(SinkModelCsv s).row(row) }
/** Holds if `row` is a summary model. */
predicate summaryModel(string row) { any(SummaryModelCsv s).row(row) }
private module MadInput implements SharedMaD::InputSig {
/** Holds if a source model exists for the given parameters. */
predicate additionalSourceModel(
string namespace, string type, boolean subtypes, string name, string signature, string ext,
string output, string kind, string provenance, string model
) {
exists(string row |
sourceModel(row) and
row.splitAt(";", 0) = namespace and
row.splitAt(";", 1) = type and
row.splitAt(";", 2) = subtypes.toString() and
subtypes = [true, false] and
row.splitAt(";", 3) = name and
row.splitAt(";", 4) = signature and
row.splitAt(";", 5) = ext and
row.splitAt(";", 6) = output and
row.splitAt(";", 7) = kind
) and
provenance = "manual" and
model = ""
}
/** Holds if a sink model exists for the given parameters. */
predicate additionalSinkModel(
string namespace, string type, boolean subtypes, string name, string signature, string ext,
string input, string kind, string provenance, string model
) {
exists(string row |
sinkModel(row) and
row.splitAt(";", 0) = namespace and
row.splitAt(";", 1) = type and
row.splitAt(";", 2) = subtypes.toString() and
subtypes = [true, false] and
row.splitAt(";", 3) = name and
row.splitAt(";", 4) = signature and
row.splitAt(";", 5) = ext and
row.splitAt(";", 6) = input and
row.splitAt(";", 7) = kind
) and
provenance = "manual" and
model = ""
}
/**
* Holds if a summary model exists for the given parameters.
*
* This predicate does not expand `@` to `*`s.
*/
predicate additionalSummaryModel(
string namespace, string type, boolean subtypes, string name, string signature, string ext,
string input, string output, string kind, string provenance, string model
) {
exists(string row |
summaryModel(row) and
row.splitAt(";", 0) = namespace and
row.splitAt(";", 1) = type and
row.splitAt(";", 2) = subtypes.toString() and
subtypes = [true, false] and
row.splitAt(";", 3) = name and
row.splitAt(";", 4) = signature and
row.splitAt(";", 5) = ext and
row.splitAt(";", 6) = input and
row.splitAt(";", 7) = output and
row.splitAt(";", 8) = kind
) and
provenance = "manual" and
model = ""
}
string namespaceSegmentSeparator() { result = "::" }
}
private module MaD = SharedMaD::ModelsAsData<Extensions, MadInput>;
import MaD
/**
* Holds if `input` is `input0`, but with all occurrences of `@` replaced
* by `n` repetitions of `*` (and similarly for `output` and `output0`).
*/
bindingset[input0, output0, n]
pragma[inline_late]
private predicate expandInputAndOutput(
string input0, string input, string output0, string output, int n
) {
input = input0.replaceAll("@", repeatStars(n)) and
output = output0.replaceAll("@", repeatStars(n))
}
/**
* Holds if a summary model exists for the given parameters.
*/
predicate summaryModel(
string namespace, string type, boolean subtypes, string name, string signature, string ext,
string input, string output, string kind, string provenance, string model
) {
exists(string input0, string output0 |
MaD::summaryModel(namespace, type, subtypes, name, signature, ext, input0, output0, kind,
provenance, model) and
expandInputAndOutput(input0, input, output0, output,
[0 .. Private::getMaxElementContentIndirectionIndex() - 1])
)
}
/** Provides a query predicate to check the CSV data for validation errors. */
module CsvValidation {
private string getInvalidModelInput() {
exists(string pred, AccessPath input, string part |
sinkModel(_, _, _, _, _, _, input, _, _, _) and pred = "sink"
or
summaryModel(_, _, _, _, _, _, input, _, _, _, _) and pred = "summary"
|
(
invalidSpecComponent(input, part) and
not part = "" and
not (part = "Argument" and pred = "sink") and
not parseArg(part, _)
or
part = input.getToken(_) and
parseParam(part, _)
) and
result = "Unrecognized input specification \"" + part + "\" in " + pred + " model."
)
}
private string getInvalidModelOutput() {
exists(string pred, string output, string part |
sourceModel(_, _, _, _, _, _, output, _, _, _) and pred = "source"
or
summaryModel(_, _, _, _, _, _, _, output, _, _, _) and pred = "summary"
|
invalidSpecComponent(output, part) and
not part = "" and
not (part = ["Argument", "Parameter"] and pred = "source") and
result = "Unrecognized output specification \"" + part + "\" in " + pred + " model."
)
}
private module KindValConfig implements SharedModelVal::KindValidationConfigSig {
predicate summaryKind(string kind) { summaryModel(_, _, _, _, _, _, _, _, kind, _, _) }
predicate sinkKind(string kind) { sinkModel(_, _, _, _, _, _, _, kind, _, _) }
predicate sourceKind(string kind) { sourceModel(_, _, _, _, _, _, _, kind, _, _) }
}
private module KindVal = SharedModelVal::KindValidation<KindValConfig>;
private string getInvalidModelSubtype() {
exists(string pred, string row |
sourceModel(row) and pred = "source"
or
sinkModel(row) and pred = "sink"
or
summaryModel(row) and pred = "summary"
|
exists(string b |
b = row.splitAt(";", 2) and
not b = ["true", "false"] and
result = "Invalid boolean \"" + b + "\" in " + pred + " model."
)
)
}
private string getInvalidModelColumnCount() {
exists(string pred, string row, int expect |
sourceModel(row) and expect = 8 and pred = "source"
or
sinkModel(row) and expect = 8 and pred = "sink"
or
summaryModel(row) and expect = 9 and pred = "summary"
|
exists(int cols |
cols = 1 + max(int n | exists(row.splitAt(";", n))) and
cols != expect and
result =
"Wrong number of columns in " + pred + " model row, expected " + expect + ", got " + cols +
"."
)
)
}
private string getInvalidModelSignature() {
exists(string pred, string namespace, string type, string name, string signature, string ext |
sourceModel(namespace, type, _, name, signature, ext, _, _, _, _) and pred = "source"
or
sinkModel(namespace, type, _, name, signature, ext, _, _, _, _) and pred = "sink"
or
summaryModel(namespace, type, _, name, signature, ext, _, _, _, _, _) and pred = "summary"
|
not namespace.regexpMatch("[a-zA-Z0-9_\\.:]*") and
result = "Dubious namespace \"" + namespace + "\" in " + pred + " model."
or
not type.regexpMatch("[a-zA-Z0-9_<>,\\+]*") and
result = "Dubious type \"" + type + "\" in " + pred + " model."
or
not name.regexpMatch("[a-zA-Z0-9_<>,]*") and
result = "Dubious member name \"" + name + "\" in " + pred + " model."
or
not signature.regexpMatch("|\\([a-zA-Z0-9_<>\\.\\+\\*,\\[\\]]*\\)") and
result = "Dubious signature \"" + signature + "\" in " + pred + " model."
or
not ext.regexpMatch("|Attribute") and
result = "Unrecognized extra API graph element \"" + ext + "\" in " + pred + " model."
)
}
/** Holds if some row in a CSV-based flow model appears to contain typos. */
query predicate invalidModelRow(string msg) {
msg =
[
getInvalidModelSignature(), getInvalidModelInput(), getInvalidModelOutput(),
getInvalidModelSubtype(), getInvalidModelColumnCount(), KindVal::getInvalidModelKind()
]
}
}
private predicate elementSpec(
string namespace, string type, boolean subtypes, string name, string signature, string ext
) {
sourceModel(namespace, type, subtypes, name, signature, ext, _, _, _, _) or
sinkModel(namespace, type, subtypes, name, signature, ext, _, _, _, _) or
summaryModel(namespace, type, subtypes, name, signature, ext, _, _, _, _, _)
}
/**
* Holds if `c` is an instantiation of a class template `templateClass`, or
* holds with `c = templateClass` if `c` is not an instantiation of any class
* template.
*
* This predicate is used instead of `Class.isConstructedFrom` (which only
* holds for template instantiations) in this file to allow for uniform
* treatment of non-templated classes and class template instantiations.
*/
private predicate isClassConstructedFrom(Class c, Class templateClass) {
c.isConstructedFrom(templateClass)
or
not c.isConstructedFrom(_) and c = templateClass
}
/**
* Holds if `f` is an instantiation of a function template `templateFunc`, or
* holds with `f = templateFunc` if `f` is not an instantiation of any function
* template.
*
* This predicate is used instead of `Function.isConstructedFrom` (which only
* holds for template instantiations) in this file to allow for uniform
* treatment of non-templated classes and class template instantiations.
*/
private predicate isFunctionConstructedFrom(Function f, Function templateFunc) {
f.isConstructedFrom(templateFunc)
or
not f.isConstructedFrom(_) and f = templateFunc
}
/** Gets the fully templated version of `f`. */
Function getFullyTemplatedFunction(Function f) {
not f.isFromUninstantiatedTemplate(_) and
(
exists(Class c, Class templateClass, int i |
isClassConstructedFrom(c, templateClass) and
f = c.getAMember(i) and
result = templateClass.getCanonicalMember(i)
)
or
not exists(f.getDeclaringType()) and
isFunctionConstructedFrom(f, result)
)
}
/** Prefixes `const` to `s` if `t` is const, or returns `s` otherwise. */
bindingset[s, t]
private string withConst(string s, Type t) {
if t.isConst() then result = "const " + s else result = s
}
/** Prefixes `volatile` to `s` if `t` is const, or returns `s` otherwise. */
bindingset[s, t]
private string withVolatile(string s, Type t) {
if t.isVolatile() then result = "volatile " + s else result = s
}
/**
* Returns `s` prefixed with appropriate specifiers from `t`, or `s` if `t` has
* no relevant specifiers.
*/
bindingset[s, t]
private string withSpecifiers(string s, Type t) {
// An `int` that is both const and volatile will be printed as
// `const volatile int` to match the behavior of `Type.getName` which
// is generated by the extractor.
result = withConst(withVolatile(s, t), t)
}
/**
* Gets the string version of `t`, after resolving typedefs. The boolean `needsSpace` is `true`
* if a space should be appended before concatenating any additional symbols
* (such as `*` or `&`) when recursively constructing the type name.
*/
private string getTypeName(Type t, boolean needsSpace) {
// We don't care about template instantiations since we always base models
// on the uninstantiated templates
not t.isFromTemplateInstantiation(_) and
(
exists(DerivedType dt, string s, boolean needsSpace0 |
dt = t and s = withSpecifiers(getTypeName(dt.getBaseType(), needsSpace0), dt)
|
dt instanceof ReferenceType and
not dt instanceof RValueReferenceType and
needsSpace = false and
(if needsSpace0 = true then result = s + " &" else result = s + "&")
or
dt instanceof RValueReferenceType and
needsSpace = false and
(if needsSpace0 = true then result = s + " &&" else result = s + "&&")
or
dt instanceof PointerType and
needsSpace = false and
(if needsSpace0 = true then result = s + " *" else result = s + "*")
or
// We don't need to check for `needsSpace0` here because the type of
// `x` in `int x[1024]` is formatted without a space between the bracket
// and the `int` by `Type.getName`. That is, calling `Type.getName` on
// the type of `x` gives `int[1024]` and not `int [1024]`.
needsSpace = false and
exists(ArrayType array | array = dt |
result = s + "[" + array.getArraySize() + "]"
or
not array.hasArraySize() and
result = s + "[]"
)
or
not dt instanceof ReferenceType and
not dt instanceof PointerType and
not dt instanceof ArrayType and
result = s and
needsSpace = needsSpace0
)
or
not t instanceof DerivedType and
not t instanceof TypedefType and
result = t.getName() and
(if result.matches(["%*", "%&", "%]"]) then needsSpace = false else needsSpace = true)
)
or
result = getTypeName(t.(TypedefType).getBaseType(), needsSpace)
}
/**
* Gets a type name for the `n`'th parameter of `f` without any template
* arguments.
*
* If `canonical = false` then the result may be a string representing a type
* for which the typedefs have been resolved. If `canonical = true` then the
* result will be a string representing a type without resolving `typedefs`.
*/
bindingset[f]
pragma[inline_late]
string getParameterTypeWithoutTemplateArguments(Function f, int n, boolean canonical) {
exists(string s, string base, string specifiers, Type t |
t = f.getParameter(n).getType() and
// The name of the string can either be the possibly typedefed name
// or an alternative name where typedefs has been resolved.
// `getTypeName(t, _)` is almost equal to `t.resolveTypedefs().getName()`,
// except that `t.resolveTypedefs()` doesn't have a result when the
// resulting type doesn't appear in the database.
(
s = t.getName() and canonical = true
or
s = getTypeName(t, _) and canonical = false
) and
parseAngles(s, base, _, specifiers) and
result = base + specifiers
)
or
f.isVarargs() and
n = f.getNumberOfParameters() and
result = "..." and
canonical = true
}
/**
* Gets the largest index of a template parameter of `templateFunction` that
* is a type template parameter.
*/
private int getLastTypeTemplateFunctionParameterIndex(Function templateFunction) {
result =
max(int index | templateFunction.getTemplateArgument(index) instanceof TypeTemplateParameter)
}
/** Gets the number of supported template parameters for `templateFunction`. */
private int getNumberOfSupportedFunctionTemplateArguments(Function templateFunction) {
result = count(int i | exists(getSupportedFunctionTemplateArgument(templateFunction, i)) | i)
}
/** Gets the `i`'th supported template parameter for `templateFunction`. */
private Locatable getSupportedFunctionTemplateArgument(Function templateFunction, int i) {
result = templateFunction.getTemplateArgument(i) and
// We don't yet support non-type template parameters in the middle of a
// template parameter list
i <= getLastTypeTemplateFunctionParameterIndex(templateFunction)
}
/**
* Normalize the `n`'th parameter of `f` by replacing template names
* with `func:N` (where `N` is the index of the template).
*/
private string getTypeNameWithoutFunctionTemplates(Function f, int n, int remaining) {
exists(Function templateFunction |
templateFunction = getFullyTemplatedFunction(f) and
remaining = getNumberOfSupportedFunctionTemplateArguments(templateFunction) and
result = getParameterTypeWithoutTemplateArguments(templateFunction, n, _)
)
or
exists(string mid, TypeTemplateParameter tp, Function templateFunction |
mid = getTypeNameWithoutFunctionTemplates(f, n, remaining + 1) and
templateFunction = getFullyTemplatedFunction(f) and
tp = getSupportedFunctionTemplateArgument(templateFunction, remaining)
|
result = mid.replaceAll(tp.getName(), "func:" + remaining.toString())
)
}
/**
* Gets the largest index of a template parameter of `templateClass` that
* is a type template parameter.
*/
private int getLastTypeTemplateClassParameterIndex(Class templateClass) {
result =
max(int index | templateClass.getTemplateArgument(index) instanceof TypeTemplateParameter)
}
/** Gets the `i`'th supported template parameter for `templateClass`. */
private Locatable getSupportedClassTemplateArgument(Class templateClass, int i) {
result = templateClass.getTemplateArgument(i) and
// We don't yet support non-type template parameters in the middle of a
// template parameter list
i <= getLastTypeTemplateClassParameterIndex(templateClass)
}
/** Gets the number of supported template parameters for `templateClass`. */
private int getNumberOfSupportedClassTemplateArguments(Class templateClass) {
result = count(int i | exists(getSupportedClassTemplateArgument(templateClass, i)) | i)
}
/**
* Normalize the `n`'th parameter of `f` by replacing template names
* with `class:N` (where `N` is the index of the template).
*/
pragma[nomagic]
private string getTypeNameWithoutClassTemplates(Function f, int n, int remaining) {
// If there is a declaring type then we start by expanding the function templates
exists(Class template |
isClassConstructedFrom(f.getDeclaringType(), template) and
remaining = getNumberOfSupportedClassTemplateArguments(template) and
result = getTypeNameWithoutFunctionTemplates(f, n, 0)
)
or
// If there is no declaring type we're done after expanding the function templates
not exists(f.getDeclaringType()) and
remaining = 0 and
result = getTypeNameWithoutFunctionTemplates(f, n, 0)
or
exists(string mid, TypeTemplateParameter tp, Class template |
mid = getTypeNameWithoutClassTemplates(f, n, remaining + 1) and
isClassConstructedFrom(f.getDeclaringType(), template) and
tp = getSupportedClassTemplateArgument(template, remaining)
|
result = mid.replaceAll(tp.getName(), "class:" + remaining.toString())
)
}
/** Gets the string representation of the `i`'th parameter of `c`. */
string getParameterTypeName(Function c, int i) {
result = getTypeNameWithoutClassTemplates(c, i, 0)
}
/** Splits `s` by `,` and gets the `i`'th element. */
bindingset[s]
pragma[inline_late]
private string getAtIndex(string s, int i) {
result = s.splitAt(",", i) and
// when `s` is `""` and `i` is `0` we get `result = ""` which we don't want.
not (s = "" and i = 0)
}
/**
* Normalizes `partiallyNormalizedSignature` by replacing the `remaining`
* number of template arguments in `partiallyNormalizedSignature` with their
* index in `typeArgs`.
*/
private string getSignatureWithoutClassTemplateNames(
string partiallyNormalizedSignature, string typeArgs, string nameArgs, int remaining
) {
elementSpecWithArguments0(_, _, _, partiallyNormalizedSignature, typeArgs, nameArgs) and
remaining = count(partiallyNormalizedSignature.indexOf(",")) + 1 and
result = partiallyNormalizedSignature
or
exists(string mid |
mid =
getSignatureWithoutClassTemplateNames(partiallyNormalizedSignature, typeArgs, nameArgs,
remaining + 1)
|
exists(string typeArg |
typeArg = getAtIndex(typeArgs, remaining) and
result = mid.replaceAll(typeArg, "class:" + remaining.toString())
)
or
// Make sure `remaining` is properly bound
remaining = [0 .. count(partiallyNormalizedSignature.indexOf(",")) + 1] and
not exists(getAtIndex(typeArgs, remaining)) and
result = mid
)
}
/**
* Normalizes `partiallyNormalizedSignature` by replacing:
* - _All_ the template arguments in `partiallyNormalizedSignature` that refer to
* template parameters in `typeArgs` with their index in `typeArgs`, and
* - The `remaining` number of template arguments in `partiallyNormalizedSignature`
* with their index in `nameArgs`.
*/
pragma[nomagic]
private string getSignatureWithoutFunctionTemplateNames(
string partiallyNormalizedSignature, string typeArgs, string nameArgs, int remaining
) {
remaining = count(partiallyNormalizedSignature.indexOf(",")) + 1 and
result =
getSignatureWithoutClassTemplateNames(partiallyNormalizedSignature, typeArgs, nameArgs, 0)
or
exists(string mid |
mid =
getSignatureWithoutFunctionTemplateNames(partiallyNormalizedSignature, typeArgs, nameArgs,
remaining + 1)
|
exists(string nameArg |
nameArg = getAtIndex(nameArgs, remaining) and
result = mid.replaceAll(nameArg, "func:" + remaining.toString())
)
or
// Make sure `remaining` is properly bound
remaining = [0 .. count(partiallyNormalizedSignature.indexOf(",")) + 1] and
not exists(getAtIndex(nameArgs, remaining)) and
result = mid
)
}
/**
* Holds if `elementSpec(_, type, _, name, signature, _)` holds and
* - `typeArgs` represents the named template parameters supplied to `type`, and
* - `nameArgs` represents the named template parameters supplied to `name`, and
* - `normalizedSignature` is `signature`, except with
* - template parameter names replaced by `func:i` if the template name is
* the `i`'th entry in `nameArgs`, and
* - template parameter names replaced by `class:i` if the template name is
* the `i`'th entry in `typeArgs`.
*
* In other words, the string `normalizedSignature` represents a "normalized"
* signature with no mention of any free template parameters.
*
* For example, consider a summary row such as:
* ```
* elementSpec(_, "MyClass<B, C>", _, myFunc<A>, "(const A &,int,C,B *)", _)
* ```
* In this case, `normalizedSignature` will be `"(const func:0 &,int,class:1,class:0 *)"`.
*/
pragma[nomagic]
private predicate elementSpecWithArguments(
string signature, string type, string name, string normalizedSignature, string typeArgs,
string nameArgs
) {
exists(string signatureWithoutParens |
elementSpecWithArguments0(signature, type, name, signatureWithoutParens, typeArgs, nameArgs) and
normalizedSignature =
getSignatureWithoutFunctionTemplateNames(signatureWithoutParens, typeArgs, nameArgs, 0)
)
}
/** Gets the `n`'th normalized signature parameter for the function `name` in class `type`. */
private string getSignatureParameterName(string signature, string type, string name, int n) {
exists(string normalizedSignature |
elementSpecWithArguments(signature, type, name, normalizedSignature, _, _) and
result = getAtIndex(normalizedSignature, n)
)
}
/**
* Gets a `Function` identified by the `(namespace, type, name)` components.
*
* If `subtypes` is `true` then the result may be an override of the function
* identified by the components.
*/
pragma[nomagic]
private Function getFunction(string namespace, string type, boolean subtypes, string name) {
elementSpec(namespace, type, subtypes, name, _, _) and
(
funcHasQualifiedName(result, namespace, name) and
subtypes = false and
type = ""
or
exists(Class namedClass, Class classWithMethod |
hasClassAndName(classWithMethod, result, name) and
classHasQualifiedName(namedClass, namespace, type)
|
// member declared in the named type or a subtype of it
subtypes = true and
classWithMethod = namedClass.getADerivedClass*()
or
// member declared directly in the named type
subtypes = false and
classWithMethod = namedClass
)
)
}
/**
* Holds if the suffix containing the entries in `signature` starting at entry
* `i` matches the suffix containing the parameters of `func` starting at entry `i`.
*
* For example, consider the signature `(int,bool,char)` and a function:
* ```
* void f(int a, bool b, char c);
* ```
* 1. The predicate holds for `i = 2` because the suffix containing all the entries
* in `signature` starting at `2` is `char`, and suffix containing all the parameters
* of `func` starting at `2` is `char`.
* 2. The predicate holds for `i = 1` because the suffix containing all the entries
* in `signature` starting at `1` is `bool,char`, and the suffix containing all the
* parameters of `func` starting at `1` is `bool, char`.
* 3. The predicate holds for `i = 0` because the suffix containing all the entries
* in `signature` starting at `0` is `int,bool,char` and the suffix containing all
* the parameters of `func` starting at `0` is `int, bool, char`.
*
* When `paramsString(func)[i]` is `class:n` then the signature name is
* compared with the `n`'th name in `type`, and when `paramsString(func)[i]`
* is `func:n` then the signature name is compared with the `n`'th name
* in `name`.
*/
pragma[nomagic]
private predicate signatureMatches(
Function func, string namespace, string signature, string type, string name, int i
) {
func = getFunction(namespace, type, _, name) and
exists(string s |
s = getSignatureParameterName(signature, type, name, i) and
s = getParameterTypeName(func, i)
) and
if exists(getParameterTypeName(func, i + 1))
then signatureMatches(func, namespace, signature, type, name, i + 1)
else i = count(signature.indexOf(","))
}
/**
* Internal: Do not use.
*
* This module only exists to expose internal predicates for testing purposes.
*/
module ExternalFlowDebug {
/**
* INTERNAL: Do not use.
*
* Exposed for testing purposes.
*/
predicate signatureMatches_debug = signatureMatches/6;
/**
* INTERNAL: Do not use.
*
* Exposed for testing purposes.
*/
predicate getSignatureParameterName_debug = getSignatureParameterName/4;
/**
* INTERNAL: Do not use.
*
* Exposed for testing purposes.
*/
predicate getParameterTypeName_debug = getParameterTypeName/2;
}
/**
* Holds if `s` can be broken into a string of the form
* `beforeAngles<betweenAngles>`,
* or `s = beforeAngles` where `beforeAngles` does not have any brackets.
*/
bindingset[s]
pragma[inline_late]
private predicate parseAngles(
string s, string beforeAngles, string betweenAngles, string afterAngles
) {
beforeAngles = s.regexpCapture("([^<]+)(?:<([^>]+)>(.*))?", 1) and
(
betweenAngles = s.regexpCapture("([^<]+)(?:<([^>]+)>(.*))?", 2) and
afterAngles = s.regexpCapture("([^<]+)(?:<([^>]+)>(.*))?", 3)
or
not exists(s.regexpCapture("([^<]+)(?:<([^>]+)>(.*))?", 2)) and
betweenAngles = "" and
afterAngles = ""
)
}
/** Holds if `s` can be broken into a string of the form `(betweenParens)`. */
bindingset[s]
pragma[inline_late]
private predicate parseParens(string s, string betweenParens) { s = "(" + betweenParens + ")" }
/**
* Holds if `elementSpec(_, type, _, name, signature, _)` and:
* - `type` introduces template parameters `typeArgs`, and
* - `name` introduces template parameters `nameArgs`, and
* - `signatureWithoutParens` equals `signature`, but with the surrounding
* parentheses removed.
*/
pragma[nomagic]
private predicate elementSpecWithArguments0(
string signature, string type, string name, string signatureWithoutParens, string typeArgs,
string nameArgs
) {
elementSpec(_, type, _, name, signature, _) and
parseAngles(name, _, nameArgs, "") and
(
type = "" and typeArgs = ""
or
parseAngles(type, _, typeArgs, "")
) and
parseParens(signature, signatureWithoutParens)
}
/**
* Holds if `elementSpec(namespace, type, subtypes, name, signature, _)` and
* `func`'s signature matches `signature`.
*
* `signature` may contain template parameter names that are bound by `type` and `name`.
*/
pragma[nomagic]
private predicate elementSpecMatchesSignature(
Function func, string namespace, string type, boolean subtypes, string name, string signature
) {
elementSpec(namespace, pragma[only_bind_into](type), subtypes, pragma[only_bind_into](name),
pragma[only_bind_into](signature), _) and
signatureMatches(func, namespace, signature, type, name, 0)
}
/**
* Holds when `method` has name `nameWithoutArgs`, and gets the enclosing
* class of `method`. Unlike `method.getClassAndName` this predicate does
* not strip typedefs from the name when `method` is an `ConversionOperator`.
*/
bindingset[nameWithoutArgs]
pragma[inline_late]
private Class getClassAndNameImpl(Function method, string nameWithoutArgs) {
result = method.getDeclaringType() and
nameWithoutArgs = "operator " + method.(ConversionOperator).getDestType()
or
result = method.getClassAndName(nameWithoutArgs) and
not method instanceof ConversionOperator
}
/**
* Holds if `classWithMethod` has `method` named `name` (excluding any
* template parameters).
*/
bindingset[name]
pragma[inline_late]
private predicate hasClassAndName(Class classWithMethod, Function method, string name) {
exists(string nameWithoutArgs |
parseAngles(name, nameWithoutArgs, _, "") and
classWithMethod = getClassAndNameImpl(method, nameWithoutArgs)
)
}
bindingset[name]
pragma[inline_late]
private predicate funcHasQualifiedName(Function func, string namespace, string name) {
exists(string nameWithoutArgs |
parseAngles(name, nameWithoutArgs, _, "") and
func.hasQualifiedName(namespace, nameWithoutArgs)
)
}
/**
* Holds if `namedClass` is in namespace `namespace` and has
* name `type` (excluding any template parameters).
*/
bindingset[type]
pragma[inline_late]
private predicate classHasQualifiedName(Class namedClass, string namespace, string type) {
exists(string typeWithoutArgs |
parseAngles(type, typeWithoutArgs, _, "") and
namedClass.hasQualifiedName(namespace, typeWithoutArgs)
)
}
/**
* Gets the element in module `namespace` that satisfies the following properties:
* 1. If the element is a member of a class-like type, then the class-like type has name `type`
* 2. If `subtypes = true` and the element is a member of a class-like type, then overrides of the element
* are also returned.
* 3. The element has name `name`
* 4. If `signature` is non-empty, then the element has a list of parameter types described by `signature`.
*/
pragma[nomagic]
private Element interpretElement0(
string namespace, string type, boolean subtypes, string name, string signature
) {
result = getFunction(namespace, type, subtypes, name) and
(
// Non-member functions
type = "" and
(
elementSpecMatchesSignature(result, namespace, type, subtypes, name, signature)
or
signature = "" and
elementSpec(namespace, type, subtypes, name, signature, _)
)
or
// Member functions
elementSpecMatchesSignature(result, namespace, type, subtypes, name, signature)
or
signature = "" and
elementSpec(namespace, type, subtypes, name, signature, _)
)
or
// Member variables
elementSpec(namespace, type, subtypes, name, signature, _) and
signature = "" and
exists(Class namedClass, Class classWithMember, MemberVariable member |
member.getName() = name and
member = classWithMember.getAMember() and
namedClass.hasQualifiedName(namespace, type) and
result = member
|
// field declared in the named type or a subtype of it (or an extension of any)
subtypes = true and
classWithMember = namedClass.getADerivedClass*()
or
// field declared directly in the named type (or an extension of it)
subtypes = false and
classWithMember = namedClass
)
or
// Global or namespace variables
elementSpec(namespace, type, subtypes, name, signature, _) and
signature = "" and
type = "" and
subtypes = false and
result = any(GlobalOrNamespaceVariable v | v.hasQualifiedName(namespace, name))
}
cached
private module Cached {
/** Gets the source/sink/summary element corresponding to the supplied parameters. */
cached
Element interpretElement(
string namespace, string type, boolean subtypes, string name, string signature, string ext
) {
elementSpec(namespace, type, subtypes, name, signature, ext) and
exists(Element e | e = interpretElement0(namespace, type, subtypes, name, signature) |
ext = "" and result = e
)
}
/**
* Holds if `node` is specified as a source with the given kind in a CSV flow
* model.
*/
cached
predicate sourceNode(DataFlow::Node node, string kind, string model) {
exists(SourceSinkInterpretationInput::InterpretNode n |
isSourceNode(n, kind, model) and n.asNode() = node
)
}
/**
* Holds if `node` is specified as a sink with the given kind in a CSV flow
* model.
*/
cached
predicate sinkNode(DataFlow::Node node, string kind, string model) {
exists(SourceSinkInterpretationInput::InterpretNode n |
isSinkNode(n, kind, model) and n.asNode() = node
)
}
}
import Cached
/**
* Holds if `node` is specified as a source with the given kind in a MaD flow
* model.
*/
predicate sourceNode(DataFlow::Node node, string kind) { sourceNode(node, kind, _) }
/**
* Holds if `node` is specified as a sink with the given kind in a MaD flow
* model.
*/
predicate sinkNode(DataFlow::Node node, string kind) { sinkNode(node, kind, _) }
private predicate interpretSummary(
Function f, string input, string output, string kind, string provenance, string model
) {
exists(
string namespace, string type, boolean subtypes, string name, string signature, string ext
|
summaryModel(namespace, type, subtypes, name, signature, ext, input, output, kind, provenance,
model) and
f = interpretElement(namespace, type, subtypes, name, signature, ext)
)
}
// adapter class for converting Mad summaries to `SummarizedCallable`s
private class SummarizedCallableAdapter extends SummarizedCallable {
SummarizedCallableAdapter() { interpretSummary(this, _, _, _, _, _) }
private predicate relevantSummaryElementManual(
string input, string output, string kind, string model
) {
exists(Provenance provenance |
interpretSummary(this, input, output, kind, provenance, model) and
provenance.isManual()
)
}
private predicate relevantSummaryElementGenerated(
string input, string output, string kind, string model
) {
exists(Provenance provenance |
interpretSummary(this, input, output, kind, provenance, model) and
provenance.isGenerated()
)
}
override predicate propagatesFlow(
string input, string output, boolean preservesValue, string model
) {
exists(string kind |
this.relevantSummaryElementManual(input, output, kind, model)
or
not this.relevantSummaryElementManual(_, _, _, _) and
this.relevantSummaryElementGenerated(input, output, kind, model)
|
if kind = "value" then preservesValue = true else preservesValue = false
)
}
override predicate hasProvenance(Provenance provenance) {
interpretSummary(this, _, _, _, provenance, _)
}
}