hohn/codeql
1
0
Fork 0
mirror of https://github.com/github/codeql.git synced 2025-12-16 16:53:25 +01:00
Code Issues Packages Projects Releases Wiki Activity

C/C++ overlay: Address review comments

Browse Source 
Split the discard predicate into two: one for single-location elements and one for multi-location elements.
This commit is contained in:
idrissrio
2025-11-28 11:28:26 +01:00
parent 3d69286382
commit eac06ddd8f
1 changed files with 33 additions and 42 deletions
Download Patch File Download Diff File Expand all files Collapse all files

75
cpp/ql/lib/semmle/code/cpp/internal/Overlay.qll
View File

@@ -16,58 +16,49 @@ private string getLocationFilePath(@location_default loc) {
}
/**
* An element with a single location. Discard if in a changed file.
* Gets the file path for an element with a single location.
*/
overlay[local]
abstract private class Discardable extends @element {
abstract string getFilePath();
predicate existsInBase() { not isOverlay() }
string toString() { none() }
}
overlay[discard_entity]
private predicate discardable(@element e) {
e = any(Discardable d | d.existsInBase() and overlayChangedFiles(d.getFilePath()))
private string getSingleLocationFilePath(@element e) {
// @var_decl has a direct location in the var_decls relation
exists(@location_default loc | var_decls(e, _, _, _, loc) | result = getLocationFilePath(loc))
//TODO: add other kinds of elements with single locations
}
/**
* An element with potentially multiple locations, e.g., variables, functions and types.
* Discard only if all locations are in changed files.
* Gets the file path for an element with potentially multiple locations.
*/
overlay[local]
abstract private class MultiDiscardable extends @element {
abstract string getFilePath();
predicate existsInBase() { not isOverlay() }
string toString() { none() }
private string getMultiLocationFilePath(@element e) {
// @variable gets its location(s) from its @var_decl(s)
exists(@var_decl vd, @location_default loc | var_decls(vd, e, _, _, loc) |
result = getLocationFilePath(loc)
)
//TODO: add other kinds of elements with multiple locations
}
/** Holds if `e` exists in the base variant. */
overlay[local]
private predicate existsInBase(@element e) {
not isOverlay() and
(exists(getSingleLocationFilePath(e)) or exists(getMultiLocationFilePath(e)))
}
/**
* Discard an element with a single location if it is in a changed file.
*/
overlay[discard_entity]
private predicate multiDiscardable(@element e) {
e =
any(MultiDiscardable d |
d.existsInBase() and
forall(string path | path = d.getFilePath() | overlayChangedFiles(path))
)
private predicate discardSingleLocationElement(@element e) {
existsInBase(e) and
overlayChangedFiles(getSingleLocationFilePath(e))
}
overlay[local]
private class DiscardableVarDecl extends Discardable instanceof @var_decl {
override string getFilePath() {
exists(@location_default loc | var_decls(this, _, _, _, loc) |
result = getLocationFilePath(loc)
)
}
}
overlay[local]
private class DiscardableVariable extends MultiDiscardable instanceof @variable {
override string getFilePath() {
exists(@var_decl vd, @location_default loc | var_decls(vd, this, _, _, loc) |
result = getLocationFilePath(loc)
)
}
/**
* Discard an element with multiple locations only if all its locations are in changed files.
*/
overlay[discard_entity]
private predicate discardMultiLocationElement(@element e) {
existsInBase(e) and
exists(getMultiLocationFilePath(e)) and
forall(string path | path = getMultiLocationFilePath(e) | overlayChangedFiles(path))
}