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[CHERI CSA] Disable pointer alignment checker for sealed capabilities. #204

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Merged
merged 1 commit into from
Jul 29, 2025
Merged

[CHERI CSA] Disable pointer alignment checker for sealed capabilities. #204

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5 changes: 5 additions & 0 deletions clang/lib/StaticAnalyzer/Checkers/PointerAlignmentChecker.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -259,6 +259,11 @@ int getTrailingZerosCount(const SVal &V, ProgramStateRef State,
if (V.isUnknownOrUndef())
return -1;

// Sealed capabilities cannot be dereferenced, and any type-punning
// will be dynamically checked during unsealing.
if (V.getType(ASTCtx)->isCHERISealedCapabilityType(ASTCtx))
return -1;

if (V.isConstant()) {
if (auto LV = V.getAs<loc::ConcreteInt>())
return LV->getValue()->countTrailingZeros();
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6 changes: 6 additions & 0 deletions clang/test/Analysis/pointer-alignment.c
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Expand Up @@ -214,3 +214,9 @@ void write_to_first_member(struct AlignedParentStruct *chunk) {
*(long long*)(&chunk->a) = 0;
}

// ----
long long * __sealed_capability sealed_cast(int * __sealed_capability in) {
// No warnings for sealed capabilities, since they will be effectively dynamically
// verified when unsealed.
return (long long * __sealed_capability)in;
}