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[clang][analyzer] PointerSubChecker should not warn on pointers converted to numerical type #111846

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Merged
merged 3 commits into from
Oct 11, 2024
Merged

[clang][analyzer] PointerSubChecker should not warn on pointers converted to numerical type #111846

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a9e1790
[clang][analyzer] PointerSubChecker should not warn on pointers conve…
balazske Oct 10, 2024
92fa6a0
added test for typedef type
balazske Oct 10, 2024
4ce3f4f
using 'long long' for pointer address
balazske Oct 11, 2024
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4 changes: 4 additions & 0 deletions clang/lib/StaticAnalyzer/Checkers/PointerSubChecker.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -61,6 +61,10 @@ void PointerSubChecker::checkPreStmt(const BinaryOperator *B,
if (LR->getSymbolicBase() || RR->getSymbolicBase())
return;

if (!B->getLHS()->getType()->isPointerType() ||
!B->getRHS()->getType()->isPointerType())
return;

const auto *ElemLR = dyn_cast<ElementRegion>(LR);
const auto *ElemRR = dyn_cast<ElementRegion>(RR);

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12 changes: 12 additions & 0 deletions clang/test/Analysis/pointer-sub.c
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Original file line number Diff line number Diff line change
@@ -1,5 +1,7 @@
// RUN: %clang_analyze_cc1 -analyzer-checker=security.PointerSub -analyzer-output=text-minimal -verify %s

typedef int * Ptr;

void f1(void) {
int x, y, z[10];
int d = &y - &x; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}}
Expand All @@ -10,6 +12,12 @@ void f1(void) {
d = &x - (&x + 1); // no-warning
d = (&x + 0) - &x; // no-warning
d = (z + 10) - z; // no-warning
d = (long long)&y - (long long)&x; // no-warning
long long l = 1;
d = l - (long long)&y; // no-warning
Ptr p1 = &x;
Ptr p2 = &y;
d = p1 - p2; // expected-warning{{Subtraction of two pointers that do not point into the same array is undefined behavior}}
}

void f2(void) {
Expand All @@ -28,6 +36,10 @@ void f2(void) {

d = (int *)((char *)(&a[4]) + sizeof(int)) - &a[4]; // no-warning (pointers into the same array data)
d = (int *)((char *)(&a[4]) + 1) - &a[4]; // expected-warning{{Subtraction of two pointers that}}

long long a1 = (long long)&a[1];
long long b1 = (long long)&b[1];
d = a1 - b1;
}

void f3(void) {
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