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4f33e7c683
Make sure code respects the GNU-extension `__attribute__((returns_nonnull))`. Extend the NullabilityChecker to check that a function returns_nonnull does not return a nullptr. This commit also reverts an old hack introduced by 49bd58f1ebe28d97e4949e9c757bc5dfd8b2d72f because it is no longer needed CPP-4741
66 lines
2.7 KiB
C
66 lines
2.7 KiB
C
// RUN: %clang_analyze_cc1 -fblocks -analyzer-checker=core,nullability,debug.ExprInspection -verify %s
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void clang_analyzer_warnIfReached(void);
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void it_takes_two(int a, int b);
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void function_pointer_arity_mismatch(void) {
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void(*fptr)() = it_takes_two;
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fptr(1); // no-crash expected-warning {{Function taking 2 arguments is called with fewer (1)}}
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// expected-warning@-1 {{passing arguments to a function without a prototype is deprecated in all versions of C and is not supported in C23}}
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}
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void block_arity_mismatch(void) {
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void(^b)() = ^(int a, int b) { };
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b(1); // no-crash expected-warning {{Block taking 2 arguments is called with fewer (1)}}
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// expected-warning@-1 {{passing arguments to a function without a prototype is deprecated in all versions of C and is not supported in C23}}
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}
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int *nonnull_return_annotation_indirect(void) __attribute__((returns_nonnull));
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int *nonnull_return_annotation_indirect(void) {
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int *x = 0;
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return x; // expected-warning {{Null returned from a function that is expected to return a non-null value}}
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}
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int *nonnull_return_annotation_direct(void) __attribute__((returns_nonnull));
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int *nonnull_return_annotation_direct(void) {
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return 0; // expected-warning {{Null returned from a function that is expected to return a non-null value}}
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} // expected-warning@-1 {{null returned from function that requires a non-null return value}}
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int *nonnull_return_annotation_assumed(int* ptr) __attribute__((returns_nonnull));
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int *nonnull_return_annotation_assumed(int* ptr) {
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if (ptr) {
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return ptr;
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}
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return ptr; // expected-warning {{Null returned from a function that is expected to return a non-null value}}
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}
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int *produce_nonnull_ptr(void) __attribute__((returns_nonnull));
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__attribute__((returns_nonnull))
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int *cannot_return_null(void) {
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int *x = produce_nonnull_ptr();
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if (!x) {
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clang_analyzer_warnIfReached();
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// expected-warning@-1 {{REACHABLE}}
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// TODO: This warning is a false positive, according to the contract of
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// produce_nonnull_ptr, x cannot be null.
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}
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// Regardless of the potential state split above, x cannot be nullptr
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// according to the produce_nonnull_ptr annotation.
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return x;
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// False positive: expected-warning@-1 {{Null returned from a function that is expected to return a non-null value}}
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}
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__attribute__((returns_nonnull)) int *passthrough(int *p) {
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return p; // no-warning: we have no evidence that `p` is null, i.e., violating the contract
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}
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__attribute__((returns_nonnull)) int *passthrough2(int *p);
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int *passthrough2(int *p) {
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return p; // expected-warning{{Null returned from a function that is expected to return a non-null value}}
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}
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void call_with_null(void) {
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passthrough2(0);
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}
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