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5030928d60
initializers.
This has some interesting interactions with our existing extensions to
support C99 designated initializers as an extension in C++. Those are
resolved as follows:
* We continue to permit the full breadth of C99 designated initializers
in C++, with the exception that we disallow a partial overwrite of an
initializer with a non-trivially-destructible type. (Full overwrite
is OK, because we won't run the first initializer at all.)
* The C99 extensions are disallowed in SFINAE contexts and during
overload resolution, where they could change the meaning of valid
programs.
* C++20 disallows reordering of initializers. We only check for that for
the simple cases that the C++20 rules permit (designators of the form
'.field_name =' and continue to allow reordering in other cases).
It would be nice to improve this behavior in future.
* All C99 designated initializer extensions produce a warning by
default in C++20 mode. People are going to learn the C++ rules based
on what Clang diagnoses, so it's important we diagnose these properly
by default.
* In C++ <= 17, we apply the C++20 rules rather than the C99 rules, and
so still diagnose C99 extensions as described above. We continue to
accept designated C++20-compatible initializers in C++ <= 17 silently
by default (but naturally still reject under -pedantic-errors).
This is not a complete implementation of P0329R4. In particular, that
paper introduces new non-C99-compatible syntax { .field { init } }, and
we do not support that yet.
This is based on a previous patch by Don Hinton, though I've made
substantial changes when addressing the above interactions.
Differential Revision: https://reviews.llvm.org/D59754
llvm-svn: 370544
127 lines
2.6 KiB
C++
127 lines
2.6 KiB
C++
// RUN: %clang_analyze_cc1 -analyzer-checker=core -verify -std=c++2a %s
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static const unsigned long long scull = 0;
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void static_int()
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{
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*(int*)scull = 0; // expected-warning{{Dereference of null pointer}}
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}
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const unsigned long long cull = 0;
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void const_int()
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{
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*(int*)cull = 0; // expected-warning{{Dereference of null pointer}}
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}
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static int * const spc = 0;
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void static_ptr()
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{
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*spc = 0; // expected-warning{{Dereference of null pointer}}
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}
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int * const pc = 0;
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void const_ptr()
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{
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*pc = 0; // expected-warning{{Dereference of null pointer}}
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}
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const unsigned long long cull_nonnull = 4;
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void nonnull_int()
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{
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*(int*)(cull_nonnull - 4) = 0; // expected-warning{{Dereference of null pointer}}
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}
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int * const pc_nonnull = (int*)sizeof(int);
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void nonnull_ptr()
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{
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*(pc_nonnull - 1) = 0; // expected-warning{{Dereference of null pointer}}
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}
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int * const constcast = const_cast<int * const>((int*)sizeof(int));
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void cast1()
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{
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*(constcast - 1) = 0; // expected-warning{{Dereference of null pointer}}
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}
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int * const recast = reinterpret_cast<int*>(sizeof(int));
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void cast2()
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{
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*(recast - 1) = 0; // expected-warning{{Dereference of null pointer}}
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}
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int * const staticcast = static_cast<int * const>((int*)sizeof(int));
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void cast3()
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{
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*(staticcast - 1) = 0; // expected-warning{{Dereference of null pointer}}
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}
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struct Foo { int a; };
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Foo * const dyncast = dynamic_cast<Foo * const>((Foo*)sizeof(Foo));
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void cast4()
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{
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// Do not handle dynamic_cast for now, because it may change the pointer value.
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(dyncast - 1)->a = 0; // no-warning
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}
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typedef int * const intptrconst;
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int * const funccast = intptrconst(sizeof(int));
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void cast5()
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{
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*(funccast - 1) = 0; // expected-warning{{Dereference of null pointer}}
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}
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struct S1
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{
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int * p;
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};
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const S1 s1 = {
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.p = (int*)sizeof(int)
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};
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void conststruct()
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{
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*(s1.p - 1) = 0; // expected-warning{{Dereference of null pointer}}
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}
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struct S2
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{
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int * const p;
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};
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S2 s2 = {
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.p = (int*)sizeof(int)
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};
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void constfield()
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{
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*(s2.p - 1) = 0; // expected-warning{{Dereference of null pointer}}
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}
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int * const parr[1] = { (int*)sizeof(int) };
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void constarr()
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{
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*(parr[0] - 1) = 0; // expected-warning{{Dereference of null pointer}}
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}
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struct S3
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{
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int * p = (int*)sizeof(int);
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};
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void recordinit()
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{
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S3 s3;
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*(s3.p - 1) = 0; // expected-warning{{Dereference of null pointer}}
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}
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extern int ext_int;
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void update_original_declaration() {
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ext_int = 2;
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}
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extern int ext_int;
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int test_redeclaration() {
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ext_int = 1;
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update_original_declaration();
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int int_int = 3 / (ext_int - 1); // no-warning
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return int_int / (ext_int - 2); // expected-warning{{Division by zero}}
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}
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