e07ead85a3
Previously we only have an extension that warn void pointer deferencing in C++, but for C we did nothing. C2x 6.5.3.2p4 says The unary * operator denotes indirection. If it points to an object, the result is an lvalue designating the object. However, there is no way to form an lvalue designating an object of an incomplete type as 6.3.2.1p1 says "an lvalue is an expression (with an object type other than void)", so the behavior is undefined. Fixes https://github.com/llvm/llvm-project/issues/53631 Signed-off-by: Jun Zhang <jun@junz.org> Differential Revision: https://reviews.llvm.org/D134461
100 lines
4.1 KiB
C
100 lines
4.1 KiB
C
// RUN: %clang_cc1 %s -ffreestanding -Wno-int-to-pointer-cast -fsyntax-only -verify -pedantic -fpascal-strings -std=c99
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#include <stdint.h>
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#include <limits.h>
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int a(void) {int p; *(1 ? &p : (void*)(0 && (a(),1))) = 10;} /* expected-error {{incomplete type 'void' is not assignable}}
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expected-warning {{ISO C does not allow indirection on operand of type 'void *'}} */
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// rdar://6091492 - ?: with __builtin_constant_p as the operand is an i-c-e.
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int expr;
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char w[__builtin_constant_p(expr) ? expr : 1];
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char v[sizeof(__builtin_constant_p(0)) == sizeof(int) ? 1 : -1];
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int implicitConversion = 1.0;
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char floatArith[(int)(1.0+2.0)]; // expected-warning {{variable length array folded to constant array as an extension}}
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// __builtin_constant_p as the condition of ?: allows arbitrary foldable
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// constants to be transmogrified into i-c-e's.
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char b[__builtin_constant_p((int)(1.0+2.0)) ? (int)(1.0+2.0) : -1];
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struct c {
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int a : (
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__builtin_constant_p((int)(1.0+2.0)) ? (int)(1.0+
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expr // expected-error {{expression is not an integer constant expression}}
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) : -1);
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};
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// Check that we can evaluate statement-expressions properly when
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// constant-folding inside an ICE.
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void PR49239(void) {
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goto check_not_vla;
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char not_vla[__builtin_constant_p(1) ? ({ 42; }) : -1]; // expected-warning {{statement expression}}
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check_not_vla:;
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_Static_assert(sizeof(not_vla) == 42, ""); // expected-warning {{C11 extension}}
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// It's not clear that this should be valid: __builtin_expect(expr1, expr2)
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// should probably be an ICE if and only if expr1 is an ICE, but we roughly
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// follow GCC in treating it as an ICE if and only if we can evaluate expr1
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// regardless of whether it's an ICE.
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goto check_also_not_vla;
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char also_not_vla[__builtin_expect(({ 76; }), 0)]; // expected-warning {{statement expression}}
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check_also_not_vla:;
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_Static_assert(sizeof(also_not_vla) == 76, ""); // expected-warning {{C11 extension}}
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}
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void test1(int n, int* p) { *(n ? p : (void *)(7-7)) = 1; }
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void test2(int n, int* p) { *(n ? p : (void *)0) = 1; }
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char array[1024/(sizeof (long))];
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int x['\xBb' == (char) 187 ? 1: -1];
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// PR1992
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void func(int x)
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{
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switch (x) {
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case sizeof("abc"): break;
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case sizeof("loooong"): func(4);
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case sizeof("\ploooong"): func(4);
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}
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}
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// rdar://4213768
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int expr;
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char y[__builtin_constant_p(expr) ? -1 : 1];
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char z[__builtin_constant_p(4) ? 1 : -1];
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// Comma tests
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int comma1[0?1,2:3]; // expected-warning {{left operand of comma operator has no effect}}
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int comma2[1 || (1, 2)]; // expected-warning {{use of logical '||' with constant operand}} \
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// expected-note {{use '|' for a bitwise operation}} \
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// expected-warning {{left operand of comma operator has no effect}}
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int comma3[(1, 2)]; // expected-warning {{variable length array folded to constant array as an extension}} \
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// expected-warning {{left operand of comma operator has no effect}}
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// Pointer + __builtin_constant_p
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char pbcp[__builtin_constant_p(4) ? (intptr_t)&expr : 0]; // expected-error {{variable length array declaration not allowed at file scope}}
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int illegaldiv1a[1 || 1/0];
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int illegaldiv1b[1 && 1/0]; //expected-error{{variable length array declaration not allowed at file scope}}
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int illegaldiv2[1/0]; // expected-error {{variable length array declaration not allowed at file scope}}
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int illegaldiv3[INT_MIN / -1]; // expected-error {{variable length array declaration not allowed at file scope}}
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// PR9262
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int illegaldiv4[0 / (1 / 0)]; // expected-error {{variable length array declaration not allowed at file scope}}
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int chooseexpr[__builtin_choose_expr(1, 1, expr)];
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int realop[(__real__ 4) == 4 ? 1 : -1];
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int imagop[(__imag__ 4) == 0 ? 1 : -1];
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int *PR14729 = 0 ?: 1/0; // expected-error {{not a compile-time constant}} expected-warning 2{{}} expected-error {{incompatible integer to pointer conversion initializing 'int *' with an expression of type 'int'}}
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int bcp_call_v;
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int bcp_call_a[] = {__builtin_constant_p(bcp_call_v && 0) ? bcp_call_v && 0 : -1};
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