f764dc99b3
Some code [0] consider that trailing arrays are flexible, whatever their size. Support for these legacy code has been introduced in f8f632498307d22e10fab0704548b270b15f1e1e but it prevents evaluation of __builtin_object_size and __builtin_dynamic_object_size in some legit cases. Introduce -fstrict-flex-arrays=<n> to have stricter conformance when it is desirable. n = 0: current behavior, any trailing array member is a flexible array. The default. n = 1: any trailing array member of undefined, 0 or 1 size is a flexible array member n = 2: any trailing array member of undefined or 0 size is a flexible array member This takes into account two specificities of clang: array bounds as macro id disqualify FAM, as well as non standard layout. Similar patch for gcc discuss here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101836 [0] https://docs.freebsd.org/en/books/developers-handbook/sockets/#sockets-essential-functions
58 lines
1.6 KiB
C
58 lines
1.6 KiB
C
// RUN: %clang_cc1 -verify=expected -Warray-bounds-pointer-arithmetic %s
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// RUN: %clang_cc1 -verify=expected -Warray-bounds-pointer-arithmetic %s -fstrict-flex-arrays=0
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// RUN: %clang_cc1 -verify=expected,strict -Warray-bounds-pointer-arithmetic %s -fstrict-flex-arrays=2
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// Test case from PR10615
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struct ext2_super_block{
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unsigned char s_uuid[8]; // expected-note {{declared here}}
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};
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void* ext2_statfs (struct ext2_super_block *es,int a)
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{
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return (void *)es->s_uuid + sizeof(int); // no-warning
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}
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void* broken (struct ext2_super_block *es,int a)
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{
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return (void *)es->s_uuid + 80; // expected-warning {{refers past the end of the array}}
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}
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// Test case reduced from PR11594
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struct S {
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int n;
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};
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void pr11594(struct S *s) {
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int a[10];
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int *p = a - s->n;
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}
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// Test case reduced from <rdar://problem/11387038>. This resulted in
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// an assertion failure because of the typedef instead of an explicit
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// constant array type.
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struct RDar11387038 {};
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typedef struct RDar11387038 RDar11387038Array[1];
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struct RDar11387038_Table {
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RDar11387038Array z; // strict-note {{array 'z' declared here}}
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};
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typedef struct RDar11387038_Table *TPtr;
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typedef TPtr *TabHandle;
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struct RDar11387038_B {
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TabHandle x;
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};
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typedef struct RDar11387038_B RDar11387038_B;
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void radar11387038(void) {
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RDar11387038_B *pRDar11387038_B;
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struct RDar11387038 *y = &(*pRDar11387038_B->x)->z[4]; // strict-warning {{array index 4 is past the end of the array (which contains 1 element)}}
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}
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void pr51682(void) {
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int arr[1];
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switch (0) {
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case 0:
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break;
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case 1:
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asm goto("" ::"r"(arr[42] >> 1)::failed);
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break;
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}
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failed:;
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}
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