Hi David.
This BPF part is OK.
> This commit adds several tests for the new BPF CO-RE functionality to
> the BPF target testsuite.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/bpf/core-attr-1.c: New test.
> * gcc.target/bpf/core-attr-2.c: Likewise.
> * gcc.target/bpf/core-attr-3.c: Likewise.
> * gcc.target/bpf/core-attr-4.c: Likewise
> * gcc.target/bpf/core-builtin-1.c: Likewise
> * gcc.target/bpf/core-builtin-2.c: Likewise.
> * gcc.target/bpf/core-builtin-3.c: Likewise.
> * gcc.target/bpf/core-section-1.c: Likewise.
> ---
> gcc/testsuite/gcc.target/bpf/core-attr-1.c | 23 +++++++
> gcc/testsuite/gcc.target/bpf/core-attr-2.c | 21 ++++++
> gcc/testsuite/gcc.target/bpf/core-attr-3.c | 41 ++++++++++++
> gcc/testsuite/gcc.target/bpf/core-attr-4.c | 35 ++++++++++
> gcc/testsuite/gcc.target/bpf/core-builtin-1.c | 64 +++++++++++++++++++
> gcc/testsuite/gcc.target/bpf/core-builtin-2.c | 26 ++++++++
> gcc/testsuite/gcc.target/bpf/core-builtin-3.c | 26 ++++++++
> gcc/testsuite/gcc.target/bpf/core-section-1.c | 38 +++++++++++
> 8 files changed, 274 insertions(+)
> create mode 100644 gcc/testsuite/gcc.target/bpf/core-attr-1.c
> create mode 100644 gcc/testsuite/gcc.target/bpf/core-attr-2.c
> create mode 100644 gcc/testsuite/gcc.target/bpf/core-attr-3.c
> create mode 100644 gcc/testsuite/gcc.target/bpf/core-attr-4.c
> create mode 100644 gcc/testsuite/gcc.target/bpf/core-builtin-1.c
> create mode 100644 gcc/testsuite/gcc.target/bpf/core-builtin-2.c
> create mode 100644 gcc/testsuite/gcc.target/bpf/core-builtin-3.c
> create mode 100644 gcc/testsuite/gcc.target/bpf/core-section-1.c
>
> diff --git a/gcc/testsuite/gcc.target/bpf/core-attr-1.c
> b/gcc/testsuite/gcc.target/bpf/core-attr-1.c
> new file mode 100644
> index 00000000000..7f0d0e50dd6
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/core-attr-1.c
> @@ -0,0 +1,23 @@
> +/* Basic test for struct __attribute__((preserve_access_index))
> + for BPF CO-RE support. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O0 -dA -gbtf -mcore" } */
> +
> +struct S {
> + int a;
> + int b;
> + int c;
> +} __attribute__((preserve_access_index));
> +
> +void
> +func (struct S * s)
> +{
> + /* 0:2 */
> + int *x = &(s->c);
> +
> + *x = 4;
> +}
> +
> +/* { dg-final { scan-assembler-times "ascii \"0:2.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "bpfcr_type" 1 } } */
> diff --git a/gcc/testsuite/gcc.target/bpf/core-attr-2.c
> b/gcc/testsuite/gcc.target/bpf/core-attr-2.c
> new file mode 100644
> index 00000000000..508e1e4c4b1
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/core-attr-2.c
> @@ -0,0 +1,21 @@
> +/* Basic test for union __attribute__((preserve_access_index))
> + for BPF CO-RE support. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O0 -dA -gbtf -mcore" } */
> +
> +union U {
> + int a;
> + char c;
> +} __attribute__((preserve_access_index));
> +
> +void
> +func (union U *u)
> +{
> + /* 0:1 */
> + char *c = &(u->c);
> + *c = 'c';
> +}
> +
> +/* { dg-final { scan-assembler-times "ascii \"0:1.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "bpfcr_type" 1 } } */
> diff --git a/gcc/testsuite/gcc.target/bpf/core-attr-3.c
> b/gcc/testsuite/gcc.target/bpf/core-attr-3.c
> new file mode 100644
> index 00000000000..1813fd07a2f
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/core-attr-3.c
> @@ -0,0 +1,41 @@
> +/* Test for __attribute__((preserve_access_index)) for BPF CO-RE support
> + for nested structure.
> +
> + Note that even though struct O lacks the attribute, when accessed as a
> + member of another attributed type, CO-RE relocations should still be
> + generated. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O0 -dA -gbtf -mcore" } */
> +
> +struct O {
> + int e;
> + int f;
> +};
> +
> +struct S {
> + int a;
> + struct {
> + int b;
> + int c;
> + } inner;
> + struct O other;
> +} __attribute__((preserve_access_index));
> +
> +void
> +func (struct S *foo)
> +{
> + /* 0:1:1 */
> + int *x = &(foo->inner.c);
> +
> + /* 0:2:0 */
> + int *y = &(foo->other.e);
> +
> + *x = 4;
> + *y = 5;
> +}
> +
> +/* { dg-final { scan-assembler-times "ascii \"0:1:1.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "ascii \"0:2:0.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +
> +/* { dg-final { scan-assembler-times "bpfcr_type" 2 } } */
> diff --git a/gcc/testsuite/gcc.target/bpf/core-attr-4.c
> b/gcc/testsuite/gcc.target/bpf/core-attr-4.c
> new file mode 100644
> index 00000000000..30d859a1c57
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/core-attr-4.c
> @@ -0,0 +1,35 @@
> +/* Test for BPF CO-RE __attribute__((preserve_access_index)) with accesses on
> + LHS and both LHS and RHS of assignment. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O0 -dA -gbtf -mcore" } */
> +
> +struct T {
> + int a;
> + int b;
> + struct U {
> + int c;
> + struct V {
> + int d;
> + int e[4];
> + int f;
> + } v;
> + } u;
> +} __attribute__((preserve_access_index));
> +
> +
> +void
> +func (struct T *t)
> +{
> + /* 0:2:1:1:3 */
> + t->u.v.e[3] = 0xa1;
> +
> + /* 0:2:0, 0:0, 0:1 */
> + t->u.c = t->a + t->b;
> +}
> +
> +/* { dg-final { scan-assembler-times "ascii \"0:2:1:1:3.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "ascii \"0:2:0.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "ascii \"0:0.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "ascii \"0:1.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "bpfcr_type" 4 } } */
> diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-1.c
> b/gcc/testsuite/gcc.target/bpf/core-builtin-1.c
> new file mode 100644
> index 00000000000..e6905418c89
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/core-builtin-1.c
> @@ -0,0 +1,64 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O0 -dA -gbtf -mcore" } */
> +
> +struct S {
> + int a;
> + int b;
> + char c;
> +};
> +
> +union U {
> + unsigned int u;
> + int i;
> + unsigned char uc[4];
> + signed char ic[4];
> +};
> +
> +struct S my_s;
> +union U my_u;
> +
> +unsigned long ula[8];
> +
> +#define _(x) (__builtin_preserve_access_index (x))
> +
> +void
> +func (void)
> +{
> + /* 1 */
> + int b = _(my_s.b);
> +
> + /* 2 */
> + char c = _(my_s.c);
> +
> + /* 2:3 */
> + unsigned char uc = _(my_u.uc[3]);
> +
> + /* 6 */
> + unsigned long ul = _(ula[6]);
> +}
> +
> +char
> +s_ptr (struct S *ps)
> +{
> + /* 0:2 */
> + char x = _(ps->c);
> + return x;
> +}
> +
> +unsigned char
> +u_ptr (union U *pu)
> +{
> + /* 0:2:3 */
> + unsigned char x = _(pu->uc[3]);
> + return x;
> +}
> +
> +/* { dg-final { scan-assembler-times "ascii \"1.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "ascii \"2.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "ascii \"2:3.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "ascii \"6.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "ascii \"0:2.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "ascii \"0:2:3.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +
> +/* { dg-final { scan-assembler-times "bpfcr_type" 6 } } */
> +/* { dg-final { scan-assembler-times "\[\t \]0x6c\[\t
> \]+\[^\n\]*core_relo_len" 1 } } */
> diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-2.c
> b/gcc/testsuite/gcc.target/bpf/core-builtin-2.c
> new file mode 100644
> index 00000000000..5e9dfecce65
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/core-builtin-2.c
> @@ -0,0 +1,26 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O0 -dA -gbtf -mcore" } */
> +
> +struct S {
> + int a;
> + union {
> + int _unused;
> + int b;
> + char c;
> + } u[4];
> +};
> +
> +struct S foo;
> +
> +#define _(x) (__builtin_preserve_access_index (x))
> +
> +void func (void)
> +{
> + char *x = __builtin_preserve_access_index (&foo.u[3].c);
> +
> + *x = 's';
> +}
> +
> +/* { dg-final { scan-assembler-times "\[\t \]0x4000002\[\t
> \]+\[^\n\]*btt_info" 1 } } */
> +/* { dg-final { scan-assembler-times "ascii \"1:3:2.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "bpfcr_type" 1 } } */
> diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-3.c
> b/gcc/testsuite/gcc.target/bpf/core-builtin-3.c
> new file mode 100644
> index 00000000000..495eeadfe69
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/core-builtin-3.c
> @@ -0,0 +1,26 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O0 -dA -gbtf -mcore" } */
> +
> +struct T {
> + int a;
> + int b;
> + struct U {
> + int c;
> + struct V {
> + int d;
> + int e[4];
> + int f;
> + } v;
> + } u;
> +};
> +
> +void func (struct T * foo)
> +{
> + /* Access string: "0:2:1:1:3" */
> + int *x = __builtin_preserve_access_index (&(foo->u.v.e[3]));
> +
> + *x = 17;
> +}
> +
> +/* { dg-final { scan-assembler-times "ascii \"0:2:1:1:3.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "bpfcr_type" 1 } } */
> diff --git a/gcc/testsuite/gcc.target/bpf/core-section-1.c
> b/gcc/testsuite/gcc.target/bpf/core-section-1.c
> new file mode 100644
> index 00000000000..b816aefd0d2
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/core-section-1.c
> @@ -0,0 +1,38 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O0 -gbtf -dA -mcore" } */
> +
> +struct T {
> + int a;
> + int b;
> + struct U {
> + int c;
> + struct V {
> + int d;
> + int e[4];
> + int f;
> + } v;
> + } u;
> +};
> +
> +__attribute__((section("foo_sec"), used))
> +int foo_func (struct T *t)
> +{
> + t->u.c = 5;
> + return __builtin_preserve_access_index (t->u.v.e[3]);
> +}
> +
> +__attribute__((section("bar_sec"), used))
> +int bar_func (struct T *t)
> +{
> + int *x = __builtin_preserve_access_index (&(t->u.v.f));
> + int old = *x;
> + *x = 4;
> + return old;
> +}
> +
> +/* { dg-final { scan-assembler-times "ascii \"0:2:1:1:3.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "ascii \"0:2:1:2.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "ascii \"foo_sec.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "ascii \"bar_sec.0\"\[\t
> \]+\[^\n\]*btf_aux_string" 1 } } */
> +/* { dg-final { scan-assembler-times "bpfcr_type" 2 } } */
> +/* { dg-final { scan-assembler-times "btfext_secinfo_rec_size" 2 } } */
