selftests/bpf: replace __regex macro with "{{...}}" patterns

Upcoming changes require a notation to specify regular expression
matches for regular verifier log messages, disassembly of BPF
instructions, disassembly of jited instructions.

Neither basic nor extended POSIX regular expressions w/o additional
escaping are good for this role because of wide use of special
characters in disassembly, for example:

    movq -0x10(%rbp), %rax  ;; () are special characters
    cmpq $0x21, %rax        ;; $ is a special character

    *(u64 *)(r10 -16) = r1  ;; * and () are special characters

This commit borrows syntax from LLVM's FileCheck utility.
It replaces __regex macro with ability to embed regular expressions
in __msg patters using "{{" "}}" pairs for escaping.
Syntax for __msg patterns:

    pattern := (<verbatim text> | regex)*
    regex := "{{" <posix extended regular expression> "}}"

For example, pattern "foo{{[0-9]+}}" matches strings like
"foo0", "foo007", etc.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240820102357.3372779-5-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/tools/testing/selftests/bpf/progs/bpf_misc.h b/tools/testing/selftests/bpf/progs/bpf_misc.h
index 4f1029743734..cc3ef20a6490 100644
--- a/tools/testing/selftests/bpf/progs/bpf_misc.h
+++ b/tools/testing/selftests/bpf/progs/bpf_misc.h
@@ -25,12 +25,15 @@
  *
  * __msg             Message expected to be found in the verifier log.
  *                   Multiple __msg attributes could be specified.
+ *                   To match a regular expression use "{{" "}}" brackets,
+ *                   e.g. "foo{{[0-9]+}}"  matches strings like "foo007".
+ *                   Extended POSIX regular expression syntax is allowed
+ *                   inside the brackets.
  * __msg_unpriv      Same as __msg but for unprivileged mode.
  *
- * __regex           Same as __msg, but using a regular expression.
- * __regex_unpriv    Same as __msg_unpriv but using a regular expression.
  * __xlated          Expect a line in a disassembly log after verifier applies rewrites.
  *                   Multiple __xlated attributes could be specified.
+ *                   Regular expressions could be specified same way as in __msg.
  * __xlated_unpriv   Same as __xlated but for unprivileged mode.
  *
  * __success         Expect program load success in privileged mode.
@@ -72,13 +75,11 @@
  *                   When test case is not run on current arch it is marked as skipped.
  */
 #define __msg(msg)		__attribute__((btf_decl_tag("comment:test_expect_msg=" XSTR(__COUNTER__) "=" msg)))
-#define __regex(regex)		__attribute__((btf_decl_tag("comment:test_expect_regex=" XSTR(__COUNTER__) "=" regex)))
 #define __xlated(msg)		__attribute__((btf_decl_tag("comment:test_expect_xlated=" XSTR(__COUNTER__) "=" msg)))
 #define __failure		__attribute__((btf_decl_tag("comment:test_expect_failure")))
 #define __success		__attribute__((btf_decl_tag("comment:test_expect_success")))
 #define __description(desc)	__attribute__((btf_decl_tag("comment:test_description=" desc)))
 #define __msg_unpriv(msg)	__attribute__((btf_decl_tag("comment:test_expect_msg_unpriv=" XSTR(__COUNTER__) "=" msg)))
-#define __regex_unpriv(regex)	__attribute__((btf_decl_tag("comment:test_expect_regex_unpriv=" XSTR(__COUNTER__) "=" regex)))
 #define __xlated_unpriv(msg)	__attribute__((btf_decl_tag("comment:test_expect_xlated_unpriv=" XSTR(__COUNTER__) "=" msg)))
 #define __failure_unpriv	__attribute__((btf_decl_tag("comment:test_expect_failure_unpriv")))
 #define __success_unpriv	__attribute__((btf_decl_tag("comment:test_expect_success_unpriv")))