From 9ab55d7f240fb05f84ec3b5e37f0c3ab2ce69053 Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Tue, 1 Dec 2020 16:20:18 +0100 Subject: genksyms: Ignore module scoped _Static_assert() The C11 _Static_assert() keyword may be used at module scope, and we need to teach genksyms about it to not abort with an error. We currently have a growing number of static_assert() (but also direct usage of _Static_assert()) users at module scope: git grep -E '^_Static_assert\(|^static_assert\(' | grep -v '^tools' | wc -l 135 More recently, when enabling CONFIG_MODVERSIONS with CONFIG_KCSAN, we observe a number of warnings: WARNING: modpost: EXPORT symbol "<..all kcsan symbols..>" [vmlinux] [...] When running a preprocessed source through 'genksyms -w' a number of syntax errors point at usage of static_assert()s. In the case of kernel/kcsan/encoding.h, new static_assert()s had been introduced which used expressions that appear to cause genksyms to not even be able to recover from the syntax error gracefully (as it appears was the case previously). Therefore, make genksyms ignore all _Static_assert() and the contained expression. With the fix, usage of _Static_assert() no longer cause "syntax error" all over the kernel, and the above modpost warnings for KCSAN are gone, too. Signed-off-by: Marco Elver Acked-by: Nick Desaulniers Signed-off-by: Masahiro Yamada --- scripts/genksyms/lex.l | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) (limited to 'scripts/genksyms/lex.l') diff --git a/scripts/genksyms/lex.l b/scripts/genksyms/lex.l index e265c5d96861..ae76472efc43 100644 --- a/scripts/genksyms/lex.l +++ b/scripts/genksyms/lex.l @@ -118,7 +118,7 @@ yylex(void) { static enum { ST_NOTSTARTED, ST_NORMAL, ST_ATTRIBUTE, ST_ASM, ST_TYPEOF, ST_TYPEOF_1, - ST_BRACKET, ST_BRACE, ST_EXPRESSION, + ST_BRACKET, ST_BRACE, ST_EXPRESSION, ST_STATIC_ASSERT, ST_TABLE_1, ST_TABLE_2, ST_TABLE_3, ST_TABLE_4, ST_TABLE_5, ST_TABLE_6 } lexstate = ST_NOTSTARTED; @@ -201,6 +201,11 @@ repeat: case EXPORT_SYMBOL_KEYW: goto fini; + + case STATIC_ASSERT_KEYW: + lexstate = ST_STATIC_ASSERT; + count = 0; + goto repeat; } } if (!suppress_type_lookup) @@ -401,6 +406,26 @@ repeat: } break; + case ST_STATIC_ASSERT: + APP; + switch (token) + { + case '(': + ++count; + goto repeat; + case ')': + if (--count == 0) + { + lexstate = ST_NORMAL; + token = STATIC_ASSERT_PHRASE; + break; + } + goto repeat; + default: + goto repeat; + } + break; + case ST_TABLE_1: goto repeat; -- cgit v1.2.3-58-ga151