[PATCH] introduce Wdirective_within_macro

[Oleg Nesterov <oleg@redhat.com>]

When used on linux kernel, sparse issues a lot of "directive in macro's
argument list" errors, "#if" within a macro invocation is widely used in
the kernel code.

Downgrade this sparse_error() to warning() and add the new
-Wdirective-within-macro knob.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 cgcc                                     | 2 +-
 lib.c                                    | 2 ++
 lib.h                                    | 1 +
 pre-process.c                            | 5 +++--
 validation/preprocessor/preprocessor22.c | 8 ++++----
 5 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/cgcc b/cgcc
index 9c6ad883..9f5897e9 100755
--- a/cgcc
+++ b/cgcc
@@ -127,7 +127,7 @@ exit 0;
 
 sub check_only_option {
     my ($arg) = @_;
-    return 1 if $arg =~ /^-W(no-?)?(address-space|bitwise|cast-to-as|cast-truncate|constant-suffix|context|decl|default-bitfield-sign|designated-init|do-while|enum-mismatch|external-function-has-definition|init-cstring|memcpy-max-count|non-pointer-null|old-initializer|one-bit-signed-bitfield|override-init-all|paren-string|ptr-subtraction-blows|return-void|sizeof-bool|sparse-all|sparse-error|transparent-union|typesign|undef|unknown-attribute)$/;
+    return 1 if $arg =~ /^-W(no-?)?(address-space|bitwise|cast-to-as|cast-truncate|constant-suffix|context|decl|default-bitfield-sign|designated-init|directive-within-macro|do-while|enum-mismatch|external-function-has-definition|init-cstring|memcpy-max-count|non-pointer-null|old-initializer|one-bit-signed-bitfield|override-init-all|paren-string|ptr-subtraction-blows|return-void|sizeof-bool|sparse-all|sparse-error|transparent-union|typesign|undef|unknown-attribute)$/;
     return 1 if $arg =~ /^-v(no-?)?(entry|dead)$/;
     return 1 if $arg =~ /^-f(dump-ir|memcpy-max-count|diagnostic-prefix)(=\S*)?$/;
     return 1 if $arg =~ /^-f(mem2reg|optim)(-enable|-disable|=last)?$/;
diff --git a/lib.c b/lib.c
index f15e4d99..264a890e 100644
--- a/lib.c
+++ b/lib.c
@@ -264,6 +264,7 @@ int Wdecl = 1;
 int Wdeclarationafterstatement = -1;
 int Wdefault_bitfield_sign = 0;
 int Wdesignated_init = 1;
+int Wdirective_within_macro = 1;
 int Wdo_while = 0;
 int Wimplicit_int = 1;
 int Winit_cstring = 0;
@@ -740,6 +741,7 @@ static const struct flag warnings[] = {
 	{ "declaration-after-statement", &Wdeclarationafterstatement },
 	{ "default-bitfield-sign", &Wdefault_bitfield_sign },
 	{ "designated-init", &Wdesignated_init },
+	{ "directive-within-macro", &Wdirective_within_macro },
 	{ "do-while", &Wdo_while },
 	{ "enum-mismatch", &Wenum_mismatch },
 	{ "external-function-has-definition", &Wexternal_function_has_definition },
diff --git a/lib.h b/lib.h
index 72651cef..49db0117 100644
--- a/lib.h
+++ b/lib.h
@@ -153,6 +153,7 @@ extern int Wdecl;
 extern int Wdeclarationafterstatement;
 extern int Wdefault_bitfield_sign;
 extern int Wdesignated_init;
+extern int Wdirective_within_macro;
 extern int Wdo_while;
 extern int Wenum_mismatch;
 extern int Wexternal_function_has_definition;
diff --git a/pre-process.c b/pre-process.c
index 433d1bf8..e79a447a 100644
--- a/pre-process.c
+++ b/pre-process.c
@@ -271,8 +271,9 @@ static struct token *collect_arg(struct token *prev, int vararg, struct position
 	while (!eof_token(next = scan_next(p))) {
 		if (next->pos.newline && match_op(next, '#')) {
 			if (!next->pos.noexpand) {
-				sparse_error(next->pos,
-					     "directive in macro's argument list");
+				if (Wdirective_within_macro)
+					warning(next->pos,
+						"directive in macro's argument list");
 				preprocessor_line(stream, p);
 				__free_token(next);	/* Free the '#' token */
 				continue;
diff --git a/validation/preprocessor/preprocessor22.c b/validation/preprocessor/preprocessor22.c
index fb28daaa..277334c6 100644
--- a/validation/preprocessor/preprocessor22.c
+++ b/validation/preprocessor/preprocessor22.c
@@ -20,10 +20,10 @@ define_struct(a, {
  * check-command: sparse -E $file
  *
  * check-error-start
-preprocessor/preprocessor22.c:6:1: error: directive in macro's argument list
-preprocessor/preprocessor22.c:8:1: error: directive in macro's argument list
-preprocessor/preprocessor22.c:10:1: error: directive in macro's argument list
-preprocessor/preprocessor22.c:12:1: error: directive in macro's argument list
+preprocessor/preprocessor22.c:6:1: warning: directive in macro's argument list
+preprocessor/preprocessor22.c:8:1: warning: directive in macro's argument list
+preprocessor/preprocessor22.c:10:1: warning: directive in macro's argument list
+preprocessor/preprocessor22.c:12:1: warning: directive in macro's argument list
  * check-error-end
  *
  * check-output-start
-- 
2.25.1.362.g51ebf55