genksyms: Track changes to enum constants
Enum constants can be used as array sizes; if the enum itself does not
appear in the symbol expansion, a change in the enum constant will go
unnoticed. Example patch that changes the ABI but does not change the
checksum with current genksyms:
| enum e {
| E1,
| E2,
|+ E3,
| E_MAX
| };
|
| struct s {
| int a[E_MAX];
| }
|
| int f(struct s *s) { ... }
| EXPORT_SYMBOL(f)
Therefore, remember the value of each enum constant and
expand each occurence to <constant> <value>. The value is not actually
computed, but instead an expression in the form
(last explicitly assigned value) + N
is used. This avoids having to parse and semantically understand whole
of C.
Note: The changes won't take effect until the lexer and parser are
rebuilt by the next patch.
Signed-off-by: Michal Marek <mmarek@suse.cz>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/scripts/genksyms/parse.y b/scripts/genksyms/parse.y
index 09a265c..ba5c242 100644
--- a/scripts/genksyms/parse.y
+++ b/scripts/genksyms/parse.y
@@ -25,6 +25,7 @@
#include <assert.h>
#include <stdlib.h>
+#include <string.h>
#include "genksyms.h"
static int is_typedef;
@@ -227,16 +228,19 @@
add_symbol(i->string, SYM_UNION, s, is_extern);
$$ = $3;
}
- | ENUM_KEYW IDENT BRACE_PHRASE
+ | ENUM_KEYW IDENT enum_body
{ struct string_list *s = *$3, *i = *$2, *r;
r = copy_node(i); r->tag = SYM_ENUM;
r->next = (*$1)->next; *$3 = r; (*$1)->next = NULL;
add_symbol(i->string, SYM_ENUM, s, is_extern);
$$ = $3;
}
-
- /* Anonymous s/u/e definitions. Nothing needs doing. */
- | ENUM_KEYW BRACE_PHRASE { $$ = $2; }
+ /*
+ * Anonymous enum definition. Tell add_symbol() to restart its counter.
+ */
+ | ENUM_KEYW enum_body
+ { add_symbol(NULL, SYM_ENUM, NULL, 0); $$ = $2; }
+ /* Anonymous s/u definitions. Nothing needs doing. */
| STRUCT_KEYW class_body { $$ = $2; }
| UNION_KEYW class_body { $$ = $2; }
;
@@ -449,6 +453,28 @@
| attribute_opt ATTRIBUTE_PHRASE
;
+enum_body:
+ '{' enumerator_list '}' { $$ = $3; }
+ | '{' enumerator_list ',' '}' { $$ = $4; }
+ ;
+
+enumerator_list:
+ enumerator
+ | enumerator_list ',' enumerator
+
+enumerator:
+ IDENT
+ {
+ const char *name = strdup((*$1)->string);
+ add_symbol(name, SYM_ENUM_CONST, NULL, 0);
+ }
+ | IDENT '=' EXPRESSION_PHRASE
+ {
+ const char *name = strdup((*$1)->string);
+ struct string_list *expr = copy_list_range(*$3, *$2);
+ add_symbol(name, SYM_ENUM_CONST, expr, 0);
+ }
+
asm_definition:
ASM_PHRASE ';' { $$ = $2; }
;