kconfig: error out if recursive dependencies are found

Sample:
config FOO
	bool "This is foo"
	depends on BAR

config BAR
	bool "This is bar"
	depends on FOO

This will result in following error message:
error: found recursive dependency: FOO -> BAR -> FOO

And will then exit with exit code equal 1 so make will stop.
Inspired by patch from: Adrian Bunk <bunk@stusta.de>

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Adrian Bunk <bunk@stusta.de>
Cc: Roman Zippel <zippel@linux-m68k.org>

3 files changed, 13 insertions, 12 deletions

diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index 8f06c474d800..c35dcc5d6189 100644
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -786,13 +786,15 @@ static struct symbol *sym_check_expr_deps(struct expr *e)
         return NULL;
 }
 
+/* return NULL when dependencies are OK */
 struct symbol *sym_check_deps(struct symbol *sym)
 {
         struct symbol *sym2;
         struct property *prop;
 
         if (sym->flags & SYMBOL_CHECK) {
-                printf("Warning! Found recursive dependency: %s", sym->name);
+                fprintf(stderr, "%s:%d:error: found recursive dependency: %s",
+                        sym->prop->file->name, sym->prop->lineno, sym->name);
                 return sym;
         }
         if (sym->flags & SYMBOL_CHECKED)
@@ -816,13 +818,8 @@ struct symbol *sym_check_deps(struct symbol *sym)
                         goto out;
         }
 out:
-        if (sym2) {
-                printf(" %s", sym->name);
-                if (sym2 == sym) {
-                        printf("\n");
-                        sym2 = NULL;
-                }
-        }
+        if (sym2)
+                fprintf(stderr, " -> %s%s", sym->name, sym2 == sym? "\n": "");
         sym->flags &= ~SYMBOL_CHECK;
         return sym2;
 }
diff --git a/scripts/kconfig/zconf.tab.c_shipped b/scripts/kconfig/zconf.tab.c_shipped
index d777fe85627f..9a06b6771eee 100644
--- a/scripts/kconfig/zconf.tab.c_shipped
+++ b/scripts/kconfig/zconf.tab.c_shipped
@@ -2132,9 +2132,11 @@ void conf_parse(const char *name)
         }
         menu_finalize(&rootmenu);
         for_all_symbols(i, sym) {
-                sym_check_deps(sym);
+                if (sym_check_deps(sym))
+                        zconfnerrs++;
         }
-
+        if (zconfnerrs)
+                exit(1);
         sym_set_change_count(1);
 }
 
diff --git a/scripts/kconfig/zconf.y b/scripts/kconfig/zconf.y
index 04a5864c03b1..92eb02bdf9c5 100644
--- a/scripts/kconfig/zconf.y
+++ b/scripts/kconfig/zconf.y
@@ -501,9 +501,11 @@ void conf_parse(const char *name)
         }
         menu_finalize(&rootmenu);
         for_all_symbols(i, sym) {
-                sym_check_deps(sym);
+                if (sym_check_deps(sym))
+                        zconfnerrs++;
         }
-
+        if (zconfnerrs)
+                exit(1);
         sym_set_change_count(1);
 }