Declare globals as extern in headers, and define in source file

Otherwise, each source file that includes the header gets its own
definition, and according to the C standard (C99 6.9p5):

> If an identifier declared with external linkage is used in an
> expression (other than as part of the operand of a sizeof operator
> whose result is an integer constant), somewhere in the entire
> program there shall be exactly one external definition for the
> identifier

Most compilers use the .bss section for zero data, but if it uses
.data instead, or if -Wl,--warn-common is used, this will cause a
linking error.

1 files changed, 5 insertions, 5 deletions

diff --git a/bounce.h b/bounce.h
index 0e12aa5..17cf5b6 100644
--- a/bounce.h
+++ b/bounce.h
@@ -110,7 +110,7 @@ static inline const char *capList(enum Cap caps) {
 	return buf;
 }
 
-bool verbose;
+extern bool verbose;
 
 void ringAlloc(size_t len);
 void ringProduce(const char *line);
@@ -134,8 +134,8 @@ void serverSend(const char *ptr, size_t len);
 void serverFormat(const char *format, ...)
 	__attribute__((format(printf, 1, 2)));
 
-char *clientPass;
-char *clientAway;
+extern char *clientPass;
+extern char *clientAway;
 struct Client *clientAlloc(struct tls *tls);
 void clientFree(struct Client *client);
 bool clientError(const struct Client *client);
@@ -146,8 +146,8 @@ void clientFormat(struct Client *client, const char *format, ...)
 size_t clientDiff(const struct Client *client);
 void clientConsume(struct Client *client);
 
-bool stateNoNames;
-enum Cap stateCaps;
+extern bool stateNoNames;
+extern enum Cap stateCaps;
 void stateLogin(
 	const char *pass, bool sasl, const char *plain,
 	const char *nick, const char *user, const char *real