libsandbox: add an eqawarn() func

Break out most of the QA static ELF warning code into a new eqawarn()
func.  This way we can handle dynamic stuff like calling portage's eqawarn
func to handle dirty details like logging.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 49 insertions, 0 deletions

diff --git a/libsandbox/eqawarn.c b/libsandbox/eqawarn.c
new file mode 100644
index 0000000..e7b0a9c
--- /dev/null
+++ b/libsandbox/eqawarn.c
@@ -0,0 +1,49 @@
+/*
+ * Dump a QA warning
+ *
+ * Copyright 1999-2009 Gentoo Foundation
+ * Licensed under the GPL-2
+ */
+
+#include "headers.h"
+#include "libsandbox.h"
+#include "sbutil.h"
+#include "wrappers.h"
+
+/* First try to use the eqawarn program from portage.  If that fails, fall
+ * back to writing to /dev/tty.  While this might annoy some people, using
+ * stderr will break tests that try to validate output #261957.
+ */
+void sb_eqawarn(const char *format, ...)
+{
+	va_list args;
+	FILE *fp;
+	sighandler_t oldsig;
+	bool is_pipe;
+
+	/* If popen() fails, then writes to it will trigger SIGPIPE */
+	oldsig = signal(SIGPIPE, SIG_IGN);
+
+	fp = sb_unwrapped_popen("xargs eqawarn 2>/dev/null", "we");
+	is_pipe = true;
+	if (!fp) {
+ do_tty:
+		is_pipe = false;
+		fp = fopen("/dev/tty", "ae");
+		if (!fp)
+			fp = stderr;
+	}
+
+	sb_fprintf(fp, "QA Notice: ");
+	va_start(args, format);
+	sb_vfprintf(fp, format, args);
+	va_end(args);
+
+	if (is_pipe) {
+		int status = pclose(fp);
+		if (WEXITSTATUS(status))
+			goto do_tty;
+	}
+
+	signal(SIGPIPE, oldsig);
+}