lx_emul: function to generate trace messages

lx_emul_trace_msg() uses Genode::trace() as message function for lightweight trace points, but also supports Linux format-string attributes by using vsnprintf().
genodelabs · Mar 25, 2024 · ac5ed43 · ac5ed43
1 parent cc88552
commit ac5ed43
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Showing 3 changed files with 13 additions and 1 deletion.
diff --git a/repos/dde_linux/src/include/lx_emul/debug.h b/repos/dde_linux/src/include/lx_emul/debug.h
@@ -23,6 +23,8 @@ __attribute__((noreturn)) void lx_emul_trace_and_stop(const char * func);
 
 void lx_emul_trace(const char * func);
 
+__attribute__((__format__(printf, 1, 2))) void lx_emul_trace_msg(char const *fmt, ...);
+
 void lx_emul_backtrace(void);
 
 #ifdef __cplusplus

diff --git a/repos/dde_linux/src/lib/lx_emul/debug.cc b/repos/dde_linux/src/lib/lx_emul/debug.cc
@@ -29,7 +29,7 @@ extern "C" void lx_emul_trace_and_stop(const char * func)
 }
 
 
-extern "C" void lx_emul_trace(const char *) {}
+extern "C" void lx_emul_trace(const char *s) { trace(s); }
 
 
 extern "C" void lx_emul_backtrace()

diff --git a/repos/dde_linux/src/lib/lx_emul/shadow/kernel/printk/printk.c b/repos/dde_linux/src/lib/lx_emul/shadow/kernel/printk/printk.c
@@ -56,3 +56,13 @@ asmlinkage int vprintk_emit(int facility, int level,
 	return 0;
 }
 
+
+void lx_emul_trace_msg(char const *fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+	vsnprintf(print_string, sizeof(print_string), fmt, args);
+	va_end(args);
+
+	lx_emul_trace(print_string);
+}