[librsvg: 13/45] rsvg_log_session!(): new macro, uses a Session to decide whether to log

[Marge Bot <marge-bot src gnome org>]

commit e372e716f45aa31539ea01c50e9864d24e220567
Author: Federico Mena Quintero <federico gnome org>
Date:   Mon Aug 22 13:48:00 2022 -0500

    rsvg_log_session!(): new macro, uses a Session to decide whether to log
    
    We'll gradually replace calls to rsvg_log!() with this other macro,
    and then rename all of them in a single shot.
    
    Part-of: <https://gitlab.gnome.org/GNOME/librsvg/-/merge_requests/731>

 src/handle.rs |  3 ++-
 src/log.rs    | 12 ++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)
---
diff --git a/src/handle.rs b/src/handle.rs
index 99827816b..e9d05e209 100644
--- a/src/handle.rs
+++ b/src/handle.rs
@@ -208,7 +208,8 @@ impl Handle {
                 .lookup_internal_node(&id)
                 .ok_or(DefsLookupErrorKind::NotFound),
             NodeId::External(_, _) => {
-                rsvg_log!(
+                rsvg_log_session!(
+                    self.session,
                     "the public API is not allowed to look up external references: {}",
                     node_id
                 );
diff --git a/src/log.rs b/src/log.rs
index a8ec06142..4505e9737 100644
--- a/src/log.rs
+++ b/src/log.rs
@@ -13,6 +13,18 @@ macro_rules! rsvg_log {
     };
 }
 
+#[macro_export]
+macro_rules! rsvg_log_session {
+    (
+        $session:expr,
+        $($arg:tt)+
+    ) => {
+        if $session.log_enabled() {
+            println!("{}", format_args!($($arg)+));
+        }
+    };
+}
+
 pub fn log_enabled() -> bool {
     static ENABLED: Lazy<bool> = Lazy::new(|| ::std::env::var_os("RSVG_LOG").is_some());