just: only report export targets if there are any

By default, messages at level "progress" and above are shown. So,
messages at that level should be useful for the user in the typical
case. For the count of export targets, this information is only useful
if the build involves export targets at all; the absence of export
targets is typically only used when debugging the build structure.

1 files changed, 13 insertions, 6 deletions

diff --git a/src/buildtool/main/main.cpp b/src/buildtool/main/main.cpp
index 6801f2b2..16385ade 100644
--- a/src/buildtool/main/main.cpp
+++ b/src/buildtool/main/main.cpp
@@ -1387,12 +1387,19 @@ auto main(int argc, char* argv[]) -> int {
                             result->id.ToString());
 
                 auto const& stat = Statistics::Instance();
-                Logger::Log(LogLevel::Info,
-                            "Export targets found: {} cached, {} uncached, "
-                            "{} not eligible for caching",
-                            stat.ExportsCachedCounter(),
-                            stat.ExportsUncachedCounter(),
-                            stat.ExportsNotEligibleCounter());
+                {
+                    auto cached = stat.ExportsCachedCounter();
+                    auto uncached = stat.ExportsUncachedCounter();
+                    auto not_eligible = stat.ExportsNotEligibleCounter();
+                    Logger::Log(cached + uncached + not_eligible > 0
+                                    ? LogLevel::Info
+                                    : LogLevel::Debug,
+                                "Export targets found: {} cached, {} uncached, "
+                                "{} not eligible for caching",
+                                cached,
+                                uncached,
+                                not_eligible);
+                }
 
                 ReportTaintedness(*result);
                 auto const& [actions, blobs, trees] = result_map.ToResult();