Merge pull request #20184 from sivanov-work:fix_gapi_empty_input

G-API: Add standalone fix for graph empty input

* Add sandalone fix for graph empty input

* Apply some review comments

* Fix whitespace

* Apply review comment: make Mat check more deeper

* Apply some comments

* Remove tracer apply exception throwing

* Apply comments: move validatio into gproto_priv.hpp

* Apply minor text correction

* Fix alignment, remove try-catch

modules/gapi/src/compiler/gcompiler.cpp

@@ -343,19 +343,26 @@ void cv::gimpl::GCompiler::validateInputMeta()
         return false; // should never happen
     };
 
+    GAPI_LOG_DEBUG(nullptr, "Total count: " << m_metas.size());
     for (const auto meta_arg_idx : ade::util::indexed(ade::util::zip(m_metas, c_expr.m_ins)))
     {
         const auto &meta  = std::get<0>(ade::util::value(meta_arg_idx));
         const auto &proto = std::get<1>(ade::util::value(meta_arg_idx));
 
+        const auto index = ade::util::index(meta_arg_idx);
+        GAPI_LOG_DEBUG(nullptr, "Process index: " << index);
+
+        // check types validity
         if (!meta_matches(meta, proto))
         {
-            const auto index  = ade::util::index(meta_arg_idx);
             util::throw_error(std::logic_error
                         ("GComputation object type / metadata descriptor mismatch "
                          "(argument " + std::to_string(index) + ")"));
             // FIXME: report what we've got and what we've expected
         }
+
+        // check value consistency
+        gimpl::proto::validate_input_meta_arg(meta); //may throw
     }
     // All checks are ok
 }

modules/gapi/src/compiler/gcompiler.hpp

@@ -29,7 +29,7 @@ class GAPI_EXPORTS GCompiler
     cv::gapi::GKernelPackage m_all_kernels;
     cv::gapi::GNetPackage    m_all_networks;
 
-    // Patters built from transformations
+    // Patterns built from transformations
     std::vector<std::unique_ptr<ade::Graph>> m_all_patterns;