YT-19324: move YT provider to ydb/library/yql

This commit is formed by the following script: https://paste.yandex-team.ru/6f92e4b8-efc5-4d34-948b-15ee2accd7e7/text.
This commit has zero effect on all projects that depend on YQL.

The summary of changes:
- `yql/providers/yt -> ydb/library/yql/providers/yt `- the whole implementation of YT provider is moved into YDB code base for further export as a part of YT YQL plugin shared library;
- `yql/providers/stat/{expr_nodes,uploader} -> ydb/library/yql/providers/stat/{expr_nodes,uploader}` - a small interface without implementation and the description of stat expr nodes;
- `yql/core/extract_predicate/ut -> ydb/library/yql/core/extract_predicate/ut`;
- `yql/core/{ut,ut_common} -> ydb/library/yql/core/{ut,ut_common}`;
- `yql/core` is gone;
- `yql/library/url_preprocessing -> ydb/library/yql/core/url_preprocessing`.

**NB**: all new targets inside `ydb/` are under `IF (NOT CMAKE_EXPORT)` clause which disables them from open-source cmake generation and ya make build. They will be enabled in the subsequent commits.

1 files changed, 62 insertions, 0 deletions

diff --git a/library/cpp/dwarf_backtrace/backtrace.cpp b/library/cpp/dwarf_backtrace/backtrace.cpp
new file mode 100644
index 0000000000..a955d07249
--- /dev/null
+++ b/library/cpp/dwarf_backtrace/backtrace.cpp
@@ -0,0 +1,62 @@
+#include "backtrace.h"
+
+#include <contrib/libs/backtrace/backtrace.h>
+
+#include <util/generic/yexception.h>
+#include <util/system/type_name.h>
+#include <util/system/execpath.h>
+
+namespace NDwarf {
+    namespace {
+        struct TContext {
+            TCallback& Callback;
+            int Counter = 0;
+            TMaybe<TError> Error;
+        };
+
+        void HandleLibBacktraceError(void* data, const char* msg, int errnum) {
+            auto* context = reinterpret_cast<TContext*>(data);
+            context->Error = TError{.Code = errnum, .Message=msg};
+        }
+
+        int HandleLibBacktraceFrame(void* data, uintptr_t pc, const char* filename, int lineno, const char* function) {
+            auto* context = reinterpret_cast<TContext*>(data);
+            TLineInfo lineInfo{
+                .FileName = filename != nullptr ? filename : "???",
+                .Line = lineno,
+                .Col = 0, // libbacktrace doesn't provide column numbers, so fill this field with a dummy value.
+                .FunctionName = function != nullptr ? CppDemangle(function) : "???",
+                .Address = pc,
+                .Index = context->Counter++,
+            };
+            return static_cast<int>(context->Callback(lineInfo));
+        }
+    }
+
+    TMaybe<TError> ResolveBacktrace(TArrayRef<const void* const> backtrace, TCallback callback) {
+        TContext context{.Callback = callback};
+        // Intentionally never freed (see https://a.yandex-team.ru/arc/trunk/arcadia/contrib/libs/backtrace/backtrace.h?rev=6789902#L80).
+        static auto* state = backtrace_create_state(
+            GetPersistentExecPath().c_str(),
+            1 /* threaded */,
+            HandleLibBacktraceError,
+            &context /* data for the error callback */
+        );
+        if (nullptr == state) {
+            static const auto initError = context.Error;
+            return initError;
+        }
+        for (const void* address : backtrace) {
+            int status = backtrace_pcinfo(
+                state,
+                reinterpret_cast<uintptr_t>(address) - 1, // last byte of the call instruction
+                HandleLibBacktraceFrame,
+                HandleLibBacktraceError,
+                &context /* data for both callbacks */);
+            if (0 != status) {
+                break;
+            }
+        }
+        return context.Error;
+    }
+}