From 49a4332eaa4f2642c894caeb6f6a01938b9b7e74 Mon Sep 17 00:00:00 2001
From: Krishnanand G <118352827+Krishnanand-G@users.noreply.github.com>
Date: Tue, 18 Aug 2026 14:19:44 +0530
Subject: [PATCH] GH-50859: [C++] Build JsonWriter when Parquet is enabled
 without JSON

json_writer_internal.cc lived in the ARROW_JSON object library, so
ARROW_JSON=OFF left parquet tools with undefined JsonWriter symbols.

Signed-off-by: Krishnanand G <118352827+Krishnanand-G@users.noreply.github.com>
---
 cpp/src/arrow/CMakeLists.txt | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/cpp/src/arrow/CMakeLists.txt b/cpp/src/arrow/CMakeLists.txt
index c5bc01c8ef9..1a9c947c2d7 100644
--- a/cpp/src/arrow/CMakeLists.txt
+++ b/cpp/src/arrow/CMakeLists.txt
@@ -1070,6 +1070,18 @@ else()
   set(ARROW_IPC_TARGET_STATIC)
 endif()
 
+# Parquet (LogicalType::ToJSON, encryption, geospatial) calls JsonWriter
+# even when ARROW_JSON=OFF. Keep the writer in its own object library.
+if(ARROW_JSON OR ARROW_PARQUET)
+  arrow_add_object_library(ARROW_JSON_WRITER json/json_writer_internal.cc)
+  foreach(ARROW_JSON_WRITER_TARGET ${ARROW_JSON_WRITER_TARGETS})
+    target_link_libraries(${ARROW_JSON_WRITER_TARGET} PRIVATE arrow::simdjson)
+  endforeach()
+else()
+  set(ARROW_JSON_WRITER_TARGET_SHARED)
+  set(ARROW_JSON_WRITER_TARGET_STATIC)
+endif()
+
 if(ARROW_JSON)
   arrow_add_object_library(ARROW_JSON
                            extension/fixed_shape_tensor.cc
@@ -1081,7 +1093,6 @@ if(ARROW_JSON)
                            json/chunker.cc
                            json/converter.cc
                            json/from_string.cc
-                           json/json_writer_internal.cc
                            json/object_parser.cc
                            json/parser.cc
                            json/reader.cc)
@@ -1195,6 +1206,7 @@ add_arrow_lib(arrow
               ${ARROW_IO_TARGET_SHARED}
               ${ARROW_IPC_TARGET_SHARED}
               ${ARROW_JSON_TARGET_SHARED}
+              ${ARROW_JSON_WRITER_TARGET_SHARED}
               ${ARROW_MEMORY_POOL_TARGET_SHARED}
               ${ARROW_ORC_TARGET_SHARED}
               ${ARROW_TELEMETRY_TARGET_SHARED}
@@ -1211,6 +1223,7 @@ add_arrow_lib(arrow
               ${ARROW_IO_TARGET_STATIC}
               ${ARROW_IPC_TARGET_STATIC}
               ${ARROW_JSON_TARGET_STATIC}
+              ${ARROW_JSON_WRITER_TARGET_STATIC}
               ${ARROW_MEMORY_POOL_TARGET_STATIC}
               ${ARROW_ORC_TARGET_STATIC}
               ${ARROW_TELEMETRY_TARGET_STATIC}