Скачать или смотреть Resolving Linking Errors in MariaDB Connector C+ +

Discover how to troubleshoot and fix linking errors in MariaDB Connector C+ + on Windows with MinGW. Our guide walks you through the necessary adjustments, ensuring smooth compilation with clear steps and solutions.
---
This video is based on the question https://stackoverflow.com/q/71712556/ asked by the user 'Alexander123456' ( https://stackoverflow.com/u/6024467/ ) and on the answer https://stackoverflow.com/a/71739130/ provided by the user 'Alexander123456' ( https://stackoverflow.com/u/6024467/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: mariadb-connector-cpp-1.0.1: Linking error for cjportedtests.exe

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Troubleshooting Linking Errors in MariaDB Connector C+ +

Linking errors can be a frustrating hurdle in software development, especially when working with libraries like MariaDB Connector C+ + . One such error arises when attempting to compile the executable cjportedtests.exe on Windows 10 using MinGW-W64 with the following error message:

[[See Video to Reveal this Text or Code Snippet]]

This error suggests that the linker cannot find a specific function or variable reference, leading to compilation failure. In this guide, we will dissect this problem and provide a solution to effectively eliminate this linking error while working with the MariaDB Connector C+ + .

Understanding the Problem

The Environment

Let's consider the environment where the error occurred:

Operating System: Windows 10

Compiler: MinGW-W64 x86_64-ucrt-posix-seh, version 11.2.0

CMake Version: 3.19.5

Error Message Analysis

When the build command was executed, the linker produced an error indicating an "undefined reference" to a symbol related to sql::SQLString. This means that while the code was callable, its implementation could not be linked correctly, which is often due to missing, incorrectly ordered, or pre-built libraries.

Source of the Problem

The error pinpointed an issue in the test_asserts.cpp file where the assertEquals function was trying to compare expected and result but could not find the necessary operator definition for sql::SQLString.

Proposed Solution

The key to resolving the linking error lies in the order of linking libraries in the CMake files. A fellow developer, Lawrin Novitsky, suggested that changing the link order will solve the problem. Here are the steps to implement the necessary changes:

Steps to Fix the Linking Error

Adjust CMakeLists.txt Files: The order in which libraries are linked can affect the success of the compilation. You should modify several CMakeLists.txt files to ensure that test_framework is linked before ${LIBRARY_NAME}.

Specific Changes:

In the following files, you will shift the linking order:

test/CJUnitTestsPort/CMakeLists.txt: Change order at lines 35 and 41.

test/unit/CMakeLists.txt: Change order at line 31.

test/unit/example/CMakeLists.txt: Change order at line 48.

test/unit/classes/CMakeLists.txt: Change orders at lines 46, 66, 87, 107, 127, 147, 167, 208.

test/unit/performance/CMakeLists.txt: Change order at line 45.

test/unit/bugs/CMakeLists.txt: Change order at line 45.

Command Line Compilation

After making these modifications, re-run the build process. If successful, you should not encounter further linking errors.

Additional Context

While the above steps aim to resolve the immediate issue, maintaining an understanding of how linking works in CMake can prevent future linking issues. Always ensure that dependent libraries are listed in a logical order according to their dependencies.

Conclusion

Linking errors can be a major obstacle for developers working with libraries like MariaDB Connector C+ + . However, making systematic order adjustments in the CMake configuration can notably resolve these issues. If you continue encountering similar problems, consider checking the compatibility of your environment and ensure that all library paths are correctly specified.

By following this guide, you should be able to tackle linking errors effectively and enhance your understanding of CMake configurations. Happy coding!