Run Clang-Tidy Inside Docker Container on Linux

Clang-Tidy is a command line tool designed to automatically analyze and improve C and C++ source code. It performs static code analysis to catch common bugs, style violations, performance issues, and more. Integrating Clang-Tidy into the development workflow helps maintain code quality, enforce best practices, and prevent subtle errors early. By running Clang-Tidy inside a Docker container with all dependencies preinstalled, you can ensure consistent analysis across all team members without requiring local setup - everyone uses the same version, minimizing discrepancies and simplifying maintenance.

Here's an example of a simple C source file, main.c:

#include <stdio.h>

int main() {
    char a[3] = {10, 20, 30};
    printf("%d\n", a[3]);

    return 0;
}

To analyze the code using Clang-Tidy from a Docker container, run the following command:

docker run -it --rm -v ./:/src xianpengshen/clang-tools:20 clang-tidy main.c -- -std=c99

• docker run - starts a new Docker container.
• -it - runs the container in interactive mode with a terminal attached.
• --rm - removes the container automatically after it exits, keeping the system clean.
• -v ./:/src - mounts the current directory into the container at /src, allowing access to the project files.
• xianpengshen/clang-tools - specifies the Docker image to use.
• clang-tidy main.c - runs the static analysis tool for given source file.
• -- - separates Clang-Tidy options from the compiler options that follow.
• -std=c99 - indicates that the code should be interpreted according to the C99 standard, which helps Clang-Tidy accurately understand and analyze the source.

Note: Clang-Tidy knows how to locate standard headers like stddef.h, so there's no need to provide them using the -I option when running inside the container. However, you can specify multiple -I options to add additional directories, ensuring all necessary headers are accessible during analysis.

Output:

2 warnings generated.
/home/adminer/main.c:5:5: warning: 2nd function call argument is an uninitialized value [clang-analyzer-core.CallAndMessage]
    5 |     printf("%d\n", a[3]);
      |     ^              ~~~~
/home/adminer/main.c:5:5: note: 2nd function call argument is an uninitialized value
    5 |     printf("%d\n", a[3]);
      |     ^              ~~~~
/home/adminer/main.c:5:20: warning: array index 3 is past the end of the array (that has type 'char[3]') [clang-diagnostic-array-bounds]
    5 |     printf("%d\n", a[3]);
      |                    ^ ~
/home/adminer/main.c:4:5: note: array 'a' declared here
    4 |     char a[3] = {10, 20, 30};
      |     ^

Clang-Tidy issues a warning that accessing a[3] is out of bounds and the value is not initialized.