CodeQL setup (#36)

In nob, add conditional run with sanitizers used by CodeQL workflow.
https://github.com/iglesias/coding-challenges/actions/runs/12557297977/job/35009713999#step:4:943

.github/workflows/codeql.yml

@@ -0,0 +1,58 @@
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  analyze:
+    name: Analyze (${{ matrix.language }})
+    runs-on: ${{ (matrix.language == 'swift' && 'macos-latest') || 'ubuntu-latest' }}
+    permissions:
+      # required for all workflows
+      security-events: write
+
+      # required to fetch internal or private CodeQL packs
+      packages: read
+
+      # only required for workflows in private repositories
+      actions: read
+      contents: read
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+        - language: c-cpp
+          build-mode: manual
+        - language: python
+          build-mode: none
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v3
+      with:
+        languages: ${{ matrix.language }}
+        build-mode: ${{ matrix.build-mode }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # For more details on CodeQL's query packs, refer to: https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-code-scanning#using-queries-in-ql-packs
+        queries: security-extended,security-and-quality
+
+    - if: matrix.build-mode == 'manual'
+      shell: bash
+      run: |
+        sudo apt-get install libboost-all-dev libgtest-dev
+        g++ -std=c++20 -DBUILD_ONLY -o nob nob.cpp
+        ./nob
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v3
+      with:
+        category: "/language:${{matrix.language}}"

nob.cpp

@@ -80,7 +80,9 @@ void build_and_run_gtest_file(std::string_view filename)
 {
     Cstr path = PATH(filename.data());
     CMD("g++", CPPFLAGS, "-o", NOEXT(path), path, "-lgtest");
+#ifndef BUILD_ONLY // github.com/iglesias/coding-challenges/actions/runs/12532941559/job/34952138092#step:4:943
     CMD(NOEXT(path));
+#endif
 }
 
 Pid build_gtest_file_async(std::string_view path)
@@ -113,6 +115,7 @@ void work_out_leetcode()
 
     for (const Pid& pid : pids) pid_wait(pid);
 
+#ifndef BUILD_ONLY  // github.com/iglesias/coding-challenges/actions/runs/12532941559/job/34952138092#step:4:943
     pids.clear();
 
     for (const auto& entry : fs::directory_iterator("leetcode")) if (fs::is_regular_file(entry.path())) {
@@ -121,6 +124,7 @@ void work_out_leetcode()
         if (filename.ends_with(".cpp")) pids.push_back(run_gtest_file_async("leetcode/" + filename)); }
 
     for (const Pid& pid : pids) pid_wait(pid);
+#endif
 }
 
 void build_codeforces_cpp_files() {