Gỡ lỗi, kiểm thử & CI

phien-gdb

gcc -std=c17 -g main.c -o app   # -g: gdb co ten bien & so dong
gdb ./app                   # (macOS: lldb ./app)

(gdb) break main            # dat breakpoint o ham main   (b)
(gdb) run                   # chay toi breakpoint          (r)
(gdb) next                  # chay 1 dong, KHONG vao ham    (n)
(gdb) step                  # BUOC VAO ham duoc goi          (s)
(gdb) print x               # in gia tri bien x             (p x)
(gdb) backtrace             # chuoi loi goi ham hien tai    (bt)
(gdb) watch tong            # dung khi 'tong' thay doi
(gdb) continue              # chay tiep                     (c)

stack-trace

(gdb) backtrace
#0  tinh_tong (a=0x0, n=5) at sum.c:7      <- noi SAP (a la NULL!)
#1  xu_ly       (data=...)   at app.c:22    <- ham goi tinh_tong
#2  main        ()           at app.c:40    <- diem bat dau

# Sinh & mo core dump (anh chup luc sap):
ulimit -c unlimited
./app                # sap -> sinh file 'core'
gdb ./app core       # mo de xem trang thai luc sap

test_util.c

#include <assert.h>
#include "util.h"

static void test_binh_phuong(void) {
    assert(binh_phuong(3) == 9);   // Arrange + Act + Assert
    assert(binh_phuong(0) == 0);
    assert(binh_phuong(-2) == 4);
}

int main(void) {
    test_binh_phuong();
    return 0;   // exit 0 = pass; assert fail -> abort (exit khac 0)
}

CMakeLists.txt (phần test)

enable_testing()
add_executable(tests test_util.c util.c)
add_test(NAME util_tests COMMAND tests)
# chay: ctest --test-dir build --output-on-failure

.github/workflows/ci.yml

name: CI
on: [push, pull_request]
jobs:
  build-test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6
      - run: sudo apt-get update && sudo apt-get install -y cmake clang-format clang-tidy
      - run: clang-format --dry-run --Werror $(git ls-files '*.c' '*.h')
      - run: cmake -S . -B build -DCMAKE_C_FLAGS="-fsanitize=address,undefined -g" -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
      - run: cmake --build build
      - run: clang-tidy -p build $(git ls-files '*.c')
      - run: ctest --test-dir build --output-on-failure