Add kernel and kernel writer skeletons

* Add the skeleton for kernel, kernel writer and their respective
  OpenCL implementation.
* Add method to write code comment and its test.

Resolves: COMPMID-6343
Signed-off-by: Viet-Hoa Do <viet-hoa.do@arm.com>
Change-Id: Ib986228154f7a00da7a5fd3b7105941325fe13b1
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/9889
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Gunes Bayir <gunes.bayir@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Benchmark: Arm Jenkins <bsgcomp@arm.com>
diff --git a/compute_kernel_writer/include/ckw/Error.h b/compute_kernel_writer/include/ckw/Error.h
index 2793791..100bdc4 100644
--- a/compute_kernel_writer/include/ckw/Error.h
+++ b/compute_kernel_writer/include/ckw/Error.h
@@ -21,8 +21,8 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-#ifndef COMPUTE_KERNEL_WRITER_INCLUDE_CKW_ERROR_H
-#define COMPUTE_KERNEL_WRITER_INCLUDE_CKW_ERROR_H
+#ifndef CKW_INCLUDE_CKW_ERROR_H
+#define CKW_INCLUDE_CKW_ERROR_H
 
 #include <stdexcept>
 #include <string>
@@ -55,6 +55,65 @@
         std::runtime_error(create_error_msg(arg0, arg1, arg2, arg3)); \
     } while(false)
 
+/** Mark the variables as unused.
+ *
+ * @param[in] ... Variables which are unused.
+ */
+#define CKW_UNUSED(...) ckw::ignore_unused(__VA_ARGS__) // NOLINT
+
+/** Mark the variables as unused.
+ *
+ * @param[in] ... Variables which are unused.
+ */
+template <typename... T>
+inline void ignore_unused(T &&...)
+{
+}
+
+/** Throw an std::runtime_error with the specified message.
+ *
+ * @param[in] msg The error message.
+ */
+#define CKW_THROW_MSG(msg)                                                              \
+    do                                                                                  \
+    {                                                                                   \
+        const std::string file(__FILE__);                                               \
+        const std::string func(__func__);                                               \
+        const std::string line(std::to_string(__LINE__));                               \
+        const std::string message(msg);                                                 \
+                                                                                        \
+        throw std::runtime_error(ckw::create_error_msg(file, func, line, message)); \
+    } while(false)
+
+#ifdef COMPUTE_KERNEL_WRITER_ASSERTS_ENABLED
+
+/** If the condition is not met, throw an std::runtime_error with the specified message.
+ *
+ * @param[in] cond The condition that is expected to be true.
+ * @param[in] msg  The error message when the condition is not met.
+ */
+#define CKW_ASSERT_MSG(cond, msg) \
+    do                            \
+    {                             \
+        if(!(cond))               \
+        {                         \
+            CKW_THROW_MSG(msg);   \
+        }                         \
+    } while(false)
+
+/** If the condition is not met, throw an std::runtime_error.
+ *
+ * @param[in] cond The condition that is expected to be true.
+ */
+#define CKW_ASSERT(cond) CKW_ASSERT_MSG(cond, #cond)
+
+#else // COMPUTE_KERNEL_WRITER_ASSERTS_ENABLED
+
+#define CKW_ASSERT_MSG(cond, msg)
+#define CKW_ASSERT(cond)
+
+#endif // COMPUTE_KERNEL_WRITER_ASSERTS_ENABLED
+
 } // namespace ckw
 
-#endif /* COMPUTE_KERNEL_WRITER_INCLUDE_CKW_ERROR_H */
+#endif // CKW_INCLUDE_CKW_ERROR_H
diff --git a/compute_kernel_writer/include/ckw/Kernel.h b/compute_kernel_writer/include/ckw/Kernel.h
new file mode 100644
index 0000000..0cab713
--- /dev/null
+++ b/compute_kernel_writer/include/ckw/Kernel.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2023 Arm Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef CKW_INCLUDE_CKW_KERNEL_H
+#define CKW_INCLUDE_CKW_KERNEL_H
+
+#include "ckw/types/TargetLanguage.h"
+#include <string>
+
+namespace ckw
+{
+
+/** The kernel that has been emitted by the kernel writer.
+ *
+ * It contains all the necessary information to compile and execute the kernel.
+ */
+class Kernel
+{
+public:
+    /** Initialize a new instance of @ref Kernel class with all emitted kernel information.
+     *
+     * @param[in] language    The target language of the kernel.
+     * @param[in] source_code The source code of the kernel.
+     */
+    Kernel(TargetLanguage language, const std::string &source_code);
+
+    /** Get the target language. */
+    TargetLanguage target_language() const;
+
+    /** Get the source code. */
+    const std::string &source_code() const;
+
+private:
+    TargetLanguage _language;
+    std::string    _source_code;
+};
+
+} // namespace ckw
+
+#endif // CKW_INCLUDE_CKW_KERNEL_H
diff --git a/compute_kernel_writer/include/ckw/KernelWriter.h b/compute_kernel_writer/include/ckw/KernelWriter.h
new file mode 100644
index 0000000..ba8a601
--- /dev/null
+++ b/compute_kernel_writer/include/ckw/KernelWriter.h
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2023 Arm Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef CKW_INCLUDE_CKW_KERNELWRITER_H
+#define CKW_INCLUDE_CKW_KERNELWRITER_H
+
+#include "ckw/types/TargetArchitecture.h"
+#include "ckw/types/TargetLanguage.h"
+#include <memory>
+#include <string>
+
+namespace ckw
+{
+
+class Kernel;
+
+/** A kernel writer.
+ *
+ * This class is used to construct a new kernel by defining arguments, declaring variable and writing code.
+ *
+ * Use @ref KernelWriter::create_instance method to create the kernel writer for the specific target architecture and language.
+ *
+ * After having finished constructing the kernel, call @ref KernelWriter::emit_kernel to get the kernel object.
+ */
+class KernelWriter
+{
+public:
+    // =============================================================================================
+    // Construtors and destructor
+    // =============================================================================================
+
+    /** Initialize a new instance of @ref KernelWriter class for the specific architecture and language.
+     *
+     * Supported target architectures and languages:
+     *
+     * Architecture                  | Languages                    |
+     * ------------------------------|------------------------------|
+     * GpuArmMaliValhall             | OpenCL                       |
+     *
+     * @param[in] architecture The architecture on which the kernel is executed.
+     * @param[in] language     The language to write the kernel.
+     */
+    static std::unique_ptr<KernelWriter> create_instance(TargetArchitecture architecture, TargetLanguage language);
+
+    /** Destructor */
+    virtual ~KernelWriter();
+
+    // =============================================================================================
+    // Misc
+    // =============================================================================================
+
+    /** Write the line comment in debug build.
+     * This function does not take effect on release build.
+     *
+     * The comment must only contain one line (i.e. no newline character is allowed).
+     *
+     * @param[in] text The comment to be written.
+     */
+    virtual void comment(const std::string &text) = 0;
+
+    // =============================================================================================
+    // Code generation
+    // =============================================================================================
+
+    /** Emit the kernel object.
+     *
+     * @param[in] name The name of the kernel object to be generated.
+     */
+    virtual std::unique_ptr<Kernel> emit_kernel(const std::string &name) = 0;
+};
+
+} // namespace ckw
+
+#endif // CKW_INCLUDE_CKW_KERNELWRITER_H
diff --git a/compute_kernel_writer/include/ckw/types/TargetArchitecture.h b/compute_kernel_writer/include/ckw/types/TargetArchitecture.h
new file mode 100644
index 0000000..25662a0
--- /dev/null
+++ b/compute_kernel_writer/include/ckw/types/TargetArchitecture.h
@@ -0,0 +1,40 @@
+/*
+* Copyright (c) 2023 Arm Limited.
+*
+* SPDX-License-Identifier: MIT
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy
+* of this software and associated documentation files (the "Software"), to
+* deal in the Software without restriction, including without limitation the
+* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+* sell copies of the Software, and to permit persons to whom the Software is
+* furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in all
+* copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+* SOFTWARE.
+*/
+
+#ifndef CKW_INCLUDE_CKW_TYPES_TARGETARCHITECTURE_H
+#define CKW_INCLUDE_CKW_TYPES_TARGETARCHITECTURE_H
+
+namespace ckw
+{
+
+/** Target platform architecture. */
+enum class TargetArchitecture
+{
+    Unknown,
+    GpuArmMaliValhall,
+};
+
+} // namespace ckw
+
+#endif // CKW_INCLUDE_CKW_TYPES_TARGETARCHITECTURE_H
diff --git a/compute_kernel_writer/include/ckw/types/TargetLanguage.h b/compute_kernel_writer/include/ckw/types/TargetLanguage.h
new file mode 100644
index 0000000..1f50757
--- /dev/null
+++ b/compute_kernel_writer/include/ckw/types/TargetLanguage.h
@@ -0,0 +1,40 @@
+/*
+* Copyright (c) 2023 Arm Limited.
+*
+* SPDX-License-Identifier: MIT
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy
+* of this software and associated documentation files (the "Software"), to
+* deal in the Software without restriction, including without limitation the
+* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+* sell copies of the Software, and to permit persons to whom the Software is
+* furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in all
+* copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+* SOFTWARE.
+*/
+
+#ifndef CKW_INCLUDE_CKW_TYPES_TARGETLANGUAGE_H
+#define CKW_INCLUDE_CKW_TYPES_TARGETLANGUAGE_H
+
+namespace ckw
+{
+
+/** Target language. */
+enum class TargetLanguage
+{
+    Unknown,
+    OpenCL
+};
+
+} // namespace ckw
+
+#endif // CKW_INCLUDE_CKW_TYPES_TARGETLANGUAGE_H