Add jerryscript-compiler.h public header to cover compiler incompatibilities (#2313)

In general, public headers should not have compiler-specific
constructs but both the core and the port headers have attributes,
which are non-standard. It's better to factor out such constructs
to a common place (a new header) and hide them behind macros, which
can then be defined on a per-compiler basis.

This patch moves the existing definitions of function attributes and
likely/unlikely builtins to the new header. At the same time, it
unifies the names of these attribute defines and where they are
used. Moreover, it touches on jerry-main and removes the uses of
`__attribute__((unused))` entirely and replaces them with the
elsewhere used `(void) ...` pattern.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

jerry-core/include/jerryscript-compiler.h

@@ -0,0 +1,120 @@
+/* Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef JERRYSCRIPT_COMPILER_H
+#define JERRYSCRIPT_COMPILER_H
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif /* __cplusplus */
+
+/** \addtogroup jerry-compiler Jerry compiler compatibility components
+ * @{
+ */
+
+#ifdef __GNUC__
+
+/*
+ * Compiler-specific macros relevant for GCC.
+ */
+#define JERRY_ATTR_ALIGNED(ALIGNMENT) __attribute__((aligned(ALIGNMENT)))
+#define JERRY_ATTR_ALWAYS_INLINE __attribute__((always_inline))
+#define JERRY_ATTR_CONST __attribute__((const))
+#define JERRY_ATTR_DEPRECATED __attribute__((deprecated))
+#define JERRY_ATTR_FORMAT(...) __attribute__((format(__VA_ARGS__)))
+#define JERRY_ATTR_HOT __attribute__((hot))
+#define JERRY_ATTR_NOINLINE __attribute__((noinline))
+#define JERRY_ATTR_NORETURN __attribute__((noreturn))
+#define JERRY_ATTR_PURE __attribute__((pure))
+#define JERRY_ATTR_SECTION(SECTION) __attribute__((section(SECTION)))
+#define JERRY_ATTR_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
+
+#define JERRY_LIKELY(x) __builtin_expect(!!(x), 1)
+#define JERRY_UNLIKELY(x) __builtin_expect(!!(x), 0)
+
+#endif /* __GNUC__ */
+
+/*
+ * Default empty definitions for all compiler-specific macros. Define any of
+ * these in a guarded block above (e.g., as for GCC) to fine tune compilation
+ * for your own compiler. */
+
+/*
+ * Attributes
+ */
+#ifndef JERRY_ATTR_ALIGNED
+#define JERRY_ATTR_ALIGNED(ALIGNMENT)
+#endif /* !JERRY_ATTR_ALIGNED */
+
+#ifndef JERRY_ATTR_ALWAYS_INLINE
+#define JERRY_ATTR_ALWAYS_INLINE
+#endif /* !JERRY_ATTR_ALWAYS_INLINE */
+
+#ifndef JERRY_ATTR_CONST
+#define JERRY_ATTR_CONST
+#endif /* !JERRY_ATTR_CONST */
+
+#ifndef JERRY_ATTR_DEPRECATED
+#define JERRY_ATTR_DEPRECATED
+#endif /* !JERRY_ATTR_DEPRECATED */
+
+#ifndef JERRY_ATTR_FORMAT
+#define JERRY_ATTR_FORMAT(...)
+#endif /* !JERRY_ATTR_FORMAT */
+
+#ifndef JERRY_ATTR_HOT
+#define JERRY_ATTR_HOT
+#endif /* !JERRY_ATTR_HOT */
+
+#ifndef JERRY_ATTR_NOINLINE
+#define JERRY_ATTR_NOINLINE
+#endif /* !JERRY_ATTR_NOINLINE */
+
+#ifndef JERRY_ATTR_NORETURN
+#define JERRY_ATTR_NORETURN
+#endif /* !JERRY_ATTR_NORETURN */
+
+#ifndef JERRY_ATTR_PURE
+#define JERRY_ATTR_PURE
+#endif /* !JERRY_ATTR_PURE */
+
+#ifndef JERRY_ATTR_SECTION
+#define JERRY_ATTR_SECTION(SECTION)
+#endif /* !JERRY_ATTR_SECTION */
+
+#ifndef JERRY_ATTR_WARN_UNUSED_RESULT
+#define JERRY_ATTR_WARN_UNUSED_RESULT
+#endif /* !JERRY_ATTR_WARN_UNUSED_RESULT */
+
+/*
+ * Condition likeliness, unlikeliness
+ */
+#ifndef JERRY_LIKELY
+#define JERRY_LIKELY(x) (x)
+#endif /* !JERRY_LIKELY */
+
+#ifndef JERRY_UNLIKELY
+#define JERRY_UNLIKELY(x) (x)
+#endif /* !JERRY_UNLIKELY */
+
+/**
+ * @}
+ */
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+#endif /* !JERRYSCRIPT_COMPILER_H */

jerry-core/include/jerryscript-core.h

@@ -20,18 +20,13 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include "jerryscript-compiler.h"
+
 #ifdef __cplusplus
 extern "C"
 {
 #endif /* __cplusplus */
 
-#ifdef __GNUC__
-#define JERRY_DEPRECATED_API __attribute__((deprecated))
-#else /* !__GNUC__ */
-/* TODO: for other compilers */
-#define JERRY_DEPRECATED_API
-#endif /* __GNUC__ */
-
 /** \addtogroup jerry Jerry engine interface
  * @{
  */
@@ -491,9 +486,9 @@ jerry_value_t jerry_get_object_keys (const jerry_value_t obj_val);
 jerry_value_t jerry_get_prototype (const jerry_value_t obj_val);
 jerry_value_t jerry_set_prototype (const jerry_value_t obj_val, const jerry_value_t proto_obj_val);
 
-JERRY_DEPRECATED_API
+JERRY_ATTR_DEPRECATED
 bool jerry_get_object_native_handle (const jerry_value_t obj_val, uintptr_t *out_handle_p);
-JERRY_DEPRECATED_API
+JERRY_ATTR_DEPRECATED
 void jerry_set_object_native_handle (const jerry_value_t obj_val, uintptr_t handle_p,
                                      jerry_object_free_callback_t freecb_p);
 

jerry-core/include/jerryscript-port.h

@@ -20,6 +20,8 @@
 #include <stdint.h>
 #include <stdio.h>
 
+#include "jerryscript-compiler.h"
+
 #ifdef __cplusplus
 extern "C"
 {
@@ -62,7 +64,7 @@ typedef enum
  *
  * Example: a libc-based port may implement this with exit() or abort(), or both.
  */
-void jerry_port_fatal (jerry_fatal_code_t code) __attribute__((noreturn));
+void JERRY_ATTR_NORETURN jerry_port_fatal (jerry_fatal_code_t code);
 
 /*
  *  I/O Port API
@@ -96,7 +98,7 @@ typedef enum
  * Example: a libc-based port may implement this with vfprintf(stderr) or
  * vfprintf(logfile), or both, depending on log level.
  */
-void jerry_port_log (jerry_log_level_t level, const char *format, ...) __attribute__ ((format (printf, 2, 3)));
+void JERRY_ATTR_FORMAT (printf, 2, 3) jerry_port_log (jerry_log_level_t level, const char *format, ...);
 
 /*
  * Date Port API