Add support for init/fini arrays to libc (#1725)

The arrays contain the addresses of functions annotated with
constructor or destructor attributes. The support is optional,
requires FEATURE_INIT_FINI cmake option to be set. As of now, the
option is _not_ available in tools/build.py directly, only via
`--cmake-param="-DFEATURE_INIT_FINI=ON"`.

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

jerry-libc/CMakeLists.txt

@@ -16,6 +16,18 @@ cmake_minimum_required (VERSION 2.8.12)
 set(JERRY_LIBC_NAME jerry-libc)
 project (${JERRY_LIBC_NAME} C ASM)
 
+# Optional features
+set(FEATURE_INIT_FINI OFF CACHE BOOL "Enable init/fini arrays?")
+
+# Status messages
+message(STATUS "FEATURE_INIT_FINI         " ${FEATURE_INIT_FINI})
+
+# Checks the optional features
+# Enable init/fini arrays
+if(FEATURE_INIT_FINI)
+  set(DEFINES_LIBC ${DEFINES_LIBC} ENABLE_INIT_FINI)
+endif()
+
 # Architecture-specific configuration
 if(${CMAKE_SYSTEM_PROCESSOR} STREQUAL "x86_64")
   set(DEFINES_LIBC ${DEFINES_LIBC} __TARGET_HOST_x64)

jerry-libc/arch/arm-v7.h

@@ -80,24 +80,37 @@
   \
   pop {r4-r12, pc};
 
+#ifdef ENABLE_INIT_FINI
 /*
+ * bl libc_init_array
+ */
+#define _INIT           \
+  bl libc_init_array;
+#else /* !ENABLE_INIT_FINI */
+#define _INIT
+#endif /* ENABLE_INIT_FINI */
+
+/*
+ * bl libc_init_array
+ *
  * ldr argc ([sp + 0x0]) -> r0
  * add argv (sp + 0x4) -> r1
- *
  * bl main
  *
  * bl exit
  *
  * infinite loop
  */
-#define _START            \
+#define _START          \
-   ldr r0, [sp, #0];      \
+  _INIT;                \
-   add r1, sp, #4;        \
+                        \
-   bl main;               \
+  ldr r0, [sp, #0];     \
-                          \
+  add r1, sp, #4;       \
-   bl exit;               \
+  bl main;              \
-   1:                     \
+                        \
-   b 1b
+  bl exit;              \
+  1:                    \
+  b 1b;
 
 /**
  * If hard-float mode:

jerry-libc/arch/x86-32.h

@@ -92,7 +92,19 @@
   pop %edi;               \
   ret;
 
+#ifdef ENABLE_INIT_FINI
 /*
+ * call libc_init_array
+ */
+#define _INIT             \
+  call libc_init_array;
+#else /* !ENABLE_INIT_FINI */
+#define _INIT
+#endif /* ENABLE_INIT_FINI */
+
+/*
+ * call libc_init_array
+ *
  * push argv (%esp + 4)
  * push argc ([%esp + 0x4])
  *
@@ -103,20 +115,22 @@
  *
  * infinite loop
  */
-#define _START             \
+#define _START            \
-   mov %esp, %eax;         \
+  _INIT;                  \
-   add $4, %eax;           \
+                          \
-   push %eax;              \
+  mov %esp, %eax;         \
-   mov 0x4 (%esp), %eax;   \
+  add $4, %eax;           \
-   push %eax;              \
+  push %eax;              \
-                           \
+  mov 0x4 (%esp), %eax;   \
-   call main;              \
+  push %eax;              \
-                           \
+                          \
-   push %eax;              \
+  call main;              \
-   call exit;              \
+                          \
-                           \
+  push %eax;              \
-   1:                      \
+  call exit;              \
-   jmp 1b
+                          \
+  1:                      \
+  jmp 1b;
 
 /*
  * setjmp

jerry-libc/arch/x86-64.h

@@ -64,7 +64,19 @@
   syscall; \
   ret;
 
+#ifdef ENABLE_INIT_FINI
 /*
+ * call libc_init_array
+ */
+#define _INIT             \
+  call libc_init_array;
+#else /* !ENABLE_INIT_FINI */
+#define _INIT
+#endif /* ENABLE_INIT_FINI */
+
+/*
+ * call libc_init_array
+ *
  * mov argc ([%rsp]) -> %rdi
  * mov argv (%rsp + 0x8) -> %rsi
  *
@@ -76,15 +88,17 @@
  * infinite loop
  */
 #define _START            \
-   mov (%rsp), %rdi;      \
+  _INIT;                  \
-   mov %rsp, %rsi;        \
-   add $8, %rsi;          \
-   callq main;            \
                           \
-   mov %rax, %rdi;        \
+  mov (%rsp), %rdi;       \
-   callq exit;            \
+  mov %rsp, %rsi;         \
-   1:                     \
+  add $8, %rsi;           \
-   jmp 1b
+  callq main;             \
+                          \
+  mov %rax, %rdi;         \
+  callq exit;             \
+  1:                      \
+  jmp 1b;
 
 /*
  * setjmp

jerry-libc/jerry-libc-defs.h

@@ -27,5 +27,11 @@
 #define __attr_used___     __attribute__((used))
 #define __attr_noreturn___ __attribute__((noreturn))
 #define __attr_noinline___ __attribute__((noinline))
+#define __attr_weak___     __attribute__((weak))
+
+#ifdef ENABLE_INIT_FINI
+void libc_init_array (void);
+void libc_fini_array (void);
+#endif /* ENABLE_INIT_FINI */
 
 #endif /* !DEFS_H */

jerry-libc/jerry-libc-init.c

@@ -0,0 +1,98 @@
+/* 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.
+ *
+ * This file is based on work under the following copyright and permission
+ * notice:
+ *
+ *    Copyright (C) 2004 CodeSourcery, LLC
+ *
+ *    Permission to use, copy, modify, and distribute this file
+ *    for any purpose is hereby granted without fee, provided that
+ *    the above copyright notice and this notice appears in all
+ *    copies.
+ *
+ *    This file is distributed WITHOUT ANY WARRANTY; without even the implied
+ *    warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#include "jerry-libc-defs.h"
+
+#ifdef ENABLE_INIT_FINI
+
+/* These magic symbols are provided by the linker.  */
+typedef void (*libc_init_fn_t) (void);
+
+extern libc_init_fn_t __preinit_array_start[] __attr_weak___;
+extern libc_init_fn_t __preinit_array_end[] __attr_weak___;
+extern libc_init_fn_t __init_array_start[] __attr_weak___;
+extern libc_init_fn_t __init_array_end[] __attr_weak___;
+extern libc_init_fn_t __fini_array_start[] __attr_weak___;
+extern libc_init_fn_t __fini_array_end[] __attr_weak___;
+extern void _init (void);
+extern void _fini (void);
+
+
+/**
+ * No-op default _init.
+ */
+void  __attr_weak___
+_init (void)
+{
+} /* _init */
+
+/**
+ * No-op default _fini.
+ */
+void  __attr_weak___
+_fini (void)
+{
+} /* _fini */
+
+/**
+ * Iterate over all the init routines.
+ */
+void
+libc_init_array (void)
+{
+  size_t count = (size_t) (__preinit_array_end - __preinit_array_start);
+  for (size_t i = 0; i < count; i++)
+  {
+    __preinit_array_start[i] ();
+  }
+
+  _init ();
+
+  count = (size_t) (__init_array_end - __init_array_start);
+  for (size_t i = 0; i < count; i++)
+  {
+    __init_array_start[i] ();
+  }
+} /* libc_init_array */
+
+/**
+ * Run all the cleanup routines.
+ */
+void
+libc_fini_array (void)
+{
+  size_t count = (size_t) (__fini_array_end - __fini_array_start);
+  for (size_t i = count; i > 0; i--)
+  {
+    __fini_array_start[i - 1] ();
+  }
+
+  _fini ();
+} /* libc_fini_array */
+
+#endif /* ENABLE_INIT_FINI */

jerry-libc/target/posix/jerry-libc-target.c

@@ -51,6 +51,10 @@ long int syscall_3 (long int syscall_no, long int arg1, long int arg2, long int
 void __attr_noreturn___ __attr_used___
 exit (int status) /**< status code */
 {
+#ifdef ENABLE_INIT_FINI
+  libc_fini_array ();
+#endif /* ENABLE_INIT_FINI */
+
   syscall_1 (SYSCALL_NO (close), (long int) stdin);
   syscall_1 (SYSCALL_NO (close), (long int) stdout);
   syscall_1 (SYSCALL_NO (close), (long int) stderr);

tools/cppcheck/suppressions-list

@@ -1,3 +1,4 @@
 wrongmathcall:tests/unit/test-libm.inc.h
 variableScope:jerry-libm/*.c
 invalidPointerCast:jerry-libm/*.c
+arithOperationsOnVoidPointer:jerry-libc/*.c