Implement setjmp / longjmp in jerry-libc.

JerryScript-DCO-1.0-Signed-off-by: Ruben Ayrapetyan r.ayrapetyan@samsung.com

build/configs/toolchain_linux_armv7l-hf.cmake

@@ -18,4 +18,9 @@ set(CMAKE_SYSTEM_PROCESSOR armv7l)
 set(CMAKE_C_COMPILER arm-linux-gnueabihf-gcc)
 set(CMAKE_CXX_COMPILER arm-linux-gnueabihf-g++)
 
-set(FLAGS_COMMON_ARCH -mlittle-endian -mthumb)
+#
+# Limit fpu to VFPv3 with d0-d15 registers
+#
+# If this is changed, setjmp / longjmp for ARMv7 should be updated accordingly
+#
+set(FLAGS_COMMON_ARCH -mlittle-endian -mthumb -mfpu=vfpv3-d16)

jerry-libc/arch/arm-v7.h

@@ -80,13 +80,88 @@
   \
   pop {r4-r12, pc};
 
+/*
+ * ldr argc ([sp + 0x0]) -> r0
+ * add argv (sp + 0x4) -> r1
+ *
+ * bl main
+ *
+ * bl exit
+ *
+ * infinite loop
+ */
 #define _START            \
    ldr r0, [sp, #0];      \
    add r1, sp, #4;        \
    bl main;               \
                           \
-   bl exit;             \
+   bl exit;               \
    1:                     \
    b 1b
 
+
+/*
+ * setjmp
+ *
+ * According to procedure call standard for the ARM architecture, the following
+ * registers are callee-saved, and so need to be stored in context:
+ *   - r4 - r11
+ *   - sp
+ *   - s16-s31
+ *
+ * Also, we should store:
+ *   - lr
+ *
+ * stmia {r4-r11, sp, lr} -> jmp_buf_0 (r0)!
+ *
+ * FIXME:
+ *       vstm should not be performed in softfp mode
+ * vstm  {s16-s31} -> jmp_buf_32 (r0)!
+ *
+ * mov r0, #0
+ *
+ * bx lr
+ */
+#define _SETJMP \
+  stmia r0!, {r4 - r11, sp, lr}; \
+                                 \
+  vstm r0!, {s16 - s31};         \
+                                 \
+  mov r0, #0;                    \
+                                 \
+  bx lr;
+
+/*
+ * longjmp
+ *
+ * See also:
+ *          _SETJMP
+ *
+ * ldmia jmp_buf_0 (r0)! -> {r4-r11, sp, lr}
+ *
+ * FIXME:
+ *       vstm should not be performed in softfp mode
+ * vldm  jmp_buf_32 (r0)! -> {s16-s31}
+ *
+ * mov r1 -> r0
+ * cmp r0, #0
+ * bne 1f
+ * mov #1 -> r0
+ * 1:
+ *
+ * bx lr
+ */
+#define _LONGJMP \
+  ldmia r0!, {r4 - r11, sp, lr}; \
+                                 \
+  vldm r0!, {s16 - s31};         \
+                                 \
+  mov r0, r1;                    \
+  cmp r0, #0;                    \
+  bne 1f;                        \
+  mov r0, #1;                    \
+  1:                             \
+                                 \
+  bx lr;
+
 #endif /* !ASM_ARM_H */

jerry-libc/arch/x86-32.h

@@ -92,6 +92,17 @@
   pop %edi;               \
   ret;
 
+/*
+ * push argv (%esp + 4)
+ * push argc ([%esp + 0x4])
+ *
+ * call main
+ *
+ * push main_ret (%eax)
+ * call exit
+ *
+ * infinite loop
+ */
 #define _START             \
    mov %esp, %eax;         \
    add $4, %eax;           \
@@ -103,7 +114,100 @@
                            \
    push %eax;              \
    call exit;              \
+                           \
    1:                      \
    jmp 1b
 
+/*
+ * setjmp
+ *
+ * According to x86_32 System V ABI, the following registers are
+ * callee-saved, and so need to be stored in context:
+ *   - %ebx
+ *   - %esp
+ *   - %ebp
+ *   - %esi
+ *   - %edi
+ *   - x87 control word
+ *
+ * Also, we should store:
+ *   - return address (to jump to upon longjmp)
+ *
+ * mov return_address ([%esp]) -> %eax
+ *
+ * mov env ([%esp + 0x4]) -> %edx
+ *
+ * mov %ebx -> jmp_buf_0  ([%edx + 0x0])
+ * mov %esp -> jmp_buf_4  ([%edx + 0x4])
+ * mov %ebp -> jmp_buf_8  ([%edx + 0x8])
+ * mov %esi -> jmp_buf_12 ([%edx + 0xc])
+ * mov %edi -> jmp_buf_16 ([%edx + 0x10])
+ * mov %eax -> jmp_buf_20 ([%edx + 0x14])
+ * fnstcw   -> jmp_buf_24 ([%edx + 0x18])
+ *
+ * ret
+ */
+#define _SETJMP \
+  mov (%esp), %eax;       \
+  mov 0x4 (%esp), %edx;   \
+                          \
+  mov %ebx, 0x00 (%edx);  \
+  mov %esp, 0x04 (%edx);  \
+  mov %ebp, 0x08 (%edx);  \
+  mov %esi, 0x0c (%edx);  \
+  mov %edi, 0x10 (%edx);  \
+  mov %eax, 0x14 (%edx);  \
+  fnstcw 0x18 (%edx);     \
+                          \
+  xor %eax, %eax;         \
+                          \
+  ret
+
+/*
+ * longjmp
+ *
+ * See also:
+ *          _SETJMP
+ *
+ * mov env ([%esp + 0x4]) -> %edx
+ * mov val ([%esp + 0x8]) -> %eax
+ *
+ * mov jmp_buf_0    ([%edx + 0x0])  -> %ebx
+ * mov jmp_buf_4    ([%edx + 0x8])  -> %esp
+ * mov jmp_buf_8    ([%edx + 0x10]) -> %ebp
+ * mov jmp_buf_12   ([%edx + 0x18]) -> %esi
+ * mov jmp_buf_16   ([%edx + 0x20]) -> %edi
+ * mov jmp_buf_20   ([%edx + 0x28]) -> %ecx
+ * fldcw jmp_buf_24 ([%edx + 0x30])
+ *
+ * mov return_address (%ecx) -> ([%esp])
+ *
+ * cmp (%eax), 0x0
+ * jnz 1f
+ * xor %eax, %eax
+ * 1:
+ *
+ * ret
+ */
+#define _LONGJMP \
+  mov 0x4 (%esp), %edx;   \
+  mov 0x8 (%esp), %eax;   \
+                          \
+  mov 0x0 (%edx), %ebx;   \
+  mov 0x4 (%edx), %esp;   \
+  mov 0x8 (%edx), %ebp;   \
+  mov 0xc (%edx), %esi;   \
+  mov 0x10 (%edx), %edi;  \
+  mov 0x14 (%edx), %ecx;  \
+  fldcw 0x18 (%edx);      \
+                          \
+  mov %ecx, (%esp);       \
+                          \
+  test %eax, %eax;        \
+  jnz 1f;                 \
+  xor %eax, %eax;         \
+ 1:                       \
+                          \
+  ret
+
 #endif /* !ASM_X86_H */

jerry-libc/arch/x86-64.h

@@ -64,6 +64,17 @@
   syscall; \
   ret;
 
+/*
+ * mov argc ([%rsp]) -> %rdi
+ * mov argv (%rsp + 0x8) -> %rsi
+ *
+ * call main
+ *
+ * mov main_ret (%rax) -> %rdi
+ * call exit
+ *
+ * infinite loop
+ */
 #define _START            \
    mov (%rsp), %rdi;      \
    mov %rsp, %rsi;        \
@@ -71,8 +82,107 @@
    callq main;            \
                           \
    mov %rax, %rdi;        \
-   callq exit;          \
+   callq exit;            \
    1:                     \
    jmp 1b
 
+/*
+ * setjmp
+ *
+ * According to x86_64 System V ABI, the following registers are
+ * callee-saved, and so need to be stored in context:
+ *   - %rbp
+ *   - %rbx
+ *   - %r12
+ *   - %r13
+ *   - %r14
+ *   - %r15
+ *   - x87 control word
+ *
+ * Also, we should store:
+ *   - %rsp (stack pointer)
+ *   - return address (to jump to upon longjmp)
+ *
+ * mov return_address ([%rsp]) -> %rax
+ *
+ * mov %rsp -> jmp_buf_0  ([%rdi + 0x0])
+ * mov %rax -> jmp_buf_8  ([%rdi + 0x8])
+ * mov %rbp -> jmp_buf_16 ([%rdi + 0x10])
+ * mov %rbx -> jmp_buf_24 ([%rdi + 0x18])
+ * mov %r12 -> jmp_buf_32 ([%rdi + 0x20])
+ * mov %r13 -> jmp_buf_40 ([%rdi + 0x28])
+ * mov %r14 -> jmp_buf_48 ([%rdi + 0x30])
+ * mov %r15 -> jmp_buf_56 ([%rdi + 0x38])
+ * fnstcw   -> jmp_buf_64 ([%rdi + 0x40])
+ *
+ * ret
+ */
+#define _SETJMP \
+  mov (%rsp), %rax;      \
+                         \
+  mov %rsp, 0x00(%rdi);  \
+  mov %rax, 0x08(%rdi);  \
+  mov %rbp, 0x10(%rdi);  \
+  mov %rbx, 0x18(%rdi);  \
+  mov %r12, 0x20(%rdi);  \
+  mov %r13, 0x28(%rdi);  \
+  mov %r14, 0x30(%rdi);  \
+  mov %r15, 0x38(%rdi);  \
+  fnstcw 0x40(%rdi);     \
+                         \
+  xor %rax, %rax;        \
+                         \
+  ret;
+
+/*
+ * longjmp
+ *
+ * See also:
+ *          _SETJMP
+ *
+ * mov jmp_buf_0  ([%rdi + 0x0])  -> %rsp
+ * mov jmp_buf_8  ([%rdi + 0x8])  -> %rax
+ * mov jmp_buf_16 ([%rdi + 0x10]) -> %rbp
+ * mov jmp_buf_24 ([%rdi + 0x18]) -> %rbx
+ * mov jmp_buf_32 ([%rdi + 0x20]) -> %r12
+ * mov jmp_buf_40 ([%rdi + 0x28]) -> %r13
+ * mov jmp_buf_48 ([%rdi + 0x30]) -> %r14
+ * mov jmp_buf_56 ([%rdi + 0x38]) -> %r15
+ * fldcw jmp_buf_64 ([%rdi + 0x40])
+ *
+ * mov return_address (%rax) -> ([%rsp])
+ *
+ * mov val (%rsi) -> %rax
+ *
+ * test (%rax), (%rax)
+ * jnz 1f
+ * mov $1, %rax
+ * 1:
+ *
+ * ret
+ */
+#define _LONGJMP \
+  mov 0x00(%rdi), %rsp; \
+  mov 0x08(%rdi), %rax; \
+  mov 0x10(%rdi), %rbp; \
+  mov 0x18(%rdi), %rbx; \
+  mov 0x20(%rdi), %r12; \
+  mov 0x28(%rdi), %r13; \
+  mov 0x30(%rdi), %r14; \
+  mov 0x38(%rdi), %r15; \
+  fldcw 0x40(%rdi);     \
+                        \
+  mov %rax, (%rsp);     \
+                        \
+  mov %rsi, %rax;       \
+                        \
+  test %rax, %rax;      \
+  jnz 1f;               \
+  mov $1, %rax;         \
+ 1:                     \
+                        \
+  ret
+
+
+
 #endif /* !ASM_X64_H */

jerry-libc/include/setjmp.h

@@ -0,0 +1,60 @@
+/* Copyright 2015 Samsung Electronics Co., Ltd.
+ *
+ * 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 JERRY_LIBC_SETJMP_H
+#define JERRY_LIBC_SETJMP_H
+
+#ifdef __cplusplus
+# define EXTERN_C "C"
+#else /* !__cplusplus */
+# define EXTERN_C
+#endif /* !__cplusplus */
+
+/**
+ * Storage for context, used for nonlocal goto
+ *
+ * x86_64 (8 * 8 + 2 bytes):
+ *   0x00 - %rsp
+ *   0x08 - return address
+ *   0x10 - %rbp
+ *   0x18 - %rbx
+ *   0x20 - %r12
+ *   0x28 - %r13
+ *   0x30 - %r14
+ *   0x38 - %r15
+ *   0x40 - x87 control word
+ *
+ * x86_32 (6 * 4 + 2 bytes):
+ *   - %ebx
+ *   - %esp
+ *   - %ebp
+ *   - %esi
+ *   - %edi
+ *   - return address (to jump to upon longjmp)
+ *   - x87 control word
+ *
+ * ARMv7 (8 * 4 + 16 * 4 bytes):
+ *   - r4 - r11
+ *   - s16 - s31 (if hardfp enabled)
+ *
+ * See also:
+ *          setjmp, longjmp
+ */
+typedef uint64_t jmp_buf[12];
+
+extern EXTERN_C int setjmp (jmp_buf env);
+extern EXTERN_C void longjmp (jmp_buf env, int val);
+
+#endif /* !JERRY_LIBC_SETJMP_H */

jerry-libc/target/linux/jerry-asm.S

@@ -38,3 +38,33 @@ syscall_3_asm:
   SYSCALL_3
 .size syscall_3_asm, . - syscall_3_asm
 
+/**
+ * setjmp (jmp_buf env)
+ *
+ * See also:
+ *          longjmp
+ *
+ * @return 0 - if returns from direct call,
+ *         nonzero - if returns after longjmp.
+ */
+.global setjmp
+.type setjmp, %function
+setjmp:
+  _SETJMP
+.size setjmp, . - setjmp
+
+/**
+ * longjmp (jmp_buf env, int val)
+ *
+ * Note:
+ *      if val is not 0, then it would be returned from setjmp,
+ *      otherwise - 0 would be returned.
+ *
+ * See also:
+ *          setjmp
+ */
+.global longjmp
+.type longjmp, %function
+longjmp:
+  _LONGJMP
+.size longjmu, . - setjmp

tests/unit/test-common.h

@@ -19,6 +19,7 @@
 #include "jrt.h"
 
 #include <math.h>
+#include <setjmp.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

tests/unit/test-longjmp.cpp

@@ -0,0 +1,82 @@
+/* Copyright 2015 Samsung Electronics Co., Ltd.
+ *
+ * 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.
+ */
+
+#include "test-common.h"
+
+#define TEST_MAX_DEPTH 10
+#define TEST_ITERATIONS_NUM 256
+
+jmp_buf buffers[TEST_MAX_DEPTH];
+
+static void
+test_setjmp_longjmp (volatile int depth)
+{
+  if (depth != TEST_MAX_DEPTH)
+  {
+    int a = 1, b = 2, c = 3;
+
+    int array[256];
+    for (int i = 0; i < 256; i++)
+    {
+      array[i] = i;
+    }
+
+    (void) a;
+    (void) b;
+    (void) c;
+    (void) array;
+
+    int k = setjmp (buffers[depth]);
+
+    if (k == 0)
+    {
+      test_setjmp_longjmp (depth + 1);
+    }
+    else
+    {
+      JERRY_ASSERT (k == depth + 1);
+
+      JERRY_ASSERT (a == 1);
+      JERRY_ASSERT (b == 2);
+      JERRY_ASSERT (c == 3);
+
+      for (int i = 0; i < 256; i++)
+      {
+        JERRY_ASSERT (array[i] == i);
+      }
+    }
+  }
+  else
+  {
+    int t = rand () % depth;
+    JERRY_ASSERT (t >= 0 && t < depth);
+
+    longjmp (buffers[t], t + 1);
+  }
+}
+
+int
+main (int __attr_unused___ argc,
+      char __attr_unused___ **argv)
+{
+  TEST_INIT ();
+
+  for (int i = 0; i < TEST_ITERATIONS_NUM; i++)
+  {
+    test_setjmp_longjmp (0);
+  }
+
+  return 0;
+} /* main */