1 files changed, 44 insertions, 0 deletions
diff --git a/bindings/linux/setjmp.h b/bindings/linux/setjmp.h
new file mode 100644
index 0000000..6da4313
--- /dev/null
+++ b/bindings/linux/setjmp.h
@@ -0,0 +1,44 @@
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2012 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ */
+
+// Linux doesn't provide setjmp/longjmp, boo.
+
+typedef void *jmp_buf[3];  // rsp, rbp, rip
+
+static inline int _setjmp(jmp_buf env) {
+  register int ret asm ("%eax");
+  __asm__ __volatile__ goto (
+      "  movq %%rsp, 0(%0)\n"  // Save rsp
+      "  movq %%rbp, 8(%0)\n"  // Save rbp
+      "  movq $1f,  16(%0)\n"  // Save rip
+      "  jmp %l[setup]\n"
+      "1:"
+      : // No outputs allowed (GCC limitation).
+      : "b" (env)  // Input
+      : // All registers clobbered except rsp, which save in env.
+        "%rcx", "%rdx", "%rdi", "%rsi", "memory", "cc",
+        "%r8" , "%r9" , "%r10", "%r11", "%r12", "%r13", "%r14", "%r15"
+      : setup      // Target labels.
+  );
+  return ret;
+
+setup:
+  return 0;
+}
+
+__attribute__((__noreturn__))
+static inline void _longjmp(jmp_buf env, int val) {
+  __asm__ __volatile__ (
+      "  movq  0(%0), %%rsp\n"  // Restore rsp
+      "  movq  8(%0), %%rbp\n"  // Restore rbp
+      "  movq  %0,    %%rbx\n"  // Restore rbx
+      "  jmpq  *16(%0)\n"       // Jump to saved rip
+    :  // No output.
+    : "r" (env), "a" (val)  // Move val to %eax
+  );
+  __builtin_unreachable();
+}