use shared header for offsets

Author: nickdesaulniers

libc/src/setjmp/x86_64/setjmp.S

@@ -7,23 +7,14 @@
 //===----------------------------------------------------------------------===//
 
 #include "src/__support/assembly.h"
+#include "src/setjmp/x86_64/setjmp.h"
 
 #define paste(ns) _ZN22 ## ns ## 6setjmpEP9__jmp_buf
 #define expand(x) paste(x)
 #define LIBC_NAMESPACE_setjump expand(LIBC_NAMESPACE)
 // aka _ZN22__llvm_libc_19_0_0_git6setjmpEP9__jmp_buf
 // aka __llvm_libc_19_0_0_git::setjmp(__jmp_buf*)
 
-// Brittle! Changing the layout of __jmp_buf will break this!
-#define RBX_OFFSET 0
-#define RBP_OFFSET 8
-#define R12_OFFSET 16
-#define R13_OFFSET 24
-#define R14_OFFSET 32
-#define R15_OFFSET 40
-#define RSP_OFFSET 48
-#define RIP_OFFSET 56
-
 .global setjump
 .global LIBC_NAMESPACE_setjump
 

libc/src/setjmp/x86_64/setjmp.h

@@ -0,0 +1,22 @@
+
+// TODO: license block
+#ifndef LLVM_LIBC_SRC_SETJMP_X86_64_SETJMP_H
+#define LLVM_LIBC_SRC_SETJMP_X86_64_SETJMP_H
+
+#ifdef __ASSEMBLER__
+#define UL(x) x
+#else
+#define UL(x) x##UL
+#endif
+
+// Brittle! Changing the layout of __jmp_buf will break this!
+#define RBX_OFFSET UL(0)
+#define RBP_OFFSET UL(8)
+#define R12_OFFSET UL(16)
+#define R13_OFFSET UL(24)
+#define R14_OFFSET UL(32)
+#define R15_OFFSET UL(40)
+#define RSP_OFFSET UL(48)
+#define RIP_OFFSET UL(56)
+
+#endif // LLVM_LIBC_SRC_SETJMP_X86_64_SETJMP_H

libc/test/include/setjmp_test.cpp

@@ -8,21 +8,22 @@
 
 #include "include/llvm-libc-macros/offsetof-macro.h"
 #include "include/llvm-libc-types/jmp_buf.h"
+#include "src/setjmp/x86_64/setjmp.h"
 #include "test/UnitTest/Test.h"
 
 // If this test fails, then *_OFFSET macro definitions in
 // libc/src/setjmp/x86_64/setjmp.S need to be fixed. This is a simple change
 // detector.
 TEST(LlvmLibcSetjmpTest, JmpBufLayout) {
 #ifdef __x86_64__
-  ASSERT_EQ(offsetof(__jmp_buf, rbx), 0UL);
-  ASSERT_EQ(offsetof(__jmp_buf, rbp), 8UL);
-  ASSERT_EQ(offsetof(__jmp_buf, r12), 16UL);
-  ASSERT_EQ(offsetof(__jmp_buf, r13), 24UL);
-  ASSERT_EQ(offsetof(__jmp_buf, r14), 32UL);
-  ASSERT_EQ(offsetof(__jmp_buf, r15), 40UL);
-  ASSERT_EQ(offsetof(__jmp_buf, rsp), 48UL);
-  ASSERT_EQ(offsetof(__jmp_buf, rip), 56UL);
+  ASSERT_EQ(offsetof(__jmp_buf, rbx), RBX_OFFSET);
+  ASSERT_EQ(offsetof(__jmp_buf, rbp), RBP_OFFSET);
+  ASSERT_EQ(offsetof(__jmp_buf, r12), R12_OFFSET);
+  ASSERT_EQ(offsetof(__jmp_buf, r13), R13_OFFSET);
+  ASSERT_EQ(offsetof(__jmp_buf, r14), R14_OFFSET);
+  ASSERT_EQ(offsetof(__jmp_buf, r15), R15_OFFSET);
+  ASSERT_EQ(offsetof(__jmp_buf, rsp), RSP_OFFSET);
+  ASSERT_EQ(offsetof(__jmp_buf, rip), RIP_OFFSET);
   ASSERT_EQ(sizeof(__jmp_buf), 64UL);
   ASSERT_EQ(alignof(__jmp_buf), 8UL);
 #endif // __x86_64__