[MCJIT] Refactor and add stub inspection to the RuntimeDyldChecker framework.

This patch introduces a 'stub_addr' builtin that can be used to find the address
of the stub for a given (<file>, <section>, <symbol>) tuple. This address can be
used both to verify the contents of stubs (by loading from the returned address)
and to verify references to stubs (by comparing against the returned address).

Example (1) - Verifying stub contents:

Load 8 bytes (assuming a 64-bit target) from the stub for 'x' in the __text
section of f.o, and compare that value against the addres of 'x'.

# rtdyld-check: *{8}(stub_addr(f.o, __text, x) = x

Example (2) - Verifying references to stubs:

Decode the immediate of the instruction at label 'l', and verify that it's
equal to the offset from the next instruction's PC to the stub for 'y' in the
__text section of f.o (i.e. it's the correct PC-rel difference).

# rtdyld-check: decode_operand(l, 4) = stub_addr(f.o, __text, y) - next_pc(l)
l:
        movq    y@GOTPCREL(%rip), %rax

Since stub inspection requires cooperation with RuntimeDyldImpl this patch
pimpl-ifies RuntimeDyldChecker. Its implementation is moved in to a new class,
RuntimeDyldCheckerImpl, that has access to the definition of RuntimeDyldImpl.

llvm-svn: 213698

1 files changed, 15 insertions, 4 deletions

diff --git a/llvm/test/ExecutionEngine/RuntimeDyld/X86/MachO_x86-64_PIC_relocations.s b/llvm/test/ExecutionEngine/RuntimeDyld/X86/MachO_x86-64_PIC_relocations.s
index e87b449bb23..847977b9eac 100644
--- a/llvm/test/ExecutionEngine/RuntimeDyld/X86/MachO_x86-64_PIC_relocations.s
+++ b/llvm/test/ExecutionEngine/RuntimeDyld/X86/MachO_x86-64_PIC_relocations.s
@@ -1,6 +1,6 @@
-# RUN: llvm-mc -triple=x86_64-apple-macosx10.9 -relocation-model=pic -filetype=obj -o %t.o %s
-# RUN: llvm-rtdyld -triple=x86_64-apple-macosx10.9 -verify -check=%s %t.o
-# RUN: rm %t.o
+# RUN: llvm-mc -triple=x86_64-apple-macosx10.9 -relocation-model=pic -filetype=obj -o %T/foo.o %s
+# RUN: sed "s,<filename>,%T/foo.o,g" %s > %T/foo.s
+# RUN: llvm-rtdyld -triple=x86_64-apple-macosx10.9 -verify -check=%T/foo.s %T/foo.o
 
         .section	__TEXT,__text,regular,pure_instructions
 	.globl	foo
@@ -20,9 +20,20 @@ insn1:
 # rtdyld-check: decode_operand(insn2, 4) = x - next_pc(insn2)
 insn2:
 	movl	x(%rip), %eax
-	movl	$0, %eax
+
+# Test PC-rel GOT relocation.
+# Verify both the contents of the GOT entry for y, and that the movq instruction
+# references the correct GOT entry address:
+# rtdyld-check: *{8}(stub_addr(<filename>, __text, y)) = y
+# rtdyld-check: decode_operand(insn3, 4) = stub_addr(<filename>, __text, y) - next_pc(insn3)
+insn3:
+        movq	y@GOTPCREL(%rip), %rax
+
+        movl	$0, %eax
 	retq
 
+        .comm   y,4,2
+
         .section	__DATA,__data
 	.globl	x
 	.align	2