Reapply r360194 "[JITLink] Add support for MachO .alt_entry atoms." with fixes.

This patch modifies MachOAtomGraphBuilder to use setLayoutNext rather than
addEdge, and fixes a bug in the section layout algorithm that could result in
atoms appearing more than once in the section ordering (which resulted in those
atoms being assigned invalid addresses during layout).

llvm-svn: 360205

1 files changed, 63 insertions, 1 deletions

diff --git a/llvm/test/ExecutionEngine/JITLink/X86/MachO_x86-64_relocations.s b/llvm/test/ExecutionEngine/JITLink/X86/MachO_x86-64_relocations.s
index 6a9f0b48fa5..9ff382dd743 100644
--- a/llvm/test/ExecutionEngine/JITLink/X86/MachO_x86-64_relocations.s
+++ b/llvm/test/ExecutionEngine/JITLink/X86/MachO_x86-64_relocations.s
@@ -129,13 +129,19 @@ Lanon_minuend_quad:
 Lanon_minuend_long:
         .long Lanon_minuend_long - named_data + 2
 
-
 # Named quad storage target (first named atom in __data).
         .globl named_data
         .p2align  3
 named_data:
         .quad   0x2222222222222222
 
+# An alt-entry point for named_data
+        .globl named_data_alt_entry
+        .p2align  3
+        .alt_entry named_data_alt_entry
+named_data_alt_entry:
+        .quad   0
+
 # Check X86_64_RELOC_UNSIGNED / extern handling by putting the address of a
 # local named function in a pointer variable.
 #
@@ -201,4 +207,60 @@ minuend_quad3:
 minuend_long3:
         .long minuend_long3 - named_data + 2
 
+# Check X86_64_RELOC_SUBTRACTOR handling for exprs of the form
+# "A: .quad/long B - C + D", where 'B' or 'C' is at a fixed offset from 'A'
+# (i.e. is part of an alt_entry chain that includes 'A').
+#
+# Check "A: .long B - C + D" where 'B' is an alt_entry for 'A'.
+# jitlink-check: *{4}subtractor_with_alt_entry_minuend_long = (subtractor_with_alt_entry_minuend_long_B - named_data + 2)[31:0]
+        .globl  subtractor_with_alt_entry_minuend_long
+        .p2align  2
+subtractor_with_alt_entry_minuend_long:
+        .long subtractor_with_alt_entry_minuend_long_B - named_data + 2
+
+        .globl  subtractor_with_alt_entry_minuend_long_B
+        .p2align  2
+        .alt_entry subtractor_with_alt_entry_minuend_long_B
+subtractor_with_alt_entry_minuend_long_B:
+        .long 0
+
+# Check "A: .quad B - C + D" where 'B' is an alt_entry for 'A'.
+# jitlink-check: *{8}subtractor_with_alt_entry_minuend_quad = (subtractor_with_alt_entry_minuend_quad_B - named_data + 2)
+        .globl  subtractor_with_alt_entry_minuend_quad
+        .p2align  3
+subtractor_with_alt_entry_minuend_quad:
+        .quad subtractor_with_alt_entry_minuend_quad_B - named_data + 2
+
+        .globl  subtractor_with_alt_entry_minuend_quad_B
+        .p2align  3
+        .alt_entry subtractor_with_alt_entry_minuend_quad_B
+subtractor_with_alt_entry_minuend_quad_B:
+        .quad 0
+
+# Check "A: .long B - C + D" where 'C' is an alt_entry for 'A'.
+# jitlink-check: *{4}subtractor_with_alt_entry_subtrahend_long = (named_data - subtractor_with_alt_entry_subtrahend_long_B + 2)[31:0]
+        .globl  subtractor_with_alt_entry_subtrahend_long
+        .p2align  2
+subtractor_with_alt_entry_subtrahend_long:
+        .long named_data - subtractor_with_alt_entry_subtrahend_long_B + 2
+
+        .globl  subtractor_with_alt_entry_subtrahend_long_B
+        .p2align  2
+        .alt_entry subtractor_with_alt_entry_subtrahend_long_B
+subtractor_with_alt_entry_subtrahend_long_B:
+        .long 0
+
+# Check "A: .quad B - C + D" where 'B' is an alt_entry for 'A'.
+# jitlink-check: *{8}subtractor_with_alt_entry_subtrahend_quad = (named_data - subtractor_with_alt_entry_subtrahend_quad_B + 2)
+        .globl  subtractor_with_alt_entry_subtrahend_quad
+        .p2align  3
+subtractor_with_alt_entry_subtrahend_quad:
+        .quad named_data - subtractor_with_alt_entry_subtrahend_quad_B + 2
+
+        .globl  subtractor_with_alt_entry_subtrahend_quad_B
+        .p2align  3
+        .alt_entry subtractor_with_alt_entry_subtrahend_quad_B
+subtractor_with_alt_entry_subtrahend_quad_B:
+        .quad 0
+
 .subsections_via_symbols