[lld] 3a8c6a3 - [lld-macho] Fix __objc_stubs ordering

[Keith Smiley via llvm-commits]

Author: Keith Smiley
Date: 2022-12-13T13:23:27-08:00
New Revision: 3a8c6a3039afa064719a498a37428ded7874188f

URL: https://github.com/llvm/llvm-project/commit/3a8c6a3039afa064719a498a37428ded7874188f
DIFF: https://github.com/llvm/llvm-project/commit/3a8c6a3039afa064719a498a37428ded7874188f.diff

LOG: [lld-macho] Fix __objc_stubs ordering

In the case of large binaries previously you could end up getting
relocation failures. This mirrors ld64's ordering of these sections. I'm
not sure this solves all cases but it should help in some.

Fixes https://github.com/llvm/llvm-project/issues/58298

Differential Revision: https://reviews.llvm.org/D139909

Added: 
    

Modified: 
    lld/MachO/OutputSegment.cpp
    lld/test/MachO/x86-64-objc-stubs.s

Removed: 
    


################################################################################
diff  --git a/lld/MachO/OutputSegment.cpp b/lld/MachO/OutputSegment.cpp
index 3b28dfd306c38..a887bc4d515de 100644
--- a/lld/MachO/OutputSegment.cpp
+++ b/lld/MachO/OutputSegment.cpp
@@ -90,10 +90,11 @@ static int sectionOrder(OutputSection *osec) {
   // Sections are uniquely identified by their segment + section name.
   if (segname == segment_names::text) {
     return StringSwitch<int>(osec->name)
-        .Case(section_names::header, -5)
-        .Case(section_names::text, -4)
-        .Case(section_names::stubs, -3)
-        .Case(section_names::stubHelper, -2)
+        .Case(section_names::header, -6)
+        .Case(section_names::text, -5)
+        .Case(section_names::stubs, -4)
+        .Case(section_names::stubHelper, -3)
+        .Case(section_names::objcStubs, -2)
         .Case(section_names::initOffsets, -1)
         .Case(section_names::unwindInfo, std::numeric_limits<int>::max() - 1)
         .Case(section_names::ehFrame, std::numeric_limits<int>::max())

diff  --git a/lld/test/MachO/x86-64-objc-stubs.s b/lld/test/MachO/x86-64-objc-stubs.s
index f29326939c7f6..5e8b9fb165f25 100644
--- a/lld/test/MachO/x86-64-objc-stubs.s
+++ b/lld/test/MachO/x86-64-objc-stubs.s
@@ -2,17 +2,35 @@
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t.o
 # RUN: %lld -arch x86_64 -lSystem -o %t.out %t.o
-# RUN: llvm-otool -vs __TEXT __objc_stubs %t.out | FileCheck %s
+# RUN: llvm-objdump --macho --section-headers %t.out > %t.txt
+# RUN: llvm-otool -vs __DATA __objc_selrefs %t.out >> %t.txt
+# RUN: llvm-otool -vs __TEXT __objc_stubs %t.out >> %t.txt
+# RUN: FileCheck %s < %t.txt
+
+# CHECK: Sections:
+# CHECK: __got            {{[0-9a-f]*}} [[#%x, GOTSTART:]] DATA
+# CHECK: __objc_selrefs   {{[0-9a-f]*}} [[#%x, SELSTART:]] DATA
+
+# CHECK: Contents of (__DATA,__objc_selrefs) section
+
+# CHECK-NEXT: {{[0-9a-f]*}}  __TEXT:__objc_methname:foo
+# CHECK-NEXT: {{[0-9a-f]*}}  __TEXT:__objc_methname:bar
+# CHECK-NEXT: [[#%x, FOOSELREF:]]  __TEXT:__objc_methname:foo
+# CHECK-NEXT: [[#%x, LENGTHSELREF:]]  __TEXT:__objc_methname:length
 
 # CHECK: Contents of (__TEXT,__objc_stubs) section
 
 # CHECK-NEXT: _objc_msgSend$foo:
-# CHECK-NEXT: 00000001000004b8	movq	0x1b51(%rip), %rsi
-# CHECK-NEXT: 00000001000004bf	jmpq	*0xb3b(%rip)
+# CHECK-NEXT: [[#%x, PC1:]]
+# CHECK-SAME: movq    0x[[#%x, FOOSELREF - PC1 - 7]](%rip), %rsi
+# CHECK-NEXT: [[#%x, PC2:]]
+# CHECK-SAME: jmpq    *0x[[#%x, GOTSTART - PC2 - 6]](%rip)
 
 # CHECK-NEXT: _objc_msgSend$length:
-# CHECK-NEXT: 00000001000004c5	movq	0x1b4c(%rip), %rsi
-# CHECK-NEXT: 00000001000004cc	jmpq	*0xb2e(%rip)
+# CHECK-NEXT: [[#%x, PC3:]]
+# CHECK-SAME: movq    0x[[#%x, LENGTHSELREF - PC3 - 7]](%rip), %rsi
+# CHECK-NEXT: [[#%x, PC4:]]
+# CHECK-SAME: jmpq    *0x[[#%x, GOTSTART - PC4 - 6]](%rip)
 
 # CHECK-EMPTY: