[lld] r359554 - [LLD][ELF] Fix getRankProximity to "ignore" not live sections

[Andrew Ng via llvm-commits]

Author: anng
Date: Tue Apr 30 05:27:06 2019
New Revision: 359554

URL: http://llvm.org/viewvc/llvm-project?rev=359554&view=rev
Log:
[LLD][ELF] Fix getRankProximity to "ignore" not live sections

This is a follow up to r358979 which made findOrphanPos only consider
live sections. Unfortunately, this required change to getRankProximity,
used by findOrphanPos, was missed.

Differential Revision: https://reviews.llvm.org/D61197

Added:
    lld/trunk/test/ELF/linkerscript/orphan-live-only.s
Modified:
    lld/trunk/ELF/Writer.cpp

Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=359554&r1=359553&r2=359554&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Tue Apr 30 05:27:06 2019
@@ -1050,9 +1050,8 @@ static int getRankProximityAux(OutputSec
 }
 
 static int getRankProximity(OutputSection *A, BaseCommand *B) {
-  if (auto *Sec = dyn_cast<OutputSection>(B))
-    return getRankProximityAux(A, Sec);
-  return -1;
+  auto *Sec = dyn_cast<OutputSection>(B);
+  return (Sec && Sec->Live) ? getRankProximityAux(A, Sec) : -1;
 }
 
 // When placing orphan sections, we want to place them after symbol assignments

Added: lld/trunk/test/ELF/linkerscript/orphan-live-only.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/orphan-live-only.s?rev=359554&view=auto
==============================================================================
--- lld/trunk/test/ELF/linkerscript/orphan-live-only.s (added)
+++ lld/trunk/test/ELF/linkerscript/orphan-live-only.s Tue Apr 30 05:27:06 2019
@@ -0,0 +1,42 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
+# RUN: echo "PHDRS { \
+# RUN:   exec PT_LOAD FLAGS(0x4 | 0x1); \
+# RUN:   ro   PT_LOAD FLAGS(0x4); \
+# RUN: } \
+# RUN: SECTIONS { \
+# RUN:  .pad : { QUAD(0); } :exec \
+# RUN:  .text : { *(.text) } \
+# RUN:  .ro : { *(.ro) } :ro \
+# RUN: }" > %t.script
+# RUN: ld.lld -o %t --script %t.script %t.o
+# RUN: llvm-readelf -S -l %t | FileCheck %s
+
+## The ".pad" section is not "live" and should be ignored by the
+## orphan placement.
+##
+## Check that the orphan section is placed correctly and belongs to
+## the correct segment.
+
+# CHECK: Section Headers
+# CHECK: .pad
+# CHECK-NEXT: .text
+# CHECK-NEXT: .orphan2
+# CHECK-NEXT: .ro
+# CHECK-NEXT: .orphan1
+
+# CHECK: Segment Sections
+# CHECK-NEXT: .pad .text .orphan2
+# CHECK-NEXT: .ro .orphan1
+
+.section .text,"ax"
+ ret
+
+.section .ro,"a"
+ .byte 0
+
+.section .orphan1,"a"
+ .byte 0
+
+.section .orphan2,"ax"
+ ret