[PATCH] D61197: [LLD][ELF] Fix getRankProximity to "ignore" not live sections

Andrew Ng via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Fri Apr 26 09:04:42 PDT 2019


andrewng created this revision.
andrewng added reviewers: ruiu, grimar.
Herald added subscribers: MaskRay, arichardson, emaste.
Herald added a reviewer: espindola.

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.


https://reviews.llvm.org/D61197

Files:
  ELF/Writer.cpp
  test/ELF/linkerscript/orphan-live-only.s


Index: test/ELF/linkerscript/orphan-live-only.s
===================================================================
--- /dev/null
+++ test/ELF/linkerscript/orphan-live-only.s
@@ -0,0 +1,38 @@
+# 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: .ro
+# CHECK-NEXT: .orphan
+
+# CHECK: Segment Sections
+# CHECK-NEXT: .pad .text
+# CHECK-NEXT: .ro .orphan
+
+.section .text,"ax"
+ ret
+
+.section .ro,"a"
+ .byte 0
+
+.section .orphan,"a"
+ .byte 0
Index: ELF/Writer.cpp
===================================================================
--- ELF/Writer.cpp
+++ ELF/Writer.cpp
@@ -1050,9 +1050,8 @@
 }
 
 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


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D61197.196860.patch
Type: text/x-patch
Size: 1615 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20190426/107a7a09/attachment.bin>


More information about the llvm-commits mailing list