[ELF] mergeSections: remove non-alive MergeInputSection

Summary: This makes it conform to what the comment says. Otherwise when getErrPlace() is called afterwards, cast<InputSection>(D) will cause incompatible cast as MergeInputSection is not a subclass of InputSection.

Reviewers: ruiu, grimar, espindola, pcc

Reviewed By: grimar

Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D50742

llvm-svn: 339904

diff --git a/lld/ELF/SyntheticSections.cpp b/lld/ELF/SyntheticSections.cpp
index 1e6e3d2..f5a2498 100644 (file)
--- a/lld/ELF/SyntheticSections.cpp
+++ b/lld/ELF/SyntheticSections.cpp
@@ -2929,8 +2929,10 @@ void elf::mergeSections() {
 
     // We do not want to handle sections that are not alive, so just remove
     // them instead of trying to merge.
-    if (!MS->Live)
+    if (!MS->Live) {
+      S = nullptr;
       continue;
+    }
 
     StringRef OutsecName = getOutputSectionName(MS);
     uint32_t Alignment = std::max<uint32_t>(MS->Alignment, MS->Entsize);

diff --git a/lld/test/ELF/x86-64-reloc-error2.s b/lld/test/ELF/x86-64-reloc-error2.s
index d49b675..81f033f 100644 (file)
--- a/lld/test/ELF/x86-64-reloc-error2.s
+++ b/lld/test/ELF/x86-64-reloc-error2.s
@@ -1,14 +1,18 @@
 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
-# RUN: not ld.lld %t.o -o /dev/null 2>&1 | FileCheck %s
+# RUN: not ld.lld --entry=func --gc-sections %t.o -o /dev/null 2>&1 | FileCheck %s
 
 ## Check we are able to find a function symbol that encloses
 ## a given location when reporting error messages.
 # CHECK: {{.*}}.o:(function func): relocation R_X86_64_32S out of range: -281474974609408 is not in [-2147483648, 2147483647]
 
+# This mergeable section will be garbage collected. We had a crash issue in that case. Test it.
+.section .rodata.str1,"aMS",@progbits,1
+.asciz "a"
+
 .section .text.func, "ax", %progbits
 .globl func
 .type func,@function
-.size func, 0x10
 func:
- movq func - 0x1000000000000, %rdx
+  movq $func - 0x1000000000000, %rdx
+.size func, .-func