[lld] r281647 - Make sure we create all necessary PT_LOADs.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Thu Sep 15 14:36:01 2016
New Revision: 281647

URL: http://llvm.org/viewvc/llvm-project?rev=281647&view=rev
Log:
Make sure we create all necessary PT_LOADs.

We were some times stopping early when using linker scripts.

Added:
    lld/trunk/test/ELF/linkerscript/non-alloc.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=281647&r1=281646&r2=281647&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Thu Sep 15 14:36:01 2016
@@ -969,8 +969,15 @@ std::vector<PhdrEntry<ELFT>> Writer<ELFT
   Phdr RelRo(PT_GNU_RELRO, PF_R);
   Phdr Note(PT_NOTE, PF_R);
   for (OutputSectionBase<ELFT> *Sec : OutputSections) {
+    // Skip non alloc section.
+    // The reason we skip instead of just breaking out of the loop is the way
+    // we implement linker scripts. We always put the linker script sections
+    // first, which means that a non alloc section can be in the middle of the
+    // file. Continuing in here means it will be included in a PT_LOAD anyway.
+    // We should probably sort sections based of SHF_ALLOC even if they are
+    // on linker scripts.
     if (!(Sec->getFlags() & SHF_ALLOC))
-      break;
+      continue;
 
     // If we meet TLS section then we create TLS header
     // and put all TLS sections inside for futher use when

Added: lld/trunk/test/ELF/linkerscript/non-alloc.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/non-alloc.s?rev=281647&view=auto
==============================================================================
--- lld/trunk/test/ELF/linkerscript/non-alloc.s (added)
+++ lld/trunk/test/ELF/linkerscript/non-alloc.s Thu Sep 15 14:36:01 2016
@@ -0,0 +1,28 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t
+
+# RUN: echo "SECTIONS { .foo : {*(foo)} }" > %t.script
+# RUN: ld.lld -o %t1 --script %t.script %t -shared
+# RUN: llvm-readobj -elf-output-style=GNU -s -l %t1 | FileCheck %s
+
+# Test that we create all necessary PT_LOAD. It is a harmless oddity that
+# foo ends in a PT_LOAD. We use to stop at the first non-alloc, causing
+# us to not create PT_LOAD for linker generated sections.
+
+# CHECK: Program Headers:
+# CHECK-NEXT:  Type
+# CHECK-NEXT:  PHDR
+# CHECK-NEXT:  LOAD {{.*}} R
+# CHECK-NEXT:  LOAD {{.*}} R E
+# CHECK-NEXT:  LOAD {{.*}} RW
+
+# CHECK:      Section to Segment mapping:
+# CHECK-NEXT:  Segment Sections...
+# CHECK-NEXT:   00
+# CHECK-NEXT:   01     .foo .dynsym .hash .dynstr
+# CHECK-NEXT:   02     .text
+# CHECK-NEXT:   03     .dynamic
+
+nop
+.section foo
+.quad 0