[lld] r293849 - Make `-z stack-size` compatible with ld.bfd.

[Rui Ueyama via llvm-commits]

Author: ruiu
Date: Wed Feb  1 19:12:45 2017
New Revision: 293849

URL: http://llvm.org/viewvc/llvm-project?rev=293849&view=rev
Log:
Make `-z stack-size` compatible with ld.bfd.

ld.bfd doesn't handle `-z stack-size=0` as a special case.
We shouldn't do that too.

Modified:
    lld/trunk/ELF/Driver.cpp
    lld/trunk/ELF/Writer.cpp
    lld/trunk/test/ELF/zstack-size.s

Modified: lld/trunk/ELF/Driver.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Driver.cpp?rev=293849&r1=293848&r2=293849&view=diff
==============================================================================
--- lld/trunk/ELF/Driver.cpp (original)
+++ lld/trunk/ELF/Driver.cpp Wed Feb  1 19:12:45 2017
@@ -575,7 +575,7 @@ void LinkerDriver::readConfigs(opt::Inpu
   Config->ZNow = hasZOption(Args, "now");
   Config->ZOrigin = hasZOption(Args, "origin");
   Config->ZRelro = !hasZOption(Args, "norelro");
-  Config->ZStackSize = getZOptionValue(Args, "stack-size", -1);
+  Config->ZStackSize = getZOptionValue(Args, "stack-size", 0);
   Config->ZWxneeded = hasZOption(Args, "wxneeded");
 
   Config->OFormatBinary = isOutputFormatBinary(Args);

Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=293849&r1=293848&r2=293849&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Wed Feb  1 19:12:45 2017
@@ -1257,11 +1257,8 @@ template <class ELFT> std::vector<PhdrEn
 
   // PT_GNU_STACK is a special section to tell the loader to make the
   // pages for the stack non-executable.
-  if (!Config->ZExecstack) {
-    PhdrEntry *Hdr = AddHdr(PT_GNU_STACK, PF_R | PF_W);
-    if (Config->ZStackSize != uint64_t(-1))
-      Hdr->p_memsz = Config->ZStackSize;
-  }
+  if (!Config->ZExecstack)
+    AddHdr(PT_GNU_STACK, PF_R | PF_W)->p_memsz = Config->ZStackSize;
 
   // PT_OPENBSD_WXNEEDED is a OpenBSD-specific header to mark the executable
   // is expected to perform W^X violations, such as calling mprotect(2) or

Modified: lld/trunk/test/ELF/zstack-size.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/zstack-size.s?rev=293849&r1=293848&r2=293849&view=diff
==============================================================================
--- lld/trunk/test/ELF/zstack-size.s (original)
+++ lld/trunk/test/ELF/zstack-size.s Wed Feb  1 19:12:45 2017
@@ -1,20 +1,33 @@
 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
 # RUN: ld.lld -z stack-size=0x1000 %t -o %t1
-# RUN: llvm-readobj -program-headers %t1 | FileCheck %s
+# RUN: llvm-readobj -program-headers %t1 | FileCheck %s -check-prefix=CHECK1
+
+# RUN: ld.lld -z stack-size=0 %t -o %t2
+# RUN: llvm-readobj -program-headers %t2 | FileCheck %s -check-prefix=CHECK2
 
 .global _start
 _start:
   nop
 
-# CHECK:     Type: PT_GNU_STACK (0x6474E551)
-# CHECK-NEXT:     Offset: 0x0
-# CHECK-NEXT:     VirtualAddress: 0x0
-# CHECK-NEXT:     PhysicalAddress: 0x0
-# CHECK-NEXT:     FileSize: 0
-# CHECK-NEXT:     MemSize: 4096
-# CHECK-NEXT:     Flags [ (0x6)
-# CHECK-NEXT:       PF_R (0x4)
-# CHECK-NEXT:       PF_W (0x2)
-# CHECK-NEXT:     ]
-# CHECK-NEXT:     Alignment: 0
+# CHECK1:     Type: PT_GNU_STACK (0x6474E551)
+# CHECK1-NEXT:     Offset: 0x0
+# CHECK1-NEXT:     VirtualAddress: 0x0
+# CHECK1-NEXT:     PhysicalAddress: 0x0
+# CHECK1-NEXT:     FileSize: 0
+# CHECK1-NEXT:     MemSize: 4096
+# CHECK1-NEXT:     Flags [ (0x6)
+# CHECK1-NEXT:       PF_R (0x4)
+# CHECK1-NEXT:       PF_W (0x2)
+# CHECK1-NEXT:     ]
+
+# CHECK2:     Type: PT_GNU_STACK (0x6474E551)
+# CHECK2-NEXT:     Offset: 0x0
+# CHECK2-NEXT:     VirtualAddress: 0x0
+# CHECK2-NEXT:     PhysicalAddress: 0x0
+# CHECK2-NEXT:     FileSize: 0
+# CHECK2-NEXT:     MemSize: 0
+# CHECK2-NEXT:     Flags [ (0x6)
+# CHECK2-NEXT:       PF_R (0x4)
+# CHECK2-NEXT:       PF_W (0x2)
+# CHECK2-NEXT:     ]