[lld] r305679 - [ELF] Emit only one error if -z max-page-size without value

[James Henderson via llvm-commits]

Author: jhenderson
Date: Mon Jun 19 06:05:15 2017
New Revision: 305679

URL: http://llvm.org/viewvc/llvm-project?rev=305679&view=rev
Log:
[ELF] Emit only one error if -z max-page-size without value

In r305364, Rui changed the mechanism that parses -z option values slightly.
This caused a bug, as demonstrated by this test, which now fails:

---
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
# RUN: ld.lld %t.o -o %t -z max-page-size

.global _start
_start:
  nop
---

Before, the link succeeded and set the max-page-size to the target default.

After we get the following two error messages:
"invalid max-page-size: "
"max-page-size: value isn't a power of 2"

The latter error is because an uninitialised variable ends up being passed back
to getMaxPageSize).

This change ensures we only get the first error.

Reviewers: ruiu

Differential Revision: https://reviews.llvm.org/D34234

Added:
    lld/trunk/test/ELF/invalid-z.s
Modified:
    lld/trunk/ELF/Driver.cpp

Modified: lld/trunk/ELF/Driver.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Driver.cpp?rev=305679&r1=305678&r2=305679&view=diff
==============================================================================
--- lld/trunk/ELF/Driver.cpp (original)
+++ lld/trunk/ELF/Driver.cpp Mon Jun 19 06:05:15 2017
@@ -301,7 +301,7 @@ static uint64_t getZOptionValue(opt::Inp
   for (auto *Arg : Args.filtered(OPT_z)) {
     std::pair<StringRef, StringRef> KV = StringRef(Arg->getValue()).split('=');
     if (KV.first == Key) {
-      uint64_t Result;
+      uint64_t Result = Default;
       if (!to_integer(KV.second, Result))
         error("invalid " + Key + ": " + KV.second);
       return Result;

Added: lld/trunk/test/ELF/invalid-z.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/invalid-z.s?rev=305679&view=auto
==============================================================================
--- lld/trunk/test/ELF/invalid-z.s (added)
+++ lld/trunk/test/ELF/invalid-z.s Mon Jun 19 06:05:15 2017
@@ -0,0 +1,9 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+# RUN: not ld.lld %t.o -o %t -z max-page-size 2>&1 | FileCheck %s
+# CHECK: invalid max-page-size
+# CHECK-NOT: error
+
+.global _start
+_start:
+  nop