llvm-mc: error when -compress-debug-sections is requested and zlib is not linked

This is a bit of a stab in the dark, since I have zlib on my machine.
Just going to bounce it off the bots & see if it sticks.

Do we have some convention for negative REQUIRES: checks? Or do I just
need to add a feature like I've done here?

llvm-svn: 205050

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/tools/llvm-mc/llvm-mc.cpp b/llvm/tools/llvm-mc/llvm-mc.cpp
index b2e7a81488d..dfa347e764a 100644
--- a/llvm/tools/llvm-mc/llvm-mc.cpp
+++ b/llvm/tools/llvm-mc/llvm-mc.cpp
@@ -384,8 +384,13 @@ int main(int argc, char **argv) {
   std::unique_ptr<MCAsmInfo> MAI(TheTarget->createMCAsmInfo(*MRI, TripleName));
   assert(MAI && "Unable to create target asm info!");
 
-  if (CompressDebugSections)
+  if (CompressDebugSections) {
+    if (!zlib::isAvailable()) {
+      errs() << ProgName << ": build tools with zlib to enable -compress-debug-sections";
+      return 1;
+    }
     MAI->setCompressDebugSections(true);
+  }
 
   // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
   // MCObjectFileInfo needs a MCContext reference in order to initialize itself.