Index: include/llvm/ProfileData/InstrProf.h
===================================================================
--- include/llvm/ProfileData/InstrProf.h
+++ include/llvm/ProfileData/InstrProf.h
@@ -295,7 +295,8 @@
   value_site_count_mismatch,
   compress_failed,
   uncompress_failed,
-  empty_raw_profile
+  empty_raw_profile,
+  zlib_unavailable
 };
 
 inline std::error_code make_error_code(instrprof_error E) {
Index: lib/ProfileData/InstrProf.cpp
===================================================================
--- lib/ProfileData/InstrProf.cpp
+++ lib/ProfileData/InstrProf.cpp
@@ -111,6 +111,8 @@
     return "Failed to uncompress data (zlib)";
   case instrprof_error::empty_raw_profile:
     return "Empty raw profile file";
+  case instrprof_error::zlib_unavailable:
+    return "Profile uses zlib compression but the profile reader was built without zlib support";
   }
   llvm_unreachable("A value of instrprof_error has no message.");
 }
@@ -430,6 +432,9 @@
     SmallString<128> UncompressedNameStrings;
     StringRef NameStrings;
     if (isCompressed) {
+      if (!llvm::zlib::isAvailable())
+        return make_error<InstrProfError>(instrprof_error::zlib_unavailable);
+
       StringRef CompressedNameStrings(reinterpret_cast<const char *>(P),
                                       CompressedSize);
       if (Error E =
Index: test/tools/llvm-profdata/nocompress.test
===================================================================
--- /dev/null
+++ test/tools/llvm-profdata/nocompress.test
@@ -0,0 +1,15 @@
+You need a checkout of clang with compiler-rt to generate the
+binary file here.  These shell commands can be used to regenerate
+it.
+$ SRC=path/to/llvm
+$ CFE=$SRC/tools/clang
+$ TESTDIR=$SRC/test/tools/llvm-profdata
+$ CFE_TESTDIR=$CFE/test/Profile
+$ clang -o a.out -fprofile-instr-generate $CFE_TESTDIR/c-general.c
+$ LLVM_PROFILE_FILE=$TESTDIR/Inputs/compressed.profraw ./a.out
+
+RUN: not llvm-profdata show %p/Inputs/compressed.profraw -o %t 2>&1 | FileCheck %s
+
+REQUIRES: nozlib
+
+CHECK: error: {{.*}} Profile uses zlib compression but the profile reader was built without zlib support