Index: llvm/docs/CommandGuide/llvm-nm.rst
===================================================================
--- llvm/docs/CommandGuide/llvm-nm.rst
+++ llvm/docs/CommandGuide/llvm-nm.rst
@@ -13,8 +13,9 @@
 
 The :program:`llvm-nm` utility lists the names of symbols from LLVM bitcode
 files, object files, and archives. Each symbol is listed along with some simple
-information about its provenance. If no filename is specified, or *-* is used as
-a filename, :program:`llvm-nm` will read a file from its standard input stream.
+information about its provenance. If no filename is specified, *a.out* is used
+as the input. If *-* is used as a filename, :program:`llvm-nm` will read a file
+from its standard input stream.
 
 :program:`llvm-nm`'s default output format is the traditional BSD :program:`nm`
 output format. Each such output record consists of an (optional) 8-digit
Index: llvm/test/Object/nm-trivial-object.test
===================================================================
--- llvm/test/Object/nm-trivial-object.test
+++ llvm/test/Object/nm-trivial-object.test
@@ -358,7 +358,7 @@
 # RUN: mkdir -p %t
 # RUN: cd %t
 # RUN: cp %p/Inputs/trivial-object-test.macho-i386 a.out
-# RUN: llvm-nm a.out | FileCheck %s -check-prefix A-OUT
+# RUN: llvm-nm | FileCheck %s -check-prefix A-OUT
 
 # A-OUT:          U _SomeOtherFunction
 # A-OUT: 00000000 T _main
Index: llvm/test/tools/llvm-nm/stdin.test
===================================================================
--- llvm/test/tools/llvm-nm/stdin.test
+++ /dev/null
@@ -1,33 +0,0 @@
-## Test llvm-nm when using stdin both explicitly (using '-' as a filename)
-## and implicitly (not specifying any filename).
-
-# RUN: yaml2obj %s -o %t.o
-
-## Pass an explicit filename to produce a baseline output. llvm-nm should
-## have the same behavior when opening a file itself and when reading that
-## file from its standard input stream.
-# RUN: llvm-nm %t.o > %t.base 2> %t.err
-
-## Make sure there is no warning message about no file redirected to stdin.
-# RUN: FileCheck %s --input-file=%t.err --allow-empty --implicit-check-not={{.}}
-
-# RUN: llvm-nm - < %t.o > %t.explicit 2> %t.err
-# RUN: FileCheck %s --input-file=%t.err --allow-empty --implicit-check-not={{.}}
-# RUN: cmp %t.base %t.explicit
-
-# RUN: llvm-nm < %t.o > %t.implicit 2> %t.err
-# RUN: FileCheck %s --input-file=%t.err --allow-empty --implicit-check-not={{.}}
-# RUN: cmp %t.base %t.implicit
-
-!ELF
-FileHeader:
-  Class:   ELFCLASS64
-  Data:    ELFDATA2LSB
-  Type:    ET_REL
-  Machine: EM_X86_64
-Sections:
-  - Name: .text
-    Type: SHT_PROGBITS
-Symbols:
-  - Name:    symbol_a
-    Section: .text
Index: llvm/tools/llvm-nm/llvm-nm.cpp
===================================================================
--- llvm/tools/llvm-nm/llvm-nm.cpp
+++ llvm/tools/llvm-nm/llvm-nm.cpp
@@ -34,7 +34,6 @@
 #include "llvm/Support/Format.h"
 #include "llvm/Support/InitLLVM.h"
 #include "llvm/Support/MemoryBuffer.h"
-#include "llvm/Support/Process.h"
 #include "llvm/Support/Program.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/TargetSelect.h"
@@ -1752,12 +1751,6 @@
 }
 
 static void dumpSymbolNamesFromFile(std::string &Filename) {
-  if (Filename == "-" && sys::Process::StandardInIsUserInput()) {
-    WithColor::warning(errs(), ToolName) << "can't read from terminal\n";
-    cl::PrintHelpMessage();
-    HadError = true;
-    return;
-  }
   ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
       MemoryBuffer::getFileOrSTDIN(Filename);
   if (error(BufferOrErr.getError(), Filename))
@@ -2089,7 +2082,7 @@
   if (OutputFormat == sysv || SizeSort)
     PrintSize = true;
   if (InputFilenames.empty())
-    InputFilenames.push_back("-");
+    InputFilenames.push_back("a.out");
   if (InputFilenames.size() > 1)
     MultipleFiles = true;