Index: llvm/test/FileCheck/dump-input-enable.txt
===================================================================
--- llvm/test/FileCheck/dump-input-enable.txt
+++ llvm/test/FileCheck/dump-input-enable.txt
@@ -42,33 +42,32 @@
 ; RUN: %ProtectFileCheckOutput FileCheck -dump-input=help \
 ; RUN: | FileCheck %s -check-prefix=HELP
 
-HELP-NOT: {{.}}
-HELP: The following description was requested by -dump-input=help
-HELP: try{{.*}}-color
-HELP-NOT: {{.}}
-
 ;--------------------------------------------------
 ; Check -dump-input=never.
 ;
 ; Include the case without -v, which isn't covered elsewhere.
 ;--------------------------------------------------
 
+; FileCheck success, no -v => no dump, no trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: FileCheck -input-file %t.good %t.check -check-prefix=CHECK \
 ; RUN:           -match-full-lines -dump-input=never 2>&1 \
 ; RUN: | FileCheck %s -match-full-lines -allow-empty \
 ; RUN:             -check-prefixes=NOTRACE,NODUMP
 
+; FileCheck fail, no -v => no dump, no trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: not FileCheck -input-file %t.err %t.check -check-prefix=CHECK \
 ; RUN:               -match-full-lines -dump-input=never 2>&1 \
 ; RUN: | FileCheck %s -match-full-lines -check-prefixes=NOTRACE,ERR,NODUMP
 
+; FileCheck success, -v => no dump, trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: FileCheck -input-file %t.good %t.check -check-prefix=CHECK \
 ; RUN:           -match-full-lines -dump-input=never -v 2>&1 \
 ; RUN: | FileCheck %s -match-full-lines -check-prefixes=TRACE,NODUMP
 
+; FileCheck fail, -v => no dump, trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: not FileCheck -input-file %t.err %t.check -check-prefix=CHECK \
 ; RUN:               -match-full-lines -dump-input=never -v 2>&1 \
@@ -78,11 +77,13 @@
 ; Check no -dump-input, which defaults to never.
 ;--------------------------------------------------
 
+; FileCheck success, -v => no dump, trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: FileCheck -input-file %t.good %t.check -check-prefix=CHECK \
 ; RUN:           -match-full-lines -v 2>&1 \
 ; RUN: | FileCheck %s -match-full-lines -check-prefixes=TRACE,NODUMP
 
+; FileCheck fail, -v => no dump, trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: not FileCheck -input-file %t.err %t.check -check-prefix=CHECK \
 ; RUN:               -match-full-lines -v 2>&1 \
@@ -94,23 +95,27 @@
 ; Include the case without -v, which isn't covered elsewhere.
 ;--------------------------------------------------
 
+; FileCheck success, no -v => no dump, no trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: FileCheck -input-file %t.good %t.check -check-prefix=CHECK \
 ; RUN:           -match-full-lines -dump-input=fail 2>&1 \
 ; RUN: | FileCheck %s -match-full-lines -allow-empty \
 ; RUN:             -check-prefixes=NOTRACE,NODUMP
 
+; FileCheck fail, no -v => dump, no trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: not FileCheck -input-file %t.err %t.check -check-prefix=CHECK \
 ; RUN:               -match-full-lines -dump-input=fail 2>&1 \
 ; RUN: | FileCheck %s -match-full-lines -check-prefixes=NOTRACE,ERR,DUMP-ERR
 
+; FileCheck success, -v => no dump, no trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: FileCheck -input-file %t.good %t.check -check-prefix=CHECK \
 ; RUN:           -match-full-lines -dump-input=fail -v 2>&1 \
 ; RUN: | FileCheck %s -match-full-lines -allow-empty \
 ; RUN:             -check-prefixes=NOTRACE,NODUMP
 
+; FileCheck fail, -v => dump, no trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: not FileCheck -input-file %t.err %t.check -check-prefix=CHECK \
 ; RUN:               -match-full-lines -dump-input=fail -v 2>&1 \
@@ -121,24 +126,32 @@
 ; Check -dump-input-on-failure.
 ;--------------------------------------------------
 
+; Command-line option.
+
+; FileCheck success, -v => no dump, no trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: FileCheck -input-file %t.good %t.check -check-prefix=CHECK \
 ; RUN:           -match-full-lines -dump-input-on-failure -v 2>&1 \
 ; RUN: | FileCheck %s -match-full-lines -allow-empty \
 ; RUN:             -check-prefixes=NOTRACE,NODUMP
 
+; FileCheck fail, -v => dump, no trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: not FileCheck -input-file %t.err %t.check -check-prefix=CHECK \
 ; RUN:               -match-full-lines -dump-input-on-failure -v 2>&1 \
 ; RUN: | FileCheck %s -match-full-lines \
 ; RUN:                -check-prefixes=NOTRACE,ERR,DUMP-ERR,DUMP-ERR-V
 
+; FILECHECK_DUMP_INPUT_ON_FAILURE=1.
+
+; FileCheck success, -v => no dump, no trace.
 ; RUN: %ProtectFileCheckOutput FILECHECK_DUMP_INPUT_ON_FAILURE=1 \
 ; RUN: FileCheck -input-file %t.good %t.check -check-prefix=CHECK \
 ; RUN:           -match-full-lines -v 2>&1 \
 ; RUN: | FileCheck %s -match-full-lines -allow-empty \
 ; RUN:                -check-prefixes=NOTRACE,NODUMP
 
+; FileCheck fail, -v => dump, no trace.
 ; RUN: %ProtectFileCheckOutput FILECHECK_DUMP_INPUT_ON_FAILURE=1 \
 ; RUN: not FileCheck -input-file %t.err %t.check -check-prefix=CHECK \
 ; RUN:               -match-full-lines -v 2>&1 \
@@ -149,23 +162,105 @@
 ; Check -dump-input=always.
 ;--------------------------------------------------
 
+; FileCheck success, -v => dump, no trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: FileCheck -input-file %t.good %t.check -check-prefix=CHECK \
 ; RUN:           -match-full-lines -dump-input=always -v 2>&1 \
 ; RUN: | FileCheck %s -match-full-lines -check-prefixes=NOTRACE,DUMP-OK
 
+; FileCheck fail, -v => dump, no trace.
 ; RUN: %ProtectFileCheckOutput \
 ; RUN: not FileCheck -input-file %t.err %t.check -check-prefix=CHECK \
 ; RUN:               -match-full-lines -dump-input=always -v 2>&1 \
 ; RUN: | FileCheck %s -match-full-lines \
 ; RUN:                -check-prefixes=NOTRACE,ERR,DUMP-ERR,DUMP-ERR-V
 
+;--------------------------------------------------
+; Check multiple -dump-input options.
+;
+; This ocurrs most commonly when a test author specifies -dump-input on a
+; specific FileCheck call while a test runner specifies -dump-input in
+; FILECHECK_OPTS, but check the behavior generally.
+;
+; "help" has precedence, and then the most verbose value wins.  The most
+; common combinations involve "fail" and "always", so test those the most.
+;--------------------------------------------------
+
+;- - - - - - - - - - - - - - - - - - - - - - - - -
+; Check duplicate.
+;- - - - - - - - - - - - - - - - - - - - - - - - -
+
+; fail, fail => fail (FileCheck fail => dump)
+; RUN: %ProtectFileCheckOutput \
+; RUN: not FileCheck -input-file %t.err %t.check -check-prefix=CHECK \
+; RUN:               -match-full-lines -dump-input=fail -dump-input=fail -v \
+; RUN:               2>&1 \
+; RUN: | FileCheck %s -match-full-lines \
+; RUN:                -check-prefixes=NOTRACE,ERR,DUMP-ERR,DUMP-ERR-V
+
+;- - - - - - - - - - - - - - - - - - - - - - - - -
+; Check precedence.
+;- - - - - - - - - - - - - - - - - - - - - - - - -
+
+; help, always => help
+; RUN: %ProtectFileCheckOutput \
+; RUN: FileCheck -input-file %t.err -color %t.check \
+; RUN:           -dump-input=help -dump-input=always \
+; RUN: | FileCheck %s -check-prefix=HELP
+
+; always, fail => always (FileCheck success => dump)
+; RUN: %ProtectFileCheckOutput \
+; RUN: FileCheck -input-file %t.good %t.check -check-prefix=CHECK \
+; RUN:           -match-full-lines -dump-input=always -dump-input=fail \
+; RUN:           -v 2>&1 \
+; RUN: | FileCheck %s -match-full-lines -check-prefixes=NOTRACE,DUMP-OK
+
+; fail, never => fail (FileCheck fail => dump)
+; RUN: %ProtectFileCheckOutput \
+; RUN: not FileCheck -input-file %t.err %t.check -check-prefix=CHECK \
+; RUN:               -match-full-lines -dump-input=fail -dump-input=never -v \
+; RUN:               2>&1 \
+; RUN: | FileCheck %s -match-full-lines \
+; RUN:                -check-prefixes=NOTRACE,ERR,DUMP-ERR,DUMP-ERR-V
+
+;- - - - - - - - - - - - - - - - - - - - - - - - -
+; Check that order doesn't matter.
+;- - - - - - - - - - - - - - - - - - - - - - - - -
+
+; fail, always => always (FileCheck success => dump)
+; RUN: %ProtectFileCheckOutput \
+; RUN: FileCheck -input-file %t.good %t.check -check-prefix=CHECK \
+; RUN:           -match-full-lines -dump-input=fail -dump-input=always \
+; RUN:           -v 2>&1 \
+; RUN: | FileCheck %s -match-full-lines -check-prefixes=NOTRACE,DUMP-OK
+
+;- - - - - - - - - - - - - - - - - - - - - - - - -
+; Check that FILECHECK_OPTS isn't handled differently.
+;- - - - - - - - - - - - - - - - - - - - - - - - -
+
+; always, fail => always (FileCheck success => dump)
+; RUN: %ProtectFileCheckOutput FILECHECK_OPTS=-dump-input=always \
+; RUN: FileCheck -input-file %t.good %t.check -check-prefix=CHECK \
+; RUN:           -match-full-lines -dump-input=fail -v 2>&1 \
+; RUN: | FileCheck %s -match-full-lines -check-prefixes=NOTRACE,DUMP-OK
+
+; fail, always => always (FileCheck success => dump)
+; RUN: %ProtectFileCheckOutput FILECHECK_OPTS=-dump-input=fail \
+; RUN: FileCheck -input-file %t.good %t.check -check-prefix=CHECK \
+; RUN:           -match-full-lines -dump-input=always -v 2>&1 \
+; RUN: | FileCheck %s -match-full-lines -check-prefixes=NOTRACE,DUMP-OK
+
 ; END.
 
 ;--------------------------------------------------
-; Check the output for all cases that actually process directives.
+; Check the output.
 ;--------------------------------------------------
 
+; HELP-NOT: {{.}}
+; HELP: The following description was requested by -dump-input=help
+; HELP: try{{.*}}-color
+; HELP-NOT: {{.}}
+
 ; Trace is sometimes suppressed.
 ; TRACE:       {{.*}}remark:{{.*}}
 ; NOTRACE-NOT: remark:
Index: llvm/utils/FileCheck/FileCheck.cpp
===================================================================
--- llvm/utils/FileCheck/FileCheck.cpp
+++ llvm/utils/FileCheck/FileCheck.cpp
@@ -108,24 +108,28 @@
              "FILECHECK_DUMP_INPUT_ON_FAILURE environment variable.\n"
              "This option is deprecated in favor of -dump-input=fail.\n"));
 
+// The order of DumpInputValue members affects their precedence, as documented
+// for -dump-input below.
 enum DumpInputValue {
   DumpInputDefault,
-  DumpInputHelp,
   DumpInputNever,
   DumpInputFail,
-  DumpInputAlways
+  DumpInputAlways,
+  DumpInputHelp
 };
 
-static cl::opt<DumpInputValue> DumpInput(
-    "dump-input", cl::init(DumpInputDefault),
+static cl::list<DumpInputValue> DumpInputs(
+    "dump-input",
     cl::desc("Dump input to stderr, adding annotations representing\n"
-             " currently enabled diagnostics\n"),
+             "currently enabled diagnostics.  When there are multiple\n"
+             "occurrences of this option, the <value> that appears earliest\n"
+             "in the list below has precedence.\n"),
     cl::value_desc("mode"),
     cl::values(clEnumValN(DumpInputHelp, "help",
                           "Explain dump format and quit"),
-               clEnumValN(DumpInputNever, "never", "Never dump input"),
+               clEnumValN(DumpInputAlways, "always", "Always dump input"),
                clEnumValN(DumpInputFail, "fail", "Dump input on failure"),
-               clEnumValN(DumpInputAlways, "always", "Always dump input")));
+               clEnumValN(DumpInputNever, "never", "Never dump input")));
 
 typedef cl::list<std::string>::const_iterator prefix_iterator;
 
@@ -516,6 +520,10 @@
   InitLLVM X(argc, argv);
   cl::ParseCommandLineOptions(argc, argv, /*Overview*/ "", /*Errs*/ nullptr,
                               "FILECHECK_OPTS");
+  DumpInputValue DumpInput =
+      DumpInputs.empty()
+          ? DumpInputDefault
+          : *std::max_element(DumpInputs.begin(), DumpInputs.end());
   if (DumpInput == DumpInputHelp) {
     DumpInputAnnotationHelp(outs());
     return 0;