Index: llvm/test/FileCheck/check-label-dag.txt
===================================================================
--- llvm/test/FileCheck/check-label-dag.txt
+++ llvm/test/FileCheck/check-label-dag.txt
@@ -1,4 +1,4 @@
-; RUN: not FileCheck -input-file %s %s 2>&1 | FileCheck --check-prefix=ERROR %s
+; RUN: not FileCheck -verbose=false -input-file %s %s 2>&1 | FileCheck --check-prefix=ERROR %s
 
 bar
 zed
Index: llvm/test/FileCheck/check-label.txt
===================================================================
--- llvm/test/FileCheck/check-label.txt
+++ llvm/test/FileCheck/check-label.txt
@@ -1,5 +1,5 @@
 ; RUN: FileCheck -input-file %s %s -check-prefix=CHECKOK
-; RUN: not FileCheck -input-file %s %s -check-prefix=CHECKFAIL 2>&1 | FileCheck %s -check-prefix=CHECKERROR
+; RUN: not FileCheck -verbose=false -input-file %s %s -check-prefix=CHECKFAIL 2>&1 | FileCheck %s -check-prefix=CHECKERROR
 
 label0:
 a
Index: llvm/test/FileCheck/check-multiple-prefixes-nomatch-2.txt
===================================================================
--- llvm/test/FileCheck/check-multiple-prefixes-nomatch-2.txt
+++ llvm/test/FileCheck/check-multiple-prefixes-nomatch-2.txt
@@ -1,4 +1,4 @@
-; RUN: not FileCheck -input-file %s %s -check-prefix=FOO -check-prefix=BAR 2>&1 | FileCheck %s
+; RUN: not FileCheck -verbose=false -input-file %s %s -check-prefix=FOO -check-prefix=BAR 2>&1 | FileCheck %s
 
 fog
 bar
Index: llvm/test/FileCheck/check-multiple-prefixes-nomatch.txt
===================================================================
--- llvm/test/FileCheck/check-multiple-prefixes-nomatch.txt
+++ llvm/test/FileCheck/check-multiple-prefixes-nomatch.txt
@@ -1,4 +1,4 @@
-; RUN: not FileCheck -input-file %s %s -check-prefix=FOO -check-prefix=BAR 2>&1 | FileCheck %s
+; RUN: not FileCheck -verbose=false -input-file %s %s -check-prefix=FOO -check-prefix=BAR 2>&1 | FileCheck %s
 
 BAR
 bar
Index: llvm/test/FileCheck/check-not-diaginfo.txt
===================================================================
--- llvm/test/FileCheck/check-not-diaginfo.txt
+++ llvm/test/FileCheck/check-not-diaginfo.txt
@@ -1,4 +1,4 @@
-; RUN: not FileCheck -input-file %s %s 2>&1 | FileCheck -check-prefix DIAG %s
+; RUN: not FileCheck -verbose=false -input-file %s %s 2>&1 | FileCheck -check-prefix DIAG %s
 
 CHECK-NOT: test
 
Index: llvm/utils/FileCheck/FileCheck.cpp
===================================================================
--- llvm/utils/FileCheck/FileCheck.cpp
+++ llvm/utils/FileCheck/FileCheck.cpp
@@ -68,6 +68,10 @@
              "Allows leading and trailing whitespace if --strict-whitespace\n"
              "is not also passed."));
 
+static cl::opt<bool> Verbose(
+    "verbose", cl::init(false),
+    cl::desc("(T.B.D.)"));
+
 typedef cl::list<std::string>::const_iterator prefix_iterator;
 
 //===----------------------------------------------------------------------===//
@@ -1301,6 +1305,13 @@
 int main(int argc, char **argv) {
   sys::PrintStackTraceOnErrorSignal();
   PrettyStackTraceProgram X(argc, argv);
+
+  // Override default value of Verbose
+  if (auto p = std::getenv("LLVM_FILECHECK")) {
+    if (StringRef(p) == "-verbose")
+      Verbose = true;
+  }
+
   cl::ParseCommandLineOptions(argc, argv);
 
   if (!ValidateCheckPrefixes()) {
@@ -1342,6 +1353,15 @@
   // Check that we have all of the expected strings, in order, in the input
   // file.
   StringRef Buffer = F->getBuffer();
+  if (Verbose) {
+    errs() << "================\nCommand line:";
+    for (int i = 0; i < argc; ++i)
+      errs() << " " << argv[i];
+    errs() << "\n================\n"
+           << Buffer
+           << "\n================\n";
+  }
+
 
   SM.AddNewSourceBuffer(std::move(F), SMLoc());
 
Index: llvm/utils/lit/lit/TestingConfig.py
===================================================================
--- llvm/utils/lit/lit/TestingConfig.py
+++ llvm/utils/lit/lit/TestingConfig.py
@@ -25,6 +25,12 @@
         pass_vars = ['LIBRARY_PATH', 'LD_LIBRARY_PATH', 'SYSTEMROOT', 'TERM',
                      'LD_PRELOAD', 'ASAN_OPTIONS', 'UBSAN_OPTIONS',
                      'LSAN_OPTIONS', 'ADB', 'ANDROID_SERIAL']
+
+        # Passed vars can be defined in LIT_PASS_VARS, like "TEMP:TMP:TMPDIR"
+        extra_pass_vars = os.environ.get("LIT_PASS_VARS")
+        if extra_pass_vars:
+            pass_vars.extend(extra_pass_vars.split(':'))
+
         for var in pass_vars:
             val = os.environ.get(var, '')
             # Check for empty string as some variables such as LD_PRELOAD cannot be empty