diff --git a/clang/test/Analysis/auto-obj-dtors-cfg-output.cpp b/clang/test/Analysis/auto-obj-dtors-cfg-output.cpp
--- a/clang/test/Analysis/auto-obj-dtors-cfg-output.cpp
+++ b/clang/test/Analysis/auto-obj-dtors-cfg-output.cpp
@@ -1,5 +1,5 @@
 // RUN: %clang_analyze_cc1 -std=c++98 -fcxx-exceptions -fexceptions -analyzer-checker=debug.DumpCFG -analyzer-config cfg-rich-constructors=false %s > %t 2>&1
-// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX98,WARNINGS,CXX98-WARNINGS %s
+// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX98,WARNINGS %s
 // RUN: %clang_analyze_cc1 -std=c++98 -fcxx-exceptions -fexceptions -analyzer-checker=debug.DumpCFG -analyzer-config cfg-rich-constructors=true %s > %t 2>&1
 // RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX98,ANALYZER,CXX98-ANALYZER %s
 // RUN: %clang_analyze_cc1 -std=c++11 -fcxx-exceptions -fexceptions -analyzer-checker=debug.DumpCFG -analyzer-config cfg-rich-constructors=false %s > %t 2>&1
diff --git a/clang/test/Analysis/cfg-rich-constructors.cpp b/clang/test/Analysis/cfg-rich-constructors.cpp
--- a/clang/test/Analysis/cfg-rich-constructors.cpp
+++ b/clang/test/Analysis/cfg-rich-constructors.cpp
@@ -1,11 +1,11 @@
 // RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG -triple x86_64-apple-darwin12 -std=c++11 -w %s > %t 2>&1
-// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX11,ELIDE,CXX11-ELIDE %s
+// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX11,CXX11-ELIDE %s
 // RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG -triple x86_64-apple-darwin12 -std=c++17 -w %s > %t 2>&1
-// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX17,ELIDE,CXX17-ELIDE %s
+// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX17 %s
 // RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG -triple x86_64-apple-darwin12 -std=c++11 -w -analyzer-config elide-constructors=false %s > %t 2>&1
-// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX11,NOELIDE,CXX11-NOELIDE %s
+// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX11,CXX11-NOELIDE %s
 // RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG -triple x86_64-apple-darwin12 -std=c++17 -w -analyzer-config elide-constructors=false %s > %t 2>&1
-// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX17,NOELIDE,CXX17-NOELIDE %s
+// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX17 %s
 
 class C {
 public:
diff --git a/clang/test/Analysis/cfg-rich-constructors.mm b/clang/test/Analysis/cfg-rich-constructors.mm
--- a/clang/test/Analysis/cfg-rich-constructors.mm
+++ b/clang/test/Analysis/cfg-rich-constructors.mm
@@ -1,11 +1,11 @@
 // RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG -triple x86_64-apple-darwin12 -std=c++11 -w %s > %t 2>&1
-// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX11,ELIDE,CXX11-ELIDE %s
+// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX11,CXX11-ELIDE %s
 // RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG -triple x86_64-apple-darwin12 -std=c++17 -w %s > %t 2>&1
-// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX17,ELIDE,CXX17-ELIDE %s
+// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX17 %s
 // RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG -triple x86_64-apple-darwin12 -std=c++11 -w -analyzer-config elide-constructors=false %s > %t 2>&1
-// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX11,NOELIDE,CXX11-NOELIDE %s
+// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX11,CXX11-NOELIDE %s
 // RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG -triple x86_64-apple-darwin12 -std=c++17 -w -analyzer-config elide-constructors=false %s > %t 2>&1
-// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX17,NOELIDE,CXX17-NOELIDE %s
+// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,CXX17 %s
 
 class D {
 public:
diff --git a/clang/test/Analysis/cfg.c b/clang/test/Analysis/cfg.c
--- a/clang/test/Analysis/cfg.c
+++ b/clang/test/Analysis/cfg.c
@@ -1,5 +1,5 @@
 // RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG -triple x86_64-apple-darwin12 -fheinous-gnu-extensions %s > %t 2>&1
-// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,WARNINGS %s
+// RUN: FileCheck --input-file=%t --check-prefix=CHECK %s
 
 // This file is the C version of cfg.cpp.
 // Tests that are C-specific should go into this file.
diff --git a/clang/test/Analysis/exploded-graph-rewriter/trimmers.dot b/clang/test/Analysis/exploded-graph-rewriter/trimmers.dot
--- a/clang/test/Analysis/exploded-graph-rewriter/trimmers.dot
+++ b/clang/test/Analysis/exploded-graph-rewriter/trimmers.dot
@@ -1,17 +1,17 @@
 // RUN: %exploded_graph_rewriter %s \
 // RUN:     | FileCheck %s -check-prefixes=ONE,TWO,THREE,FOUR
 // RUN: %exploded_graph_rewriter -s %s \
-// RUN:     | FileCheck %s -check-prefixes=ONE,TWO,NOTHREE,FOUR
+// RUN:     | FileCheck %s -check-prefixes=ONE,TWO,NOTTHREE,FOUR
 // RUN: %exploded_graph_rewriter --to=0x2 %s \
-// RUN:     | FileCheck %s -check-prefixes=ONE,TWO,NOTHREE,NOFOUR
+// RUN:     | FileCheck %s -check-prefixes=ONE,TWO,NOTTHREE,NOTFOUR
 // RUN: %exploded_graph_rewriter --to 2 %s \
-// RUN:     | FileCheck %s -check-prefixes=ONE,TWO,NOTHREE,NOFOUR
+// RUN:     | FileCheck %s -check-prefixes=ONE,TWO,NOTTHREE,NOTFOUR
 // RUN: %exploded_graph_rewriter --to 2,3 %s \
-// RUN:     | FileCheck %s -check-prefixes=ONE,TWO,THREE,NOFOUR
+// RUN:     | FileCheck %s -check-prefixes=ONE,TWO,THREE,NOTFOUR
 // RUN: %exploded_graph_rewriter --to 4 %s \
 // RUN:     | FileCheck %s -check-prefixes=ONE,TWO,THREE,FOUR
 // RUN: %exploded_graph_rewriter --to 4 -s %s \
-// RUN:     | FileCheck %s -check-prefixes=ONE,TWO,NOTHREE,FOUR
+// RUN:     | FileCheck %s -check-prefixes=ONE,TWO,NOTTHREE,FOUR
 
 Node0x1 [shape=record,label=
  "{{ "state_id": 0, "program_state": null, "program_points": [
diff --git a/clang/test/Analysis/lit.local.cfg b/clang/test/Analysis/lit.local.cfg
--- a/clang/test/Analysis/lit.local.cfg
+++ b/clang/test/Analysis/lit.local.cfg
@@ -1,5 +1,5 @@
 # -*- Python -*- vim: set ft=python ts=4 sw=4 expandtab tw=79:
-
+from lit.llvm.subst import ToolSubst
 import site
 
 # Load the custom analyzer test format, which runs the test again with Z3 if it
@@ -26,3 +26,9 @@
 
 if not config.root.clang_staticanalyzer:
     config.unsupported = True
+
+fc = ToolSubst('FileCheck', unresolved='fatal')
+# Insert this first. Then, we'll first update the blank FileCheck command; then,
+# the default substitution of FileCheck will replace it to its full path.
+config.substitutions.insert(0, (fc.regex,
+    'FileCheck --allow-unused-prefixes=false'))