Revert r375114: "[lit] Make internal diff work in pipelines"

This series of patches still breaks a Windows bot.

llvm-svn: 375121
diff --git a/llvm/utils/lit/tests/Inputs/shtest-shell/diff-error-0.txt b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-error-0.txt
new file mode 100644
index 0000000..81888cf
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-error-0.txt
@@ -0,0 +1,3 @@
+# Check error on a unsupported diff (cannot be part of a pipeline).
+#
+# RUN: diff diff-error-0.txt diff-error-0.txt | echo Output
diff --git a/llvm/utils/lit/tests/Inputs/shtest-shell/diff-pipes.txt b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-pipes.txt
deleted file mode 100644
index ce0abca..0000000
--- a/llvm/utils/lit/tests/Inputs/shtest-shell/diff-pipes.txt
+++ /dev/null
@@ -1,15 +0,0 @@
-# RUN: echo foo > %t.foo
-# RUN: echo bar > %t.bar
-
-# Check output pipe.
-# RUN: diff %t.foo %t.foo | FileCheck -allow-empty -check-prefix=EMPTY %s
-# RUN: diff -u %t.foo %t.bar | FileCheck %s && false || true
-
-# Fail so lit will print output.
-# RUN: false
-
-# CHECK:      @@
-# CHECK-NEXT: -foo
-# CHECK-NEXT: +bar
-
-# EMPTY-NOT: {{.}}
diff --git a/llvm/utils/lit/tests/Inputs/shtest-shell/diff-unified-error-0.txt b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-unified-error-0.txt
new file mode 100644
index 0000000..ee3858a
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-unified-error-0.txt
@@ -0,0 +1,3 @@
+# Check bad -U argument.
+# RUN: echo foo > %t
+# RUN: diff -U 30.1 %t %t
diff --git a/llvm/utils/lit/tests/Inputs/shtest-shell/diff-unified-error-1.txt b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-unified-error-1.txt
new file mode 100644
index 0000000..e46e8b5
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-unified-error-1.txt
@@ -0,0 +1,3 @@
+# Check bad -U argument.
+# RUN: echo foo > %t
+# RUN: diff -U-1 %t %t
diff --git a/llvm/utils/lit/tests/Inputs/shtest-shell/diff-unified.txt b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-unified.txt
index e977c19..a6a7eef 100644
--- a/llvm/utils/lit/tests/Inputs/shtest-shell/diff-unified.txt
+++ b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-unified.txt
@@ -30,9 +30,5 @@
 # RUN: diff -U4 %t.foo %t.bar && false || true
 # RUN: diff -U0 %t.foo %t.bar && false || true
 
-# Check bad -U argument.
-# RUN: diff -U 30.1 %t.foo %t.foo && false || true
-# RUN: diff -U-1 %t.foo %t.foo && false || true
-
 # Fail so lit will print output.
 # RUN: false
diff --git a/llvm/utils/lit/tests/max-failures.py b/llvm/utils/lit/tests/max-failures.py
index 7bd5c32..6ad3753 100644
--- a/llvm/utils/lit/tests/max-failures.py
+++ b/llvm/utils/lit/tests/max-failures.py
@@ -8,7 +8,7 @@
 #
 # END.
 
-# CHECK: Failing Tests (30)
+# CHECK: Failing Tests (32)
 # CHECK: Failing Tests (1)
 # CHECK: Failing Tests (2)
 # CHECK: error: argument --max-failures: requires positive integer, but found '0'
diff --git a/llvm/utils/lit/tests/shtest-shell.py b/llvm/utils/lit/tests/shtest-shell.py
index dd5bfbe..1fc8b30 100644
--- a/llvm/utils/lit/tests/shtest-shell.py
+++ b/llvm/utils/lit/tests/shtest-shell.py
@@ -86,20 +86,28 @@
 # CHECK: ***
 
 
+# CHECK: FAIL: shtest-shell :: diff-error-0.txt
+# CHECK: *** TEST 'shtest-shell :: diff-error-0.txt' FAILED ***
+# CHECK: $ "diff" "diff-error-0.txt" "diff-error-0.txt"
+# CHECK: # command stderr:
+# CHECK: Unsupported: 'diff' cannot be part of a pipeline
+# CHECK: error: command failed with exit status: 127
+# CHECK: ***
+
 # CHECK: FAIL: shtest-shell :: diff-error-1.txt
 # CHECK: *** TEST 'shtest-shell :: diff-error-1.txt' FAILED ***
 # CHECK: $ "diff" "-B" "temp1.txt" "temp2.txt"
 # CHECK: # command stderr:
 # CHECK: Unsupported: 'diff': option -B not recognized
-# CHECK: error: command failed with exit status: 1
+# CHECK: error: command failed with exit status: 127
 # CHECK: ***
 
 # CHECK: FAIL: shtest-shell :: diff-error-2.txt
 # CHECK: *** TEST 'shtest-shell :: diff-error-2.txt' FAILED ***
 # CHECK: $ "diff" "temp.txt"
 # CHECK: # command stderr:
-# CHECK: Error: missing or extra operand
-# CHECK: error: command failed with exit status: 1
+# CHECK: Error:  missing or extra operand
+# CHECK: error: command failed with exit status: 127
 # CHECK: ***
 
 # CHECK: FAIL: shtest-shell :: diff-error-3.txt
@@ -126,43 +134,18 @@
 # CHECK: *** TEST 'shtest-shell :: diff-error-5.txt' FAILED ***
 # CHECK: $ "diff"
 # CHECK: # command stderr:
-# CHECK: Error: missing or extra operand
-# CHECK: error: command failed with exit status: 1
+# CHECK: Error:  missing or extra operand
+# CHECK: error: command failed with exit status: 127
 # CHECK: ***
 
 # CHECK: FAIL: shtest-shell :: diff-error-6.txt
 # CHECK: *** TEST 'shtest-shell :: diff-error-6.txt' FAILED ***
 # CHECK: $ "diff"
 # CHECK: # command stderr:
-# CHECK: Error: missing or extra operand
-# CHECK: error: command failed with exit status: 1
+# CHECK: Error:  missing or extra operand
+# CHECK: error: command failed with exit status: 127
 # CHECK: ***
 
-
-# CHECK: FAIL: shtest-shell :: diff-pipes.txt
-
-# CHECK: *** TEST 'shtest-shell :: diff-pipes.txt' FAILED ***
-
-# CHECK: $ "diff" "{{[^"]*}}.foo" "{{[^"]*}}.foo"
-# CHECK-NOT: note
-# CHECK-NOT: error
-# CHECK: $ "FileCheck"
-# CHECK-NOT: note
-# CHECK-NOT: error
-
-# CHECK: $ "diff" "-u" "{{[^"]*}}.foo" "{{[^"]*}}.bar"
-# CHECK: note: command had no output on stdout or stderr
-# CHECK: error: command failed with exit status: 1
-# CHECK: $ "FileCheck"
-# CHECK-NOT: note
-# CHECK-NOT: error
-# CHECK: $ "true"
-
-# CHECK: $ "false"
-
-# CHECK: ***
-
-
 # CHECK: FAIL: shtest-shell :: diff-r-error-0.txt
 # CHECK: *** TEST 'shtest-shell :: diff-r-error-0.txt' FAILED ***
 # CHECK: $ "diff" "-r" 
@@ -272,6 +255,23 @@
 # CHECK: ***
 
 
+# CHECK: FAIL: shtest-shell :: diff-unified-error-0.txt
+# CHECK: *** TEST 'shtest-shell :: diff-unified-error-0.txt' FAILED ***
+# CHECK: $ "diff" "-U" "30.1" "{{[^"]*}}" "{{[^"]*}}"
+# CHECK: # command stderr:
+# CHECK: Error: invalid '-U' argument: 30.1
+# CHECK: error: command failed with exit status: 127
+# CHECK: ***
+
+# CHECK: FAIL: shtest-shell :: diff-unified-error-1.txt
+# CHECK: *** TEST 'shtest-shell :: diff-unified-error-1.txt' FAILED ***
+# CHECK: $ "diff" "-U-1" "{{[^"]*}}" "{{[^"]*}}"
+# CHECK: # command stderr:
+# CHECK: Error: invalid '-U' argument: -1
+# CHECK: error: command failed with exit status: 127
+# CHECK: ***
+
+
 # CHECK: FAIL: shtest-shell :: diff-unified.txt
 
 # CHECK: *** TEST 'shtest-shell :: diff-unified.txt' FAILED ***
@@ -330,18 +330,6 @@
 # CHECK-NEXT: error: command failed with exit status: 1
 # CHECK-NEXT: $ "true"
 
-# CHECK: $ "diff" "-U" "30.1" "{{[^"]*}}" "{{[^"]*}}"
-# CHECK: # command stderr:
-# CHECK: Error: invalid '-U' argument: 30.1
-# CHECK: error: command failed with exit status: 1
-# CHECK: $ "true"
-
-# CHECK: $ "diff" "-U-1" "{{[^"]*}}" "{{[^"]*}}"
-# CHECK: # command stderr:
-# CHECK: Error: invalid '-U' argument: -1
-# CHECK: error: command failed with exit status: 1
-# CHECK: $ "true"
-
 # CHECK: $ "false"
 
 # CHECK: ***
@@ -426,4 +414,4 @@
 # CHECK: PASS: shtest-shell :: sequencing-0.txt
 # CHECK: XFAIL: shtest-shell :: sequencing-1.txt
 # CHECK: PASS: shtest-shell :: valid-shell.txt
-# CHECK: Failing Tests (30)
+# CHECK: Failing Tests (32)