Reland r374389: [lit] Clean up internal diff's encoding handling

To avoid breaking some tests, D66574, D68664, D67643, and D68668
landed together.  However, D68664 introduced an issue now addressed by
D68839, with which these are now all relanding.

Differential Revision: https://reviews.llvm.org/D68664

llvm-svn: 374649

6 files changed, 66 insertions, 2 deletions

diff --git a/llvm/utils/lit/tests/Inputs/shtest-shell/diff-encodings.txt b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-encodings.txt
new file mode 100644
index 00000000000..d8b9718a099
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-encodings.txt
@@ -0,0 +1,9 @@
+# Check that diff falls back to binary mode if it cannot decode a file.
+
+# RUN: diff -u diff-in.bin diff-in.bin
+# RUN: diff -u diff-in.utf16 diff-in.bin && false || true
+# RUN: diff -u diff-in.utf8 diff-in.bin && false || true
+# RUN: diff -u diff-in.bin diff-in.utf8 && false || true
+
+# Fail so lit will print output.
+# RUN: false
diff --git a/llvm/utils/lit/tests/Inputs/shtest-shell/diff-in.bin b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-in.bin
new file mode 100644
index 00000000000..06b800b707c
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-in.bin
diff --git a/llvm/utils/lit/tests/Inputs/shtest-shell/diff-in.utf16 b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-in.utf16
new file mode 100644
index 00000000000..d7d9feefa7d
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-in.utf16
diff --git a/llvm/utils/lit/tests/Inputs/shtest-shell/diff-in.utf8 b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-in.utf8
new file mode 100644
index 00000000000..86e041dad66
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-shell/diff-in.utf8
@@ -0,0 +1,3 @@
+foo
+bar
+baz
diff --git a/llvm/utils/lit/tests/max-failures.py b/llvm/utils/lit/tests/max-failures.py
index cee06fa255d..5149a91ec00 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 (27)
+# CHECK: Failing Tests (28)
 # 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 3978e4470a9..6d9b1aa459c 100644
--- a/llvm/utils/lit/tests/shtest-shell.py
+++ b/llvm/utils/lit/tests/shtest-shell.py
@@ -34,6 +34,58 @@
 # CHECK: error: command failed with exit status: 127
 # CHECK: ***
 
+
+# CHECK: FAIL: shtest-shell :: diff-encodings.txt
+# CHECK: *** TEST 'shtest-shell :: diff-encodings.txt' FAILED ***
+
+# CHECK: $ "diff" "-u" "diff-in.bin" "diff-in.bin"
+# CHECK-NOT: error
+
+# CHECK: $ "diff" "-u" "diff-in.utf16" "diff-in.bin"
+# CHECK: # command output:
+# CHECK-NEXT: ---
+# CHECK-NEXT: +++
+# CHECK-NEXT: @@
+# CHECK-NEXT: {{^ .f.o.o.$}}
+# CHECK-NEXT: {{^-.b.a.r.$}}
+# CHECK-NEXT: {{^\+.b.a.r..}}
+# CHECK-NEXT: {{^ .b.a.z.$}}
+# CHECK: error: command failed with exit status: 1
+# CHECK: $ "true"
+
+# CHECK: $ "diff" "-u" "diff-in.utf8" "diff-in.bin"
+# CHECK: # command output:
+# CHECK-NEXT: ---
+# CHECK-NEXT: +++
+# CHECK-NEXT: @@
+# CHECK-NEXT: -foo
+# CHECK-NEXT: -bar
+# CHECK-NEXT: -baz
+# CHECK-NEXT: {{^\+.f.o.o.$}}
+# CHECK-NEXT: {{^\+.b.a.r..}}
+# CHECK-NEXT: {{^\+.b.a.z.$}}
+# CHECK: error: command failed with exit status: 1
+# CHECK: $ "true"
+
+# CHECK: $ "diff" "-u" "diff-in.bin" "diff-in.utf8"
+# CHECK: # command output:
+# CHECK-NEXT: ---
+# CHECK-NEXT: +++
+# CHECK-NEXT: @@
+# CHECK-NEXT: {{^\-.f.o.o.$}}
+# CHECK-NEXT: {{^\-.b.a.r..}}
+# CHECK-NEXT: {{^\-.b.a.z.$}}
+# CHECK-NEXT: +foo
+# CHECK-NEXT: +bar
+# CHECK-NEXT: +baz
+# CHECK: error: command failed with exit status: 1
+# CHECK: $ "true"
+
+# CHECK: $ "false"
+
+# 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"
@@ -245,4 +297,4 @@
 # CHECK: PASS: shtest-shell :: sequencing-0.txt
 # CHECK: XFAIL: shtest-shell :: sequencing-1.txt
 # CHECK: PASS: shtest-shell :: valid-shell.txt
-# CHECK: Failing Tests (27)
+# CHECK: Failing Tests (28)