[lit] Fix internal diff newlines for -w/-b

[jdenny]

Summary

For example, without this patch:

$ python $LIT_BUILTINS/diff.py -b foo.txt bar.txt
*** /tmp/foo.txt
--- /tmp/bar.txt
***************
*** 1,2 ****
  1! 2--- 1,2 ----
  1! 20

With this patch:

$ python $LIT_BUILTINS/diff.py -b foo.txt bar.txt
*** /tmp/foo.txt
--- /tmp/bar.txt
***************
*** 1,2 ****
  1
! 2
--- 1,2 ----
  1
! 20

[rnk]

lgtm

[jdenny]

Thanks for the quick review. Will push hopefully tomorrow.

llvm/utils/lit/lit/builtin_commands/diff.py

def compareTwoTextFiles(flags, filepaths, filelines_bin, encoding):
     exitCode = 0
     def compose2(f, g):
         return lambda x: f(g(x))
 
     f = lambda x: x
     if flags.strip_trailing_cr:
         f = compose2(lambda line: line.replace('\r\n', '\n'), f)
     if flags.ignore_all_space or flags.ignore_space_change:
-        ignoreSpace = lambda line, separator: separator.join(line.split())
+        ignoreSpace = lambda line, separator: \
+                          separator.join(line.split()) + "\n"
         ignoreAllSpaceOrSpaceChange = functools.partial(ignoreSpace, separator='' if flags.ignore_all_space else ' ')
         f = compose2(ignoreAllSpaceOrSpaceChange, f)
 
     for idx, lines in enumerate(filelines):
         filelines[idx]= [f(line) for line in lines]
 
     func = difflib.unified_diff if flags.unified_diff else difflib.context_diff
     for diff in func(filelines[0], filelines[1], filepaths[0], filepaths[1],

llvm/utils/lit/tests/Inputs/shtest-shell/diff-b.txt

+# RUN: echo 'f o o' > %t.0
+# RUN: echo 'b a r' >> %t.0
+
+# RUN: echo 'f  o  o' > %t.1
+# RUN: echo 'bar' >> %t.1
+
+# Due to -b, only second line has a change.
+# RUN: diff -b %t.0 %t.1

llvm/utils/lit/tests/Inputs/shtest-shell/diff-w.txt

+# RUN: echo 'f o o' > %t.0
+# RUN: echo 'b a r' >> %t.0
+# RUN: echo 'b a z' >> %t.0
+
+# RUN: echo 'f  o  o' > %t.1
+# RUN: echo 'bar' >> %t.1
+# RUN: echo 'b a t' >> %t.1
+
+# Due to -w, only third line has a change.
+# RUN: diff -w %t.0 %t.1

llvm/utils/lit/tests/max-failures.py

 # Check the behavior of --max-failures option.
 #
 # RUN: not %{lit} -j 1 -v %{inputs}/max-failures > %t.out
 # RUN: not %{lit} --max-failures=1 -j 1 -v %{inputs}/max-failures >> %t.out
 # RUN: not %{lit} --max-failures=2 -j 1 -v %{inputs}/max-failures >> %t.out
 # RUN: not %{lit} --max-failures=0 -j 1 -v %{inputs}/max-failures 2>> %t.out
 # RUN: FileCheck < %t.out %s
 #
 # END.
 
-# CHECK: Failing Tests (33)
+# CHECK: Failing Tests (35)
 # CHECK: Failing Tests (1)
 # CHECK: Failing Tests (2)
 # CHECK: error: argument --max-failures: requires positive integer, but found '0'

llvm/utils/lit/tests/shtest-shell.py

 # CHECK: FAIL: shtest-shell :: colon-error.txt
 # CHECK: *** TEST 'shtest-shell :: colon-error.txt' FAILED ***
 # CHECK: $ ":"
 # CHECK: # command stderr:
 # CHECK: Unsupported: ':' cannot be part of a pipeline
 # CHECK: error: command failed with exit status: 127
 # CHECK: ***
 
+# CHECK: PASS: shtest-shell :: dev-null.txt
+
+# CHECK: FAIL: shtest-shell :: diff-b.txt
+# CHECK: *** TEST 'shtest-shell :: diff-b.txt' FAILED ***
+# CHECK: $ "diff" "-b" "{{[^"]*}}.0" "{{[^"]*}}.1"
+# CHECK: # command output:
+# CHECK: 1,2
+# CHECK-NEXT: {{^  }}f o o
+# CHECK-NEXT: ! b a r
+# CHECK-NEXT: ---
+# CHECK-NEXT: {{^  }}f o o
+# CHECK-NEXT: ! bar
+# CHECK-EMPTY:
+# CHECK: error: command failed with exit status: 1
+# 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: error: command failed with exit status: 1
 # CHECK: $ "true"
 
 # CHECK: $ "false"
 
 # CHECK: ***
 
 
+# CHECK: FAIL: shtest-shell :: diff-w.txt
+# CHECK: *** TEST 'shtest-shell :: diff-w.txt' FAILED ***
+# CHECK: $ "diff" "-w" "{{[^"]*}}.0" "{{[^"]*}}.1"
+# CHECK: # command output:
+# CHECK: 1,3
+# CHECK-NEXT: {{^  }}foo
+# CHECK-NEXT: {{^  }}bar
+# CHECK-NEXT: ! baz
+# CHECK-NEXT: ---
+# CHECK-NEXT: {{^  }}foo
+# CHECK-NEXT: {{^  }}bar
+# CHECK-NEXT: ! bat
+# CHECK-EMPTY:
+# CHECK: error: command failed with exit status: 1
+# CHECK: ***
+
 # CHECK: FAIL: shtest-shell :: error-0.txt
 # CHECK: *** TEST 'shtest-shell :: error-0.txt' FAILED ***
 # CHECK: $ "not-a-real-command"
 # CHECK: # command stderr:
 # CHECK: 'not-a-real-command': command not found
 # CHECK: error: command failed with exit status: 127
 # CHECK: ***
 

 # CHECK-NEXT: {{^.f.o.o.$}}
 # CHECK-NEXT: {{^.b.a.r..}}
 # CHECK-NEXT: {{^.b.a.z.$}}
 # CHECK-NOT: error
 # CHECK: $ "false"
 # CHECK: ***
 
 # CHECK: PASS: shtest-shell :: valid-shell.txt
-# CHECK: Failing Tests (33)
+# CHECK: Failing Tests (35)