LineIterator: Provide a variant that keeps blank lines

It isn't always useful to skip blank lines, as evidenced by the
somewhat awkward use of line_iterator in llvm-cov. This adds a knob to
control whether or not to skip blanks.

llvm-svn: 217960

1 files changed, 87 insertions, 9 deletions

diff --git a/llvm/unittests/Support/LineIteratorTest.cpp b/llvm/unittests/Support/LineIteratorTest.cpp
index 8ec6c93..67f9d97 100644
--- a/llvm/unittests/Support/LineIteratorTest.cpp
+++ b/llvm/unittests/Support/LineIteratorTest.cpp
@@ -40,15 +40,17 @@ TEST(LineIteratorTest, Basic) {
   EXPECT_EQ(E, I);
 }
 
-TEST(LineIteratorTest, CommentSkipping) {
+TEST(LineIteratorTest, CommentAndBlankSkipping) {
   std::unique_ptr<MemoryBuffer> Buffer(
       MemoryBuffer::getMemBuffer("line 1\n"
                                  "line 2\n"
                                  "# Comment 1\n"
-                                 "line 4\n"
+                                 "\n"
+                                 "line 5\n"
+                                 "\n"
                                  "# Comment 2"));
 
-  line_iterator I = line_iterator(*Buffer, '#'), E;
+  line_iterator I = line_iterator(*Buffer, true, '#'), E;
 
   EXPECT_FALSE(I.is_at_eof());
   EXPECT_NE(E, I);
@@ -59,14 +61,51 @@ TEST(LineIteratorTest, CommentSkipping) {
   EXPECT_EQ("line 2", *I);
   EXPECT_EQ(2, I.line_number());
   ++I;
-  EXPECT_EQ("line 4", *I);
-  EXPECT_EQ(4, I.line_number());
+  EXPECT_EQ("line 5", *I);
+  EXPECT_EQ(5, I.line_number());
+  ++I;
+
+  EXPECT_TRUE(I.is_at_eof());
+  EXPECT_EQ(E, I);
+}
+
+TEST(LineIteratorTest, CommentSkippingKeepBlanks) {
+  std::unique_ptr<MemoryBuffer> Buffer(
+      MemoryBuffer::getMemBuffer("line 1\n"
+                                 "line 2\n"
+                                 "# Comment 1\n"
+                                 "# Comment 2\n"
+                                 "\n"
+                                 "line 6\n"
+                                 "\n"
+                                 "# Comment 3"));
+
+  line_iterator I = line_iterator(*Buffer, false, '#'), E;
+
+  EXPECT_FALSE(I.is_at_eof());
+  EXPECT_NE(E, I);
+
+  EXPECT_EQ("line 1", *I);
+  EXPECT_EQ(1, I.line_number());
+  ++I;
+  EXPECT_EQ("line 2", *I);
+  EXPECT_EQ(2, I.line_number());
+  ++I;
+  EXPECT_EQ("", *I);
+  EXPECT_EQ(5, I.line_number());
+  ++I;
+  EXPECT_EQ("line 6", *I);
+  EXPECT_EQ(6, I.line_number());
+  ++I;
+  EXPECT_EQ("", *I);
+  EXPECT_EQ(7, I.line_number());
   ++I;
 
   EXPECT_TRUE(I.is_at_eof());
   EXPECT_EQ(E, I);
 }
 
+
 TEST(LineIteratorTest, BlankSkipping) {
   std::unique_ptr<MemoryBuffer> Buffer = MemoryBuffer::getMemBuffer("\n\n\n"
                                                                     "line 1\n"
@@ -90,10 +129,49 @@ TEST(LineIteratorTest, BlankSkipping) {
   EXPECT_EQ(E, I);
 }
 
+TEST(LineIteratorTest, BlankKeeping) {
+  std::unique_ptr<MemoryBuffer> Buffer = MemoryBuffer::getMemBuffer("\n\n"
+                                                                    "line 3\n"
+                                                                    "\n"
+                                                                    "line 5\n"
+                                                                    "\n\n");
+  line_iterator I = line_iterator(*Buffer, false), E;
+
+  EXPECT_FALSE(I.is_at_eof());
+  EXPECT_NE(E, I);
+
+  EXPECT_EQ("", *I);
+  EXPECT_EQ(1, I.line_number());
+  ++I;
+  EXPECT_EQ("", *I);
+  EXPECT_EQ(2, I.line_number());
+  ++I;
+  EXPECT_EQ("line 3", *I);
+  EXPECT_EQ(3, I.line_number());
+  ++I;
+  EXPECT_EQ("", *I);
+  EXPECT_EQ(4, I.line_number());
+  ++I;
+  EXPECT_EQ("line 5", *I);
+  EXPECT_EQ(5, I.line_number());
+  ++I;
+  EXPECT_EQ("", *I);
+  EXPECT_EQ(6, I.line_number());
+  ++I;
+  EXPECT_EQ("", *I);
+  EXPECT_EQ(7, I.line_number());
+  ++I;
+
+  EXPECT_TRUE(I.is_at_eof());
+  EXPECT_EQ(E, I);
+}
+
 TEST(LineIteratorTest, EmptyBuffers) {
   std::unique_ptr<MemoryBuffer> Buffer = MemoryBuffer::getMemBuffer("");
   EXPECT_TRUE(line_iterator(*Buffer).is_at_eof());
   EXPECT_EQ(line_iterator(), line_iterator(*Buffer));
+  EXPECT_TRUE(line_iterator(*Buffer, false).is_at_eof());
+  EXPECT_EQ(line_iterator(), line_iterator(*Buffer, false));
 
   Buffer = MemoryBuffer::getMemBuffer("\n\n\n");
   EXPECT_TRUE(line_iterator(*Buffer).is_at_eof());
@@ -102,14 +180,14 @@ TEST(LineIteratorTest, EmptyBuffers) {
   Buffer = MemoryBuffer::getMemBuffer("# foo\n"
                                       "\n"
                                       "# bar");
-  EXPECT_TRUE(line_iterator(*Buffer, '#').is_at_eof());
-  EXPECT_EQ(line_iterator(), line_iterator(*Buffer, '#'));
+  EXPECT_TRUE(line_iterator(*Buffer, true, '#').is_at_eof());
+  EXPECT_EQ(line_iterator(), line_iterator(*Buffer, true, '#'));
 
   Buffer = MemoryBuffer::getMemBuffer("\n"
                                       "# baz\n"
                                       "\n");
-  EXPECT_TRUE(line_iterator(*Buffer, '#').is_at_eof());
-  EXPECT_EQ(line_iterator(), line_iterator(*Buffer, '#'));
+  EXPECT_TRUE(line_iterator(*Buffer, true, '#').is_at_eof());
+  EXPECT_EQ(line_iterator(), line_iterator(*Buffer, true, '#'));
 }
 
 } // anonymous namespace