Option spell checking: Penalize delimiter flags if input has no argument

If the user passes a flag like `-version` to a program, it's more likely
they mean `--version` than `-version:`, since there's no parameter
passed. Hence, give delimited arguments a penalty of 1 if the user input
doesn't contain the delimiter or no data after it.

The motivation is that with this, lld-link can suggest "--version"
instead of "-version:" for "-version" and "-nodefaultlib" instead of
"-nodefaultlib:" for "-nodefaultlibs".

Differential Revision: https://reviews.llvm.org/D61382

llvm-svn: 359701

1 files changed, 13 insertions, 4 deletions

diff --git a/llvm/unittests/Option/OptionParsingTest.cpp b/llvm/unittests/Option/OptionParsingTest.cpp
index ee741c25d05..e1d7a473ee7 100644
--- a/llvm/unittests/Option/OptionParsingTest.cpp
+++ b/llvm/unittests/Option/OptionParsingTest.cpp
@@ -298,10 +298,19 @@ TEST(Option, FindNearest) {
   EXPECT_EQ(1U, T.findNearest("/framb:foo", Nearest));
   EXPECT_EQ(Nearest, "/cramb:foo");
 
-  // `--glormp` should have an editing distance of 1 to `--glormp=`.
-  EXPECT_EQ(1U, T.findNearest("--glormp", Nearest));
-  EXPECT_EQ(Nearest, "--glormp=");
-  EXPECT_EQ(0U, T.findNearest("--glormp=foo", Nearest));
+  // `--glormp` should have an editing distance > 0 from `--glormp=`.
+  EXPECT_GT(T.findNearest("--glorrmp", Nearest), 0U);
+  EXPECT_EQ(Nearest, "--glorrmp=");
+  EXPECT_EQ(0U, T.findNearest("--glorrmp=foo", Nearest));
+
+  // `--blurmps` should correct to `--blurmp`, not `--blurmp=`, even though
+  // both naively have an editing distance of 1.
+  EXPECT_EQ(1U, T.findNearest("--blurmps", Nearest));
+  EXPECT_EQ(Nearest, "--blurmp");
+
+  // ...but `--blurmps=foo` should correct to `--blurmp=foo`.
+  EXPECT_EQ(1U, T.findNearest("--blurmps=foo", Nearest));
+  EXPECT_EQ(Nearest, "--blurmp=foo");
 
   // Flags should be included and excluded as specified.
   EXPECT_EQ(1U, T.findNearest("-doopf", Nearest, /*FlagsToInclude=*/OptFlag2));