Option parsing: support case-insensitive option matching.

Link.exe's command line options are case-insensitive. This patch
adds a new attribute to OptTable to let the option parser to compare
options, ignoring case.

Command lines are generally case-insensitive on Windows. CL.exe is an
exception. So this new attribute should be useful for other commands
running on Windows.

Differential Revision: http://llvm-reviews.chandlerc.com/D1485

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189416 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/Option/OptionParsingTest.cpp b/unittests/Option/OptionParsingTest.cpp
index 86286d1..11d6d1e 100644
--- a/unittests/Option/OptionParsingTest.cpp
+++ b/unittests/Option/OptionParsingTest.cpp
@@ -20,7 +20,7 @@
 enum ID {
   OPT_INVALID = 0, // This is not an option ID.
 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM, \
-              HELPTEXT, METAVAR) OPT_##ID,
+               HELPTEXT, METAVAR) OPT_##ID,
 #include "Opts.inc"
   LastOption
 #undef OPTION
@@ -48,8 +48,8 @@
 namespace {
 class TestOptTable : public OptTable {
 public:
-  TestOptTable()
-    : OptTable(InfoTable, array_lengthof(InfoTable)) {}
+  TestOptTable(bool IgnoreCase = false)
+    : OptTable(InfoTable, array_lengthof(InfoTable), IgnoreCase) {}
 };
 }
 
@@ -157,6 +157,26 @@
   EXPECT_EQ(AL->getAllArgValues(OPT_B)[1], "bar");
 }
 
+TEST(Option, IgnoreCase) {
+  TestOptTable T(true);
+  unsigned MAI, MAC;
+
+  const char *MyArgs[] = { "-a", "-joo" };
+  OwningPtr<InputArgList> AL(T.ParseArgs(MyArgs, array_endof(MyArgs), MAI, MAC));
+  EXPECT_TRUE(AL->hasArg(OPT_A));
+  EXPECT_TRUE(AL->hasArg(OPT_B));
+}
+
+TEST(Option, DoNotIgnoreCase) {
+  TestOptTable T;
+  unsigned MAI, MAC;
+
+  const char *MyArgs[] = { "-a", "-joo" };
+  OwningPtr<InputArgList> AL(T.ParseArgs(MyArgs, array_endof(MyArgs), MAI, MAC));
+  EXPECT_FALSE(AL->hasArg(OPT_A));
+  EXPECT_FALSE(AL->hasArg(OPT_B));
+}
+
 TEST(Option, SlurpEmpty) {
   TestOptTable T;
   unsigned MAI, MAC;