[Support] Fix Windows Command Shell Command line parsing for quoted arguments

[MyDeveloperDay]

Summary

PR38471 - Check readability-identifier-naming is not working on Windows 10

clang-tidy command line parsing fails to read single quoted -checks when using windows cmd.exe prompt

The following will fail to read the values of -checks due argv not removing the single quote (') on windows cmd shell (unlike unix variants & cygwin)
see (https://bugs.llvm.org/show_bug.cgi?id=38471) for more details

clang-tidy.exe -checks='-*,readability-identifier-naming' test.cpp -- -std=c++11

this results in Windows only supporting double quote usage and this is confusing with lots of the examples using single quotes

clang-tidy.exe -checks="-*,readability-identifier-naming" test.cpp -- -std=c++11

As I'm fairly new to LLVM this may not be the best place to do this, whilst this was reported up in clang-tidy I suspect it could have an effect on any of the llvm tools being run in a windows command shell (but not inside bash.exe)

If you think this can be done better elsewhere or is unnecessary I'll be happy to change/abandon it

Picking reviewers from code owners and common reviewers to changes in this area feel free to adjust as necessary.

[chandlerc]

This wasn't sent to the llvm-commits mailing list. Please abandon this revision in Phab and create a new one with the list subscribed.

[MyDeveloperDay]

Abandoning...recreated as D56901: [Support] Fix Windows Command Shell Command line parsing for quoted arguments

lib/Support/CommandLine.cpp

if (I == Sub.OptionsMap.end())
     return nullptr;
 
   auto O = I->second;
   if (O->getFormattingFlag() == cl::AlwaysPrefix)
     return nullptr;
 
   Value = Arg.substr(EqualPos + 1);
   Arg = Arg.substr(0, EqualPos);
+
+  // Windows Cmd Shell will not remove the '' from a --checks='abc' type command
+  // when passed via argv, unlike Linux or cygwin shells.
+  if (Triple(sys::getProcessTriple()).isOSWindows()) {
+    // Pull off the leading and trailing 's.
+    if (Value.size() > 1 && Value[0] == '\'' && Value[Value.size() - 1] == '\'')
+      Value = Value.substr(1, Value.size() - 2);
+  }
   return I->second;
 }
 
 SubCommand *CommandLineParser::LookupSubCommand(StringRef Name) {
   if (Name.empty())
     return &*TopLevelSubCommand;
   for (auto S : RegisteredSubCommands) {
     if (S == &*AllSubCommands)

unittests/Support/CommandLineTest.cpp

TEST(CommandLineTest, PrefixOptions) {
   EXPECT_TRUE(MacroDefs.empty());
   const char *args6[] = {"prog", "-DHAVE_FOO"};
   EXPECT_TRUE(
       cl::ParseCommandLineOptions(2, args6, StringRef(), &llvm::nulls()));
   EXPECT_TRUE(MacroDefs.size() == 1);
   EXPECT_TRUE(MacroDefs.front().compare("HAVE_FOO") == 0);
 }
 
+TEST(CommandLineTest, WindowsCmdShellQuotesArg) {
+  if (!Triple(sys::getProcessTriple()).isOSWindows())
+    return;
+
+  StackOption<std::string, cl::opt<std::string>> Checks(
+      "checks", cl::desc("The checks"), cl::init(""));
+
+  const char *argsCmdShell[] = {"clang-tidy.exe",
+                                "-checks='-*,readability-identifier-naming'"};
+
+  EXPECT_TRUE(cl::ParseCommandLineOptions(2, argsCmdShell, StringRef(),
+                                          &llvm::nulls()));
+
+  EXPECT_TRUE(Checks.compare("-*,readability-identifier-naming") == 0);
+
+  cl::ResetAllOptionOccurrences();
+
+  const char *argsCmdShell2[] = {"clang-tidy.exe",
+                                 "-checks=-*,readability-identifier-naming"};
+
+  EXPECT_TRUE(cl::ParseCommandLineOptions(2, argsCmdShell2, StringRef(),
+                                          &llvm::nulls()));
+
+  EXPECT_TRUE(Checks.compare("-*,readability-identifier-naming") == 0);
+}
+
 } // anonymous namespace