Fix a bug PlatformDarwin::SDKSupportsModule

[aprantl]

Summary

This fixes a bug PlatformDarwin::SDKSupportsModule introduced by https://reviews.llvm.org/D47889.
VersionTuple::tryParse() can deal with an optional third (micro) component, but the parse will fail when there are extra characters after the version number (e.g.: trying to parse the substring "12.0.sdk" out of "iPhoneSimulator12.0.sdk" fails after that patch).
Fixed here by stripping the ".sdk" suffix first.

rdar://problem/45041492

[jingham]

Looks good to me.

[shafik]

source/Plugins/Platform/MacOSX/PlatformDarwin.cpp

1405

Could we avoid C-style casts, and in this case use static_cast although in this case it is obvious, using explicit casts avoids bugs in the long-term due to changes in type and cv-qualifiers etc... and makes your intent clear.

I personally would advocate for -Wold-style-cast being a hard error in C++ code.

1408

Same comment here.

[labath]

lgtm. Sorry about the trouble.

[aprantl]

Looks like this landed in r345274 and wasn't properly closed.

source/Plugins/Platform/MacOSX/PlatformDarwin.h

public:
   lldb_private::FileSpec LocateExecutable(const char *basename) override;
 
   lldb_private::Status
   LaunchProcess(lldb_private::ProcessLaunchInfo &launch_info) override;
 
   static std::tuple<llvm::VersionTuple, llvm::StringRef>
   ParseVersionBuildDir(llvm::StringRef str);
 
+  enum class SDKType {
+    MacOSX = 0,
+    iPhoneSimulator,
+    iPhoneOS,
+  };
+
 protected:
   void ReadLibdispatchOffsetsAddress(lldb_private::Process *process);
 
   void ReadLibdispatchOffsets(lldb_private::Process *process);
 
   virtual lldb_private::Status GetSharedModuleWithLocalCache(
       const lldb_private::ModuleSpec &module_spec, lldb::ModuleSP &module_sp,
       const lldb_private::FileSpecList *module_search_paths_ptr,
       lldb::ModuleSP *old_module_sp_ptr, bool *did_create_ptr);
 
-  enum class SDKType {
-    MacOSX = 0,
-    iPhoneSimulator,
-    iPhoneOS,
-  };
-
   static bool SDKSupportsModules(SDKType sdk_type, llvm::VersionTuple version);
 
   static bool SDKSupportsModules(SDKType desired_type,
                                  const lldb_private::FileSpec &sdk_path);
 
   struct SDKEnumeratorInfo {
     lldb_private::FileSpec found_path;
     SDKType sdk_type;

source/Plugins/Platform/MacOSX/PlatformDarwin.cpp

 
 bool PlatformDarwin::SDKSupportsModules(SDKType desired_type,
                                         const FileSpec &sdk_path) {
   ConstString last_path_component = sdk_path.GetLastPathComponent();
 
   if (last_path_component) {
     const llvm::StringRef sdk_name = last_path_component.GetStringRef();
 
-    llvm::StringRef version_part;
-
-    if (sdk_name.startswith(sdk_strings[(int)desired_type])) {
-      version_part =
-          sdk_name.drop_front(strlen(sdk_strings[(int)desired_type]));
-    } else {
+    if (!sdk_name.startswith(sdk_strings[(int)desired_type]))
       return false;
-    }
+    auto version_part =
+        sdk_name.drop_front(strlen(sdk_strings[(int)desired_type]));
+    version_part.consume_back(".sdk");
 
     llvm::VersionTuple version;
     if (version.tryParse(version_part))
       return false;
     return SDKSupportsModules(desired_type, version);
   }
 
   return false;

unittests/Platform/PlatformDarwinTest.cpp

 
 #include "llvm/ADT/StringRef.h"
 
 #include <tuple>
 
 using namespace lldb;
 using namespace lldb_private;
 
+struct PlatformDarwinTester : public PlatformDarwin {
+  static bool SDKSupportsModules(SDKType desired_type,
+                                 const lldb_private::FileSpec &sdk_path) {
+    return PlatformDarwin::SDKSupportsModules(desired_type, sdk_path);
+  }
+};
+
 TEST(PlatformDarwinTest, TestParseVersionBuildDir) {
   llvm::VersionTuple V;
   llvm::StringRef D;
 
   std::tie(V, D) = PlatformDarwin::ParseVersionBuildDir("1.2.3 (test1)");
   EXPECT_EQ(llvm::VersionTuple(1, 2, 3), V);
   EXPECT_EQ("test1", D);
 
TEST(PlatformDarwinTest, TestParseVersionBuildDir) {
   EXPECT_EQ("test", D);
 
   std::tie(V, D) = PlatformDarwin::ParseVersionBuildDir("2.3.4 test");
   EXPECT_EQ(llvm::VersionTuple(2, 3, 4), V);
   EXPECT_EQ("", D);
 
   std::tie(V, D) = PlatformDarwin::ParseVersionBuildDir("3.4.5");
   EXPECT_EQ(llvm::VersionTuple(3, 4, 5), V);
+
+  std::string base = "/Applications/Xcode.app/Contents/Developer/Platforms/";
+  EXPECT_TRUE(PlatformDarwinTester::SDKSupportsModules(
+      PlatformDarwin::SDKType::iPhoneSimulator,
+      FileSpec(base +
+          "iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator12.0.sdk",
+          false)));
+  EXPECT_FALSE(PlatformDarwinTester::SDKSupportsModules(
+      PlatformDarwin::SDKType::iPhoneSimulator,
+      FileSpec(base +
+          "iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator7.2.sdk",
+          false)));
+  EXPECT_TRUE(PlatformDarwinTester::SDKSupportsModules(
+      PlatformDarwin::SDKType::MacOSX,
+      FileSpec(base + "MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk",
+               false)));
+  EXPECT_FALSE(PlatformDarwinTester::SDKSupportsModules(
+      PlatformDarwin::SDKType::MacOSX,
+      FileSpec(base + "MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk", false)));
 }