ModuleInterface: remark potential version differences between SDK and prebuilt modules

Prebuilt-module directory now contains a SystemVersion.plist file copied from the SDK
it's built from. This patch teaches the compiler to remark this version and the SDK version
when -Rmodule-interface-rebuild is specified. The difference between these versions could
help us debug unusable prebuilt modules.

Author: nkcsgexi

include/swift/AST/DiagnosticsFrontend.def

@@ -366,6 +366,9 @@ ERROR(error_extracting_flags_from_module_interface,none,
       "error extracting flags from module interface", ())
 REMARK(rebuilding_module_from_interface,none,
        "rebuilding module '%0' from interface '%1'", (StringRef, StringRef))
+NOTE(sdk_version_pbm_version,none,
+     "SDK build version is '%0'; prebuilt modules were "
+     "built using SDK build version: '%1'", (StringRef, StringRef))
 NOTE(out_of_date_module_here,none,
      "%select{compiled|cached|forwarding|prebuilt}0 module is out of date: '%1'",
      (unsigned, StringRef))

include/swift/Basic/Platform.h

@@ -106,6 +106,13 @@ namespace swift {
   /// Retrieve the target SDK version for the given SDKInfo and target triple.
   llvm::VersionTuple getTargetSDKVersion(clang::driver::DarwinSDKInfo &SDKInfo,
                                          const llvm::Triple &triple);
+
+  /// Get SDK build version.
+  std::string getSDKBuildVersion(StringRef SDKPath);
+  std::string getSDKBuildVersionFromPlist(StringRef Path);
+
+  /// Get SDK name.
+  std::string getSDKName(StringRef SDKPath);
 } // end namespace swift
 
 #endif // SWIFT_BASIC_PLATFORM_H

include/swift/IDE/Utils.h

@@ -101,10 +101,6 @@ void walkOverriddenDecls(const ValueDecl *VD,
 
 void collectModuleNames(StringRef SDKPath, std::vector<std::string> &Modules);
 
-std::string getSDKName(StringRef Path);
-
-std::string getSDKVersion(StringRef Path);
-
 struct PlaceholderOccurrence {
   /// The complete placeholder string.
   StringRef FullPlaceholder;

lib/Basic/Platform.cpp

@@ -473,3 +473,47 @@ swift::getTargetSDKVersion(clang::driver::DarwinSDKInfo &SDKInfo,
 
   return SDKVersion;
 }
+
+static std::string getPlistEntry(const llvm::Twine &Path, StringRef KeyName) {
+  auto BufOrErr = llvm::MemoryBuffer::getFile(Path);
+  if (!BufOrErr) {
+    // FIXME: diagnose properly
+    return {};
+  }
+
+  std::string Key = "<key>";
+  Key += KeyName;
+  Key += "</key>";
+
+  StringRef Lines = BufOrErr.get()->getBuffer();
+  while (!Lines.empty()) {
+    StringRef CurLine;
+    std::tie(CurLine, Lines) = Lines.split('\n');
+    if (CurLine.find(Key) != StringRef::npos) {
+      std::tie(CurLine, Lines) = Lines.split('\n');
+      unsigned Begin = CurLine.find("<string>") + strlen("<string>");
+      unsigned End = CurLine.find("</string>");
+      return CurLine.substr(Begin, End - Begin).str();
+    }
+  }
+
+  return {};
+}
+
+std::string swift::getSDKBuildVersionFromPlist(StringRef Path) {
+  return getPlistEntry(Path, "ProductBuildVersion");
+}
+
+std::string swift::getSDKBuildVersion(StringRef Path) {
+  return getSDKBuildVersionFromPlist((llvm::Twine(Path) +
+    "/System/Library/CoreServices/SystemVersion.plist").str());
+}
+
+std::string swift::getSDKName(StringRef Path) {
+  std::string Name = getPlistEntry(llvm::Twine(Path)+"/SDKSettings.plist",
+                                   "CanonicalName");
+  if (Name.empty() && Path.endswith(".sdk")) {
+    Name = llvm::sys::path::filename(Path).drop_back(strlen(".sdk")).str();
+  }
+  return Name;
+}

lib/Frontend/ModuleInterfaceLoader.cpp

@@ -286,10 +286,18 @@ struct ModuleRebuildInfo {
   /// Emits a diagnostic for all out-of-date compiled or forwarding modules
   /// encountered while trying to load a module.
   void diagnose(ASTContext &ctx, SourceLoc loc, StringRef moduleName,
-                 StringRef interfacePath) {
+                 StringRef interfacePath, StringRef prebuiltCacheDir) {
     ctx.Diags.diagnose(loc, diag::rebuilding_module_from_interface,
                        moduleName, interfacePath);
-
+    auto SDKVer = getSDKBuildVersion(ctx.SearchPathOpts.SDKPath);
+    llvm::SmallString<64> buffer = prebuiltCacheDir;
+    llvm::sys::path::append(buffer, "SystemVersion.plist");
+    auto PBMVer = getSDKBuildVersionFromPlist(buffer.str());
+    if (!SDKVer.empty() && !PBMVer.empty()) {
+      // Remark the potential version difference.
+      ctx.Diags.diagnose(loc, diag::sdk_version_pbm_version, SDKVer,
+                         PBMVer);
+    }
     // We may have found multiple failing modules, that failed for different
     // reasons. Emit a note for each of them.
     for (auto &mod : outOfDateModules) {
@@ -911,7 +919,7 @@ class ModuleInterfaceLoaderImpl {
     // Diagnose that we didn't find a loadable module, if we were asked to.
     auto remarkRebuild = [&]() {
       rebuildInfo.diagnose(ctx, diagnosticLoc, moduleName,
-                           interfacePath);
+                           interfacePath, prebuiltCacheDir);
     };
     // If we found an out-of-date .swiftmodule, we still want to add it as
     // a dependency of the .swiftinterface. That way if it's updated, but

lib/IDE/Utils.cpp

@@ -13,6 +13,7 @@
 #include "swift/IDE/Utils.h"
 #include "swift/Basic/Edit.h"
 #include "swift/Basic/SourceManager.h"
+#include "swift/Basic/Platform.h"
 #include "swift/ClangImporter/ClangModule.h"
 #include "swift/Driver/FrontendUtil.h"
 #include "swift/Frontend/Frontend.h"
@@ -664,46 +665,6 @@ ide::replacePlaceholders(std::unique_ptr<llvm::MemoryBuffer> InputBuf,
   });
 }
 
-static std::string getPlistEntry(const llvm::Twine &Path, StringRef KeyName) {
-  auto BufOrErr = llvm::MemoryBuffer::getFile(Path);
-  if (!BufOrErr) {
-    llvm::errs() << "could not open '" << Path << "': " << BufOrErr.getError().message() << '\n';
-    return {};
-  }
-
-  std::string Key = "<key>";
-  Key += KeyName;
-  Key += "</key>";
-
-  StringRef Lines = BufOrErr.get()->getBuffer();
-  while (!Lines.empty()) {
-    StringRef CurLine;
-    std::tie(CurLine, Lines) = Lines.split('\n');
-    if (CurLine.find(Key) != StringRef::npos) {
-      std::tie(CurLine, Lines) = Lines.split('\n');
-      unsigned Begin = CurLine.find("<string>") + strlen("<string>");
-      unsigned End = CurLine.find("</string>");
-      return CurLine.substr(Begin, End - Begin).str();
-    }
-  }
-
-  return {};
-}
-
-std::string ide::getSDKName(StringRef Path) {
-  std::string Name = getPlistEntry(llvm::Twine(Path)+"/SDKSettings.plist",
-                                   "CanonicalName");
-  if (Name.empty() && Path.endswith(".sdk")) {
-    Name = llvm::sys::path::filename(Path).drop_back(strlen(".sdk")).str();
-  }
-  return Name;
-}
-
-std::string ide::getSDKVersion(StringRef Path) {
-  return getPlistEntry(llvm::Twine(Path)+"/System/Library/CoreServices/"
-                       "SystemVersion.plist", "ProductBuildVersion");
-}
-
 // Modules failing to load are commented-out.
 static const char *OSXModuleList[] = {
   "AGL",

test/ModuleInterface/ModuleCache/Inputs/sdk-build-ver.1.plist

@@ -0,0 +1,6 @@
+<plist version="1.0">
+<dict>
+	<key>ProductBuildVersion</key>
+	<string>11111</string>
+</dict>
+</plist>

test/ModuleInterface/ModuleCache/Inputs/sdk-build-ver.2.plist

@@ -0,0 +1,6 @@
+<plist version="1.0">
+<dict>
+	<key>ProductBuildVersion</key>
+	<string>22222</string>
+</dict>
+</plist>

test/ModuleInterface/ModuleCache/RebuildRemarks/out-of-date-forwarding-module.swift

@@ -1,6 +1,10 @@
 // RUN: %empty-directory(%t/ModuleCache)
 // RUN: %empty-directory(%t/Build)
 // RUN: %empty-directory(%t/PrebuiltCache)
+// RUN: %empty-directory(%t/System/Library/CoreServices)
+
+// RUN: cp %S/../Inputs/sdk-build-ver.1.plist %t/System/Library/CoreServices/SystemVersion.plist
+// RUN: cp %S/../Inputs/sdk-build-ver.2.plist %t/PrebuiltCache/SystemVersion.plist
 
 // 1. Create a dummy module
 // RUN: echo 'public func publicFunction() {}' > %t/TestModule.swift
@@ -30,3 +34,4 @@ import TestModule // expected-remark {{rebuilding module 'TestModule' from inter
 // expected-note @-2 {{dependency is out of date}}
 // expected-note @-3 {{prebuilt module is out of date}}
 // expected-note @-4 {{dependency is out of date}}
+// expected-note @-5 {{SDK build version is '11111'; prebuilt modules were built using SDK build version: '22222'}}

tools/swift-api-digester/swift-api-digester.cpp

@@ -26,6 +26,7 @@
 // can be reflected as source-breaking changes for API users. If they are,
 // the output of api-digester will include such changes.
 
+#include "swift/Basic/Platform.h"
 #include "swift/Frontend/PrintingDiagnosticConsumer.h"
 #include "swift/Frontend/SerializedDiagnosticConsumer.h"
 #include "swift/AST/DiagnosticsModuleDiffer.h"
@@ -2704,7 +2705,7 @@ static CheckerOptions getCheckOpts(int argc, char *argv[]) {
     Opts.ToolArgs.push_back(argv[i]);
 
   if (!options::SDK.empty()) {
-    auto Ver = getSDKVersion(options::SDK);
+    auto Ver = getSDKBuildVersion(options::SDK);
     if (!Ver.empty()) {
       Opts.ToolArgs.push_back("-sdk-version");
       Opts.ToolArgs.push_back(Ver);