[Implicit Modules] Add -cc1 option -fmodules-strict-context-hash which includes search paths and diagnostics.

This is a recommit of r375322 and r375327 with a fix for the Windows test breakage.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@375466 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 22 insertions, 1 deletions

diff --git a/include/clang/Driver/CC1Options.td b/include/clang/Driver/CC1Options.td
index e0974fbb5a..4518aca82e 100644
--- a/include/clang/Driver/CC1Options.td
+++ b/include/clang/Driver/CC1Options.td
@@ -815,6 +815,9 @@ def fdisable_module_hash : Flag<["-"], "fdisable-module-hash">,
   HelpText<"Disable the module hash">;
 def fmodules_hash_content : Flag<["-"], "fmodules-hash-content">,
   HelpText<"Enable hashing the content of a module file">;
+def fmodules_strict_context_hash : Flag<["-"], "fmodules-strict-context-hash">,
+  HelpText<"Enable hashing of all compiler options that could impact the "
+           "semantics of a module in an implicit build">;
 def c_isystem : JoinedOrSeparate<["-"], "c-isystem">, MetaVarName<"<directory>">,
   HelpText<"Add directory to the C SYSTEM include search path">;
 def objc_isystem : JoinedOrSeparate<["-"], "objc-isystem">,
diff --git a/include/clang/Lex/HeaderSearchOptions.h b/include/clang/Lex/HeaderSearchOptions.h
index 3c309744ba..5c19a41986 100644
--- a/include/clang/Lex/HeaderSearchOptions.h
+++ b/include/clang/Lex/HeaderSearchOptions.h
@@ -11,6 +11,7 @@
 
 #include "clang/Basic/LLVM.h"
 #include "llvm/ADT/CachedHashString.h"
+#include "llvm/ADT/Hashing.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/StringRef.h"
 #include <cstdint>
@@ -206,6 +207,13 @@ public:
 
   unsigned ModulesHashContent : 1;
 
+  /// Whether we should include all things that could impact the module in the
+  /// hash.
+  ///
+  /// This includes things like the full header search path, and enabled
+  /// diagnostics.
+  unsigned ModulesStrictContextHash : 1;
+
   HeaderSearchOptions(StringRef _Sysroot = "/")
       : Sysroot(_Sysroot), ModuleFormat("raw"), DisableModuleHash(false),
         ImplicitModuleMaps(false), ModuleMapFileHomeIsCwd(false),
@@ -214,7 +222,8 @@ public:
         ModulesValidateOncePerBuildSession(false),
         ModulesValidateSystemHeaders(false),
         ValidateASTInputFilesContent(false), UseDebugInfo(false),
-        ModulesValidateDiagnosticOptions(true), ModulesHashContent(false) {}
+        ModulesValidateDiagnosticOptions(true), ModulesHashContent(false),
+        ModulesStrictContextHash(false) {}
 
   /// AddPath - Add the \p Path path to the specified \p Group list.
   void AddPath(StringRef Path, frontend::IncludeDirGroup Group,
@@ -238,6 +247,15 @@ public:
   }
 };
 
+inline llvm::hash_code hash_value(const HeaderSearchOptions::Entry &E) {
+  return llvm::hash_combine(E.Path, E.Group, E.IsFramework, E.IgnoreSysRoot);
+}
+
+inline llvm::hash_code
+hash_value(const HeaderSearchOptions::SystemHeaderPrefix &SHP) {
+  return llvm::hash_combine(SHP.Prefix, SHP.IsSystemHeader);
+}
+
 } // namespace clang
 
 #endif // LLVM_CLANG_LEX_HEADERSEARCHOPTIONS_H