Merge pull request #10086 from benlangmuir/eng/blangmuir/local-submodule-visibility-transitive-import

[stable/20240723][clang][modules] Fix local submodule visibility of macros from transitive import

Author: akyrtzi

clang/include/clang/Basic/Module.h

@@ -907,10 +907,11 @@ class VisibleModuleSet {
                          StringRef Message)>;
 
   /// Make a specific module visible.
-  void setVisible(Module *M, SourceLocation Loc,
-                  VisibleCallback Vis = [](Module *) {},
-                  ConflictCallback Cb = [](ArrayRef<Module *>, Module *,
-                                           StringRef) {});
+  void setVisible(
+      Module *M, SourceLocation Loc, bool IncludeExports = true,
+      VisibleCallback Vis = [](Module *) {},
+      ConflictCallback Cb = [](ArrayRef<Module *>, Module *, StringRef) {});
+
 private:
   /// Import locations for each visible module. Indexed by the module's
   /// VisibilityID.

clang/include/clang/Lex/Preprocessor.h

@@ -1766,7 +1766,8 @@ class Preprocessor {
   bool LexAfterModuleImport(Token &Result);
   void CollectPpImportSuffix(SmallVectorImpl<Token> &Toks);
 
-  void makeModuleVisible(Module *M, SourceLocation Loc);
+  void makeModuleVisible(Module *M, SourceLocation Loc,
+                         bool IncludeExports = true);
 
   SourceLocation getModuleImportLoc(Module *M) const {
     return CurSubmoduleState->VisibleModules.getImportLoc(M);

clang/lib/Basic/Module.cpp

@@ -678,7 +678,8 @@ LLVM_DUMP_METHOD void Module::dump() const {
 }
 
 void VisibleModuleSet::setVisible(Module *M, SourceLocation Loc,
-                                  VisibleCallback Vis, ConflictCallback Cb) {
+                                  bool IncludeExports, VisibleCallback Vis,
+                                  ConflictCallback Cb) {
   // We can't import a global module fragment so the location can be invalid.
   assert((M->isGlobalModule() || Loc.isValid()) &&
          "setVisible expects a valid import location");
@@ -704,12 +705,14 @@ void VisibleModuleSet::setVisible(Module *M, SourceLocation Loc,
     Vis(V.M);
 
     // Make any exported modules visible.
-    SmallVector<Module *, 16> Exports;
-    V.M->getExportedModules(Exports);
-    for (Module *E : Exports) {
-      // Don't import non-importable modules.
-      if (!E->isUnimportable())
-        VisitModule({E, &V});
+    if (IncludeExports) {
+      SmallVector<Module *, 16> Exports;
+      V.M->getExportedModules(Exports);
+      for (Module *E : Exports) {
+        // Don't import non-importable modules.
+        if (!E->isUnimportable())
+          VisitModule({E, &V});
+      }
     }
 
     for (auto &C : V.M->Conflicts) {

clang/lib/Lex/PPLexerChange.cpp

@@ -759,9 +759,10 @@ void Preprocessor::EnterSubmodule(Module *M, SourceLocation ImportLoc,
   // Switch to this submodule as the current submodule.
   CurSubmoduleState = &State;
 
-  // This module is visible to itself.
+  // This module is visible to itself, but exports should not be made visible
+  // until they are imported.
   if (FirstTime)
-    makeModuleVisible(M, ImportLoc);
+    makeModuleVisible(M, ImportLoc, /*IncludeExports=*/false);
 }
 
 bool Preprocessor::needModuleMacros() const {

clang/lib/Lex/Preprocessor.cpp

@@ -1336,9 +1336,10 @@ bool Preprocessor::LexAfterModuleImport(Token &Result) {
   return true;
 }
 
-void Preprocessor::makeModuleVisible(Module *M, SourceLocation Loc) {
+void Preprocessor::makeModuleVisible(Module *M, SourceLocation Loc,
+                                     bool IncludeExports) {
   CurSubmoduleState->VisibleModules.setVisible(
-      M, Loc, [](Module *) {},
+      M, Loc, IncludeExports, [](Module *) {},
       [&](ArrayRef<Module *> Path, Module *Conflict, StringRef Message) {
         // FIXME: Include the path in the diagnostic.
         // FIXME: Include the import location for the conflicting module.

clang/test/Modules/local-submodule-visibility-transitive-import.c

@@ -0,0 +1,62 @@
+// Checks that macros from transitive imports work with local submodule
+// visibility. In the below test, previously a() and d() failed because
+// OTHER_MACRO1 and OTHER_MACRO3 were not visible at the use site.
+
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t \
+// RUN:   -fmodules-local-submodule-visibility -I%t %t/tu.c -verify
+
+//--- Other1.h
+#define OTHER_MACRO1(...)
+
+//--- Other2.h
+#define OTHER_MACRO2(...)
+
+//--- Other3.h
+#define OTHER_MACRO3(...)
+
+//--- module.modulemap
+module Other {
+  module O1 { header "Other1.h" }
+  module O2 { header "Other2.h" }
+  module O3 { header "Other3.h" }
+}
+
+//--- Top/A.h
+#include "Other1.h"
+#define MACRO_A OTHER_MACRO1(x, y)
+
+//--- Top/B.h
+#include "Other2.h"
+#define MACRO_B OTHER_MACRO2(x, y)
+
+//--- Top/C.h
+#include "D.h"
+
+//--- Top/D.h
+#include "Other3.h"
+#define MACRO_D OTHER_MACRO3(x, y)
+
+//--- Top/Top.h
+#include "A.h"
+#include "B.h"
+#include "C.h"
+
+void a() MACRO_A;
+void b() MACRO_B;
+void d() MACRO_D;
+
+//--- Top/module.modulemap
+module Top {
+  umbrella header "Top.h"
+  module A { header "A.h" export * }
+  module D { header "D.h" export * }
+  module * { export * }
+  export *
+  export Other.O3
+}
+
+//--- tu.c
+#include "Top/Top.h"
+// expected-no-diagnostics