Fix Issue 17630 - selective imports find symbols in private imports o…

changelog/fix17630.dd

@@ -0,0 +1,21 @@
+Fix Issue 17630 - selective imports find symbols in private imports of other modules
+
+Selectively importing a symbol should work only if the symbol
+imported is defined or publicly imported in the imported module.
+Due to a compiler bug, selectively importing a symbol works even
+if the symbol is defined in a privately imported module in the
+imported module.
+-----------------------------------------------------------
+//a.d
+int bar;
+
+//b.d
+import a;
+
+//c.d
+import b : bar;
+------------------------------------------------------------
+The above code will now result in a deprecation message
+which states that `bar` cannot be accessed since it is
+privately imported in `b`.
+

src/dmd/backend/global.d

@@ -21,7 +21,8 @@ import core.stdc.stdint;
 
 import dmd.backend.cdef;
 import dmd.backend.cc;
-import dmd.backend.cc : Symbol, block, Classsym, Blockx, code;
+import dmd.backend.cc : Symbol, block, Classsym, Blockx;
+import dmd.backend.code_x86 : code;
 import dmd.backend.code;
 import dmd.backend.el;
 import dmd.backend.el : elem;

src/dmd/dsymbolsem.d

@@ -1145,10 +1145,12 @@ private extern(C++) final class DsymbolSemanticVisitor : Visitor
             sc.protection = imp.protection;
             for (size_t i = 0; i < imp.aliasdecls.dim; i++)
             {
+                bool flag;
                 AliasDeclaration ad = imp.aliasdecls[i];
                 //printf("\tImport %s alias %s = %s, scope = %p\n", toPrettyChars(), aliases[i].toChars(), names[i].toChars(), ad._scope);
-                if (imp.mod.search(imp.loc, imp.names[i]))
+                if (imp.mod.search(imp.loc, imp.names[i]) /*, IgnorePrivateImports*/)
                 {
+                    flag = true;
                     ad.dsymbolSemantic(sc);
                     // If the import declaration is in non-root module,
                     // analysis of the aliased symbol is deferred.
@@ -1158,11 +1160,19 @@ private extern(C++) final class DsymbolSemanticVisitor : Visitor
                 {
                     Dsymbol s = imp.mod.search_correct(imp.names[i]);
                     if (s)
-                        imp.mod.error(imp.loc, "import `%s` not found, did you mean %s `%s`?", imp.names[i].toChars(), s.kind(), s.toChars());
+                        imp.mod.error(imp.loc, "import `%s` not found, did you mean %s `%s`?", imp.names[i].toChars(), s.kind(), s.toPrettyChars());
                     else
                         imp.mod.error(imp.loc, "import `%s` not found", imp.names[i].toChars());
                     ad.type = Type.terror;
                 }
+
+                // Deprecated in 2018-01.
+                // Change to error in 2019-01 by deleteting the following 3 lines and uncommenting
+                // the IgnorePrivateImports parameter from above.
+                // @@@DEPRECATED_2019-01@@@.
+                Dsymbol s = imp.mod.search(imp.loc, imp.names[i], IgnorePrivateImports);
+                if (!s && flag)
+                    .deprecation(imp.loc, "Symbol `%s` is not visible because it is privately imported", imp.names[i].toChars());
             }
             sc = sc.pop();
         }

src/dmd/gluelayer.d

@@ -63,7 +63,7 @@ else version (MARS)
     public import dmd.backend.cc : block, Blockx, Symbol;
     public import dmd.backend.type : type;
     public import dmd.backend.el : elem;
-    public import dmd.backend.code : code;
+    public import dmd.backend.code_x86 : code;
 
     extern (C++)
     {

test/fail_compilation/fail17630.d

@@ -0,0 +1,14 @@
+// REQUIRED_ARGS: -de
+// EXTRA_SOURCES: imports/b17630.d
+/*
+TEST_OUTPUT:
+---
+fail_compilation/fail17630.d(12): Deprecation: Symbol `Erase` is not visible because it is privately imported
+---
+*/
+
+void main()
+{
+    import imports.a17630 : Erase;
+    assert(Erase == 2);
+}

test/fail_compilation/imports/a17630.d

@@ -0,0 +1,3 @@
+module a17630;
+
+import b17630;

test/fail_compilation/imports/b17630.d

@@ -0,0 +1,3 @@
+module b17630;
+
+int Erase;