Deprecated full import/module name mismatch

Fix issue 15086

Author: Jonathan Marler

changelog/deprecate_full_import_module_name_mismatch.dd

@@ -0,0 +1,29 @@
+Deprecated import statements that match a module's filename but completely mismatches its name
+
+Deprecated import statements that match a module's filename but completely mismatches its name, i.e.
+---
+// main.d
+import foo;
+---
+---
+// foo.d
+module bar;
+---
+The above code will now print:
+
+$(CONSOLE Deprecation: module `bar` from file foo.d must be imported with 'import bar;')
+
+Note that no deprecation occurs if the import name matches the module name at least partially, i.e.
+---
+// main.d
+import foo.bar1
+import foo.bar2;
+---
+---
+// foo/bar1.d
+module pkg.foo.bar1; // OK (module pkg.foo.bar1 partially matches import foo.bar1)
+---
+---
+// foo/bar2.d
+module bar2; // OK (module bar2 partially matches import foo.bar2)
+---

src/dmd/dmodule.d

@@ -514,7 +514,36 @@ extern (C++) final class Module : Package
             buf.printf("%s\t(%s)", ident.toChars(), m.srcfile.toChars());
             message("import    %s", buf.peekString());
         }
-        m = m.parse();
+        {
+            auto originalModule = m;
+            m = m.parse();
+
+            // verify the module name matches the imported module name
+            if (m is originalModule && m.md !is null)
+            {
+                bool mismatch = false;
+                if (!ident.equals(m.md.id))
+                {
+                    mismatch = true;
+                }
+                else
+                {
+                    auto mdPackageCount = (m.md.packages == null) ? 0 : m.md.packages.dim;
+                    auto packageCount   = (packages      == null) ? 0 : packages.dim;
+                    for (size_t i = 1; i <= mdPackageCount && i <= packageCount; i++)
+                    {
+                        if (!(*m.md.packages)[mdPackageCount - i].equals((*packages)[packageCount - i]))
+                        {
+                            mismatch = true;
+                            break;
+                        }
+                    }
+                }
+                if (mismatch)
+                    m.deprecation(loc, "from file %s must be imported with 'import %s;'",
+                        m.srcfile.name.toChars(), m.toPrettyChars());
+            }
+        }
 
         // Call onImport here because if the module is going to be compiled then we
         // need to determine it early because it affects semantic analysis. This is

test/compilable/badimport.d

@@ -0,0 +1,10 @@
+/*
+C1OMPILED_IMPORTS: imports/wrongpkgname.d
+REQUIRED_ARGS: -Ifail_compilation
+PERMUTE_ARGS:
+TEST_OUTPUT:
+---
+compilable/badimport.d(10): Deprecation: module `wrongpkg.wrongpkgname` from file compilable/imports/wrongpkgname.d must be imported with 'import wrongpkg.wrongpkgname;'
+---
+*/
+import imports.wrongpkgname;

test/compilable/badimport2.d

@@ -0,0 +1,9 @@
+/*
+REQUIRED_ARGS: -Icompilable/imports
+PERMUTE_ARGS:
+TEST_OUTPUT:
+---
+compilable/badimport2.d(9): Deprecation: module `wrong_mod_name_bleh` from file compilable/imports/wrong_mod_name.d must be imported with 'import wrong_mod_name_bleh;'
+---
+*/
+import wrong_mod_name;

test/compilable/imports/a15086.d

@@ -0,0 +1 @@
+module foo;

test/compilable/imports/wrong_mod_name.d

@@ -0,0 +1 @@
+module wrong_mod_name_bleh;

test/compilable/imports/wrongpkgname.d

@@ -0,0 +1 @@
+module wrongpkg.wrongpkgname;

test/compilable/test15086.d

@@ -0,0 +1,8 @@
+/*
+PERMUTE_ARGS:
+TEST_OUTPUT:
+---
+compilable/test15086.d(8): Deprecation: module `foo` from file compilable/imports/a15086.d must be imported with 'import foo;'
+---
+*/
+import imports.a15086;

test/compilable/test313f.d

@@ -1,7 +1,8 @@
 // REQUIRED_ARGS: -de
-import imports.f313;
+// EXTRA_SOURCES: imports/f313.d
+import foo.bar;
 
 void test()
 {
-    imports.f313.bug();
+    foo.bar.bug();
 }

test/compilable/test314.d

@@ -1,11 +1,12 @@
 // REQUIRED_ARGS: -de
+// EXTRA_SOURCES: imports/a314.d
 module imports.test314; // package imports
 
-import imports.a314;
+import imports.pkg.a314;
 
 void main()
 {
-    imports.a314.bug("This should work.\n");
+    imports.pkg.a314.bug("This should work.\n");
     renamed.bug("This should work.\n");
     bug("This should work.\n");
 }