Unified import mismatch behavior whether or not modules were given on the command line

Fix issue 15086

Author: Jonathan Marler

changelog/deprecate_compile_seperately_inconsistency.dd

@@ -0,0 +1,21 @@
+Make imports behave the same whether or not both modules were given on the command line
+
+Before, if an import statement matches a filename but does not match its module name, an error is asserted, but only if both modules have been given on the command line. Now it will be an error even if the modules are not both given on the command line, i.e.
+---
+// main.d
+import foo;
+---
+---
+// foo.d
+module bar;
+---
+Before, this module would fail if compiled like this:
+$(CONSOLE dmd -c main.d foo.d)
+
+and pass if compiled like this:
+$(CONSOLE
+dmd -c main.d
+dmd -c foo.d
+)
+
+Now it will fail in both cases.

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");
 }