d: Add -fbuilding-libphobos-tests option

Currently, the druntime and phobos unittests are compiled as a separate
check program, then ran by the libphobos.unittest/unittest.exp script.
As PR d/89255 notes, this process lacks proper multilib handling.

As a first step, a new internal option that instructs the compiler to
put the reference to all unittest functions in another symbol has been
added.  This will allow each module to be compiled separately as a
standalone program using dg-runtest without running into collisions in
the D runtime module registry.

gcc/d/ChangeLog:

2019-04-12  Iain Buclaw  <ibuclaw@gdcproject.org>

	* d-tree.h (DECL_IN_UNITTEST_CONDITION_P): Define.
	* decl.cc (DeclVisitor): Add in_version_unittest_ field.
	(DeclVisitor::visit(ConditionalDeclaration)): New override.
	(DeclVisitor::visit(FuncDeclaration)): Set
	DECL_IN_UNITTEST_CONDITION_P.
	* lang.opt (-fbuilding-libphobos-tests): Add option.
	* modules.cc (current_testing_module): New static variable.
	(build_module_tree): Generate second moduleinfo symbol to hold
	reference to unittests if flag_building_libphobos_tests.
	(register_module_decl): Check DECL_IN_UNITTEST_CONDITION_P to decide
	which moduleinfo the decl should be registered against.

From-SVN: r270301

1 files changed, 73 insertions, 7 deletions

diff --git a/gcc/d/modules.cc b/gcc/d/modules.cc
index e9bd441..315f5d8 100644
--- a/gcc/d/modules.cc
+++ b/gcc/d/modules.cc
@@ -110,6 +110,11 @@ enum module_info_flags
 
 static module_info *current_moduleinfo;
 
+/* When compiling with -fbuilding-libphobos-tests, this contains information
+   about the module that gets compiled in only when unittests are enabled.  */
+
+static module_info *current_testing_module;
+
 /* The declaration of the current module being compiled.  */
 
 static Module *current_module_decl;
@@ -706,8 +711,10 @@ build_module_tree (Module *decl)
   assert (!current_moduleinfo && !current_module_decl);
 
   module_info mi = module_info ();
+  module_info mitest = module_info ();
 
   current_moduleinfo = &mi;
+  current_testing_module = &mitest;
   current_module_decl = decl;
 
   /* Layout module members.  */
@@ -720,6 +727,53 @@ build_module_tree (Module *decl)
 	}
     }
 
+  /* For libphobos-internal use only.  Generate a separate module info symbol
+     that references all compiled in unittests, this allows compiling library
+     modules and linking to libphobos without having run-time conflicts because
+     of two ModuleInfo records with the same name being present in two DSOs.  */
+  if (flag_building_libphobos_tests)
+    {
+      /* Associate the module info symbol with a mock module.  */
+      const char *name = concat (GDC_PREFIX ("modtest__"),
+				 decl->ident->toChars (), NULL);
+      Module *tm = Module::create (decl->arg, Identifier::idPool (name), 0, 0);
+      Dsymbols members;
+
+      /* Setting parent puts module in the same package as the current, to
+	 avoid any symbol conflicts.  */
+      tm->parent = decl->parent;
+      tm->needmoduleinfo = decl->needmoduleinfo;
+      tm->members = &members;
+      /* Register the current module as being imported by the mock module.
+	 This informs run-time that there is a dependency between the two.  */
+      tm->aimports.push (decl);
+
+      if (mitest.ctors || mitest.ctorgates)
+	tm->sctor = build_funcs_gates_fn (get_identifier ("*__modtestctor"),
+					  mitest.ctors, mitest.ctorgates);
+
+      if (mitest.dtors)
+	tm->sdtor = build_funcs_gates_fn (get_identifier ("*__modtestdtor"),
+					  mitest.dtors, NULL);
+
+      if (mitest.sharedctors || mitest.sharedctorgates)
+	tm->ssharedctor
+	  = build_funcs_gates_fn (get_identifier ("*__modtestsharedctor"),
+				  mitest.sharedctors, mitest.sharedctorgates);
+
+      if (mitest.shareddtors)
+	tm->sshareddtor
+	  = build_funcs_gates_fn (get_identifier ("*__modtestshareddtor"),
+				  mitest.shareddtors, NULL);
+
+      if (mi.unitTests)
+	tm->stest = build_funcs_gates_fn (get_identifier ("*__modtest"),
+					  mi.unitTests, NULL);
+
+      mi.unitTests = NULL;
+      layout_moduleinfo (tm);
+    }
+
   /* Default behavior is to always generate module info because of templates.
      Can be switched off for not compiling against runtime library.  */
   if (!global.params.betterC
@@ -751,6 +805,7 @@ build_module_tree (Module *decl)
     }
 
   current_moduleinfo = NULL;
+  current_testing_module = NULL;
   current_module_decl = NULL;
 }
 
@@ -777,13 +832,24 @@ register_module_decl (Declaration *d)
     {
       tree decl = get_symbol_decl (fd);
 
+      /* Any module constructors or destructors that are only present when
+	 compiling in unittests are kept track of separately so they are
+	 not omitted when compiling with -fbuilding-libphobos-tests.  */
+      module_info *minfo;
+      if (flag_building_libphobos_tests && DECL_IN_UNITTEST_CONDITION_P (decl))
+	minfo = current_testing_module;
+      else
+	minfo = current_moduleinfo;
+
+      gcc_assert (minfo != NULL);
+
       /* If a static constructor, push into the current ModuleInfo.
 	 Checks for `shared' first because it derives from the non-shared
 	 constructor type in the front-end.  */
       if (fd->isSharedStaticCtorDeclaration ())
-	vec_safe_push (current_moduleinfo->sharedctors, decl);
+	vec_safe_push (minfo->sharedctors, decl);
       else if (fd->isStaticCtorDeclaration ())
-	vec_safe_push (current_moduleinfo->ctors, decl);
+	vec_safe_push (minfo->ctors, decl);
 
       /* If a static destructor, do same as with constructors, but also
 	 increment the destructor's vgate at construction time.  */
@@ -793,9 +859,9 @@ register_module_decl (Declaration *d)
 	  if (vgate != NULL)
 	    {
 	      tree gate = get_symbol_decl (vgate);
-	      vec_safe_push (current_moduleinfo->sharedctorgates, gate);
+	      vec_safe_push (minfo->sharedctorgates, gate);
 	    }
-	  vec_safe_insert (current_moduleinfo->shareddtors, 0, decl);
+	  vec_safe_insert (minfo->shareddtors, 0, decl);
 	}
       else if (fd->isStaticDtorDeclaration ())
 	{
@@ -803,14 +869,14 @@ register_module_decl (Declaration *d)
 	  if (vgate != NULL)
 	    {
 	      tree gate = get_symbol_decl (vgate);
-	      vec_safe_push (current_moduleinfo->ctorgates, gate);
+	      vec_safe_push (minfo->ctorgates, gate);
 	    }
-	  vec_safe_insert (current_moduleinfo->dtors, 0, decl);
+	  vec_safe_insert (minfo->dtors, 0, decl);
 	}
 
       /* If a unittest function.  */
       if (fd->isUnitTestDeclaration ())
-	vec_safe_push (current_moduleinfo->unitTests, decl);
+	vec_safe_push (minfo->unitTests, decl);
     }
 }