Changeset df9317bd

Timestamp:

Jun 24, 2019, 3:36:31 PM (5 years ago)

Author:

Andrew Beach <ajbeach@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

1335e6f

Parents:

e98c7ab

Message:

Filled in the definition of PtrsAssignable?.

File:

• src/ResolvExpr/PtrsAssignable.cc (modified) (2 diffs)

src/ResolvExpr/PtrsAssignable.cc

@@ -9 +9 @@
 // Author           : Richard C. Bilson
 // Created On       : Sun May 17 11:44:11 2015
-// Last Modified By : Peter A. Buhr
-// Last Modified On : Wed Mar  2 17:36:05 2016
-// Update Count     : 8
-//
-
-#include "AST/Fwd.hpp"
+// Last Modified By : Andrew
+// Last Modified On : Mon Jun 24 15:29:00 2019
+// Update Count     : 9
+//
+
+#include "typeops.h"
+
+#include "AST/Pass.hpp"
+#include "AST/Type.hpp"
+#include "AST/TypeEnvironment.hpp"
 #include "Common/PassVisitor.h"
 #include "ResolvExpr/TypeEnvironment.h"  // for EqvClass, TypeEnvironment
@@ -108 +112 @@
         void PtrsAssignable::postvisit(  __attribute__((unused)) OneType *oneType ) {}
 
+// TODO: Get rid of the `_new` suffix when the old version is removed.
+struct PtrsAssignable_new : public ast::WithShortCircuiting {
+        const ast::Type * dst;
+        const ast::TypeEnvironment & typeEnv;
+        int result;
+
+        PtrsAssignable_new( const ast::Type * dst, const ast::TypeEnvironment & env ) :
+                dst( dst ), typeEnv( env ), result( 0 ) {}
+
+        void previsit( Type * ) { visit_children = false; }
+
+        void postvisit( const ast::EnumInstType * ) {
+                if ( dynamic_cast< const ast::BasicType * >( dst ) ) {
+                        // int * = E *, etc. is safe. This isn't technically correct, as each
+                        // enum has one basic type that it is compatible with, an that type can
+                        // differ from enum to enum. Without replicating GCC's internal logic,
+                        // there is no way to know which type this particular enum is compatible
+                        // with, so punt on this for now.
+                        result = 1;
+                }
+        }
+        void postvisit( const ast::TypeInstType * inst ) {
+                if ( const ast::EqvClass * eqv = typeEnv.lookup( inst->name ) ) {
+                        if ( eqv->bound ) {
+                                // T * = S * for any S depends on the type bound to T
+                                result = ptrsAssignable( eqv->bound, dst, typeEnv );
+                        }
+                }
+        }
+};
+
 int ptrsAssignable( const ast::Type * src, const ast::Type * dst,
                 const ast::TypeEnvironment & env ) {
-        #warning unimplemented
-        (void)src;
-        (void)dst;
-        (void)env;
-        assert(0);
+        if ( const ast::TypeInstType * dstAsInst = dynamic_cast< const ast::TypeInstType * >( dst ) ) {
+                if ( const ast::EqvClass * eqv = env.lookup( dstAsInst->name ) ) {
+                        return ptrsAssignable( src, eqv->bound, env );
+                }
+        }
+        if ( dynamic_cast< const ast::VoidType * >( dst ) ) {
+                return -1;
+        } else {
+                ast::Pass<PtrsAssignable_new> visitor( dst, env );
+                src->accept( visitor );
+                return visitor.pass.result;
+        }
+
+// see ticket #136 (this should be able to replace the visitor).
+#if 0
+        if ( const ast::TypeInstType * dstAsTypeInst =
+                        dynamic_cast< const ast::TypeInstType* >( dst ) ) {
+                if ( const ast::EqvClass * eqv = env.lookup( dstAsTypeInst->get_name() ) ) {
+                        return ptrsAssignable( src, eqv->type, env );
+                } // if
+        } // if
+        if ( dynamic_cast< VoidType* >( dst ) ) {
+                // void * = T * for any T is unsafe
+                // xxx - this should be safe, but that currently breaks the build
+                return -1;
+        } else if ( dynamic_cast< EnumInstType * >( src ) ) {
+                if ( dynamic_cast< BasicType * >( dst ) ) {
+                        // int * = E *, etc. is safe. This isn't technically correct, as each
+                        // enum has one basic type that it is compatible with, an that type can
+                        // differ from enum to enum. Without replicating GCC's internal logic,
+                        // there is no way to know which type this particular enum is compatible
+                        // with, so punt on this for now.
+                        return 1;
+                }
+        } else if ( const ast::TypeInstType * typeInstType =
+                        dynamic_cast< const ast::TypeInstType * >( src ) ) {
+                if ( const ast::EqvClass * eqv = env.lookup( typeInstType->name ) ) {
+                        if ( eqv->bound ) {
+                                // T * = S * for any S depends on the type bound to T
+                                return ptrsAssignable( eqv->bound, dst, env );
+                        }
+                }
+        }
         return 0;
+#endif
 }