Changeset e7d6968 for src/InitTweak

Timestamp:

Oct 23, 2020, 9:08:09 PM (4 years ago)

Author:

Fangren Yu <f37yu@…>

Branches:

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

Children:

c532847

Parents:

37b7d95 (diff), 3aec25f (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge branch 'master' of plg.uwaterloo.ca:software/cfa/cfa-cc into master

Location:

src/InitTweak

Files:

• FixGlobalInit.cc (modified) (1 diff)
• FixInit.cc (modified) (1 diff)
• InitTweak.cc (modified) (1 diff)
• InitTweak.h (modified) (1 diff)

src/InitTweak/FixGlobalInit.cc

@@ -153 +153 @@
                         } // if
                         if ( Statement * ctor = ctorInit->ctor ) {
+                                addDataSectonAttribute( objDecl );
                                 initStatements.push_back( ctor );
                                 objDecl->init = nullptr;

src/InitTweak/FixInit.cc

@@ -802 +802 @@
                                 if ( Statement * ctor = ctorInit->get_ctor() ) {
                                         if ( objDecl->get_storageClasses().is_static ) {
+
+                                                // The ojbect needs to go in the data section, regardless of dtor complexity below.
+                                                // The attribute works, and is meant to apply, both for leaving the static local alone,
+                                                // and for hoisting it out as a static global.
+                                                addDataSectonAttribute( objDecl );
+
                                                 // originally wanted to take advantage of gcc nested functions, but
                                                 // we get memory errors with this approach. To remedy this, the static

src/InitTweak/InitTweak.cc

@@ -1103 +1103 @@
                 return isCopyFunction( decl, "?{}" );
         }
+
+        void addDataSectonAttribute( ObjectDecl * objDecl ) {
+                Type *strLitT = new PointerType( Type::Qualifiers( ),
+                        new BasicType( Type::Qualifiers( ), BasicType::Char ) );
+                std::list< Expression * > attr_params;
+                attr_params.push_back( 
+                        new ConstantExpr( Constant( strLitT, "\".data#\"", std::nullopt ) ) );
+                objDecl->attributes.push_back(new Attribute("section", attr_params));
+        }
+
 }

src/InitTweak/InitTweak.h

@@ -108 +108 @@
         bool isConstExpr( Initializer * init );
 
+        /// Modifies objDecl to have:
+        ///    __attribute__((section (".data#")))
+        /// which makes gcc put the declared variable in the data section,
+        /// which is helpful for global constants on newer gcc versions,
+        /// so that CFA's generated initialization won't segfault when writing it via a const cast.
+        /// The trailing # is an injected assembly comment, to suppress the "a" in
+        ///    .section .data,"a"
+        ///    .section .data#,"a"
+        /// to avoid assembler warning "ignoring changed section attributes for .data"
+        void addDataSectonAttribute( ObjectDecl * objDecl );
+
         class InitExpander_old {
         public: