Changeset 6cf27a07

Timestamp:

Jul 21, 2016, 2:07:01 PM (8 years ago)

Author:

Rob Schluntz <rschlunt@…>

Branches:

ADT, aaron-thesis, arm-eh, ast-experimental, cleanup-dtors, ctor, deferred_resn, demangler, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, memory, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, pthread-emulation, qualifiedEnum, resolv-new, with_gc

Children:

ccb447e

Parents:

b81adcc4

Message:

reorganize global init so that it is simpler and generates less unnecessary code

Location:

src

Files:

• InitTweak/FixGlobalInit.cc (modified) (2 diffs)
• InitTweak/FixInit.cc (modified) (3 diffs)
• InitTweak/FixInit.h (modified) (1 diff)
• InitTweak/GenInit.cc (modified) (4 diffs)
• InitTweak/InitTweak.cc (modified) (1 diff)
• SymTab/Autogen.h (modified) (1 diff)
• main.cc (modified) (3 diffs)
• tests/.expect/extension.txt (modified) (1 diff)

src/InitTweak/FixGlobalInit.cc

@@ -97 +97 @@
                 std::list< Statement * > & destroyStatements = destroyFunction->get_statements()->get_kids();
 
-                if ( ! tryConstruct( objDecl ) ) return; // don't construct @= or designated objects
-                if ( objDecl->get_storageClass() == DeclarationNode::Extern ) return;
                 // C allows you to initialize objects with constant expressions
                 // xxx - this is an optimization. Need to first resolve constructors before we decide
@@ -104 +102 @@
                 // if ( isConstExpr( objDecl->get_init() ) ) return;
 
-                if ( dynamic_cast< ArrayType * > ( objDecl->get_type() ) ) {
-                        // xxx - initialize each element of the array
-                } else {
-                        // insert constructor for objDecl into global init function
-                        UntypedExpr * init = new UntypedExpr( new NameExpr( "?{}" ) );
-                        init->get_args().push_back( new AddressExpr( new VariableExpr( objDecl ) ) );
-                        init->get_args().splice( init->get_args().end(), makeInitList( objDecl->get_init() ) );
-                        objDecl->set_init( NULL );
-                        initStatements.push_back( new ImplicitCtorDtorStmt( new ExprStmt( noLabels, init ) ) );
+                if ( ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() ) ) {
+                        // a decision should have been made by the resolver, so ctor and init are not both non-NULL
+                        assert( ! ctorInit->get_ctor() || ! ctorInit->get_init() );
 
-                        // add destructor calls to global destroy function
-                        UntypedExpr * destroy = new UntypedExpr( new NameExpr( "^?{}" ) );
-                        destroy->get_args().push_back( new AddressExpr( new VariableExpr( objDecl ) ) );
-                        destroyStatements.push_front( new ImplicitCtorDtorStmt( new ExprStmt( noLabels, destroy ) ) );
+                        Statement * dtor = ctorInit->get_dtor();
+                        if ( dtor && ! isInstrinsicSingleArgCallStmt( dtor ) ) {
+                                // don't need to call intrinsic dtor, because it does nothing, but
+                                // non-intrinsic dtors must be called
+                                destroyStatements.push_front( dtor );
+                                ctorInit->set_dtor( NULL );
+                        } // if
+                        if ( Statement * ctor = ctorInit->get_ctor() ) {
+                                initStatements.push_back( ctor );
+                                objDecl->set_init( NULL );
+                                ctorInit->set_ctor( NULL );
+                        } else if ( Initializer * init = ctorInit->get_init() ) {
+                                objDecl->set_init( init );
+                                ctorInit->set_init( NULL );
+                        } else {
+                                // no constructor and no initializer, which is okay
+                                objDecl->set_init( NULL );
+                        } // if
+                        delete ctorInit;
                 } // if
         }

src/InitTweak/FixInit.cc

@@ -18 +18 @@
 #include <iterator>
 #include <algorithm>
+#include "InitTweak.h"
 #include "FixInit.h"
-#include "InitTweak.h"
+#include "FixGlobalInit.h"
 #include "ResolvExpr/Resolver.h"
 #include "ResolvExpr/typeops.h"
@@ -83 +84 @@
                 };
 
+                // debug
                 struct printSet {
                         typedef ObjDeclCollector::ObjectSet ObjectSet;
@@ -171 +173 @@
         } // namespace
 
-        void fix( std::list< Declaration * > & translationUnit ) {
+        void fix( std::list< Declaration * > & translationUnit, const std::string & filename, bool inLibrary ) {
+                // fixes ConstructorInit for global variables. should happen before fixInitializers.
+                InitTweak::fixGlobalInit( translationUnit, filename, inLibrary );
+
                 InsertImplicitCalls::insert( translationUnit );
                 ResolveCopyCtors::resolveImplicitCalls( translationUnit );

src/InitTweak/FixInit.h

@@ -27 +27 @@
   /// replace constructor initializers with expression statements
   /// and unwrap basic C-style initializers
-        void fix( std::list< Declaration * > & translationUnit );
+        void fix( std::list< Declaration * > & translationUnit, const std::string & name, bool inLibrary );
 } // namespace
 

src/InitTweak/GenInit.cc

@@ -61 +61 @@
                 static void generateCtorDtor( std::list< Declaration * > &translationUnit );
 
-                CtorDtor() : inFunction( false ) {}
-
                 virtual DeclarationWithType * mutate( ObjectDecl * );
                 virtual DeclarationWithType * mutate( FunctionDecl *functionDecl );
@@ -77 +75 @@
 
           protected:
-                bool inFunction;
         };
 
@@ -216 +213 @@
 
         DeclarationWithType * CtorDtor::mutate( ObjectDecl * objDecl ) {
-                // hands off if designated or if @=
+                // hands off if designated, if @=, or if extern
                 if ( tryConstruct( objDecl ) ) {
-                        if ( inFunction ) {
-                                if ( ArrayType * at = dynamic_cast< ArrayType * >( objDecl->get_type() ) ) {
-                                        // call into makeArrayFunction from validate.cc to generate calls to ctor/dtor for each element of array
-                                        // TODO: walk initializers and generate appropriate ctor if element has initializer.
-                                        // Initializer could be nested (depends on the depth of the array type on the object)
-
-                                        std::list< Expression * > args = makeInitList( objDecl->get_init() );
-                                        if ( args.empty() ) {
-                                                std::list< Statement * > ctor;
-                                                std::list< Statement * > dtor;
-
-                                                SymTab::genImplicitCall( NULL, new VariableExpr( objDecl ), "?{}", back_inserter( ctor ), objDecl );
-                                                SymTab::genImplicitCall( NULL, new VariableExpr( objDecl ), "^?{}", front_inserter( dtor ), objDecl, false );
-
-                                                // Currently genArrayCall produces a single Statement - a CompoundStmt
-                                                // which  wraps everything that needs to happen. As such, it's technically
-                                                // possible to use a Statement ** in the above calls, but this is inherently
-                                                // unsafe, so instead we take the slightly less efficient route, but will be
-                                                // immediately informed if somehow the above assumption is broken. In this case,
-                                                // we could always wrap the list of statements at this point with a CompoundStmt,
-                                                // but it seems reasonable at the moment for this to be done by genArrayCall
-                                                // itself
-                                                assert( ctor.size() == 1 && dynamic_cast< ImplicitCtorDtorStmt * >( ctor.front() ) );
-                                                assert( dtor.size() == 1 && dynamic_cast< ImplicitCtorDtorStmt * >( dtor.front() ) );
+                        if ( ArrayType * at = dynamic_cast< ArrayType * >( objDecl->get_type() ) ) {
+                                // call into makeArrayFunction from validate.cc to generate calls to ctor/dtor for each element of array
+                                // TODO: walk initializers and generate appropriate ctor if element has initializer.
+                                // Initializer could be nested (depends on the depth of the array type on the object)
+
+                                std::list< Expression * > args = makeInitList( objDecl->get_init() );
+                                if ( args.empty() ) {
+                                        std::list< Statement * > ctor;
+                                        std::list< Statement * > dtor;
+
+                                        SymTab::genImplicitCall( NULL, new VariableExpr( objDecl ), "?{}", back_inserter( ctor ), objDecl );
+                                        SymTab::genImplicitCall( NULL, new VariableExpr( objDecl ), "^?{}", front_inserter( dtor ), objDecl, false );
+
+                                        // Currently genImplicitCall produces a single Statement - a CompoundStmt
+                                        // which  wraps everything that needs to happen. As such, it's technically
+                                        // possible to use a Statement ** in the above calls, but this is inherently
+                                        // unsafe, so instead we take the slightly less efficient route, but will be
+                                        // immediately informed if somehow the above assumption is broken. In this case,
+                                        // we could always wrap the list of statements at this point with a CompoundStmt,
+                                        // but it seems reasonable at the moment for this to be done by genImplicitCall
+                                        // itself. It is possible that genImplicitCall produces no statements (e.g. if
+                                        // an array type does not have a dimension). In this case, it's fine to ignore
+                                        // the object for the purposes of construction.
+                                        assert( ctor.size() == dtor.size() && ctor.size() <= 1 );
+                                        if ( ctor.size() == 1 ) {
+                                                assert( dynamic_cast< ImplicitCtorDtorStmt * > ( ctor.front() ) && dynamic_cast< ImplicitCtorDtorStmt * > ( dtor.front() ) );
                                                 objDecl->set_init( new ConstructorInit( ctor.front(), dtor.front(), objDecl->get_init() ) );
-                                        } else {
-                                                // array came with an initializer list: initialize each element
-                                                // may have more initializers than elements in the array - need to check at each index that
-                                                // we haven't exceeded size. This requires precomputing the size because it might be a side-effecting
-                                                // computation.
-                                                // may have fewer initializers than elements in the array - need to default construct
-                                                // remaining elements.
-                                                // might be able to merge this with the case above.
-
                                         }
                                 } else {
-                                        // it's sufficient to attempt to call the ctor/dtor for the given object and its initializer
-                                        Expression * ctor = makeCtorDtorExpr( "?{}", objDecl, makeInitList( objDecl->get_init() ) );
-                                        Expression * dtor = makeCtorDtorExpr( "^?{}", objDecl, std::list< Expression * >() );
-
-                                        // need to remember init expression, in case no ctors exist
-                                        // if ctor does exist, want to use ctor expression instead of init
-                                        // push this decision to the resolver
-                                        ExprStmt * ctorStmt = new ExprStmt( noLabels, ctor );
-                                        ExprStmt * dtorStmt = new ExprStmt( noLabels, dtor );
-                                        objDecl->set_init( new ConstructorInit( new ImplicitCtorDtorStmt( ctorStmt ), new ImplicitCtorDtorStmt( dtorStmt ), objDecl->get_init() ) );
+                                        // array came with an initializer list: initialize each element
+                                        // may have more initializers than elements in the array - need to check at each index that
+                                        // we haven't exceeded size. This requires precomputing the size because it might be a side-effecting
+                                        // computation.
+                                        // may have fewer initializers than elements in the array - need to default construct
+                                        // remaining elements.
+                                        // might be able to merge this with the case above.
+
                                 }
+                        } else {
+                                // it's sufficient to attempt to call the ctor/dtor for the given object and its initializer
+                                Expression * ctor = makeCtorDtorExpr( "?{}", objDecl, makeInitList( objDecl->get_init() ) );
+                                Expression * dtor = makeCtorDtorExpr( "^?{}", objDecl, std::list< Expression * >() );
+
+                                // need to remember init expression, in case no ctors exist
+                                // if ctor does exist, want to use ctor expression instead of init
+                                // push this decision to the resolver
+                                ExprStmt * ctorStmt = new ExprStmt( noLabels, ctor );
+                                ExprStmt * dtorStmt = new ExprStmt( noLabels, dtor );
+                                objDecl->set_init( new ConstructorInit( new ImplicitCtorDtorStmt( ctorStmt ), new ImplicitCtorDtorStmt( dtorStmt ), objDecl->get_init() ) );
                         }
                 }
@@ -272 +271 @@
         DeclarationWithType * CtorDtor::mutate( FunctionDecl *functionDecl ) {
                 // parameters should not be constructed and destructed, so don't mutate FunctionType
-                bool oldInFunc = inFunction;
                 mutateAll( functionDecl->get_oldDecls(), *this );
-                inFunction = true;
                 functionDecl->set_statements( maybeMutate( functionDecl->get_statements(), *this ) );
-                inFunction = oldInFunc;
                 return functionDecl;
         }

src/InitTweak/InitTweak.cc

@@ -57 +57 @@
                         (objDecl->get_init() == NULL ||
                                 ( objDecl->get_init() != NULL && objDecl->get_init()->get_maybeConstructed() )) &&
-                        ! isDesignated( objDecl->get_init() );
+                        ! isDesignated( objDecl->get_init() )
+                        && objDecl->get_storageClass() != DeclarationNode::Extern;
         }
 

src/SymTab/Autogen.h

@@ -144 +144 @@
                 genCall( srcParam, dstParam, fname, back_inserter( stmts ), obj->get_type(), forward );
 
-                // currently genCall should produce only one element, but if that changes then the next line needs to be updated to grab the statement which contains the call
-                assert( stmts.size() == 1 );
-                Statement * callStmt = stmts.front();
-                if ( (fname == "?{}" || fname == "^?{}") && ( !obj || ( obj && obj->get_bitfieldWidth() == NULL ) ) ) {
-                        // implicitly generated ctor/dtor calls should be wrapped
-                        // so that later passes are aware they were generated.
-                        // xxx - don't mark as an implicit ctor/dtor if obj is a bitfield,
-                        // because this causes the address to be taken at codegen, which is illegal in C.
-                        callStmt = new ImplicitCtorDtorStmt( callStmt );
-                }
-                *out++ = callStmt;
+                // currently genCall should produce at most one element, but if that changes then the next line needs to be updated to grab the statement which contains the call
+                assert( stmts.size() <= 1 );
+    if ( stmts.size() == 1 ) {
+                Statement * callStmt = stmts.front();
+                if ( (fname == "?{}" || fname == "^?{}") && ( !obj || ( obj && obj->get_bitfieldWidth() == NULL ) ) ) {
+                        // implicitly generated ctor/dtor calls should be wrapped
+                        // so that later passes are aware they were generated.
+                        // xxx - don't mark as an implicit ctor/dtor if obj is a bitfield,
+                        // because this causes the address to be taken at codegen, which is illegal in C.
+                        callStmt = new ImplicitCtorDtorStmt( callStmt );
+                }
+                *out++ = callStmt;
+    }
         }
 } // namespace SymTab

src/main.cc

@@ -42 +42 @@
 #include "InitTweak/GenInit.h"
 #include "InitTweak/FixInit.h"
-#include "InitTweak/FixGlobalInit.h"
 //#include "Explain/GenProlog.h"
 //#include "Try/Visit.h"
@@ -282 +281 @@
                 OPTPRINT( "fixNames" )
                 CodeGen::fixNames( translationUnit );
-                OPTPRINT( "fixGlobalInit" );
-                InitTweak::fixGlobalInit( translationUnit, filename, libcfap || treep );
                 OPTPRINT( "tweakInit" )
                 InitTweak::genInit( translationUnit );
@@ -304 +301 @@
                 }
 
+                // fix ObjectDecl - replaces ConstructorInit nodes
                 OPTPRINT( "fixInit" )
-                // fix ObjectDecl - replaces ConstructorInit nodes
-                InitTweak::fix( translationUnit );
+                InitTweak::fix( translationUnit, filename, libcfap || treep );
                 if ( ctorinitp ) {
                         dump ( translationUnit );

src/tests/.expect/extension.txt

@@ -100 +100 @@
     ((void)((__extension__ __a__i_2 , __extension__ __b__i_2) , __extension__ __c__i_2));
 }
-__attribute__ ((constructor(),)) static void _init_extension(void){
-    int _global_init0;
-    ((void)((*((int *)(&__a__i_1)))=_global_init0) /* ?{} */);
-    int _global_init1;
-    ((void)((*((int *)(&__b__i_1)))=_global_init1) /* ?{} */);
-    int _global_init2;
-    ((void)((*((int *)(&__c__i_1)))=_global_init2) /* ?{} */);
-}
-__attribute__ ((destructor(),)) static void _destroy_extension(void){
-    ((void)((*((int *)(&__c__i_1)))) /* ^?{} */);
-    ((void)((*((int *)(&__b__i_1)))) /* ^?{} */);
-    ((void)((*((int *)(&__a__i_1)))) /* ^?{} */);
-}