Symbol_IR.cpp

/*******************************************************************************
 * Copyright (c) 2015, 2018 IBM Corp. and others
 *
 * This program and the accompanying materials are made available under
 * the terms of the Eclipse Public License 2.0 which accompanies this
 * distribution and is available at http://eclipse.org/legal/epl-2.0
 * or the Apache License, Version 2.0 which accompanies this distribution
 * and is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License, v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception [1] and GNU General Public
 * License, version 2 with the OpenJDK Assembly Exception [2].
 *
 * [1] https://www.gnu.org/software/classpath/license.html
 * [2] http://openjdk.java.net/legal/assembly-exception.html
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
 *******************************************************************************/

#include "ddr/config.hpp"

#include "ddr/ir/Symbol_IR.hpp"

#include <assert.h>
#include <algorithm>
#include <map>
#include <stack>
#include <stdlib.h>
#include <string.h>
#include "ddr/std/unordered_map.hpp"
#include <vector>

#include "ddr/ir/ClassType.hpp"
#include "ddr/ir/ClassUDT.hpp"
#include "ddr/ir/EnumUDT.hpp"
#include "ddr/ir/EnumUDT.hpp"
#include "ddr/ir/NamespaceUDT.hpp"
#include "ddr/ir/NamespaceUDT.hpp"
#include "ddr/ir/TypedefUDT.hpp"
#include "ddr/ir/TypedefUDT.hpp"
#include "ddr/ir/UnionUDT.hpp"

using std::map;
using std::stack;

Symbol_IR::~Symbol_IR()
{
	for (std::vector<Type *>::const_iterator it = _types.begin(); it != _types.end(); ++it) {
		delete *it;
	}
	_types.clear();
}

DDR_RC
Symbol_IR::applyOverridesList(OMRPortLibrary *portLibrary, const char *overridesListFile)
{
	DDR_RC rc = DDR_RC_OK;
	OMRPORT_ACCESS_FROM_OMRPORT(portLibrary);
	vector<string> filenames;

	/* Read list of type override files from specified file. */
	intptr_t fd = omrfile_open(overridesListFile, EsOpenRead, 0);
	if (0 > fd) {
		ERRMSG("Failure attempting to open %s\nExiting...\n", overridesListFile);
		rc = DDR_RC_ERROR;
	} else {
		int64_t offset = omrfile_seek(fd, 0, EsSeekEnd);
		if (-1 != offset) {
			char *buff = (char *)malloc(offset + 1);
			if (NULL == buff) {
				ERRMSG("Unable to allocate memory for file contents: %s", overridesListFile);
				rc = DDR_RC_ERROR;
				goto closeFile;
			}
			memset(buff, 0, offset + 1);
			omrfile_seek(fd, 0, EsSeekSet);
			/* Read each line as a file name. */
			if (offset == omrfile_read(fd, buff, offset)) {
				for (char *nextLine = strtok(buff, "\r\n"); NULL != nextLine; nextLine = strtok(NULL, "\r\n")) {
					string line(nextLine);
					size_t commentPosition = line.find("#");
					if (string::npos != commentPosition) {
						line.erase(commentPosition, line.length());
					}
					line.erase(line.find_last_not_of(" \t") + 1, line.length());
					if (!line.empty()) {
						filenames.push_back(line);
					}
				}
			}
			free(buff);
		}
closeFile:
		omrfile_close(fd);
	}
	for (vector<string>::const_iterator it = filenames.begin(); filenames.end() != it; ++it) {
		rc = applyOverridesFile(portLibrary, it->c_str());
		if (DDR_RC_OK != rc) {
			break;
		}
	}
	return rc;
}

static bool
startsWith(const string &str, const string &prefix)
{
	return 0 == str.compare(0, prefix.length(), prefix);
}

DDR_RC
Symbol_IR::applyOverridesFile(OMRPortLibrary *portLibrary, const char *overridesFile)
{
	DDR_RC rc = DDR_RC_OK;
	OMRPORT_ACCESS_FROM_OMRPORT(portLibrary);

	/* Read list of type overrides from specified file. */
	vector<FieldOverride> overrideList;
	intptr_t fd = omrfile_open(overridesFile, EsOpenRead, 0);
	if (0 > fd) {
		ERRMSG("Failure attempting to open %s\nExiting...\n", overridesFile);
		rc = DDR_RC_ERROR;
	} else {
		int64_t offset = omrfile_seek(fd, 0, EsSeekEnd);
		if (-1 != offset) {
			char *buff = (char *)malloc(offset + 1);
			if (NULL == buff) {
				ERRMSG("Unable to allocate memory for file contents: %s", overridesFile);
				rc = DDR_RC_ERROR;
				goto closeFile;
			}
			memset(buff, 0, offset + 1);
			omrfile_seek(fd, 0, EsSeekSet);

			/*
			 * Read each line, expecting one of the following formats:
			 *   opaquetype={TypeName}
			 *   fieldoverride.{StructureName}.{fieldName}={newName}
			 *   typeoverride.{StructureName}.{fieldName}={newType}"
			 */
			if (offset != omrfile_read(fd, buff, offset)) {
				ERRMSG("Failure reading %s", overridesFile);
				rc = DDR_RC_ERROR;
			} else {
				const string blobprefix = "ddrblob.";
				const string opaquetype = "opaquetype=";
				const string fieldoverride = "fieldoverride.";
				const string typeoverride = "typeoverride.";

				for (char *nextLine = strtok(buff, "\r\n");
						NULL != nextLine;
						nextLine = strtok(NULL, "\r\n")) {
					string line = nextLine;

					/* Remove comment portion of the line, if present. */
					size_t commentPosition = line.find("#");
					if (string::npos != commentPosition) {
						line.erase(commentPosition, line.length());
					}
					line.erase(line.find_last_not_of(" \t") + 1, line.length());

					/* Ignore the prefix "ddrblob.", if present. */
					if (startsWith(line, blobprefix)) {
						line.erase(0, blobprefix.length());
					}

					/* Check for opaque types. */
					if (startsWith(line, opaquetype)) {
						line.erase(0, opaquetype.length());
						if (!line.empty()) {
							_opaqueTypeNames.insert(line);
						}
						continue;
					}

					/* Check if the override is a typeoverride or a fieldoverride. */
					bool isTypeOverride = false;
					if (startsWith(line, fieldoverride)) {
						line.erase(0, fieldoverride.length());
					} else if (startsWith(line, typeoverride)) {
						isTypeOverride = true;
						line.erase(0, typeoverride.length());
					} else {
						continue;
					}

					/* Correctly formatted lines must have exactly 1 dot and 1 equals in that order. */
					size_t dotPosition = line.find('.');
					if ((string::npos == dotPosition) || (string::npos != line.find('.', dotPosition + 1))) {
						/* not exactly one '.' */
						continue;
					}
					size_t equalsPosition = line.find('=', dotPosition);
					if ((string::npos == equalsPosition) || (string::npos != line.find('=', equalsPosition + 1))) {
						/* not exactly one '=' after the '.' */
						continue;
					}
					/* Get the structure name, field name, and override name. Add to list to process. */
					FieldOverride override = {
						line.substr(0, dotPosition),
						line.substr(dotPosition + 1, equalsPosition - dotPosition - 1),
						line.substr(equalsPosition + 1),
						isTypeOverride
					};
					overrideList.push_back(override);
				}
			}
			free(buff);
		}
closeFile:
		omrfile_close(fd);
	}

	/* Create a map of type name to vector of types to check all types
	 * by name for type overrides.
	 */
	map<string, vector<Type *> > typeNames;
	for (vector<Type *>::const_iterator it = _types.begin(); it != _types.end(); ++it) {
		Type *type = *it;
		typeNames[type->_name].push_back(type);
	}

	/* Apply the type overrides. */
	for (vector<FieldOverride>::const_iterator it = overrideList.begin(); it != overrideList.end(); ++it) {
		const FieldOverride &type = *it;
		/* Check if the structure to override exists. */
		map<string, vector<Type *> >::const_iterator typeEntry = typeNames.find(type.structName);
		if (typeNames.end() != typeEntry) {
			Type *replacementType = NULL;
			if (type.isTypeOverride) {
				/* If the type for the override exists in the IR, use it. Otherwise, create it. */
				map<string, vector<Type *> >::const_iterator overEntry = typeNames.find(type.overrideName);
				if (typeNames.end() != overEntry) {
					replacementType = overEntry->second.front();
				} else {
					replacementType = new Type(0);
					replacementType->_name = type.overrideName;
					typeNames[replacementType->_name].push_back(replacementType);
				}
			}

			/* Iterate over the types with a matching name for the override. */
			const vector<Type *> &typesWithName = typeEntry->second;
			for (vector<Type *>::const_iterator it2 = typesWithName.begin(); it2 != typesWithName.end(); ++it2) {
				(*it2)->renameFieldsAndMacros(type, replacementType);
			}
		}
	}

	return rc;
}

/* Compute the field offsets for all types in the IR from the sizes of the fields. */
void
Symbol_IR::computeOffsets()
{
	/* For each Type in the ir, compute the field offsets from the size of each field. */
	for (vector<Type *>::const_iterator it = _types.begin(); it != _types.end(); ++it) {
		(*it)->computeFieldOffsets();
	}
}

void
Symbol_IR::removeDuplicates()
{
	for (vector<Type *>::iterator it = _types.begin(); it != _types.end();) {
		if ((*it)->insertUnique(this)) {
			++it;
		} else {
			it = _types.erase(it);
		}
	}
}

class MergeVisitor : public TypeVisitor
{
private:
	Symbol_IR * const _ir;
	Type * const _other;
	vector<Type *> *const _merged;

public:
	MergeVisitor(Symbol_IR *ir, Type *other, vector<Type *> *merged)
		: _ir(ir), _other(other), _merged(merged)
	{
	}

	virtual DDR_RC visitType(Type *type) const;
	virtual DDR_RC visitClass(ClassUDT *type) const;
	virtual DDR_RC visitEnum(EnumUDT *type) const;
	virtual DDR_RC visitNamespace(NamespaceUDT *type) const;
	virtual DDR_RC visitTypedef(TypedefUDT *type) const;
	virtual DDR_RC visitUnion(UnionUDT *type) const;

private:
	DDR_RC visitComposite(ClassType *type) const;
};

DDR_RC
MergeVisitor::visitType(Type *type) const
{
	/* No merging necessary for base types. */
	return DDR_RC_OK;
}

DDR_RC
MergeVisitor::visitNamespace(NamespaceUDT *type) const
{
	/* Merge by adding the fields/subtypes of '_other' into 'type'. */
	NamespaceUDT *other = (NamespaceUDT *)_other;
	_ir->mergeTypes(type->getSubUDTS(), other->getSubUDTS(), type, _merged);
	return DDR_RC_OK;
}

DDR_RC
MergeVisitor::visitEnum(EnumUDT *type) const
{
	/* Merge by adding the fields/subtypes of '_other' into 'type'. */
	EnumUDT *other = (EnumUDT *)_other;
	_ir->mergeEnums(&type->_enumMembers, &other->_enumMembers);
	return DDR_RC_OK;
}

DDR_RC
MergeVisitor::visitTypedef(TypedefUDT *type) const
{
	/* No merging necessary for typedefs. */
	return DDR_RC_OK;
}

DDR_RC
MergeVisitor::visitComposite(ClassType *type) const
{
	/* Merge by adding the fields/subtypes of '_other' into 'type'. */
	visitNamespace(type);
	ClassType *other = (ClassType *)_other;
	_ir->mergeFields(&type->_fieldMembers, &other->_fieldMembers, type, _merged);
	_ir->mergeEnums(&type->_enumMembers, &other->_enumMembers);
	return DDR_RC_OK;
}

DDR_RC
MergeVisitor::visitClass(ClassUDT *type) const
{
	return visitComposite(type);
}

DDR_RC
MergeVisitor::visitUnion(UnionUDT *type) const
{
	return visitComposite(type);
}

template<typename T> void
Symbol_IR::mergeTypes(vector<T *> *source, vector<T *> *other,
		NamespaceUDT *outerNamespace, vector<Type *> *merged)
{
	if ((NULL != source) && (NULL != other)) {
		for (typename vector<T *>::iterator it = other->begin(); it != other->end();) {
			Type *otherType = (Type *)*it;
			Type *sourceType = findTypeInMap(otherType);

			/* Types in the other list not in the source list are added. */
			/* Types in both lists are merged. */
			if (NULL != sourceType) {
				sourceType->acceptVisitor(MergeVisitor(this, otherType, merged));
				++it;
			} else {
				it = other->erase(it);
				source->push_back((T *)otherType);
				if (NULL != outerNamespace) {
					((UDT *)otherType)->_outerNamespace = outerNamespace;
				}
				addTypeToMap(otherType);
				merged->push_back(otherType);
			}
		}
	}
}

void
Symbol_IR::mergeFields(vector<Field *> *source, vector<Field *> *other, Type *type, vector<Type *> *merged)
{
	/* Create a map of all fields in the source list. */
	set<string> fieldNames;
	for (vector<Field *>::const_iterator it = source->begin(); it != source->end(); ++it) {
		fieldNames.insert((*it)->_name);
	}
	bool fieldsMerged = false;
	for (vector<Field *>::iterator it = other->begin(); it != other->end();) {
		/* Fields in the other list not in the source list are added. */
		Field * field = *it;
		const string &fieldName = field->_name;
		if (fieldNames.end() == fieldNames.find(fieldName)) {
			it = other->erase(it);
			source->push_back(field);
			fieldNames.insert(fieldName);
			fieldsMerged = true;
		} else {
			++it;
		}
	}
	if (fieldsMerged) {
		/* We must revisit 'type' to fix the type of the newly added fields. */
		merged->push_back(type);
	}
}

void
Symbol_IR::mergeEnums(vector<EnumMember *> *source, vector<EnumMember *> *other)
{
	/* Create a map of all fields in the source list. */
	set<string> enumNames;
	for (vector<EnumMember *>::const_iterator it = source->begin(); it != source->end(); ++it) {
		enumNames.insert((*it)->_name);
	}
	for (vector<EnumMember *>::iterator it = other->begin(); it != other->end();) {
		EnumMember *member = *it;
		const string & memberName = (*it)->_name;
		/* Fields in the other list not in the source list are added. */
		if (enumNames.end() == enumNames.find(memberName)) {
			it = other->erase(it);
			source->push_back(member);
			enumNames.insert(memberName);
		} else {
			++it;
		}
	}
}

class TypeReplaceVisitor : public TypeVisitor
{
private:
	Symbol_IR * const _ir;

public:
	explicit TypeReplaceVisitor(Symbol_IR *ir)
		: _ir(ir)
	{
	}

	virtual DDR_RC visitType(Type *type) const;
	virtual DDR_RC visitClass(ClassUDT *type) const;
	virtual DDR_RC visitEnum(EnumUDT *type) const;
	virtual DDR_RC visitNamespace(NamespaceUDT *type) const;
	virtual DDR_RC visitTypedef(TypedefUDT *type) const;
	virtual DDR_RC visitUnion(UnionUDT *type) const;

private:
	DDR_RC visitComposite(ClassType *type) const;
};

class TypeCheck
{
private:
    const Type * const _other;

public:
    explicit TypeCheck(const Type *other)
    	: _other(other)
    {
    }

    bool operator()(Type *compare) const {
		return *compare == *_other;
	}
};

DDR_RC
TypeReplaceVisitor::visitType(Type *type) const
{
	return DDR_RC_OK;
}

DDR_RC
TypeReplaceVisitor::visitNamespace(NamespaceUDT *type) const
{
	DDR_RC rc = DDR_RC_OK;

	for (vector<UDT *>::const_iterator it = type->_subUDTs.begin(); it != type->_subUDTs.end(); ++it) {
		rc = (*it)->acceptVisitor(*this);
		if (DDR_RC_OK != rc) {
			break;
		}
	}

	return rc;
}

DDR_RC
TypeReplaceVisitor::visitEnum(EnumUDT *type) const
{
	return DDR_RC_OK;
}

DDR_RC
TypeReplaceVisitor::visitTypedef(TypedefUDT *type) const
{
	return _ir->replaceTypeUsingMap(&type->_aliasedType, type);
}

DDR_RC
TypeReplaceVisitor::visitComposite(ClassType *type) const
{
	DDR_RC rc = visitNamespace(type);

	if (DDR_RC_OK == rc) {
		for (vector<Field *>::const_iterator it = type->_fieldMembers.begin(); it != type->_fieldMembers.end(); ++it) {
			rc = _ir->replaceTypeUsingMap(&(*it)->_fieldType, type);
			if (DDR_RC_OK != rc) {
				break;
			}
		}
	}

	return rc;
}

DDR_RC
TypeReplaceVisitor::visitClass(ClassUDT *type) const
{
	DDR_RC rc = visitComposite(type);

	if (DDR_RC_OK == rc) {
		rc = _ir->replaceTypeUsingMap((Type **)&type->_superClass, type);
	}

	return rc;
}

DDR_RC
TypeReplaceVisitor::visitUnion(UnionUDT *type) const
{
	return visitComposite(type);
}

DDR_RC
Symbol_IR::replaceTypeUsingMap(Type **type, Type *outer)
{
	DDR_RC rc = DDR_RC_OK;
	if (NULL != type) {
		Type *oldType = *type;
		if ((NULL != oldType) && (_typeSet.end() == _typeSet.find(oldType))) {
			Type *replacementType = findTypeInMap(oldType);
			if (NULL == replacementType) {
				ERRMSG("Error replacing type '%s' in '%s'",
						oldType->getFullName().c_str(),
						outer->getFullName().c_str());
				rc = DDR_RC_ERROR;
			} else if (oldType == replacementType) {
				/* don't create a cycle */
				ERRMSG("Cycle found replacing type '%s' in '%s'",
						oldType->getFullName().c_str(),
						outer->getFullName().c_str());
				rc = DDR_RC_ERROR;
				*type = NULL;
			} else {
				*type = replacementType;
			}
		}
	}
	return rc;
}

static string
getTypeNameKey(Type *type)
{
	string prefix = type->getSymbolKindName();
	string fullname = type->getFullName();

	return prefix.empty() ? fullname : (prefix + " " + fullname);
}

Type *
Symbol_IR::findTypeInMap(Type *typeToFind)
{
	Type *returnType = NULL;
	if ((NULL != typeToFind) && !typeToFind->isAnonymousType()) {
		const string nameKey = getTypeNameKey(typeToFind);
		unordered_map<string, set<Type *> >::const_iterator map_it = _typeMap.find(nameKey);

		if (_typeMap.end() != map_it) {
			const set<Type *> &matches = map_it->second;
			if (1 == matches.size()) {
				returnType = *matches.begin();
			} else if (1 < matches.size()) {
				set<Type *>::const_iterator it = find_if(matches.begin(), matches.end(), TypeCheck(typeToFind));
				if (matches.end() != it) {
					returnType = *it;
				}
			}
		}
	}
	return returnType;
}

void
Symbol_IR::addTypeToMap(Type *type)
{
	Type * const startType = type;
	stack<vector<UDT *>::const_iterator> itStack;
	vector<UDT *> *subs = NULL;

	subs = type->getSubUDTS();
	if ((NULL != subs) && !subs->empty()) {
		itStack.push(subs->begin());
	}

	while (NULL != type) {
		if (!type->isAnonymousType()) {
			_typeMap[getTypeNameKey(type)].insert(type);
		}
		_typeSet.insert(type);

		subs = type->getSubUDTS();

		if (NULL == subs || subs->empty()) {
			if (startType == type) {
				type = NULL;
			} else {
				type = type->getNamespace();
			}
		} else if (subs->end() == itStack.top()) {
			if (startType == type) {
				type = NULL;
			} else {
				type = type->getNamespace();
			}
			itStack.pop();
		} else {
			type = *itStack.top();
			itStack.top()++;
			subs = type->getSubUDTS();
			if ((NULL != subs) && !subs->empty()) {
				itStack.push(subs->begin());
			}
		}
	}
}

DDR_RC
Symbol_IR::mergeIR(Symbol_IR *other)
{
	DDR_RC rc = DDR_RC_OK;

	/* Create map of this source IR of type full name to type. Use it to replace all
	 * pointers in types acquired from other IRs. The problem of encountering
	 * types to replace that are not yet in this IR is solved by doing all of the type
	 * replacement after all types are merged.
	 */
	if (_typeMap.empty() && _typeSet.empty()) {
		for (vector<Type *>::const_iterator it = _types.begin(); it != _types.end(); ++it) {
			addTypeToMap(*it);
		}
	}

	vector<Type *> mergedTypes;

	mergeTypes(&_types, &other->_types, NULL, &mergedTypes);

	const TypeReplaceVisitor typeReplacer(this);

	for (vector<Type *>::const_iterator it = mergedTypes.begin(); it != mergedTypes.end(); ++it) {
		rc = (*it)->acceptVisitor(typeReplacer);
		if (DDR_RC_OK != rc) {
			break;
		}
	}

	return rc;
}