macdependency/macho/dynamicloader.cpp
2009-09-17 12:10:32 +00:00

285 lines
10 KiB
C++

#include "dynamicloader.h"
#include <QtCore/QProcess>
#include <QtCore/QFileInfo>
#include <QtCore/QStringList>
/*
This class emulates the search path mechanism of dyld
http://developer.apple.com/documentation/Darwin/Reference/Manpages/man1/dyld.1.html
Unfortunately the several documents from apple contradict each other. Therefore I analyzed the source of the original dyld
http://www.opensource.apple.com/source/dyld/dyld-97.1/src/dyld.cpp
*/
const char* DynamicLoader::EnvironmentPathVariable::KEY_VALUE_SEPARATOR = "=";
const char* DynamicLoader::EnvironmentPathVariable::PATHS_SEPARATOR = ";";
const char* DynamicLoader::EnvironmentPathVariable::HOME_PATH = getenv("HOME");
DynamicLoader::EnvironmentPathVariable::EnvironmentPathVariable() {
// default constructor (should not be used explicitly)
}
DynamicLoader::EnvironmentPathVariable::EnvironmentPathVariable(const char* name, const QStringList& environmentVariables, const QStringList& defaultValues)
{
// environment variables contain several <key>=<value> pairs
// find name in variables
int index = environmentVariables.indexOf(QRegExp(QString(name)+"=.*"));
if (index != -1) {
// separate value from name
QString variable = environmentVariables.at(index);
QStringList parts = variable.split(KEY_VALUE_SEPARATOR);
if (parts.size() == 2 && !parts.at(1).isEmpty()) {
// parses and splits at ";"
QStringList paths = parts.at(1).split(PATHS_SEPARATOR);
setPaths(paths);
}
} else {
setPaths(defaultValues);
}
}
void DynamicLoader::EnvironmentPathVariable::setPaths(const QStringList& paths) {
values = paths;
// replace ~ by home directory
int index;
while ((index = values.indexOf(QRegExp("^~.*"))) != -1) {
values[index].replace(0, 1, HOME_PATH);
}
}
bool DynamicLoader::EnvironmentPathVariable::isEmpty() const {
if (values.size() > 0) {
return values.at(0).isEmpty();
}
return true;
}
QStringList DynamicLoader::EnvironmentPathVariable::splitPathVariable(const QString& pathVariable) {
return pathVariable.split(PATHS_SEPARATOR, QString::SkipEmptyParts);
}
// the order must be the order of the enum!
const char* DynamicLoader::ENVIRONMENT_VARIABLE_NAMES[DynamicLoader::NumEnvironmentVariables] = {
"LD_LIBRARY_PATH",
"DYLD_FRAMEWORK_PATH",
"DYLD_LIBRARY_PATH",
"DYLD_FALLBACK_FRAMEWORK_PATH",
"DYLD_FALLBACK_LIBRARY_PATH",
"DYLD_IMAGE_SUFFIX"
};
const char* DynamicLoader::PLACEHOLDERS[DynamicLoader::NumPlaceholders] = {
"@executable_path",
"@loader_path",
"@rpath"
};
const char* DynamicLoader::PATH_SEPARATOR = "/";
// unfortunately cannot make QStringList const here, but treat it as const
QStringList DynamicLoader::ENVIRONMENT_VARIABLE_DEFAULT_VALUES[DynamicLoader::NumEnvironmentVariables] = {
QStringList(),
QStringList(),
QStringList(),
QStringList() << "~/Library/Frameworks" << "/Library/Frameworks" << "/Network/Library/Frameworks" << "/System/Library/Frameworks",
QStringList() << "~/lib" << "/usr/local/lib" << "/lib" << "/usr/lib",
QStringList()
};
DynamicLoader::DynamicLoader()
{
// get environment variables
QStringList environment = QProcess::systemEnvironment();
// init/read out some variables
for (unsigned int i=0; i < NumEnvironmentVariables; i++) {
environmentVariables[i] = EnvironmentPathVariable(ENVIRONMENT_VARIABLE_NAMES[i], environment, ENVIRONMENT_VARIABLE_DEFAULT_VALUES[i]);
}
}
QString DynamicLoader::replacePlaceholder(const QString& name, const MachOArchitecture* architecture) const {
QString resolvedName = name;
if (name.startsWith(PLACEHOLDERS[ExecutablePath])) {
resolvedName.replace(0, strlen(PLACEHOLDERS[ExecutablePath]), architecture->getFile()->getExecutablePath());
} else if (name.startsWith(PLACEHOLDERS[LoaderPath])) {
resolvedName.replace(0, strlen(PLACEHOLDERS[LoaderPath]), architecture->getFile()->getPath());
} else {
return QString();
}
return resolvedName;
}
QString DynamicLoader::getPathname(const QString& name, const MachOArchitecture* architecture, const QString& workingPath) const {
// simple name (only the last part of the name, after the last PATH_SEPARATOR)
int lastSlashPosition = name.lastIndexOf(PATH_SEPARATOR);
QString simpleName = name;
if (lastSlashPosition != -1 && lastSlashPosition < name.length() - 1) {
simpleName = simpleName.mid(lastSlashPosition+1);
}
// try LD_LIBRARY_PATH
QString pathName;
pathName = getExistingPathname(simpleName, environmentVariables[LdLibraryPath]);
if (!pathName.isEmpty())
return pathName;
QString frameworkName = getFrameworkName(name);
if (!frameworkName.isEmpty()) {
// strip the already contained suffix
pathName = getExistingPathname(frameworkName, environmentVariables[DyldFrameworkPath]);
if (!pathName.isEmpty())
return pathName;
}
pathName = getExistingPathname(simpleName, environmentVariables[DyldLibraryPath]);
if (!pathName.isEmpty())
return pathName;
// resolve placeholder
QString resolvedName = replacePlaceholder(name, architecture);
if (!resolvedName.isNull()) {
pathName = getExistingPathname(resolvedName);
if (!pathName.isEmpty())
return pathName;
}
if (name.startsWith(PLACEHOLDERS[RPath])) {
// substitute @rpath with all -rpath paths up the load chain
std::vector<QString*> rPaths = architecture->getRPaths();
for (std::vector<QString*>::iterator it = rPaths.begin(); it != rPaths.end(); ++it) {
resolvedName = name;
resolvedName.replace(0, strlen(PLACEHOLDERS[RPath]), (**it));
pathName = getExistingPathname(resolvedName);
if (!pathName.isEmpty())
return pathName;
}
// after checking against all stored rpaths substitute @rpath with LD_LIBRARY_PATH (if it is set)
EnvironmentPathVariable ldLibraryPaths = environmentVariables[LdLibraryPath];
if (!ldLibraryPaths.isEmpty()) {
for (int i = 0; i < ldLibraryPaths.getPaths().size(); ++i) {
resolvedName = name;
resolvedName.replace(0, strlen(PLACEHOLDERS[RPath]), ldLibraryPaths.getPaths()[i]);
pathName = getExistingPathname(resolvedName);
if (!pathName.isEmpty())
return pathName;
}
}
}
// check pure path (either absolute or relative to working directory)
if (name.startsWith(PATH_SEPARATOR)) {
pathName = getExistingPathname(name);
} else {
pathName = getExistingPathname(name, workingPath);
}
if (!pathName.isEmpty())
return pathName;
// try fallbacks (or its defaults)
if (!frameworkName.isEmpty()) {
pathName = getExistingPathname(frameworkName, environmentVariables[DyldFallbackFrameworkPath]);
if (!pathName.isEmpty())
return pathName;
}
return getExistingPathname(name, environmentVariables[DyldFallbackLibraryPath]);
}
// returns the name is of a framework without any preceeding path information if name specifies a framework, otherwise an invalid QString
QString DynamicLoader::getFrameworkName(const QString& name, const bool strippedSuffix) const {
// fail fast in case of dylibs
if (!name.contains(".framework/")) {
return QString();
}
/* first look for the form Foo.framework/Foo
next look for the form Foo.framework/Versions/A/Foo
A and Foo are arbitrary strings without a slash */
// get Foo (part after last slash)
int lastSlashPosition = name.lastIndexOf(PATH_SEPARATOR);
if (lastSlashPosition < 0 || lastSlashPosition == name.length() -1) {
return false;
}
const QString foo = name.mid(lastSlashPosition+1);
const QString frameworkPart = foo+".framework/";
if (name.endsWith(frameworkPart+foo)) {
// strip first part
return frameworkPart+foo;
}
const QString regExp = frameworkPart+"Versions/"+"[^"+PATH_SEPARATOR+"]*"+PATH_SEPARATOR + foo;
int startPosition = name.indexOf(QRegExp(regExp));
if (startPosition == -1 && strippedSuffix == false) {
// maybe we have a case, where name contains a suffix in foo (which then of course occurs only in the last foo)
// does foo already contain a suffix?
int suffixStart = foo.lastIndexOf("_");
if (suffixStart >= 0) {
QString newName = name;
newName.remove(lastSlashPosition+1+suffixStart);
return getFrameworkName(newName, true);
}
}
// strip first part
return name.mid(startPosition);
}
QString DynamicLoader::getExistingPathname(const QString& name, const EnvironmentPathVariable& environmentPathVariable) const {
QString result;
QStringList directories = environmentPathVariable.getPaths();
for (int i=0; i<directories.size(); i++) {
result = getExistingPathname(name, directories.at(i));
if (!result.isNull())
return result;
}
return result;
}
QString DynamicLoader::getExistingPathname(const QString& file, const QString& directory) const {
QString name = file;
if (!directory.isEmpty()) {
if (!directory.endsWith("/")) {
name = directory + "/" + file;
} else {
name = directory + file;
}
}
return getExistingPathname(name);
}
QString DynamicLoader::getExistingPathname(const QString& name) const {
QFileInfo fileInformation(name);
// first try with suffix
if (!environmentVariables[DyldImageSuffix].isEmpty()) {
const QString suffix = environmentVariables[DyldImageSuffix].getPaths().first();
QString nameWithSuffix = name;
// where should we append suffix?
if (name.endsWith(".dylib")) {
nameWithSuffix.insert(name.lastIndexOf("."), suffix);
} else {
nameWithSuffix = name + suffix;
}
fileInformation = nameWithSuffix;
if (fileInformation.exists()) {
return nameWithSuffix;
}
}
// then without suffix
fileInformation = name;
if (fileInformation.exists()) {
return name;
}
return QString();
}