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Diffstat (limited to 'gcc-4.9/gcc/go/gofrontend/import-archive.cc')
| -rw-r--r-- | gcc-4.9/gcc/go/gofrontend/import-archive.cc | 660 |
1 files changed, 660 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/go/gofrontend/import-archive.cc b/gcc-4.9/gcc/go/gofrontend/import-archive.cc new file mode 100644 index 000000000..9a1d5b3d7 --- /dev/null +++ b/gcc-4.9/gcc/go/gofrontend/import-archive.cc @@ -0,0 +1,660 @@ +// import-archive.cc -- Go frontend read import data from an archive file. + +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include "go-system.h" + +#include "import.h" + +#ifndef O_BINARY +#define O_BINARY 0 +#endif + +// Archive magic numbers. + +static const char armag[] = +{ + '!', '<', 'a', 'r', 'c', 'h', '>', '\n' +}; + +static const char armagt[] = +{ + '!', '<', 't', 'h', 'i', 'n', '>', '\n' +}; + +static const char arfmag[2] = { '`', '\n' }; + +// The header of an entry in an archive. This is all readable text, +// padded with spaces where necesary. + +struct Archive_header +{ + // The entry name. + char ar_name[16]; + // The file modification time. + char ar_date[12]; + // The user's UID in decimal. + char ar_uid[6]; + // The user's GID in decimal. + char ar_gid[6]; + // The file mode in octal. + char ar_mode[8]; + // The file size in decimal. + char ar_size[10]; + // The final magic code. + char ar_fmag[2]; +}; + +// The functions in this file extract Go export data from an archive. + +const int Import::archive_magic_len; + +// Return true if BYTES, which are from the start of the file, are an +// archive magic number. + +bool +Import::is_archive_magic(const char* bytes) +{ + return (memcmp(bytes, armag, Import::archive_magic_len) == 0 + || memcmp(bytes, armagt, Import::archive_magic_len) == 0); +} + +// An object used to read an archive file. + +class Archive_file +{ + public: + Archive_file(const std::string& filename, int fd, Location location) + : filename_(filename), fd_(fd), filesize_(-1), extended_names_(), + is_thin_archive_(false), location_(location), nested_archives_() + { } + + // Initialize. + bool + initialize(); + + // Return the file name. + const std::string& + filename() const + { return this->filename_; } + + // Get the file size. + off_t + filesize() const + { return this->filesize_; } + + // Return whether this is a thin archive. + bool + is_thin_archive() const + { return this->is_thin_archive_; } + + // Return the location of the import statement. + Location + location() const + { return this->location_; } + + // Read bytes. + bool + read(off_t offset, off_t size, char*); + + // Read the archive header at OFF, setting *PNAME, *SIZE, and + // *NESTED_OFF. + bool + read_header(off_t off, std::string* pname, off_t* size, off_t* nested_off); + + // Interpret the header of HDR, the header of the archive member at + // file offset OFF. Return whether it succeeded. Set *SIZE to the + // size of the member. Set *PNAME to the name of the member. Set + // *NESTED_OFF to the offset in a nested archive. + bool + interpret_header(const Archive_header* hdr, off_t off, + std::string* pname, off_t* size, off_t* nested_off) const; + + // Get the file and offset for an archive member. + bool + get_file_and_offset(off_t off, const std::string& hdrname, + off_t nested_off, int* memfd, off_t* memoff, + std::string* memname); + + private: + // For keeping track of open nested archives in a thin archive file. + typedef std::map<std::string, Archive_file*> Nested_archive_table; + + // The name of the file. + std::string filename_; + // The file descriptor. + int fd_; + // The file size; + off_t filesize_; + // The extended name table. + std::string extended_names_; + // Whether this is a thin archive. + bool is_thin_archive_; + // The location of the import statements. + Location location_; + // Table of nested archives. + Nested_archive_table nested_archives_; +}; + +bool +Archive_file::initialize() +{ + struct stat st; + if (fstat(this->fd_, &st) < 0) + { + error_at(this->location_, "%s: %m", this->filename_.c_str()); + return false; + } + this->filesize_ = st.st_size; + + char buf[sizeof(armagt)]; + if (::lseek(this->fd_, 0, SEEK_SET) < 0 + || ::read(this->fd_, buf, sizeof(armagt)) != sizeof(armagt)) + { + error_at(this->location_, "%s: %m", this->filename_.c_str()); + return false; + } + this->is_thin_archive_ = memcmp(buf, armagt, sizeof(armagt)) == 0; + + if (this->filesize_ == sizeof(armag)) + { + // Empty archive. + return true; + } + + // Look for the extended name table. + std::string filename; + off_t size; + if (!this->read_header(sizeof(armagt), &filename, &size, NULL)) + return false; + if (filename.empty()) + { + // We found the symbol table. + off_t off = sizeof(armagt) + sizeof(Archive_header) + size; + if ((off & 1) != 0) + ++off; + if (!this->read_header(off, &filename, &size, NULL)) + filename.clear(); + } + if (filename == "/") + { + char* rdbuf = new char[size]; + if (::read(this->fd_, rdbuf, size) != size) + { + error_at(this->location_, "%s: could not read extended names", + filename.c_str()); + delete[] rdbuf; + return false; + } + this->extended_names_.assign(rdbuf, size); + delete[] rdbuf; + } + + return true; +} + +// Read bytes from the file. + +bool +Archive_file::read(off_t offset, off_t size, char* buf) +{ + if (::lseek(this->fd_, offset, SEEK_SET) < 0 + || ::read(this->fd_, buf, size) != size) + { + error_at(this->location_, "%s: %m", this->filename_.c_str()); + return false; + } + return true; +} + +// Read the header at OFF. Set *PNAME to the name, *SIZE to the size, +// and *NESTED_OFF to the nested offset. + +bool +Archive_file::read_header(off_t off, std::string* pname, off_t* size, + off_t* nested_off) +{ + Archive_header hdr; + if (::lseek(this->fd_, off, SEEK_SET) < 0) + { + error_at(this->location_, "%s: %m", this->filename_.c_str()); + return false; + } + ssize_t got = ::read(this->fd_, &hdr, sizeof hdr); + if (got != sizeof hdr) + { + if (got < 0) + error_at(this->location_, "%s: %m", this->filename_.c_str()); + else if (got > 0) + error_at(this->location_, "%s: short archive header at %ld", + this->filename_.c_str(), static_cast<long>(off)); + else + error_at(this->location_, "%s: unexpected EOF at %ld", + this->filename_.c_str(), static_cast<long>(off)); + } + off_t local_nested_off; + if (!this->interpret_header(&hdr, off, pname, size, &local_nested_off)) + return false; + if (nested_off != NULL) + *nested_off = local_nested_off; + return true; +} + +// Interpret the header of HDR, the header of the archive member at +// file offset OFF. + +bool +Archive_file::interpret_header(const Archive_header* hdr, off_t off, + std::string* pname, off_t* size, + off_t* nested_off) const +{ + if (memcmp(hdr->ar_fmag, arfmag, sizeof arfmag) != 0) + { + error_at(this->location_, "%s: malformed archive header at %lu", + this->filename_.c_str(), static_cast<unsigned long>(off)); + return false; + } + + const int size_string_size = sizeof hdr->ar_size; + char size_string[size_string_size + 1]; + memcpy(size_string, hdr->ar_size, size_string_size); + char* ps = size_string + size_string_size; + while (ps[-1] == ' ') + --ps; + *ps = '\0'; + + errno = 0; + char* end; + *size = strtol(size_string, &end, 10); + if (*end != '\0' + || *size < 0 + || (*size == LONG_MAX && errno == ERANGE)) + { + error_at(this->location_, "%s: malformed archive header size at %lu", + this->filename_.c_str(), static_cast<unsigned long>(off)); + return false; + } + + *nested_off = 0; + if (hdr->ar_name[0] != '/') + { + const char* name_end = strchr(hdr->ar_name, '/'); + if (name_end == NULL + || name_end - hdr->ar_name >= static_cast<int>(sizeof hdr->ar_name)) + { + error_at(this->location_, "%s: malformed archive header name at %lu", + this->filename_.c_str(), static_cast<unsigned long>(off)); + return false; + } + pname->assign(hdr->ar_name, name_end - hdr->ar_name); + } + else if (hdr->ar_name[1] == ' ') + { + // This is the symbol table. + pname->clear(); + } + else if (hdr->ar_name[1] == '/') + { + // This is the extended name table. + pname->assign(1, '/'); + } + else + { + errno = 0; + long x = strtol(hdr->ar_name + 1, &end, 10); + long y = 0; + if (*end == ':') + y = strtol(end + 1, &end, 10); + if (*end != ' ' + || x < 0 + || (x == LONG_MAX && errno == ERANGE) + || static_cast<size_t>(x) >= this->extended_names_.size()) + { + error_at(this->location_, "%s: bad extended name index at %lu", + this->filename_.c_str(), static_cast<unsigned long>(off)); + return false; + } + + const char* name = this->extended_names_.data() + x; + const char* name_end = strchr(name, '\n'); + if (static_cast<size_t>(name_end - name) > this->extended_names_.size() + || name_end[-1] != '/') + { + error_at(this->location_, "%s: bad extended name entry at header %lu", + this->filename_.c_str(), static_cast<unsigned long>(off)); + return false; + } + pname->assign(name, name_end - 1 - name); + *nested_off = y; + } + + return true; +} + +// Get the file and offset for an archive member. + +bool +Archive_file::get_file_and_offset(off_t off, const std::string& hdrname, + off_t nested_off, int* memfd, off_t* memoff, + std::string* memname) +{ + if (!this->is_thin_archive_) + { + *memfd = this->fd_; + *memoff = off + sizeof(Archive_header); + *memname = this->filename_ + '(' + hdrname + ')'; + return true; + } + + std::string filename = hdrname; + if (!IS_ABSOLUTE_PATH(filename.c_str())) + { + const char* archive_path = this->filename_.c_str(); + const char* basename = lbasename(archive_path); + if (basename > archive_path) + filename.replace(0, 0, + this->filename_.substr(0, basename - archive_path)); + } + + if (nested_off > 0) + { + // This is a member of a nested archive. + Archive_file* nfile; + Nested_archive_table::const_iterator p = + this->nested_archives_.find(filename); + if (p != this->nested_archives_.end()) + nfile = p->second; + else + { + int nfd = open(filename.c_str(), O_RDONLY | O_BINARY); + if (nfd < 0) + { + error_at(this->location_, "%s: can't open nested archive %s", + this->filename_.c_str(), filename.c_str()); + return false; + } + nfile = new Archive_file(filename, nfd, this->location_); + if (!nfile->initialize()) + { + delete nfile; + return false; + } + this->nested_archives_[filename] = nfile; + } + + std::string nname; + off_t nsize; + off_t nnested_off; + if (!nfile->read_header(nested_off, &nname, &nsize, &nnested_off)) + return false; + return nfile->get_file_and_offset(nested_off, nname, nnested_off, + memfd, memoff, memname); + } + + // An external member of a thin archive. + *memfd = open(filename.c_str(), O_RDONLY | O_BINARY); + if (*memfd < 0) + { + error_at(this->location_, "%s: %m", filename.c_str()); + return false; + } + *memoff = 0; + *memname = filename; + return true; +} + +// An archive member iterator. This is more-or-less copied from gold. + +class Archive_iterator +{ + public: + // The header of an archive member. This is what this iterator + // points to. + struct Header + { + // The name of the member. + std::string name; + // The file offset of the member. + off_t off; + // The file offset of a nested archive member. + off_t nested_off; + // The size of the member. + off_t size; + }; + + Archive_iterator(Archive_file* afile, off_t off) + : afile_(afile), off_(off) + { this->read_next_header(); } + + const Header& + operator*() const + { return this->header_; } + + const Header* + operator->() const + { return &this->header_; } + + Archive_iterator& + operator++() + { + if (this->off_ == this->afile_->filesize()) + return *this; + this->off_ += sizeof(Archive_header); + if (!this->afile_->is_thin_archive()) + this->off_ += this->header_.size; + if ((this->off_ & 1) != 0) + ++this->off_; + this->read_next_header(); + return *this; + } + + Archive_iterator + operator++(int) + { + Archive_iterator ret = *this; + ++*this; + return ret; + } + + bool + operator==(const Archive_iterator p) const + { return this->off_ == p->off; } + + bool + operator!=(const Archive_iterator p) const + { return this->off_ != p->off; } + + private: + void + read_next_header(); + + // The underlying archive file. + Archive_file* afile_; + // The current offset in the file. + off_t off_; + // The current archive header. + Header header_; +}; + +// Read the next archive header. + +void +Archive_iterator::read_next_header() +{ + off_t filesize = this->afile_->filesize(); + while (true) + { + if (filesize - this->off_ < static_cast<off_t>(sizeof(Archive_header))) + { + if (filesize != this->off_) + { + error_at(this->afile_->location(), + "%s: short archive header at %lu", + this->afile_->filename().c_str(), + static_cast<unsigned long>(this->off_)); + this->off_ = filesize; + } + this->header_.off = filesize; + return; + } + + char buf[sizeof(Archive_header)]; + if (!this->afile_->read(this->off_, sizeof(Archive_header), buf)) + { + this->header_.off = filesize; + return; + } + + const Archive_header* hdr = reinterpret_cast<const Archive_header*>(buf); + if (!this->afile_->interpret_header(hdr, this->off_, &this->header_.name, + &this->header_.size, + &this->header_.nested_off)) + { + this->header_.off = filesize; + return; + } + this->header_.off = this->off_; + + // Skip special members. + if (!this->header_.name.empty() && this->header_.name != "/") + return; + + this->off_ += sizeof(Archive_header) + this->header_.size; + if ((this->off_ & 1) != 0) + ++this->off_; + } +} + +// Initial iterator. + +Archive_iterator +archive_begin(Archive_file* afile) +{ + return Archive_iterator(afile, sizeof(armag)); +} + +// Final iterator. + +Archive_iterator +archive_end(Archive_file* afile) +{ + return Archive_iterator(afile, afile->filesize()); +} + +// A type of Import_stream which concatenates other Import_streams +// together. + +class Stream_concatenate : public Import::Stream +{ + public: + Stream_concatenate() + : inputs_() + { } + + // Add a new stream. + void + add(Import::Stream* is) + { this->inputs_.push_back(is); } + + protected: + bool + do_peek(size_t, const char**); + + void + do_advance(size_t); + + private: + std::list<Import::Stream*> inputs_; +}; + +// Peek ahead. + +bool +Stream_concatenate::do_peek(size_t length, const char** bytes) +{ + while (true) + { + if (this->inputs_.empty()) + return false; + if (this->inputs_.front()->peek(length, bytes)) + return true; + delete this->inputs_.front(); + this->inputs_.pop_front(); + } +} + +// Advance. + +void +Stream_concatenate::do_advance(size_t skip) +{ + while (true) + { + if (this->inputs_.empty()) + return; + if (!this->inputs_.front()->at_eof()) + { + // We just assume that this will do the right thing. It + // should be OK since we should never want to skip past + // multiple streams. + this->inputs_.front()->advance(skip); + return; + } + delete this->inputs_.front(); + this->inputs_.pop_front(); + } +} + +// Import data from an archive. We walk through the archive and +// import data from each member. + +Import::Stream* +Import::find_archive_export_data(const std::string& filename, int fd, + Location location) +{ + Archive_file afile(filename, fd, location); + if (!afile.initialize()) + return NULL; + + Stream_concatenate* ret = new Stream_concatenate; + + bool any_data = false; + bool any_members = false; + Archive_iterator pend = archive_end(&afile); + for (Archive_iterator p = archive_begin(&afile); p != pend; p++) + { + any_members = true; + int member_fd; + off_t member_off; + std::string member_name; + if (!afile.get_file_and_offset(p->off, p->name, p->nested_off, + &member_fd, &member_off, &member_name)) + return NULL; + + Import::Stream* is = Import::find_object_export_data(member_name, + member_fd, + member_off, + location); + if (is != NULL) + { + ret->add(is); + any_data = true; + } + } + + if (!any_members) + { + // It's normal to have an empty archive file when using gobuild. + return new Stream_from_string(""); + } + + if (!any_data) + { + delete ret; + return NULL; + } + + return ret; +} |