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mirror of https://github.com/rui314/mold.git synced 2024-12-27 10:23:41 +03:00
mold/output_file.cc
2021-04-28 19:15:20 +09:00

127 lines
3.6 KiB
C++

#include "mold.h"
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
static u32 get_umask() {
u32 orig_umask = umask(0);
umask(orig_umask);
return orig_umask;
}
template <typename E>
class MemoryMappedOutputFile : public OutputFile<E> {
public:
MemoryMappedOutputFile(Context<E> &ctx, std::string path, i64 filesize)
: OutputFile<E>(path, filesize, true) {
std::string dir = path_dirname(path);
this->tmpfile = (char *)save_string(ctx, dir + "/.mold-XXXXXX").data();
i64 fd = mkstemp(this->tmpfile);
if (fd == -1)
Fatal(ctx) << "cannot open " << this->tmpfile << ": " << strerror(errno);
if (rename(path.c_str(), this->tmpfile) == 0) {
::close(fd);
fd = ::open(this->tmpfile, O_RDWR | O_CREAT, 0777);
if (fd == -1) {
if (errno != ETXTBSY)
Fatal(ctx) << "cannot open " << path << ": " << strerror(errno);
unlink(this->tmpfile);
fd = ::open(this->tmpfile, O_RDWR | O_CREAT, 0777);
if (fd == -1)
Fatal(ctx) << "cannot open " << path << ": " << strerror(errno);
}
}
if (ftruncate(fd, filesize))
Fatal(ctx) << "ftruncate failed";
if (fchmod(fd, (0777 & ~get_umask())) == -1)
Fatal(ctx) << "fchmod failed";
this->buf = (u8 *)mmap(nullptr, filesize, PROT_READ | PROT_WRITE,
MAP_SHARED, fd, 0);
if (this->buf == MAP_FAILED)
Fatal(ctx) << path << ": mmap failed: " << strerror(errno);
::close(fd);
}
void close(Context<E> &ctx) override {
Timer t(ctx, "close_file");
if (!ctx.buildid)
munmap(this->buf, this->filesize);
if (rename(this->tmpfile, this->path.c_str()) == -1)
Fatal(ctx) << this->path << ": rename failed: " << strerror(errno);
this->tmpfile = nullptr;
}
};
template <typename E>
class MallocOutputFile : public OutputFile<E> {
public:
MallocOutputFile(Context<E> &ctx, std::string path, u64 filesize)
: OutputFile<E>(path, filesize, false) {
this->buf = (u8 *)mmap(NULL, filesize, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_ANONYMOUS, -1, 0);
if (this->buf == MAP_FAILED)
Fatal(ctx) << "mmap failed: " << strerror(errno);
}
void close(Context<E> &ctx) override {
Timer t(ctx, "close_file");
if (this->path == "-") {
fwrite(this->buf, this->filesize, 1, stdout);
return;
}
i64 fd = ::open(this->path.c_str(), O_RDWR | O_CREAT, 0777);
if (fd == -1)
Fatal(ctx) << "cannot open " << this->path << ": " << strerror(errno);
FILE *fp = fdopen(fd, "w");
fwrite(this->buf, this->filesize, 1, fp);
fclose(fp);
}
};
template <typename E>
std::unique_ptr<OutputFile<E>>
OutputFile<E>::open(Context<E> &ctx, std::string path, u64 filesize) {
Timer t(ctx, "open_file");
if (path.starts_with('/') && !ctx.arg.chroot.empty())
path = ctx.arg.chroot + "/" + path_clean(path);
bool is_special = false;
if (path == "-") {
is_special = true;
} else {
struct stat st;
if (stat(path.c_str(), &st) == 0 && (st.st_mode & S_IFMT) != S_IFREG)
is_special = true;
}
std::unique_ptr<OutputFile<E>> file;
if (is_special)
file = std::make_unique<MallocOutputFile<E>>(ctx, path, filesize);
else
file = std::make_unique<MemoryMappedOutputFile<E>>(ctx, path, filesize);
if (ctx.arg.filler != -1)
memset(file->buf, ctx.arg.filler, filesize);
return file;
}
template
std::unique_ptr<OutputFile<X86_64>>
OutputFile<X86_64>::open(Context<X86_64> &ctx, std::string path, u64 filesize);
template
std::unique_ptr<OutputFile<I386>>
OutputFile<I386>::open(Context<I386> &ctx, std::string path, u64 filesize);