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[Mach-O] wip

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This commit is contained in:
Rui Ueyama 2021-10-26 14:21:37 +09:00
parent 986516545a
commit e12055de49
1 changed files with 26 additions and 30 deletions
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56
macho/output-file.cc
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@ -1,3 +1,15 @@
// This file implements the same functionality as elf/output-file.cc.
// We have two different implemetntations for ELF and Mach-O because
// we implemented a special optimization for ELF or Linux.
//
// On Linux, it is faster to write to an existing file than creating a
// new file and writing to it. So, we overwrite an existing executable
// if exists.
//
// On macOS, it looks like the system does not assume that an executable
// is mutated once it is created. Due to some code signing mechanism or
// something, we always have to create a fresh file.
#include "mold.h"
#include <fcntl.h>
@ -19,32 +31,18 @@ public:
: OutputFile(path, filesize, true) {
std::string dir(path_dirname(path));
output_tmpfile = (char *)save_string(ctx, dir + "/.mold-XXXXXX").data();
i64 fd = mkstemp(output_tmpfile);
if (fd == -1)
Fatal(ctx) << "cannot open " << output_tmpfile << ": " << errno_string();
if (rename(path.c_str(), output_tmpfile) == 0) {
::close(fd);
fd = ::open(output_tmpfile, O_RDWR | O_CREAT, perm);
if (fd == -1) {
if (errno != ETXTBSY)
Fatal(ctx) << "cannot open " << path << ": " << errno_string();
unlink(output_tmpfile);
fd = ::open(output_tmpfile, O_RDWR | O_CREAT, perm);
if (fd == -1)
Fatal(ctx) << "cannot open " << path << ": " << errno_string();
}
}
if (ftruncate(fd, filesize))
Fatal(ctx) << "ftruncate failed";
if (fchmod(fd, (perm & ~get_umask())) == -1)
if (fchmod(fd, perm) == -1)
Fatal(ctx) << "fchmod failed";
this->buf = (u8 *)mmap(nullptr, filesize, PROT_READ | PROT_WRITE,
MAP_SHARED, fd, 0);
if (this->buf == MAP_FAILED)
buf = (u8 *)mmap(nullptr, filesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (buf == MAP_FAILED)
Fatal(ctx) << path << ": mmap failed: " << errno_string();
::close(fd);
}
@ -52,11 +50,9 @@ public:
void close(Context &ctx) override {
Timer t(ctx, "close_file");
if (!this->is_unmapped)
munmap(this->buf, this->filesize);
if (rename(output_tmpfile, this->path.c_str()) == -1)
Fatal(ctx) << this->path << ": rename failed: " << errno_string();
munmap(buf, filesize);
if (rename(output_tmpfile, path.c_str()) == -1)
Fatal(ctx) << path << ": rename failed: " << errno_string();
output_tmpfile = nullptr;
}
};
@ -65,27 +61,27 @@ class MallocOutputFile : public OutputFile {
public:
MallocOutputFile(Context &ctx, std::string path, i64 filesize, i64 perm)
: OutputFile(path, filesize, false), perm(perm) {
this->buf = (u8 *)mmap(NULL, filesize, PROT_READ | PROT_WRITE,
buf = (u8 *)mmap(NULL, filesize, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_ANONYMOUS, -1, 0);
if (this->buf == MAP_FAILED)
if (buf == MAP_FAILED)
Fatal(ctx) << "mmap failed: " << errno_string();
}
void close(Context &ctx) override {
Timer t(ctx, "close_file");
if (this->path == "-") {
fwrite(this->buf, this->filesize, 1, stdout);
if (path == "-") {
fwrite(buf, filesize, 1, stdout);
fclose(stdout);
return;
}
i64 fd = ::open(this->path.c_str(), O_RDWR | O_CREAT, perm);
i64 fd = ::open(path.c_str(), O_RDWR | O_CREAT, perm);
if (fd == -1)
Fatal(ctx) << "cannot open " << this->path << ": " << errno_string();
Fatal(ctx) << "cannot open " << path << ": " << errno_string();
FILE *fp = fdopen(fd, "w");
fwrite(this->buf, this->filesize, 1, fp);
fwrite(buf, filesize, 1, fp);
fclose(fp);
}