merlin-utils/link.cpp
2019-12-10 13:27:53 -05:00

417 lines
8.5 KiB
C++

/* c++17 */
#include <vector>
#include <unordered_map>
#include <string>
#include <string_view>
#include <system_error>
#include <algorithm>
#include <cstdint>
#include <cassert>
#include <cstdio>
#include <err.h>
#include <sysexits.h>
#include <unistd.h>
#include <afp/finder_info.h>
#include "mapped_file.h"
#include "omf.h"
#include "rel.h"
void save_omf(const std::string &path, std::vector<omf::segment> &segments, bool compress, bool expressload);
int set_file_type(const std::string &path, uint16_t file_type, uint32_t aux_type, std::error_code &ec);
void set_file_type(const std::string &path, uint16_t file_type, uint32_t aux_type);
/* since span isn't standard yet */
typedef std::basic_string_view<uint8_t> byte_view;
struct symbol {
std::string name;
std::string file;
uint32_t value = 0;
unsigned id = 0;
unsigned count = 0;
bool absolute = false;
bool defined = false;
};
std::unordered_map<std::string, unsigned> symbol_map;
std::vector<symbol> symbol_table;
struct pending_reloc : public omf::reloc {
unsigned id = 0;
};
std::vector<pending_reloc> relocations;
std::vector<omf::segment> segments;
/* nb - pointer may be invalidated by next call */
symbol *find_symbol(const std::string &name) {
auto iter = symbol_map.find(name);
if (iter != symbol_map.end()) return &symbol_table[iter->second - 1];
unsigned id = symbol_table.size() + 1;
symbol_map.emplace(name, id);
auto &rv = symbol_table.emplace_back();
rv.name = name;
rv.id = id;
return &rv;
}
struct cookie {
std::string file;
std::vector<unsigned> remap;
//std::vector<std::pair<unsigned, unsigned>> zero;
uint32_t begin = 0;
uint32_t end = 0;
};
void process_labels(byte_view &data, cookie &cookie) {
for(;;) {
assert(data.size());
unsigned flag = data[0];
if (flag == 0x00) return;
unsigned length = flag & 0x1f;
assert(length != 0);
assert(data.size() >= length + 4);
std::string name(data.data() + 1, data.data() + 1 + length);
data.remove_prefix(1 + length);
uint32_t value = data[0] | (data[1] << 8) | (data[2] << 16);
data.remove_prefix(3);
symbol *e = find_symbol(name);
switch (flag & ~0x1f) {
case SYMBOL_EXTERNAL:
/* map the unit symbol # to a global symbol # */
value &= 0x7fff;
if (cookie.remap.size() < value + 1)
cookie.remap.resize(value + 1);
cookie.remap[value] = e->id;
break;
case SYMBOL_ENTRY+SYMBOL_ABSOLUTE:
if (e->defined && e->absolute && e->value == value)
break; /* allow redef */
case SYMBOL_ENTRY:
if (e->defined) {
warnx("%s previously defined (%s)", e->name.c_str(), e->file.c_str());
break;
}
e->defined = true;
e->file = cookie.file;
if (flag & SYMBOL_ABSOLUTE) {
e->absolute = true;
e->value = value;
} else {
e->absolute = false;
e->value = value - 0x8000 + cookie.begin;
}
break;
default:
errx(1, "%s: Unsupported flag: %02x\n", cookie.file.c_str(), flag);
break;
}
}
}
void process_reloc(byte_view &data, cookie &cookie) {
auto &seg = segments.back();
for(;;) {
assert(data.size());
unsigned flag = data[0];
if (flag == 0x00) return;
assert(data.size() >= 4);
uint32_t offset = data[1] | (data[2] << 8);
unsigned x = data[3];
data.remove_prefix(4);
offset += cookie.begin;
bool external = false;
unsigned shift = 0;
uint32_t value = 0;
unsigned size = 0;
if (flag == 0xff) {
/* shift */
assert(data.size() >= 4);
unsigned flag = data[0];
value = data[1] | (data[2] << 8) | (data[3] << 16);
value -= 0x8000;
external = flag & 0x04;
switch(flag & ~0x04) {
case 0xd0:
shift = -16;
size = 1;
break;
case 0xd1:
shift = -8;
size = 2;
break;
case 0xd3:
shift = -8;
size = 1;
break;
default: /* bad */
errx(1, "%s: Unsupported flag: %02x\n", cookie.file.c_str(), flag);
break;
}
data.remove_prefix(4);
} else {
assert((flag & ~(0x0f|0x10|0x20|0x80)) == 0);
// offset already adjusted by start so below comparisons are wrong.
switch(flag & (0x80 + 0x20)) {
case 0:
size = 1;
assert(offset + 0 < cookie.end);
break;
case 0x20:
size = 3;
assert(offset + 2 < cookie.end);
break;
case 0x80:
size = 2;
assert(offset + 1 < cookie.end);
break;
default: /* bad size */
errx(1, "%s: Unsupported flag: %02x\n", cookie.file.c_str(), flag);
break;
}
external = flag & 0x10;
switch(size) {
case 3: value |= seg.data[offset+2] << 16;
case 2: value |= seg.data[offset+1] << 8;
case 1: value |= seg.data[offset+0];
}
if (size > 1) value -= 0x8000;
value += cookie.begin;
}
/* external resolutions are deferred for later */
if (external) {
/* x = local symbol # */
pending_reloc r;
assert(x < cookie.remap.size());
r.id = cookie.remap[x]; /* label reference is 0-based */
r.size = size;
r.offset = offset;
r.value = value;
r.shift = shift;
symbol_table[r.id].count += 1;
relocations.emplace_back(r);
} else {
omf::reloc r;
r.size = size;
r.offset = offset;
r.value = value;
r.shift = shift;
seg.relocs.emplace_back(r);
}
/* clear out the inline relocation data */
for(unsigned i = 0; i < size; ++i) {
seg.data[offset + i] = 0;
}
//cookie.zero.emplace_back(std::make_pair(offset, size));
}
}
/*
void add_libraries() {
auto iter = libs.begin();
auto end = libs.end();
for(;;) {
}
}
*/
void process_unit(const std::string &path) {
cookie cookie;
/* skip over relocs, do symbols first */
std::error_code ec;
mapped_file mf(path, mapped_file::readonly, ec);
if (ec) {
errx(1, "Unable to open %s: %s", path.c_str(), ec.message().c_str());
}
afp::finder_info fi;
fi.read(path, ec);
if (ec) {
errx(1, "Error reading filetype %s: %s", path.c_str(), ec.message().c_str());
}
if (fi.prodos_file_type() != 0xf8) {
errx(1, "Wrong file type: %s", path.c_str());
}
uint32_t offset = fi.prodos_aux_type();
if (offset+2 > mf.size()) {
errx(1, "Invalid aux type %s", path.c_str());
}
omf::segment &seg = segments.back();
cookie.begin = seg.data.size();
cookie.end = cookie.begin + offset;
cookie.file = path;
seg.data.insert(seg.data.end(), mf.data(), mf.data() + offset);
byte_view data(mf.data() + offset, mf.size() - offset);
byte_view rr = data;
/* skip over the relocation records so we can process the labels first. */
/* this is so external references can use the global symbol id */
assert(data.size() >= 2);
for(;;) {
if (data[0] == 0) break;
assert(data.size() >= 6);
data.remove_prefix(4);
}
data.remove_prefix(1);
process_labels(data, cookie);
assert(data.size() == 1);
/* now relocations */
process_reloc(rr, cookie);
}
void finalize(void) {
/* this needs to be updated if supporting multiple segments */
auto &seg = segments.back();
for (auto &r : relocations) {
assert(r.id <= symbol_map.size());
const auto &label = symbol_table[r.id];
r.value = label.value;
seg.relocs.emplace_back(r);
}
relocations.clear();
}
void print_symbols(void) {
if (symbol_table.empty()) return;
/* alpha */
std::sort(symbol_table.begin(), symbol_table.end(),
[](const symbol &a, const symbol &b){
return a.name < b.name;
});
for (const auto &lab : symbol_table) {
fprintf(stdout, "%-20s: $%06x\n", lab.name.c_str(), lab.value);
}
fputs("\n", stdout);
/* numeric */
std::sort(symbol_table.begin(), symbol_table.end(),
[](const symbol &a, const symbol &b){
return a.value < b.value;
});
for (const auto &lab : symbol_table) {
fprintf(stdout, "%-20s: $%06x\n", lab.name.c_str(), lab.value);
}
}
void usage(int ex) {
fputs("merlin-link [-o outfile] infile...\n", stderr);
exit(ex);
}
int main(int argc, char **argv) {
int c;
std::string gs_out = "gs.out";
bool express = true;
bool compress = true;
while ((c = getopt(argc, argv, "o:XC")) != -1) {
switch(c) {
case 'o':
gs_out = optarg;
break;
case 'X': express = false; break;
case 'C': compress = false; break;
case ':':
case '?':
default:
usage(EX_USAGE);
break;
}
}
argv += optind;
argc -= optind;
if (!argc) usage(EX_USAGE);
segments.emplace_back();
for (int i = 0; i < argc; ++i) {
char *path = argv[i];
try {
process_unit(path);
} catch (std::exception &ex) {
errx(EX_DATAERR, "%s: %s", path, ex.what());
}
}
print_symbols();
try {
save_omf(gs_out, segments, compress, express);
set_file_type(gs_out, 0xb3, 0x0000);
exit(0);
} catch (std::exception &ex) {
errx(EX_OSERR, "%s: %s", gs_out.c_str(), ex.what());
}
}