Files
rgbds/src/link/section.cpp
2025-01-29 12:53:44 -05:00

389 lines
11 KiB
C++

// SPDX-License-Identifier: MIT
#include "link/section.hpp"
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <unordered_map>
#include "error.hpp"
#include "helpers.hpp"
std::vector<std::unique_ptr<Section>> sectionList;
std::unordered_map<std::string, size_t> sectionMap; // Indexes into `sectionList`
void sect_ForEach(void (*callback)(Section &)) {
for (auto &ptr : sectionList) {
callback(*ptr);
}
}
static void checkAgainstFixedAddress(Section const &target, Section const &other, uint16_t org) {
if (target.isAddressFixed) {
if (target.org != org) {
fprintf(
stderr,
"error: Section \"%s\" is defined with address $%04" PRIx16 " at ",
target.name.c_str(),
target.org
);
target.src->dump(target.lineNo);
fprintf(stderr, ", but with address $%04" PRIx16 " at ", other.org);
other.src->dump(other.lineNo);
putc('\n', stderr);
exit(1);
}
} else if (target.isAlignFixed) {
if ((org - target.alignOfs) & target.alignMask) {
fprintf(
stderr,
"error: Section \"%s\" is defined with %d-byte alignment (offset %" PRIu16 ") at ",
target.name.c_str(),
target.alignMask + 1,
target.alignOfs
);
target.src->dump(target.lineNo);
fprintf(stderr, ", but with address $%04" PRIx16 " at ", other.org);
other.src->dump(other.lineNo);
putc('\n', stderr);
exit(1);
}
}
}
static bool checkAgainstFixedAlign(Section const &target, Section const &other, int32_t ofs) {
if (target.isAddressFixed) {
if ((target.org - ofs) & other.alignMask) {
fprintf(
stderr,
"error: Section \"%s\" is defined with address $%04" PRIx16 " at ",
target.name.c_str(),
target.org
);
target.src->dump(target.lineNo);
fprintf(
stderr,
", but with %d-byte alignment (offset %" PRIu16 ") at ",
other.alignMask + 1,
other.alignOfs
);
other.src->dump(other.lineNo);
putc('\n', stderr);
exit(1);
}
return false;
} else if (target.isAlignFixed
&& (other.alignMask & target.alignOfs) != (target.alignMask & ofs)) {
fprintf(
stderr,
"error: Section \"%s\" is defined with %d-byte alignment (offset %" PRIu16 ") at ",
target.name.c_str(),
target.alignMask + 1,
target.alignOfs
);
target.src->dump(target.lineNo);
fprintf(
stderr,
", but with %d-byte alignment (offset %" PRIu16 ") at ",
other.alignMask + 1,
other.alignOfs
);
other.src->dump(other.lineNo);
putc('\n', stderr);
exit(1);
} else {
return !target.isAlignFixed || (other.alignMask > target.alignMask);
}
}
static void checkSectUnionCompat(Section &target, Section &other) {
if (other.isAddressFixed) {
checkAgainstFixedAddress(target, other, other.org);
target.isAddressFixed = true;
target.org = other.org;
} else if (other.isAlignFixed) {
if (checkAgainstFixedAlign(target, other, other.alignOfs)) {
target.isAlignFixed = true;
target.alignMask = other.alignMask;
}
}
}
static void checkFragmentCompat(Section &target, Section &other) {
if (other.isAddressFixed) {
uint16_t org = other.org - target.size;
checkAgainstFixedAddress(target, other, org);
target.isAddressFixed = true;
target.org = org;
} else if (other.isAlignFixed) {
int32_t ofs = (other.alignOfs - target.size) % (other.alignMask + 1);
if (ofs < 0) {
ofs += other.alignMask + 1;
}
if (checkAgainstFixedAlign(target, other, ofs)) {
target.isAlignFixed = true;
target.alignMask = other.alignMask;
target.alignOfs = ofs;
}
}
}
static void mergeSections(Section &target, std::unique_ptr<Section> &&other) {
if (target.modifier != other->modifier) {
fprintf(
stderr,
"error: Section \"%s\" is defined as SECTION %s at ",
target.name.c_str(),
sectionModNames[target.modifier]
);
target.src->dump(target.lineNo);
fprintf(stderr, ", but as SECTION %s at ", sectionModNames[other->modifier]);
other->src->dump(other->lineNo);
putc('\n', stderr);
exit(1);
} else if (other->modifier == SECTION_NORMAL) {
fprintf(stderr, "error: Section \"%s\" is defined at ", target.name.c_str());
target.src->dump(target.lineNo);
fputs(", but also at ", stderr);
other->src->dump(other->lineNo);
putc('\n', stderr);
exit(1);
} else if (target.type != other->type) {
fprintf(
stderr,
"error: Section \"%s\" is defined with type %s at ",
target.name.c_str(),
sectionTypeInfo[target.type].name.c_str()
);
target.src->dump(target.lineNo);
fprintf(stderr, ", but with type %s at ", sectionTypeInfo[other->type].name.c_str());
other->src->dump(other->lineNo);
putc('\n', stderr);
exit(1);
}
if (other->isBankFixed) {
if (!target.isBankFixed) {
target.isBankFixed = true;
target.bank = other->bank;
} else if (target.bank != other->bank) {
fprintf(
stderr,
"error: Section \"%s\" is defined with bank %" PRIu32 " at ",
target.name.c_str(),
target.bank
);
target.src->dump(target.lineNo);
fprintf(stderr, ", but with bank %" PRIu32 " at ", other->bank);
other->src->dump(other->lineNo);
putc('\n', stderr);
exit(1);
}
}
switch (other->modifier) {
case SECTION_UNION:
checkSectUnionCompat(target, *other);
if (other->size > target.size) {
target.size = other->size;
}
break;
case SECTION_FRAGMENT:
checkFragmentCompat(target, *other);
// Append `other` to `target`
other->offset = target.size;
target.size += other->size;
// Normally we'd check that `sect_HasData`, but SDCC areas may be `_INVALID` here
if (!other->data.empty()) {
target.data.insert(target.data.end(), RANGE(other->data));
// Adjust patches' PC offsets
for (Patch &patch : other->patches) {
patch.pcOffset += other->offset;
}
} else if (!target.data.empty()) {
assume(other->size == 0);
}
break;
case SECTION_NORMAL:
unreachable_();
}
// Note that the order in which fragments are stored in the `nextu` list does not
// really matter, only that offsets were properly computed above
other->nextu = std::move(target.nextu);
target.nextu = std::move(other);
}
void sect_AddSection(std::unique_ptr<Section> &&section) {
// Check if the section already exists
if (Section *target = sect_GetSection(section->name); target) {
mergeSections(*target, std::move(section));
} else if (section->modifier == SECTION_UNION && sect_HasData(section->type)) {
errx(
"Section \"%s\" is of type %s, which cannot be unionized",
section->name.c_str(),
sectionTypeInfo[section->type].name.c_str()
);
} else {
// If not, add it
sectionMap.emplace(section->name, sectionList.size());
sectionList.push_back(std::move(section));
}
}
Section *sect_GetSection(std::string const &name) {
auto search = sectionMap.find(name);
return search != sectionMap.end() ? sectionList[search->second].get() : nullptr;
}
static void doSanityChecks(Section &section) {
// Sanity check the section's type
if (section.type < 0 || section.type >= SECTTYPE_INVALID) {
// This is trapped early in RGBDS objects (because then the format is not parseable),
// which leaves SDAS objects.
error(
nullptr,
0,
"Section \"%s\" has not been assigned a type by a linker script",
section.name.c_str()
);
return;
}
if (is32kMode && section.type == SECTTYPE_ROMX) {
if (section.isBankFixed && section.bank != 1) {
error(
nullptr,
0,
"Section \"%s\" has type ROMX, which must be in bank 1 (if any) with option `-t`",
section.name.c_str()
);
} else {
section.type = SECTTYPE_ROM0;
}
}
if (isWRAM0Mode && section.type == SECTTYPE_WRAMX) {
if (section.isBankFixed && section.bank != 1) {
error(
nullptr,
0,
"Section \"%s\" has type WRAMX, which must be in bank 1 with options `-w` or `-d`",
section.name.c_str()
);
} else {
section.type = SECTTYPE_WRAM0;
}
}
if (isDmgMode && section.type == SECTTYPE_VRAM && section.bank == 1) {
error(
nullptr,
0,
"Section \"%s\" has type VRAM, which must be in bank 0 with option `-d`",
section.name.c_str()
);
}
// Check if alignment is reasonable, this is important to avoid UB
// An alignment of zero is equivalent to no alignment, basically
if (section.isAlignFixed && section.alignMask == 0) {
section.isAlignFixed = false;
}
// Too large an alignment may not be satisfiable
if (section.isAlignFixed && (section.alignMask & sectionTypeInfo[section.type].startAddr)) {
error(
nullptr,
0,
"Section \"%s\" has type %s, which cannot be aligned to $%04x bytes",
section.name.c_str(),
sectionTypeInfo[section.type].name.c_str(),
section.alignMask + 1
);
}
uint32_t minbank = sectionTypeInfo[section.type].firstBank,
maxbank = sectionTypeInfo[section.type].lastBank;
if (section.isBankFixed && section.bank < minbank && section.bank > maxbank) {
error(
nullptr,
0,
minbank == maxbank
? "Cannot place section \"%s\" in bank %" PRIu32 ", it must be %" PRIu32
: "Cannot place section \"%s\" in bank %" PRIu32 ", it must be between %" PRIu32
" and %" PRIu32,
section.name.c_str(),
section.bank,
minbank,
maxbank
);
}
// Check if section has a chance to be placed
if (section.size > sectionTypeInfo[section.type].size) {
error(
nullptr,
0,
"Section \"%s\" is bigger than the max size for that type: $%" PRIx16 " > $%" PRIx16,
section.name.c_str(),
section.size,
sectionTypeInfo[section.type].size
);
}
// Translate loose constraints to strong ones when they're equivalent
if (minbank == maxbank) {
section.bank = minbank;
section.isBankFixed = true;
}
if (section.isAddressFixed) {
// It doesn't make sense to have both org and alignment set
if (section.isAlignFixed) {
if ((section.org & section.alignMask) != section.alignOfs) {
error(
nullptr,
0,
"Section \"%s\"'s fixed address doesn't match its alignment",
section.name.c_str()
);
}
section.isAlignFixed = false;
}
// Ensure the target address is valid
if (section.org < sectionTypeInfo[section.type].startAddr
|| section.org > endaddr(section.type)) {
error(
nullptr,
0,
"Section \"%s\"'s fixed address $%04" PRIx16 " is outside of range [$%04" PRIx16
"; $%04" PRIx16 "]",
section.name.c_str(),
section.org,
sectionTypeInfo[section.type].startAddr,
endaddr(section.type)
);
}
if (section.org + section.size > endaddr(section.type) + 1) {
error(
nullptr,
0,
"Section \"%s\"'s end address $%04x is greater than last address $%04x",
section.name.c_str(),
section.org + section.size,
endaddr(section.type) + 1
);
}
}
}
void sect_DoSanityChecks() {
sect_ForEach(doSanityChecks);
}