ref: 74e40654e64f321399f3e2bb04019f83c96ce6fa
dir: /src/link/section.c/
/*
* This file is part of RGBDS.
*
* Copyright (c) 2019, Eldred Habert and RGBDS contributors.
*
* SPDX-License-Identifier: MIT
*/
#include <assert.h>
#include <inttypes.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include "link/main.h"
#include "link/section.h"
#include "error.h"
#include "hashmap.h"
#include "linkdefs.h"
HashMap sections;
struct ForEachArg {
void (*callback)(struct Section *section, void *arg);
void *arg;
};
static void forEach(void *section, void *arg)
{
struct ForEachArg *callbackArg = (struct ForEachArg *)arg;
callbackArg->callback((struct Section *)section, callbackArg->arg);
}
void sect_ForEach(void (*callback)(struct Section *, void *), void *arg)
{
struct ForEachArg callbackArg = { .callback = callback, .arg = arg};
hash_ForEach(sections, forEach, &callbackArg);
}
static void checkSectUnionCompat(struct Section *target, struct Section *other)
{
if (other->isAddressFixed) {
if (target->isAddressFixed) {
if (target->org != other->org)
errx("Section \"%s\" is defined with conflicting addresses $%04"
PRIx16 " and $%04" PRIx16,
other->name, target->org, other->org);
} else if (target->isAlignFixed) {
if ((other->org - target->alignOfs) & target->alignMask)
errx("Section \"%s\" is defined with conflicting %d-byte alignment (offset %"
PRIu16 ") and address $%04" PRIx16,
other->name, target->alignMask + 1,
target->alignOfs, other->org);
}
target->isAddressFixed = true;
target->org = other->org;
} else if (other->isAlignFixed) {
if (target->isAddressFixed) {
if ((target->org - other->alignOfs) & other->alignMask)
errx("Section \"%s\" is defined with conflicting address $%04"
PRIx16 " and %d-byte alignment (offset %" PRIu16 ")",
other->name, target->org,
other->alignMask + 1, other->alignOfs);
} else if (target->isAlignFixed
&& (other->alignMask & target->alignOfs)
!= (target->alignMask & other->alignOfs)) {
errx("Section \"%s\" is defined with conflicting %d-byte alignment (offset %"
PRIu16 ") and %d-byte alignment (offset %" PRIu16 ")",
other->name, target->alignMask + 1, target->alignOfs,
other->alignMask + 1, other->alignOfs);
} else if (!target->isAlignFixed || (other->alignMask > target->alignMask)) {
target->isAlignFixed = true;
target->alignMask = other->alignMask;
}
}
}
static void checkFragmentCompat(struct Section *target, struct Section *other)
{
if (other->isAddressFixed) {
uint16_t org = other->org - target->size;
if (target->isAddressFixed) {
if (target->org != org)
errx("Section \"%s\" is defined with conflicting addresses $%04"
PRIx16 " and $%04" PRIx16,
other->name, target->org, other->org);
} else if (target->isAlignFixed) {
if ((org - target->alignOfs) & target->alignMask)
errx("Section \"%s\" is defined with conflicting %d-byte alignment (offset %"
PRIu16 ") and address $%04" PRIx16,
other->name, target->alignMask + 1,
target->alignOfs, 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 (target->isAddressFixed) {
if ((target->org - ofs) & other->alignMask)
errx("Section \"%s\" is defined with conflicting address $%04"
PRIx16 " and %d-byte alignment (offset %" PRIu16 ")",
other->name, target->org,
other->alignMask + 1, other->alignOfs);
} else if (target->isAlignFixed
&& (other->alignMask & target->alignOfs) != (target->alignMask & ofs)) {
errx("Section \"%s\" is defined with conflicting %d-byte alignment (offset %"
PRIu16 ") and %d-byte alignment (offset %" PRIu16 ")",
other->name, target->alignMask + 1, target->alignOfs,
other->alignMask + 1, other->alignOfs);
} else if (!target->isAlignFixed || (other->alignMask > target->alignMask)) {
target->isAlignFixed = true;
target->alignMask = other->alignMask;
target->alignOfs = ofs;
}
}
}
static void mergeSections(struct Section *target, struct Section *other, enum SectionModifier mod)
{
// Common checks
if (target->type != other->type)
errx("Section \"%s\" is defined with conflicting types %s and %s",
other->name, sectionTypeInfo[target->type].name, sectionTypeInfo[other->type].name);
if (other->isBankFixed) {
if (!target->isBankFixed) {
target->isBankFixed = true;
target->bank = other->bank;
} else if (target->bank != other->bank) {
errx("Section \"%s\" is defined with conflicting banks %" PRIu32 " and %"
PRIu32, other->name, target->bank, other->bank);
}
}
switch (mod) {
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`
// Note that the order in which fragments are stored in the `nextu` list does not
// really matter, only that offsets are properly computed
other->offset = target->size;
target->size += other->size;
// Normally we'd check that `sect_HasData`, but SDCC areas may be `_INVALID` here
// Note that if either fragment has data (= a non-NULL `data` pointer), then it's
// assumed that both fragments "have data", and thus should either have a non-NULL
// `data` pointer, or a size of 0.
if (other->data) {
if (target->data) {
// Ensure we're not allocating 0 bytes
target->data = realloc(target->data,
sizeof(*target->data) * target->size + 1);
if (!target->data)
errx("Failed to concatenate \"%s\"'s fragments", target->name);
memcpy(&target->data[other->offset], other->data, other->size);
} else {
assert(target->size == other->size); // It has been increased just above
target->data = other->data;
other->data = NULL; // Prevent a double free()
}
// Adjust patches' PC offsets
for (uint32_t patchID = 0; patchID < other->nbPatches; patchID++)
other->patches[patchID].pcOffset += other->offset;
} else if (target->data) {
assert(other->size == 0);
}
break;
case SECTION_NORMAL:
unreachable_();
}
other->nextu = target->nextu;
target->nextu = other;
}
void sect_AddSection(struct Section *section)
{
// Check if the section already exists
struct Section *other = hash_GetElement(sections, section->name);
if (other) {
if (section->modifier != other->modifier)
errx("Section \"%s\" defined as %s and %s", section->name,
sectionModNames[section->modifier], sectionModNames[other->modifier]);
else if (section->modifier == SECTION_NORMAL)
errx("Section name \"%s\" is already in use", section->name);
else
mergeSections(other, section, section->modifier);
} else if (section->modifier == SECTION_UNION && sect_HasData(section->type)) {
errx("Section \"%s\" is of type %s, which cannot be unionized",
section->name, sectionTypeInfo[section->type].name);
} else {
// If not, add it
hash_AddElement(sections, section->name, section);
}
}
struct Section *sect_GetSection(char const *name)
{
return (struct Section *)hash_GetElement(sections, name);
}
void sect_CleanupSections(void)
{
hash_EmptyMap(sections);
}
static void doSanityChecks(struct Section *section, void *ptr)
{
(void)ptr;
// Sanity check the section's type
if (section->type < 0 || section->type >= SECTTYPE_INVALID) {
error(NULL, 0, "Section \"%s\" has an invalid type", section->name);
return;
}
if (is32kMode && section->type == SECTTYPE_ROMX) {
if (section->isBankFixed && section->bank != 1)
error(NULL, 0, "%s: ROMX sections must be in bank 1 (if any) with option -t",
section->name);
else
section->type = SECTTYPE_ROM0;
}
if (isWRA0Mode && section->type == SECTTYPE_WRAMX) {
if (section->isBankFixed && section->bank != 1)
error(NULL, 0, "%s: WRAMX sections must be in bank 1 with options -w or -d",
section->name);
else
section->type = SECTTYPE_WRAMX;
}
if (isDmgMode && section->type == SECTTYPE_VRAM && section->bank == 1)
error(NULL, 0, "%s: VRAM bank 1 can't be used with option -d",
section->name);
// 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(NULL, 0, "%s: %s sections cannot be aligned to $%04x bytes",
section->name, sectionTypeInfo[section->type].name, 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(NULL, 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, section->bank, minbank, maxbank);
// Check if section has a chance to be placed
if (section->size > sectionTypeInfo[section->type].size)
error(NULL, 0, "Section \"%s\" is bigger than the max size for that type: %#" PRIx16 " > %#" PRIx16,
section->name, 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(NULL, 0, "Section \"%s\"'s fixed address doesn't match its alignment",
section->name);
section->isAlignFixed = false;
}
// Ensure the target address is valid
if (section->org < sectionTypeInfo[section->type].startAddr
|| section->org > endaddr(section->type))
error(NULL, 0, "Section \"%s\"'s fixed address %#" PRIx16 " is outside of range [%#"
PRIx16 "; %#" PRIx16 "]", section->name, section->org,
sectionTypeInfo[section->type].startAddr, endaddr(section->type));
if (section->org + section->size > endaddr(section->type) + 1)
error(NULL, 0, "Section \"%s\"'s end address %#x is greater than last address %#x",
section->name, section->org + section->size,
endaddr(section->type) + 1);
}
#undef fail
}
void sect_DoSanityChecks(void)
{
sect_ForEach(doSanityChecks, NULL);
}