1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
//===- lib/ReaderWriter/ELF/PPC/PPCTargetHandler.cpp ----------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "PPCTargetHandler.h"
#include "PPCLinkingContext.h"
using namespace lld;
using namespace elf;
using namespace llvm::ELF;
/// \brief The following relocation routines are derived from the
/// SYSTEM V APPLICATION BINARY INTERFACE: PowerPC Processor Supplement
/// Symbols used:
/// A: Added used to compute the value, r_addend
/// P: Place address of the field being relocated, r_offset
/// S: Value of the symbol whose index resides in the relocation entry.
/// \brief low24 (S + A - P) >> 2 : Verify
static int relocB24PCREL(uint8_t *location, uint64_t P, uint64_t S,
uint64_t A) {
int32_t result = (uint32_t)(((S + A) - P));
if ((result < 0x1000000) && (result > -0x1000000)) {
result &= ~-(0x1000000);
*reinterpret_cast<llvm::support::ubig32_t *>(location) = result |
(uint32_t)*reinterpret_cast<llvm::support::ubig32_t *>(location);
return 0;
}
return 1;
}
error_code PPCTargetRelocationHandler::applyRelocation(
ELFWriter &writer, llvm::FileOutputBuffer &buf, const lld::AtomLayout &atom,
const Reference &ref) const {
uint8_t *atomContent = buf.getBufferStart() + atom._fileOffset;
uint8_t *location = atomContent + ref.offsetInAtom();
uint64_t targetVAddress = writer.addressOfAtom(ref.target());
uint64_t relocVAddress = atom._virtualAddr + ref.offsetInAtom();
switch (ref.kind()) {
case R_PPC_REL24:
relocB24PCREL(location, relocVAddress, targetVAddress, ref.addend());
break;
case lld::Reference::kindLayoutAfter:
case lld::Reference::kindLayoutBefore:
case lld::Reference::kindInGroup:
break;
default : {
std::string str;
llvm::raw_string_ostream s(str);
auto name = _context.stringFromRelocKind(ref.kind());
s << "Unhandled relocation: " << (name ? *name : "<unknown>") << " ("
<< ref.kind() << ")";
s.flush();
llvm_unreachable(str.c_str());
}
}
return error_code::success();
}
PPCTargetHandler::PPCTargetHandler(PPCLinkingContext &targetInfo)
: DefaultTargetHandler(targetInfo), _relocationHandler(targetInfo),
_targetLayout(targetInfo) {}
|
