1 //===- MCExpr.cpp - Assembly Level Expression Implementation --------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 #include "llvm/MC/MCExpr.h"
10 #include "llvm/ADT/Statistic.h"
11 #include "llvm/ADT/StringExtras.h"
12 #include "llvm/ADT/StringSwitch.h"
13 #include "llvm/Config/llvm-config.h"
14 #include "llvm/MC/MCAsmBackend.h"
15 #include "llvm/MC/MCAsmInfo.h"
16 #include "llvm/MC/MCAsmLayout.h"
17 #include "llvm/MC/MCAssembler.h"
18 #include "llvm/MC/MCContext.h"
19 #include "llvm/MC/MCObjectWriter.h"
20 #include "llvm/MC/MCSymbol.h"
21 #include "llvm/MC/MCValue.h"
22 #include "llvm/Support/Casting.h"
23 #include "llvm/Support/Compiler.h"
24 #include "llvm/Support/Debug.h"
25 #include "llvm/Support/ErrorHandling.h"
26 #include "llvm/Support/raw_ostream.h"
32 #define DEBUG_TYPE "mcexpr"
37 STATISTIC(MCExprEvaluate, "Number of MCExpr evaluations");
39 } // end namespace stats
40 } // end anonymous namespace
42 void MCExpr::print(raw_ostream &OS, const MCAsmInfo *MAI, bool InParens) const {
45 return cast<MCTargetExpr>(this)->printImpl(OS, MAI);
46 case MCExpr::Constant: {
47 auto Value = cast<MCConstantExpr>(*this).getValue();
48 auto PrintInHex = cast<MCConstantExpr>(*this).useHexFormat();
49 auto SizeInBytes = cast<MCConstantExpr>(*this).getSizeInBytes();
51 switch (SizeInBytes) {
53 OS << "0x" << Twine::utohexstr(Value);
56 OS << format("0x%02" PRIx64, Value);
59 OS << format("0x%04" PRIx64, Value);
62 OS << format("0x%08" PRIx64, Value);
65 OS << format("0x%016" PRIx64, Value);
72 case MCExpr::SymbolRef: {
73 const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(*this);
74 const MCSymbol &Sym = SRE.getSymbol();
75 // Parenthesize names that start with $ so that they don't look like
78 !InParens && !Sym.getName().empty() && Sym.getName()[0] == '$';
86 if (SRE.getKind() != MCSymbolRefExpr::VK_None)
87 SRE.printVariantKind(OS);
93 const MCUnaryExpr &UE = cast<MCUnaryExpr>(*this);
94 switch (UE.getOpcode()) {
95 case MCUnaryExpr::LNot: OS << '!'; break;
96 case MCUnaryExpr::Minus: OS << '-'; break;
97 case MCUnaryExpr::Not: OS << '~'; break;
98 case MCUnaryExpr::Plus: OS << '+'; break;
100 bool Binary = UE.getSubExpr()->getKind() == MCExpr::Binary;
101 if (Binary) OS << "(";
102 UE.getSubExpr()->print(OS, MAI);
103 if (Binary) OS << ")";
107 case MCExpr::Binary: {
108 const MCBinaryExpr &BE = cast<MCBinaryExpr>(*this);
110 // Only print parens around the LHS if it is non-trivial.
111 if (isa<MCConstantExpr>(BE.getLHS()) || isa<MCSymbolRefExpr>(BE.getLHS())) {
112 BE.getLHS()->print(OS, MAI);
115 BE.getLHS()->print(OS, MAI);
119 switch (BE.getOpcode()) {
120 case MCBinaryExpr::Add:
121 // Print "X-42" instead of "X+-42".
122 if (const MCConstantExpr *RHSC = dyn_cast<MCConstantExpr>(BE.getRHS())) {
123 if (RHSC->getValue() < 0) {
124 OS << RHSC->getValue();
131 case MCBinaryExpr::AShr: OS << ">>"; break;
132 case MCBinaryExpr::And: OS << '&'; break;
133 case MCBinaryExpr::Div: OS << '/'; break;
134 case MCBinaryExpr::EQ: OS << "=="; break;
135 case MCBinaryExpr::GT: OS << '>'; break;
136 case MCBinaryExpr::GTE: OS << ">="; break;
137 case MCBinaryExpr::LAnd: OS << "&&"; break;
138 case MCBinaryExpr::LOr: OS << "||"; break;
139 case MCBinaryExpr::LShr: OS << ">>"; break;
140 case MCBinaryExpr::LT: OS << '<'; break;
141 case MCBinaryExpr::LTE: OS << "<="; break;
142 case MCBinaryExpr::Mod: OS << '%'; break;
143 case MCBinaryExpr::Mul: OS << '*'; break;
144 case MCBinaryExpr::NE: OS << "!="; break;
145 case MCBinaryExpr::Or: OS << '|'; break;
146 case MCBinaryExpr::Shl: OS << "<<"; break;
147 case MCBinaryExpr::Sub: OS << '-'; break;
148 case MCBinaryExpr::Xor: OS << '^'; break;
151 // Only print parens around the LHS if it is non-trivial.
152 if (isa<MCConstantExpr>(BE.getRHS()) || isa<MCSymbolRefExpr>(BE.getRHS())) {
153 BE.getRHS()->print(OS, MAI);
156 BE.getRHS()->print(OS, MAI);
163 llvm_unreachable("Invalid expression kind!");
166 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
167 LLVM_DUMP_METHOD void MCExpr::dump() const {
175 const MCBinaryExpr *MCBinaryExpr::create(Opcode Opc, const MCExpr *LHS,
176 const MCExpr *RHS, MCContext &Ctx,
178 return new (Ctx) MCBinaryExpr(Opc, LHS, RHS, Loc);
181 const MCUnaryExpr *MCUnaryExpr::create(Opcode Opc, const MCExpr *Expr,
182 MCContext &Ctx, SMLoc Loc) {
183 return new (Ctx) MCUnaryExpr(Opc, Expr, Loc);
186 const MCConstantExpr *MCConstantExpr::create(int64_t Value, MCContext &Ctx,
188 unsigned SizeInBytes) {
189 return new (Ctx) MCConstantExpr(Value, PrintInHex, SizeInBytes);
194 MCSymbolRefExpr::MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind,
195 const MCAsmInfo *MAI, SMLoc Loc)
196 : MCExpr(MCExpr::SymbolRef, Loc,
197 encodeSubclassData(Kind, MAI->useParensForSymbolVariant(),
198 MAI->hasSubsectionsViaSymbols())),
203 const MCSymbolRefExpr *MCSymbolRefExpr::create(const MCSymbol *Sym,
205 MCContext &Ctx, SMLoc Loc) {
206 return new (Ctx) MCSymbolRefExpr(Sym, Kind, Ctx.getAsmInfo(), Loc);
209 const MCSymbolRefExpr *MCSymbolRefExpr::create(StringRef Name, VariantKind Kind,
211 return create(Ctx.getOrCreateSymbol(Name), Kind, Ctx);
214 StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) {
216 case VK_Invalid: return "<<invalid>>";
217 case VK_None: return "<<none>>";
219 case VK_DTPOFF: return "DTPOFF";
220 case VK_DTPREL: return "DTPREL";
221 case VK_GOT: return "GOT";
222 case VK_GOTOFF: return "GOTOFF";
223 case VK_GOTREL: return "GOTREL";
224 case VK_PCREL: return "PCREL";
225 case VK_GOTPCREL: return "GOTPCREL";
226 case VK_GOTTPOFF: return "GOTTPOFF";
227 case VK_INDNTPOFF: return "INDNTPOFF";
228 case VK_NTPOFF: return "NTPOFF";
229 case VK_GOTNTPOFF: return "GOTNTPOFF";
230 case VK_PLT: return "PLT";
231 case VK_TLSGD: return "TLSGD";
232 case VK_TLSLD: return "TLSLD";
233 case VK_TLSLDM: return "TLSLDM";
234 case VK_TPOFF: return "TPOFF";
235 case VK_TPREL: return "TPREL";
236 case VK_TLSCALL: return "tlscall";
237 case VK_TLSDESC: return "tlsdesc";
238 case VK_TLVP: return "TLVP";
239 case VK_TLVPPAGE: return "TLVPPAGE";
240 case VK_TLVPPAGEOFF: return "TLVPPAGEOFF";
241 case VK_PAGE: return "PAGE";
242 case VK_PAGEOFF: return "PAGEOFF";
243 case VK_GOTPAGE: return "GOTPAGE";
244 case VK_GOTPAGEOFF: return "GOTPAGEOFF";
245 case VK_SECREL: return "SECREL32";
246 case VK_SIZE: return "SIZE";
247 case VK_WEAKREF: return "WEAKREF";
248 case VK_X86_ABS8: return "ABS8";
249 case VK_ARM_NONE: return "none";
250 case VK_ARM_GOT_PREL: return "GOT_PREL";
251 case VK_ARM_TARGET1: return "target1";
252 case VK_ARM_TARGET2: return "target2";
253 case VK_ARM_PREL31: return "prel31";
254 case VK_ARM_SBREL: return "sbrel";
255 case VK_ARM_TLSLDO: return "tlsldo";
256 case VK_ARM_TLSDESCSEQ: return "tlsdescseq";
257 case VK_AVR_NONE: return "none";
258 case VK_AVR_LO8: return "lo8";
259 case VK_AVR_HI8: return "hi8";
260 case VK_AVR_HLO8: return "hlo8";
261 case VK_AVR_DIFF8: return "diff8";
262 case VK_AVR_DIFF16: return "diff16";
263 case VK_AVR_DIFF32: return "diff32";
264 case VK_PPC_LO: return "l";
265 case VK_PPC_HI: return "h";
266 case VK_PPC_HA: return "ha";
267 case VK_PPC_HIGH: return "high";
268 case VK_PPC_HIGHA: return "higha";
269 case VK_PPC_HIGHER: return "higher";
270 case VK_PPC_HIGHERA: return "highera";
271 case VK_PPC_HIGHEST: return "highest";
272 case VK_PPC_HIGHESTA: return "highesta";
273 case VK_PPC_GOT_LO: return "got@l";
274 case VK_PPC_GOT_HI: return "got@h";
275 case VK_PPC_GOT_HA: return "got@ha";
276 case VK_PPC_TOCBASE: return "tocbase";
277 case VK_PPC_TOC: return "toc";
278 case VK_PPC_TOC_LO: return "toc@l";
279 case VK_PPC_TOC_HI: return "toc@h";
280 case VK_PPC_TOC_HA: return "toc@ha";
281 case VK_PPC_U: return "u";
282 case VK_PPC_L: return "l";
283 case VK_PPC_DTPMOD: return "dtpmod";
284 case VK_PPC_TPREL_LO: return "tprel@l";
285 case VK_PPC_TPREL_HI: return "tprel@h";
286 case VK_PPC_TPREL_HA: return "tprel@ha";
287 case VK_PPC_TPREL_HIGH: return "tprel@high";
288 case VK_PPC_TPREL_HIGHA: return "tprel@higha";
289 case VK_PPC_TPREL_HIGHER: return "tprel@higher";
290 case VK_PPC_TPREL_HIGHERA: return "tprel@highera";
291 case VK_PPC_TPREL_HIGHEST: return "tprel@highest";
292 case VK_PPC_TPREL_HIGHESTA: return "tprel@highesta";
293 case VK_PPC_DTPREL_LO: return "dtprel@l";
294 case VK_PPC_DTPREL_HI: return "dtprel@h";
295 case VK_PPC_DTPREL_HA: return "dtprel@ha";
296 case VK_PPC_DTPREL_HIGH: return "dtprel@high";
297 case VK_PPC_DTPREL_HIGHA: return "dtprel@higha";
298 case VK_PPC_DTPREL_HIGHER: return "dtprel@higher";
299 case VK_PPC_DTPREL_HIGHERA: return "dtprel@highera";
300 case VK_PPC_DTPREL_HIGHEST: return "dtprel@highest";
301 case VK_PPC_DTPREL_HIGHESTA: return "dtprel@highesta";
302 case VK_PPC_GOT_TPREL: return "got@tprel";
303 case VK_PPC_GOT_TPREL_LO: return "got@tprel@l";
304 case VK_PPC_GOT_TPREL_HI: return "got@tprel@h";
305 case VK_PPC_GOT_TPREL_HA: return "got@tprel@ha";
306 case VK_PPC_GOT_DTPREL: return "got@dtprel";
307 case VK_PPC_GOT_DTPREL_LO: return "got@dtprel@l";
308 case VK_PPC_GOT_DTPREL_HI: return "got@dtprel@h";
309 case VK_PPC_GOT_DTPREL_HA: return "got@dtprel@ha";
310 case VK_PPC_TLS: return "tls";
311 case VK_PPC_GOT_TLSGD: return "got@tlsgd";
312 case VK_PPC_GOT_TLSGD_LO: return "got@tlsgd@l";
313 case VK_PPC_GOT_TLSGD_HI: return "got@tlsgd@h";
314 case VK_PPC_GOT_TLSGD_HA: return "got@tlsgd@ha";
315 case VK_PPC_TLSGD: return "tlsgd";
316 case VK_PPC_GOT_TLSLD: return "got@tlsld";
317 case VK_PPC_GOT_TLSLD_LO: return "got@tlsld@l";
318 case VK_PPC_GOT_TLSLD_HI: return "got@tlsld@h";
319 case VK_PPC_GOT_TLSLD_HA: return "got@tlsld@ha";
320 case VK_PPC_GOT_PCREL:
322 case VK_PPC_TLSLD: return "tlsld";
323 case VK_PPC_LOCAL: return "local";
324 case VK_PPC_NOTOC: return "notoc";
325 case VK_COFF_IMGREL32: return "IMGREL";
326 case VK_Hexagon_LO16: return "LO16";
327 case VK_Hexagon_HI16: return "HI16";
328 case VK_Hexagon_GPREL: return "GPREL";
329 case VK_Hexagon_GD_GOT: return "GDGOT";
330 case VK_Hexagon_LD_GOT: return "LDGOT";
331 case VK_Hexagon_GD_PLT: return "GDPLT";
332 case VK_Hexagon_LD_PLT: return "LDPLT";
333 case VK_Hexagon_IE: return "IE";
334 case VK_Hexagon_IE_GOT: return "IEGOT";
335 case VK_WASM_TYPEINDEX: return "TYPEINDEX";
336 case VK_WASM_MBREL: return "MBREL";
337 case VK_WASM_TBREL: return "TBREL";
338 case VK_AMDGPU_GOTPCREL32_LO: return "gotpcrel32@lo";
339 case VK_AMDGPU_GOTPCREL32_HI: return "gotpcrel32@hi";
340 case VK_AMDGPU_REL32_LO: return "rel32@lo";
341 case VK_AMDGPU_REL32_HI: return "rel32@hi";
342 case VK_AMDGPU_REL64: return "rel64";
343 case VK_AMDGPU_ABS32_LO: return "abs32@lo";
344 case VK_AMDGPU_ABS32_HI: return "abs32@hi";
345 case VK_VE_HI32: return "hi";
346 case VK_VE_LO32: return "lo";
347 case VK_VE_PC_HI32: return "pc_hi";
348 case VK_VE_PC_LO32: return "pc_lo";
349 case VK_VE_GOT_HI32: return "got_hi";
350 case VK_VE_GOT_LO32: return "got_lo";
351 case VK_VE_GOTOFF_HI32: return "gotoff_hi";
352 case VK_VE_GOTOFF_LO32: return "gotoff_lo";
353 case VK_VE_PLT_HI32: return "plt_hi";
354 case VK_VE_PLT_LO32: return "plt_lo";
355 case VK_VE_TLS_GD_HI32: return "tls_gd_hi";
356 case VK_VE_TLS_GD_LO32: return "tls_gd_lo";
357 case VK_VE_TPOFF_HI32: return "tpoff_hi";
358 case VK_VE_TPOFF_LO32: return "tpoff_lo";
360 llvm_unreachable("Invalid variant kind");
363 MCSymbolRefExpr::VariantKind
364 MCSymbolRefExpr::getVariantKindForName(StringRef Name) {
365 return StringSwitch<VariantKind>(Name.lower())
366 .Case("dtprel", VK_DTPREL)
367 .Case("dtpoff", VK_DTPOFF)
369 .Case("gotoff", VK_GOTOFF)
370 .Case("gotrel", VK_GOTREL)
371 .Case("pcrel", VK_PCREL)
372 .Case("gotpcrel", VK_GOTPCREL)
373 .Case("gottpoff", VK_GOTTPOFF)
374 .Case("indntpoff", VK_INDNTPOFF)
375 .Case("ntpoff", VK_NTPOFF)
376 .Case("gotntpoff", VK_GOTNTPOFF)
378 .Case("tlscall", VK_TLSCALL)
379 .Case("tlsdesc", VK_TLSDESC)
380 .Case("tlsgd", VK_TLSGD)
381 .Case("tlsld", VK_TLSLD)
382 .Case("tlsldm", VK_TLSLDM)
383 .Case("tpoff", VK_TPOFF)
384 .Case("tprel", VK_TPREL)
385 .Case("tlvp", VK_TLVP)
386 .Case("tlvppage", VK_TLVPPAGE)
387 .Case("tlvppageoff", VK_TLVPPAGEOFF)
388 .Case("page", VK_PAGE)
389 .Case("pageoff", VK_PAGEOFF)
390 .Case("gotpage", VK_GOTPAGE)
391 .Case("gotpageoff", VK_GOTPAGEOFF)
392 .Case("imgrel", VK_COFF_IMGREL32)
393 .Case("secrel32", VK_SECREL)
394 .Case("size", VK_SIZE)
395 .Case("abs8", VK_X86_ABS8)
396 .Case("l", VK_PPC_LO)
397 .Case("h", VK_PPC_HI)
398 .Case("ha", VK_PPC_HA)
399 .Case("high", VK_PPC_HIGH)
400 .Case("higha", VK_PPC_HIGHA)
401 .Case("higher", VK_PPC_HIGHER)
402 .Case("highera", VK_PPC_HIGHERA)
403 .Case("highest", VK_PPC_HIGHEST)
404 .Case("highesta", VK_PPC_HIGHESTA)
405 .Case("got@l", VK_PPC_GOT_LO)
406 .Case("got@h", VK_PPC_GOT_HI)
407 .Case("got@ha", VK_PPC_GOT_HA)
408 .Case("local", VK_PPC_LOCAL)
409 .Case("tocbase", VK_PPC_TOCBASE)
410 .Case("toc", VK_PPC_TOC)
411 .Case("toc@l", VK_PPC_TOC_LO)
412 .Case("toc@h", VK_PPC_TOC_HI)
413 .Case("toc@ha", VK_PPC_TOC_HA)
416 .Case("tls", VK_PPC_TLS)
417 .Case("dtpmod", VK_PPC_DTPMOD)
418 .Case("tprel@l", VK_PPC_TPREL_LO)
419 .Case("tprel@h", VK_PPC_TPREL_HI)
420 .Case("tprel@ha", VK_PPC_TPREL_HA)
421 .Case("tprel@high", VK_PPC_TPREL_HIGH)
422 .Case("tprel@higha", VK_PPC_TPREL_HIGHA)
423 .Case("tprel@higher", VK_PPC_TPREL_HIGHER)
424 .Case("tprel@highera", VK_PPC_TPREL_HIGHERA)
425 .Case("tprel@highest", VK_PPC_TPREL_HIGHEST)
426 .Case("tprel@highesta", VK_PPC_TPREL_HIGHESTA)
427 .Case("dtprel@l", VK_PPC_DTPREL_LO)
428 .Case("dtprel@h", VK_PPC_DTPREL_HI)
429 .Case("dtprel@ha", VK_PPC_DTPREL_HA)
430 .Case("dtprel@high", VK_PPC_DTPREL_HIGH)
431 .Case("dtprel@higha", VK_PPC_DTPREL_HIGHA)
432 .Case("dtprel@higher", VK_PPC_DTPREL_HIGHER)
433 .Case("dtprel@highera", VK_PPC_DTPREL_HIGHERA)
434 .Case("dtprel@highest", VK_PPC_DTPREL_HIGHEST)
435 .Case("dtprel@highesta", VK_PPC_DTPREL_HIGHESTA)
436 .Case("got@tprel", VK_PPC_GOT_TPREL)
437 .Case("got@tprel@l", VK_PPC_GOT_TPREL_LO)
438 .Case("got@tprel@h", VK_PPC_GOT_TPREL_HI)
439 .Case("got@tprel@ha", VK_PPC_GOT_TPREL_HA)
440 .Case("got@dtprel", VK_PPC_GOT_DTPREL)
441 .Case("got@dtprel@l", VK_PPC_GOT_DTPREL_LO)
442 .Case("got@dtprel@h", VK_PPC_GOT_DTPREL_HI)
443 .Case("got@dtprel@ha", VK_PPC_GOT_DTPREL_HA)
444 .Case("got@tlsgd", VK_PPC_GOT_TLSGD)
445 .Case("got@tlsgd@l", VK_PPC_GOT_TLSGD_LO)
446 .Case("got@tlsgd@h", VK_PPC_GOT_TLSGD_HI)
447 .Case("got@tlsgd@ha", VK_PPC_GOT_TLSGD_HA)
448 .Case("got@tlsld", VK_PPC_GOT_TLSLD)
449 .Case("got@tlsld@l", VK_PPC_GOT_TLSLD_LO)
450 .Case("got@tlsld@h", VK_PPC_GOT_TLSLD_HI)
451 .Case("got@tlsld@ha", VK_PPC_GOT_TLSLD_HA)
452 .Case("got@pcrel", VK_PPC_GOT_PCREL)
453 .Case("notoc", VK_PPC_NOTOC)
454 .Case("gdgot", VK_Hexagon_GD_GOT)
455 .Case("gdplt", VK_Hexagon_GD_PLT)
456 .Case("iegot", VK_Hexagon_IE_GOT)
457 .Case("ie", VK_Hexagon_IE)
458 .Case("ldgot", VK_Hexagon_LD_GOT)
459 .Case("ldplt", VK_Hexagon_LD_PLT)
460 .Case("none", VK_ARM_NONE)
461 .Case("got_prel", VK_ARM_GOT_PREL)
462 .Case("target1", VK_ARM_TARGET1)
463 .Case("target2", VK_ARM_TARGET2)
464 .Case("prel31", VK_ARM_PREL31)
465 .Case("sbrel", VK_ARM_SBREL)
466 .Case("tlsldo", VK_ARM_TLSLDO)
467 .Case("lo8", VK_AVR_LO8)
468 .Case("hi8", VK_AVR_HI8)
469 .Case("hlo8", VK_AVR_HLO8)
470 .Case("typeindex", VK_WASM_TYPEINDEX)
471 .Case("tbrel", VK_WASM_TBREL)
472 .Case("mbrel", VK_WASM_MBREL)
473 .Case("gotpcrel32@lo", VK_AMDGPU_GOTPCREL32_LO)
474 .Case("gotpcrel32@hi", VK_AMDGPU_GOTPCREL32_HI)
475 .Case("rel32@lo", VK_AMDGPU_REL32_LO)
476 .Case("rel32@hi", VK_AMDGPU_REL32_HI)
477 .Case("rel64", VK_AMDGPU_REL64)
478 .Case("abs32@lo", VK_AMDGPU_ABS32_LO)
479 .Case("abs32@hi", VK_AMDGPU_ABS32_HI)
480 .Case("hi", VK_VE_HI32)
481 .Case("lo", VK_VE_LO32)
482 .Case("pc_hi", VK_VE_PC_HI32)
483 .Case("pc_lo", VK_VE_PC_LO32)
484 .Case("got_hi", VK_VE_GOT_HI32)
485 .Case("got_lo", VK_VE_GOT_LO32)
486 .Case("gotoff_hi", VK_VE_GOTOFF_HI32)
487 .Case("gotoff_lo", VK_VE_GOTOFF_LO32)
488 .Case("plt_hi", VK_VE_PLT_HI32)
489 .Case("plt_lo", VK_VE_PLT_LO32)
490 .Case("tls_gd_hi", VK_VE_TLS_GD_HI32)
491 .Case("tls_gd_lo", VK_VE_TLS_GD_LO32)
492 .Case("tpoff_hi", VK_VE_TPOFF_HI32)
493 .Case("tpoff_lo", VK_VE_TPOFF_LO32)
494 .Default(VK_Invalid);
497 void MCSymbolRefExpr::printVariantKind(raw_ostream &OS) const {
498 if (useParensForSymbolVariant())
499 OS << '(' << MCSymbolRefExpr::getVariantKindName(getKind()) << ')';
501 OS << '@' << MCSymbolRefExpr::getVariantKindName(getKind());
506 void MCTargetExpr::anchor() {}
510 bool MCExpr::evaluateAsAbsolute(int64_t &Res) const {
511 return evaluateAsAbsolute(Res, nullptr, nullptr, nullptr, false);
514 bool MCExpr::evaluateAsAbsolute(int64_t &Res,
515 const MCAsmLayout &Layout) const {
516 return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, nullptr, false);
519 bool MCExpr::evaluateAsAbsolute(int64_t &Res,
520 const MCAsmLayout &Layout,
521 const SectionAddrMap &Addrs) const {
522 // Setting InSet causes us to absolutize differences across sections and that
523 // is what the MachO writer uses Addrs for.
524 return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, &Addrs, true);
527 bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const {
528 return evaluateAsAbsolute(Res, &Asm, nullptr, nullptr, false);
531 bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm) const {
532 return evaluateAsAbsolute(Res, Asm, nullptr, nullptr, false);
535 bool MCExpr::evaluateKnownAbsolute(int64_t &Res,
536 const MCAsmLayout &Layout) const {
537 return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, nullptr,
541 bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
542 const MCAsmLayout *Layout,
543 const SectionAddrMap *Addrs, bool InSet) const {
546 // Fast path constants.
547 if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(this)) {
548 Res = CE->getValue();
553 evaluateAsRelocatableImpl(Value, Asm, Layout, nullptr, Addrs, InSet);
555 // Record the current value.
556 Res = Value.getConstant();
558 return IsRelocatable && Value.isAbsolute();
561 /// Helper method for \see EvaluateSymbolAdd().
562 static void AttemptToFoldSymbolOffsetDifference(
563 const MCAssembler *Asm, const MCAsmLayout *Layout,
564 const SectionAddrMap *Addrs, bool InSet, const MCSymbolRefExpr *&A,
565 const MCSymbolRefExpr *&B, int64_t &Addend) {
569 const MCSymbol &SA = A->getSymbol();
570 const MCSymbol &SB = B->getSymbol();
572 if (SA.isUndefined() || SB.isUndefined())
575 if (!Asm->getWriter().isSymbolRefDifferenceFullyResolved(*Asm, A, B, InSet))
578 MCFragment *FA = SA.getFragment();
579 MCFragment *FB = SB.getFragment();
580 if (FA == FB && !SA.isVariable() && !SA.isUnset() && !SB.isVariable() &&
582 Addend += (SA.getOffset() - SB.getOffset());
584 // Pointers to Thumb symbols need to have their low-bit set to allow
586 if (Asm->isThumbFunc(&SA))
589 // If symbol is labeled as micromips, we set low-bit to ensure
590 // correct offset in .gcc_except_table
591 if (Asm->getBackend().isMicroMips(&SA))
594 // Clear the symbol expr pointers to indicate we have folded these
603 const MCSection &SecA = *FA->getParent();
604 const MCSection &SecB = *FB->getParent();
606 if ((&SecA != &SecB) && !Addrs)
609 // One of the symbol involved is part of a fragment being laid out. Quit now
610 // to avoid a self loop.
611 if (!Layout->canGetFragmentOffset(FA) || !Layout->canGetFragmentOffset(FB))
615 Addend += Layout->getSymbolOffset(A->getSymbol()) -
616 Layout->getSymbolOffset(B->getSymbol());
617 if (Addrs && (&SecA != &SecB))
618 Addend += (Addrs->lookup(&SecA) - Addrs->lookup(&SecB));
620 // Pointers to Thumb symbols need to have their low-bit set to allow
622 if (Asm->isThumbFunc(&SA))
625 // If symbol is labeled as micromips, we set low-bit to ensure
626 // correct offset in .gcc_except_table
627 if (Asm->getBackend().isMicroMips(&SA))
630 // Clear the symbol expr pointers to indicate we have folded these
635 static bool canFold(const MCAssembler *Asm, const MCSymbolRefExpr *A,
636 const MCSymbolRefExpr *B, bool InSet) {
640 if (!Asm->getBackend().requiresDiffExpressionRelocations())
643 const MCSymbol &CheckSym = A ? A->getSymbol() : B->getSymbol();
644 if (!CheckSym.isInSection())
647 if (!CheckSym.getSection().hasInstructions())
653 /// Evaluate the result of an add between (conceptually) two MCValues.
655 /// This routine conceptually attempts to construct an MCValue:
656 /// Result = (Result_A - Result_B + Result_Cst)
657 /// from two MCValue's LHS and RHS where
658 /// Result = LHS + RHS
660 /// Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
662 /// This routine attempts to aggressively fold the operands such that the result
663 /// is representable in an MCValue, but may not always succeed.
665 /// \returns True on success, false if the result is not representable in an
668 /// NOTE: It is really important to have both the Asm and Layout arguments.
669 /// They might look redundant, but this function can be used before layout
670 /// is done (see the object streamer for example) and having the Asm argument
671 /// lets us avoid relaxations early.
673 EvaluateSymbolicAdd(const MCAssembler *Asm, const MCAsmLayout *Layout,
674 const SectionAddrMap *Addrs, bool InSet, const MCValue &LHS,
675 const MCSymbolRefExpr *RHS_A, const MCSymbolRefExpr *RHS_B,
676 int64_t RHS_Cst, MCValue &Res) {
677 // FIXME: This routine (and other evaluation parts) are *incredibly* sloppy
678 // about dealing with modifiers. This will ultimately bite us, one day.
679 const MCSymbolRefExpr *LHS_A = LHS.getSymA();
680 const MCSymbolRefExpr *LHS_B = LHS.getSymB();
681 int64_t LHS_Cst = LHS.getConstant();
683 // Fold the result constant immediately.
684 int64_t Result_Cst = LHS_Cst + RHS_Cst;
686 assert((!Layout || Asm) &&
687 "Must have an assembler object if layout is given!");
689 // If we have a layout, we can fold resolved differences. Do not do this if
690 // the backend requires this to be emitted as individual relocations, unless
691 // the InSet flag is set to get the current difference anyway (used for
692 // example to calculate symbol sizes).
693 if (Asm && canFold(Asm, LHS_A, LHS_B, InSet)) {
694 // First, fold out any differences which are fully resolved. By
695 // reassociating terms in
696 // Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
697 // we have the four possible differences:
702 // Since we are attempting to be as aggressive as possible about folding, we
703 // attempt to evaluate each possible alternative.
704 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, LHS_B,
706 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, RHS_B,
708 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, LHS_B,
710 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, RHS_B,
714 // We can't represent the addition or subtraction of two symbols.
715 if ((LHS_A && RHS_A) || (LHS_B && RHS_B))
718 // At this point, we have at most one additive symbol and one subtractive
719 // symbol -- find them.
720 const MCSymbolRefExpr *A = LHS_A ? LHS_A : RHS_A;
721 const MCSymbolRefExpr *B = LHS_B ? LHS_B : RHS_B;
723 Res = MCValue::get(A, B, Result_Cst);
727 bool MCExpr::evaluateAsRelocatable(MCValue &Res,
728 const MCAsmLayout *Layout,
729 const MCFixup *Fixup) const {
730 MCAssembler *Assembler = Layout ? &Layout->getAssembler() : nullptr;
731 return evaluateAsRelocatableImpl(Res, Assembler, Layout, Fixup, nullptr,
735 bool MCExpr::evaluateAsValue(MCValue &Res, const MCAsmLayout &Layout) const {
736 MCAssembler *Assembler = &Layout.getAssembler();
737 return evaluateAsRelocatableImpl(Res, Assembler, &Layout, nullptr, nullptr,
741 static bool canExpand(const MCSymbol &Sym, bool InSet) {
742 const MCExpr *Expr = Sym.getVariableValue();
743 const auto *Inner = dyn_cast<MCSymbolRefExpr>(Expr);
745 if (Inner->getKind() == MCSymbolRefExpr::VK_WEAKREF)
751 return !Sym.isInSection();
754 bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
755 const MCAsmLayout *Layout,
756 const MCFixup *Fixup,
757 const SectionAddrMap *Addrs,
759 ++stats::MCExprEvaluate;
763 return cast<MCTargetExpr>(this)->evaluateAsRelocatableImpl(Res, Layout,
767 Res = MCValue::get(cast<MCConstantExpr>(this)->getValue());
771 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this);
772 const MCSymbol &Sym = SRE->getSymbol();
774 // Evaluate recursively if this is a variable.
775 if (Sym.isVariable() && SRE->getKind() == MCSymbolRefExpr::VK_None &&
776 canExpand(Sym, InSet)) {
777 bool IsMachO = SRE->hasSubsectionsViaSymbols();
778 if (Sym.getVariableValue()->evaluateAsRelocatableImpl(
779 Res, Asm, Layout, Fixup, Addrs, InSet || IsMachO)) {
783 const MCSymbolRefExpr *A = Res.getSymA();
784 const MCSymbolRefExpr *B = Res.getSymB();
785 // FIXME: This is small hack. Given
788 // the OS X assembler will completely drop the 4. We should probably
789 // include it in the relocation or produce an error if that is not
791 // Allow constant expressions.
794 // Allows aliases with zero offset.
795 if (Res.getConstant() == 0 && (!A || !B))
800 Res = MCValue::get(SRE, nullptr, 0);
805 const MCUnaryExpr *AUE = cast<MCUnaryExpr>(this);
808 if (!AUE->getSubExpr()->evaluateAsRelocatableImpl(Value, Asm, Layout, Fixup,
812 switch (AUE->getOpcode()) {
813 case MCUnaryExpr::LNot:
814 if (!Value.isAbsolute())
816 Res = MCValue::get(!Value.getConstant());
818 case MCUnaryExpr::Minus:
819 /// -(a - b + const) ==> (b - a - const)
820 if (Value.getSymA() && !Value.getSymB())
823 // The cast avoids undefined behavior if the constant is INT64_MIN.
824 Res = MCValue::get(Value.getSymB(), Value.getSymA(),
825 -(uint64_t)Value.getConstant());
827 case MCUnaryExpr::Not:
828 if (!Value.isAbsolute())
830 Res = MCValue::get(~Value.getConstant());
832 case MCUnaryExpr::Plus:
841 const MCBinaryExpr *ABE = cast<MCBinaryExpr>(this);
842 MCValue LHSValue, RHSValue;
844 if (!ABE->getLHS()->evaluateAsRelocatableImpl(LHSValue, Asm, Layout, Fixup,
846 !ABE->getRHS()->evaluateAsRelocatableImpl(RHSValue, Asm, Layout, Fixup,
848 // Check if both are Target Expressions, see if we can compare them.
849 if (const MCTargetExpr *L = dyn_cast<MCTargetExpr>(ABE->getLHS()))
850 if (const MCTargetExpr *R = cast<MCTargetExpr>(ABE->getRHS())) {
851 switch (ABE->getOpcode()) {
852 case MCBinaryExpr::EQ:
853 Res = MCValue::get((L->isEqualTo(R)) ? -1 : 0);
855 case MCBinaryExpr::NE:
856 Res = MCValue::get((R->isEqualTo(R)) ? 0 : -1);
864 // We only support a few operations on non-constant expressions, handle
866 if (!LHSValue.isAbsolute() || !RHSValue.isAbsolute()) {
867 switch (ABE->getOpcode()) {
870 case MCBinaryExpr::Sub:
871 // Negate RHS and add.
872 // The cast avoids undefined behavior if the constant is INT64_MIN.
873 return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue,
874 RHSValue.getSymB(), RHSValue.getSymA(),
875 -(uint64_t)RHSValue.getConstant(), Res);
877 case MCBinaryExpr::Add:
878 return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue,
879 RHSValue.getSymA(), RHSValue.getSymB(),
880 RHSValue.getConstant(), Res);
884 // FIXME: We need target hooks for the evaluation. It may be limited in
885 // width, and gas defines the result of comparisons differently from
887 int64_t LHS = LHSValue.getConstant(), RHS = RHSValue.getConstant();
889 auto Op = ABE->getOpcode();
891 case MCBinaryExpr::AShr: Result = LHS >> RHS; break;
892 case MCBinaryExpr::Add: Result = LHS + RHS; break;
893 case MCBinaryExpr::And: Result = LHS & RHS; break;
894 case MCBinaryExpr::Div:
895 case MCBinaryExpr::Mod:
896 // Handle division by zero. gas just emits a warning and keeps going,
897 // we try to be stricter.
898 // FIXME: Currently the caller of this function has no way to understand
899 // we're bailing out because of 'division by zero'. Therefore, it will
900 // emit a 'expected relocatable expression' error. It would be nice to
901 // change this code to emit a better diagnostic.
904 if (ABE->getOpcode() == MCBinaryExpr::Div)
909 case MCBinaryExpr::EQ: Result = LHS == RHS; break;
910 case MCBinaryExpr::GT: Result = LHS > RHS; break;
911 case MCBinaryExpr::GTE: Result = LHS >= RHS; break;
912 case MCBinaryExpr::LAnd: Result = LHS && RHS; break;
913 case MCBinaryExpr::LOr: Result = LHS || RHS; break;
914 case MCBinaryExpr::LShr: Result = uint64_t(LHS) >> uint64_t(RHS); break;
915 case MCBinaryExpr::LT: Result = LHS < RHS; break;
916 case MCBinaryExpr::LTE: Result = LHS <= RHS; break;
917 case MCBinaryExpr::Mul: Result = LHS * RHS; break;
918 case MCBinaryExpr::NE: Result = LHS != RHS; break;
919 case MCBinaryExpr::Or: Result = LHS | RHS; break;
920 case MCBinaryExpr::Shl: Result = uint64_t(LHS) << uint64_t(RHS); break;
921 case MCBinaryExpr::Sub: Result = LHS - RHS; break;
922 case MCBinaryExpr::Xor: Result = LHS ^ RHS; break;
927 Res = MCValue::get(Result);
929 case MCBinaryExpr::EQ:
930 case MCBinaryExpr::GT:
931 case MCBinaryExpr::GTE:
932 case MCBinaryExpr::LT:
933 case MCBinaryExpr::LTE:
934 case MCBinaryExpr::NE:
935 // A comparison operator returns a -1 if true and 0 if false.
936 Res = MCValue::get(Result ? -1 : 0);
944 llvm_unreachable("Invalid assembly expression kind!");
947 MCFragment *MCExpr::findAssociatedFragment() const {
950 // We never look through target specific expressions.
951 return cast<MCTargetExpr>(this)->findAssociatedFragment();
954 return MCSymbol::AbsolutePseudoFragment;
957 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this);
958 const MCSymbol &Sym = SRE->getSymbol();
959 return Sym.getFragment();
963 return cast<MCUnaryExpr>(this)->getSubExpr()->findAssociatedFragment();
966 const MCBinaryExpr *BE = cast<MCBinaryExpr>(this);
967 MCFragment *LHS_F = BE->getLHS()->findAssociatedFragment();
968 MCFragment *RHS_F = BE->getRHS()->findAssociatedFragment();
970 // If either is absolute, return the other.
971 if (LHS_F == MCSymbol::AbsolutePseudoFragment)
973 if (RHS_F == MCSymbol::AbsolutePseudoFragment)
976 // Not always correct, but probably the best we can do without more context.
977 if (BE->getOpcode() == MCBinaryExpr::Sub)
978 return MCSymbol::AbsolutePseudoFragment;
980 // Otherwise, return the first non-null fragment.
981 return LHS_F ? LHS_F : RHS_F;
985 llvm_unreachable("Invalid assembly expression kind!");