Magic-Mirror/llvm-capstone
1
0
Fork 0
mirror of https://github.com/capstone-engine/llvm-capstone.git synced 2025-02-13 13:45:16 +00:00
Code Issues Actions 2 Packages Projects Releases Wiki Activity

[lld-macho][nfc] Use includeInSymtab for all symtab-skipping logic

Browse Source 
{D123302} got me looking deeper at `includeInSymtab`. I thought it was a
little odd that there were excluded (live) symbols for which
`includeInSymtab` was false; we shouldn't have so many different ways to
exclude a symbol. As such, this diff makes the `L`-prefixed-symbol
exclusion code use `includeInSymtab` too. (Note that as part of our
support for `__eh_frame`, we will also be excluding all `__eh_frame`
symbols from the symtab in a future diff.)

Another thing I noticed is that the `emitStabs` code never has to deal
with excluded symbols because `SymtabSection::finalize()` already
filters them out. As such, I've updated the comments and asserts from
{D123302} to reflect this.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D123433
This commit is contained in:
Jez Ng 2022-04-11 15:45:25 -04:00
parent a2b212bafc
commit 1cff723ff5
8 changed files with 31 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
lld/MachO/ConcatOutputSection.cpp
View File

@ -334,9 +334,9 @@ void TextOutputSection::finalize() {
/*noDeadStrip=*/false, /*isWeakDefCanBeHidden=*/false);
} else {
r.referent = thunkInfo.sym = make<Defined>(
thunkName, /*file=*/nullptr, thunkInfo.isec, /*value=*/0,
thunkSize, /*isWeakDef=*/false, /*isExternal=*/false,
/*isPrivateExtern=*/true, /*isThumb=*/false,
thunkName, /*file=*/nullptr, thunkInfo.isec, /*value=*/0, thunkSize,
/*isWeakDef=*/false, /*isExternal=*/false, /*isPrivateExtern=*/true,
/*includeInSymtab=*/true, /*isThumb=*/false,
/*isReferencedDynamically=*/false, /*noDeadStrip=*/false,
/*isWeakDefCanBeHidden=*/false);
}

13
lld/MachO/Driver.cpp
View File

@ -530,14 +530,11 @@ static void replaceCommonSymbols() {
// FIXME: CommonSymbol should store isReferencedDynamically, noDeadStrip
// and pass them on here.
replaceSymbol<Defined>(sym, sym->getName(), common->getFile(), isec,
/*value=*/0,
/*size=*/0,
/*isWeakDef=*/false,
/*isExternal=*/true, common->privateExtern,
/*isThumb=*/false,
/*isReferencedDynamically=*/false,
/*noDeadStrip=*/false);
replaceSymbol<Defined>(
sym, sym->getName(), common->getFile(), isec, /*value=*/0, /*size=*/0,
/*isWeakDef=*/false, /*isExternal=*/true, common->privateExtern,
/*includeInSymtab=*/true, /*isThumb=*/false,
/*isReferencedDynamically=*/false, /*noDeadStrip=*/false);
}
}

5
lld/MachO/InputFiles.cpp
View File

@ -636,9 +636,10 @@ static macho::Symbol *createDefined(const NList &sym, StringRef name,
}
assert(!isWeakDefCanBeHidden &&
"weak_def_can_be_hidden on already-hidden symbol?");
bool includeInSymtab = !name.startswith("l") && !name.startswith("L");
return make<Defined>(
name, isec->getFile(), isec, value, size, sym.n_desc & N_WEAK_DEF,
/*isExternal=*/false, /*isPrivateExtern=*/false,
/*isExternal=*/false, /*isPrivateExtern=*/false, includeInSymtab,
sym.n_desc & N_ARM_THUMB_DEF, sym.n_desc & REFERENCED_DYNAMICALLY,
sym.n_desc & N_NO_DEAD_STRIP);
}
@ -658,7 +659,7 @@ static macho::Symbol *createAbsolute(const NList &sym, InputFile *file,
return make<Defined>(name, file, nullptr, sym.n_value, /*size=*/0,
/*isWeakDef=*/false,
/*isExternal=*/false, /*isPrivateExtern=*/false,
sym.n_desc & N_ARM_THUMB_DEF,
/*includeInSymtab=*/true, sym.n_desc & N_ARM_THUMB_DEF,
/*isReferencedDynamically=*/false,
sym.n_desc & N_NO_DEAD_STRIP);
}

11
lld/MachO/SymbolTable.cpp
View File

@ -103,8 +103,9 @@ Defined *SymbolTable::addDefined(StringRef name, InputFile *file,
!isPrivateExtern;
Defined *defined = replaceSymbol<Defined>(
s, name, file, isec, value, size, isWeakDef, /*isExternal=*/true,
isPrivateExtern, isThumb, isReferencedDynamically, noDeadStrip,
overridesWeakDef, isWeakDefCanBeHidden, interposable);
isPrivateExtern, /*includeInSymtab=*/true, isThumb,
isReferencedDynamically, noDeadStrip, overridesWeakDef,
isWeakDefCanBeHidden, interposable);
return defined;
}
@ -233,9 +234,9 @@ Defined *SymbolTable::addSynthetic(StringRef name, InputSection *isec,
assert(!isec || !isec->getFile()); // See makeSyntheticInputSection().
Defined *s =
addDefined(name, /*file=*/nullptr, isec, value, /*size=*/0,
/*isWeakDef=*/false, isPrivateExtern,
/*isThumb=*/false, referencedDynamically,
/*noDeadStrip=*/false, /*isWeakDefCanBeHidden=*/false);
/*isWeakDef=*/false, isPrivateExtern, /*isThumb=*/false,
referencedDynamically, /*noDeadStrip=*/false,
/*isWeakDefCanBeHidden=*/false);
s->includeInSymtab = includeInSymtab;
return s;
}

4
lld/MachO/Symbols.cpp
View File

@ -42,12 +42,12 @@ uint64_t Symbol::getTlvVA() const { return in.tlvPointers->getVA(gotIndex); }
Defined::Defined(StringRefZ name, InputFile *file, InputSection *isec,
uint64_t value, uint64_t size, bool isWeakDef, bool isExternal,
bool isPrivateExtern, bool isThumb,
bool isPrivateExtern, bool includeInSymtab, bool isThumb,
bool isReferencedDynamically, bool noDeadStrip,
bool canOverrideWeakDef, bool isWeakDefCanBeHidden,
bool interposable)
: Symbol(DefinedKind, name, file), overridesWeakDef(canOverrideWeakDef),
privateExtern(isPrivateExtern), includeInSymtab(true),
privateExtern(isPrivateExtern), includeInSymtab(includeInSymtab),
wasIdenticalCodeFolded(false), thumb(isThumb),
referencedDynamically(isReferencedDynamically), noDeadStrip(noDeadStrip),
interposable(interposable), weakDefCanBeHidden(isWeakDefCanBeHidden),

6
lld/MachO/Symbols.h
View File

@ -117,9 +117,9 @@ class Defined : public Symbol {
public:
Defined(StringRefZ name, InputFile *file, InputSection *isec, uint64_t value,
uint64_t size, bool isWeakDef, bool isExternal, bool isPrivateExtern,
bool isThumb, bool isReferencedDynamically, bool noDeadStrip,
bool canOverrideWeakDef = false, bool isWeakDefCanBeHidden = false,
bool interposable = false);
bool includeInSymtab, bool isThumb, bool isReferencedDynamically,
bool noDeadStrip, bool canOverrideWeakDef = false,
bool isWeakDefCanBeHidden = false, bool interposable = false);
bool isWeakDef() const override { return weakDef; }
bool isExternalWeakDef() const {

17
lld/MachO/SyntheticSections.cpp
View File

@ -634,6 +634,7 @@ void StubHelperSection::setup() {
make<Defined>("__dyld_private", nullptr, in.imageLoaderCache, 0, 0,
/*isWeakDef=*/false,
/*isExternal=*/false, /*isPrivateExtern=*/false,
/*includeInSymtab=*/true,
/*isThumb=*/false, /*isReferencedDynamically=*/false,
/*noDeadStrip=*/false);
dyldPrivate->used = true;
@ -896,6 +897,9 @@ void SymtabSection::emitStabs() {
assert(sym->isLive() &&
"dead symbols should not be in localSymbols, externalSymbols");
if (auto *defined = dyn_cast<Defined>(sym)) {
// Excluded symbols should have been filtered out in finalizeContents().
assert(defined->includeInSymtab);
if (defined->isAbsolute())
continue;
@ -909,10 +913,6 @@ void SymtabSection::emitStabs() {
if (!file || !file->compileUnit)
continue;
// All symbols that set includeInSymtab to false are synthetic symbols.
// Those have `file` set to nullptr and were already skipped due to that.
assert(defined->includeInSymtab);
symbolsNeedingStabs.push_back(defined);
}
}
@ -969,11 +969,10 @@ void SymtabSection::finalizeContents() {
if (auto *objFile = dyn_cast<ObjFile>(file)) {
for (Symbol *sym : objFile->symbols) {
if (auto *defined = dyn_cast_or_null<Defined>(sym)) {
if (!defined->isExternal() && defined->isLive()) {
StringRef name = defined->getName();
if (!name.startswith("l") && !name.startswith("L"))
addSymbol(localSymbols, sym);
}
if (defined->isExternal() || !defined->isLive() ||
!defined->includeInSymtab)
continue;
addSymbol(localSymbols, sym);
}
}
}

1
lld/MachO/UnwindInfoSection.cpp
View File

@ -270,6 +270,7 @@ void UnwindInfoSectionImpl<Ptr>::prepareRelocations(ConcatInputSection *isec) {
s = make<Defined>("<internal>", /*file=*/nullptr, referentIsec,
r.addend, /*size=*/0, /*isWeakDef=*/false,
/*isExternal=*/false, /*isPrivateExtern=*/false,
/*includeInSymtab=*/true,
/*isThumb=*/false, /*isReferencedDynamically=*/false,
/*noDeadStrip=*/false);
in.got->addEntry(s);