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-fsanitize=function: fix .subsections_via_symbols #87527

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speednoisemovement merged 2 commits into from
Apr 8, 2024
Merged

-fsanitize=function: fix .subsections_via_symbols #87527

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-fsanitize=function: fix .subsections_via_symbols
speednoisemovement Apr 2, 2024
90db989
Use ArrayRef; style
speednoisemovement Apr 8, 2024
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Use ArrayRef; style
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@speednoisemovement
speednoisemovement committed Apr 8, 2024
commit 90db989814f94a4da8f34bd09c3838c91a0d0679
2 changes: 1 addition & 1 deletion llvm/include/llvm/CodeGen/AsmPrinter.h
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Expand Up @@ -869,7 +869,7 @@ class AsmPrinter : public MachineFunctionPass {
virtual void emitFunctionHeaderComment();

/// This method emits prefix-like data before the current function.
void emitFunctionPrefix(const SmallVector<const Constant *, 1> &Prefix);
void emitFunctionPrefix(ArrayRef<const Constant *> Prefix);

/// Emit a blob of inline asm to the output streamer.
void
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18 changes: 7 additions & 11 deletions llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
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Expand Up @@ -927,21 +927,18 @@ void AsmPrinter::emitDebugValue(const MCExpr *Value, unsigned Size) const {

void AsmPrinter::emitFunctionHeaderComment() {}

void AsmPrinter::emitFunctionPrefix(
const SmallVector<const Constant *, 1> &Prefix) {
void AsmPrinter::emitFunctionPrefix(ArrayRef<const Constant *> Prefix) {
const Function &F = MF->getFunction();
if (!MAI->hasSubsectionsViaSymbols()) {
for (auto &C : Prefix) {
for (auto &C : Prefix)
emitGlobalConstant(F.getParent()->getDataLayout(), C);
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@MaskRay MaskRay Apr 6, 2024

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omit braces https://llvm.org/docs/CodingStandards.html#don-t-use-braces-on-simple-single-statement-bodies-of-if-else-loop-statements

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@speednoisemovement speednoisemovement Apr 8, 2024

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Done

}
return;
}
// Preserving prefix data on platforms which use subsections-via-symbols
// is a bit tricky. Here we introduce a symbol for the prefix data
// Preserving prefix-like data on platforms which use subsections-via-symbols
// is a bit tricky. Here we introduce a symbol for the prefix-like data
// and use the .alt_entry attribute to mark the function's real entry point
// as an alternative entry point to the prefix-data symbol.
MCSymbol *PrefixSym = OutContext.createLinkerPrivateTempSymbol();
OutStreamer->emitLabel(PrefixSym);
// as an alternative entry point to the symbol that precedes the function..
OutStreamer->emitLabel(OutContext.createLinkerPrivateTempSymbol());

for (auto &C : Prefix) {
emitGlobalConstant(F.getParent()->getDataLayout(), C);
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@MaskRay MaskRay Apr 6, 2024

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omit braces https://llvm.org/docs/CodingStandards.html#don-t-use-braces-on-simple-single-statement-bodies-of-if-else-loop-statements

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@speednoisemovement speednoisemovement Apr 8, 2024

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Done

Expand Down Expand Up @@ -990,9 +987,8 @@ void AsmPrinter::emitFunctionHeader() {
OutStreamer->emitSymbolAttribute(CurrentFnSym, MCSA_Cold);

// Emit the prefix data.
if (F.hasPrefixData()) {
if (F.hasPrefixData())
emitFunctionPrefix({F.getPrefixData()});
}

// Emit KCFI type information before patchable-function-prefix nops.
emitKCFITypeId(*MF);
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2 changes: 1 addition & 1 deletion llvm/test/CodeGen/AArch64/func-sanitizer.ll
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Expand Up @@ -8,7 +8,7 @@
; CHECK-NEXT: // %bb.0:
; CHECK-NEXT: ret

; MACHO: ltmp0
; MACHO: ltmp0:
; MACHO-NEXT: .long 3238382334 ; 0xc105cafe
; MACHO-NEXT: .long 42 ; 0x2a
; MACHO-NEXT: .alt_entry __Z3funv
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2 changes: 1 addition & 1 deletion llvm/test/CodeGen/X86/func-sanitizer.ll
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Expand Up @@ -9,7 +9,7 @@
; CHECK-NEXT: # %bb.0:
; CHECK-NEXT: retq

; MACHO: ltmp0
; MACHO: ltmp0:
; MACHO-NEXT: .long 3238382334 ## 0xc105cafe
; MACHO-NEXT: .long 42 ## 0x2a
; MACHO-NEXT: .alt_entry __Z3funv
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