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[SIL] Fix use-after-free in SILFunction::print. #29949

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Merged
merged 1 commit into from
Feb 21, 2020
Merged

[SIL] Fix use-after-free in SILFunction::print. #29949

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30 changes: 16 additions & 14 deletions lib/SIL/SILPrinter.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -437,14 +437,13 @@ void SILType::dump() const {
}

/// Prints the name and type of the given SIL function with the given
/// `PrintOptions`. Mutates `printOptions`, setting `GenericEnv` and
/// `AlternativeTypeNames`.
static void printSILFunctionNameAndType(llvm::raw_ostream &OS,
const SILFunction *function,
PrintOptions &printOptions) {
/// `PrintOptions`. Computes mapping for sugared type names and stores the
/// result in `sugaredTypeNames`.
static void printSILFunctionNameAndType(
llvm::raw_ostream &OS, const SILFunction *function,
llvm::DenseMap<CanType, Identifier> &sugaredTypeNames) {
function->printName(OS);
OS << " : $";
llvm::DenseMap<CanType, Identifier> aliases;
auto genSig = function->getLoweredFunctionType()->getSubstGenericSignature();
auto *genEnv = function->getGenericEnvironment();
// If `genSig` and `genEnv` are both defined, get sugared names of generic
Expand All @@ -470,22 +469,24 @@ static void printSILFunctionNameAndType(llvm::raw_ostream &OS,
continue;
// Otherwise, add sugared name mapping for the type (and its archetype, if
// defined).
aliases[paramTy->getCanonicalType()] = name;
sugaredTypeNames[paramTy->getCanonicalType()] = name;
if (auto *archetypeTy =
genEnv->mapTypeIntoContext(paramTy)->getAs<ArchetypeType>())
aliases[archetypeTy->getCanonicalType()] = name;
sugaredTypeNames[archetypeTy->getCanonicalType()] = name;
}
}
auto printOptions = PrintOptions::printSIL();
printOptions.GenericEnv = genEnv;
printOptions.AlternativeTypeNames = aliases.empty() ? nullptr : &aliases;
printOptions.AlternativeTypeNames =
sugaredTypeNames.empty() ? nullptr : &sugaredTypeNames;
function->getLoweredFunctionType()->print(OS, printOptions);
}

/// Prints the name and type of the given SIL function.
static void printSILFunctionNameAndType(llvm::raw_ostream &OS,
const SILFunction *function) {
auto printOptions = PrintOptions::printSIL();
printSILFunctionNameAndType(OS, function, printOptions);
llvm::DenseMap<CanType, Identifier> sugaredTypeNames;
printSILFunctionNameAndType(OS, function, sugaredTypeNames);
}

namespace {
Expand Down Expand Up @@ -2513,16 +2514,17 @@ void SILFunction::print(SILPrintContext &PrintCtx) const {
if (!isExternalDeclaration() && hasOwnership())
OS << "[ossa] ";

auto printOptions = PrintOptions::printSIL();
printSILFunctionNameAndType(OS, this, printOptions);
llvm::DenseMap<CanType, Identifier> sugaredTypeNames;
printSILFunctionNameAndType(OS, this, sugaredTypeNames);

if (!isExternalDeclaration()) {
if (auto eCount = getEntryCount()) {
OS << " !function_entry_count(" << eCount.getValue() << ")";
}
OS << " {\n";

SILPrinter(PrintCtx, printOptions.AlternativeTypeNames).print(this);
SILPrinter(PrintCtx, sugaredTypeNames.empty() ? nullptr : &sugaredTypeNames)
.print(this);
OS << "} // end sil function '" << getName() << '\'';
}

Expand Down
7 changes: 7 additions & 0 deletions validation-test/SIL/crashers_fixed/047-swift-silfunction-print.swift
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Original file line number Diff line number Diff line change
@@ -0,0 +1,7 @@
// RUN: %target-swift-frontend -emit-sil %s

// SR-12239: use-after-free in `SILFunction::print`.

func outer<C>(_ x: C) {
func inner<C>(_ x: C) {}
}