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4bd532ab9a
Swift string literals are only permitted to contain well-formed UTF-8, but C does not share this restriction, and ClangImporter wasn't checking for that before it created `StringLiteralExpr`s for imported macros; this could cause crashes when importing a header. This commit makes us drop these macros instead. Although invalid UTF-8 always *did* cause a segfault in my testing, I'm not convinced that there isn't a way to cause a miscompile with a bug like this. If we somehow did generate code that fed ill-formed UTF-8 to the builtin literal init for Swift.String, the resulting string could cause undefined behavior at runtime. So I have additionally added a defensive assertion to StringLiteralInst that any UTF-8 string represented in SIL is well-formed. Hopefully that will catch any non-crashing compiler bugs like this one. Fixes rdar://67840900.
81 lines
2.5 KiB
C++
81 lines
2.5 KiB
C++
//===--- Unicode.h - Unicode utilities --------------------------*- C++ -*-===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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#ifndef SWIFT_BASIC_UNICODE_H
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#define SWIFT_BASIC_UNICODE_H
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#include "swift/Basic/LLVM.h"
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#include "llvm/ADT/StringRef.h"
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namespace swift {
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namespace unicode {
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StringRef extractFirstExtendedGraphemeCluster(StringRef S);
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static inline bool isSingleExtendedGraphemeCluster(StringRef S) {
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StringRef First = extractFirstExtendedGraphemeCluster(S);
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if (First.empty())
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return false;
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return First == S;
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}
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enum class GraphemeClusterBreakProperty : uint8_t {
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Other,
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CR,
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LF,
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Control,
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Extend,
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Regional_Indicator,
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Prepend,
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SpacingMark,
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L,
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V,
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T,
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LV,
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LVT,
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};
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/// Extended grapheme cluster boundary rules, represented as a matrix. Indexed
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/// by first code point, then by second code point in least-significant-bit
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/// order. A set bit means that a boundary is prohibited between two code
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/// points.
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extern const uint16_t ExtendedGraphemeClusterNoBoundaryRulesMatrix[];
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/// Returns the value of the Grapheme_Cluster_Break property for a given code
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/// point.
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GraphemeClusterBreakProperty getGraphemeClusterBreakProperty(uint32_t C);
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/// Determine if there is an extended grapheme cluster boundary between code
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/// points with given Grapheme_Cluster_Break property values.
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static inline bool
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isExtendedGraphemeClusterBoundary(GraphemeClusterBreakProperty GCB1,
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GraphemeClusterBreakProperty GCB2) {
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auto RuleRow =
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ExtendedGraphemeClusterNoBoundaryRulesMatrix[static_cast<unsigned>(GCB1)];
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return !(RuleRow & (1 << static_cast<unsigned>(GCB2)));
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}
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bool isSingleUnicodeScalar(StringRef S);
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unsigned extractFirstUnicodeScalar(StringRef S);
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/// Returns true if \p S does not contain any ill-formed subsequences. This does
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/// not check whether all of the characters in it are actually allocated or
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/// used correctly; it just checks that every byte can be grouped into a code
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/// unit (Unicode scalar).
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bool isWellFormedUTF8(StringRef S);
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} // end namespace unicode
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} // end namespace swift
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#endif // SWIFT_BASIC_UNICODE_H
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