10b57cec5SDimitry Andric //= OSLog.h - Analysis of calls to os_log builtins --*- C++ -*-===============// 20b57cec5SDimitry Andric // 30b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 40b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 50b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 60b57cec5SDimitry Andric // 70b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 80b57cec5SDimitry Andric // 90b57cec5SDimitry Andric // This file defines APIs for determining the layout of the data buffer for 100b57cec5SDimitry Andric // os_log() and os_trace(). 110b57cec5SDimitry Andric // 120b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 130b57cec5SDimitry Andric 1404eeddc0SDimitry Andric #ifndef LLVM_CLANG_AST_OSLOG_H 1504eeddc0SDimitry Andric #define LLVM_CLANG_AST_OSLOG_H 160b57cec5SDimitry Andric 170b57cec5SDimitry Andric #include "clang/AST/ASTContext.h" 180b57cec5SDimitry Andric #include "clang/AST/Expr.h" 190b57cec5SDimitry Andric 200b57cec5SDimitry Andric namespace clang { 210b57cec5SDimitry Andric namespace analyze_os_log { 220b57cec5SDimitry Andric 230b57cec5SDimitry Andric /// An OSLogBufferItem represents a single item in the data written by a call 240b57cec5SDimitry Andric /// to os_log() or os_trace(). 250b57cec5SDimitry Andric class OSLogBufferItem { 260b57cec5SDimitry Andric public: 270b57cec5SDimitry Andric enum Kind { 280b57cec5SDimitry Andric // The item is a scalar (int, float, raw pointer, etc.). No further copying 290b57cec5SDimitry Andric // is required. This is the only kind allowed by os_trace(). 300b57cec5SDimitry Andric ScalarKind = 0, 310b57cec5SDimitry Andric 320b57cec5SDimitry Andric // The item is a count, which describes the length of the following item to 330b57cec5SDimitry Andric // be copied. A count may only be followed by an item of kind StringKind, 340b57cec5SDimitry Andric // WideStringKind, or PointerKind. 350b57cec5SDimitry Andric CountKind, 360b57cec5SDimitry Andric 370b57cec5SDimitry Andric // The item is a pointer to a C string. If preceded by a count 'n', 380b57cec5SDimitry Andric // os_log() will copy at most 'n' bytes from the pointer. 390b57cec5SDimitry Andric StringKind, 400b57cec5SDimitry Andric 410b57cec5SDimitry Andric // The item is a pointer to a block of raw data. This item must be preceded 420b57cec5SDimitry Andric // by a count 'n'. os_log() will copy exactly 'n' bytes from the pointer. 430b57cec5SDimitry Andric PointerKind, 440b57cec5SDimitry Andric 450b57cec5SDimitry Andric // The item is a pointer to an Objective-C object. os_log() may retain the 460b57cec5SDimitry Andric // object for later processing. 470b57cec5SDimitry Andric ObjCObjKind, 480b57cec5SDimitry Andric 490b57cec5SDimitry Andric // The item is a pointer to wide-char string. 500b57cec5SDimitry Andric WideStringKind, 510b57cec5SDimitry Andric 520b57cec5SDimitry Andric // The item is corresponding to the '%m' format specifier, no value is 530b57cec5SDimitry Andric // populated in the buffer and the runtime is loading the errno value. 540b57cec5SDimitry Andric ErrnoKind, 550b57cec5SDimitry Andric 560b57cec5SDimitry Andric // The item is a mask type. 570b57cec5SDimitry Andric MaskKind 580b57cec5SDimitry Andric }; 590b57cec5SDimitry Andric 600b57cec5SDimitry Andric enum { 610b57cec5SDimitry Andric // The item is marked "private" in the format string. 620b57cec5SDimitry Andric IsPrivate = 0x1, 630b57cec5SDimitry Andric 640b57cec5SDimitry Andric // The item is marked "public" in the format string. 650b57cec5SDimitry Andric IsPublic = 0x2, 660b57cec5SDimitry Andric 670b57cec5SDimitry Andric // The item is marked "sensitive" in the format string. 680b57cec5SDimitry Andric IsSensitive = 0x4 | IsPrivate 690b57cec5SDimitry Andric }; 700b57cec5SDimitry Andric 710b57cec5SDimitry Andric private: 720b57cec5SDimitry Andric Kind TheKind = ScalarKind; 730b57cec5SDimitry Andric const Expr *TheExpr = nullptr; 740b57cec5SDimitry Andric CharUnits ConstValue; 750b57cec5SDimitry Andric CharUnits Size; // size of the data, not including the header bytes 760b57cec5SDimitry Andric unsigned Flags = 0; 770b57cec5SDimitry Andric StringRef MaskType; 780b57cec5SDimitry Andric 790b57cec5SDimitry Andric public: 800b57cec5SDimitry Andric OSLogBufferItem(Kind kind, const Expr *expr, CharUnits size, unsigned flags, 810b57cec5SDimitry Andric StringRef maskType = StringRef()) TheKind(kind)820b57cec5SDimitry Andric : TheKind(kind), TheExpr(expr), Size(size), Flags(flags), 830b57cec5SDimitry Andric MaskType(maskType) { 840b57cec5SDimitry Andric assert(((Flags == 0) || (Flags == IsPrivate) || (Flags == IsPublic) || 850b57cec5SDimitry Andric (Flags == IsSensitive)) && 860b57cec5SDimitry Andric "unexpected privacy flag"); 870b57cec5SDimitry Andric } 880b57cec5SDimitry Andric OSLogBufferItem(ASTContext & Ctx,CharUnits value,unsigned flags)890b57cec5SDimitry Andric OSLogBufferItem(ASTContext &Ctx, CharUnits value, unsigned flags) 900b57cec5SDimitry Andric : TheKind(CountKind), ConstValue(value), 910b57cec5SDimitry Andric Size(Ctx.getTypeSizeInChars(Ctx.IntTy)), Flags(flags) {} 920b57cec5SDimitry Andric getDescriptorByte()930b57cec5SDimitry Andric unsigned char getDescriptorByte() const { 940b57cec5SDimitry Andric unsigned char result = Flags; 950b57cec5SDimitry Andric result |= ((unsigned)getKind()) << 4; 960b57cec5SDimitry Andric return result; 970b57cec5SDimitry Andric } 980b57cec5SDimitry Andric getSizeByte()990b57cec5SDimitry Andric unsigned char getSizeByte() const { return size().getQuantity(); } 1000b57cec5SDimitry Andric getKind()1010b57cec5SDimitry Andric Kind getKind() const { return TheKind; } getIsPrivate()1020b57cec5SDimitry Andric bool getIsPrivate() const { return (Flags & IsPrivate) != 0; } 1030b57cec5SDimitry Andric getExpr()1040b57cec5SDimitry Andric const Expr *getExpr() const { return TheExpr; } getConstValue()1050b57cec5SDimitry Andric CharUnits getConstValue() const { return ConstValue; } size()1060b57cec5SDimitry Andric CharUnits size() const { return Size; } 1070b57cec5SDimitry Andric getMaskType()1080b57cec5SDimitry Andric StringRef getMaskType() const { return MaskType; } 1090b57cec5SDimitry Andric }; 1100b57cec5SDimitry Andric 1110b57cec5SDimitry Andric class OSLogBufferLayout { 1120b57cec5SDimitry Andric public: 1130b57cec5SDimitry Andric SmallVector<OSLogBufferItem, 4> Items; 1140b57cec5SDimitry Andric 1150b57cec5SDimitry Andric enum Flags { HasPrivateItems = 1, HasNonScalarItems = 1 << 1 }; 1160b57cec5SDimitry Andric size()1170b57cec5SDimitry Andric CharUnits size() const { 1180b57cec5SDimitry Andric CharUnits result; 1190b57cec5SDimitry Andric result += CharUnits::fromQuantity(2); // summary byte, num-args byte 1200b57cec5SDimitry Andric for (auto &item : Items) { 1210b57cec5SDimitry Andric // descriptor byte, size byte 1220b57cec5SDimitry Andric result += item.size() + CharUnits::fromQuantity(2); 1230b57cec5SDimitry Andric } 1240b57cec5SDimitry Andric return result; 1250b57cec5SDimitry Andric } 1260b57cec5SDimitry Andric hasPrivateItems()1270b57cec5SDimitry Andric bool hasPrivateItems() const { 1280b57cec5SDimitry Andric return llvm::any_of( 1290b57cec5SDimitry Andric Items, [](const OSLogBufferItem &Item) { return Item.getIsPrivate(); }); 1300b57cec5SDimitry Andric } 1310b57cec5SDimitry Andric hasNonScalarOrMask()1320b57cec5SDimitry Andric bool hasNonScalarOrMask() const { 1330b57cec5SDimitry Andric return llvm::any_of(Items, [](const OSLogBufferItem &Item) { 1340b57cec5SDimitry Andric return Item.getKind() != OSLogBufferItem::ScalarKind || 1350b57cec5SDimitry Andric !Item.getMaskType().empty(); 1360b57cec5SDimitry Andric }); 1370b57cec5SDimitry Andric } 1380b57cec5SDimitry Andric getSummaryByte()1390b57cec5SDimitry Andric unsigned char getSummaryByte() const { 1400b57cec5SDimitry Andric unsigned char result = 0; 1410b57cec5SDimitry Andric if (hasPrivateItems()) 1420b57cec5SDimitry Andric result |= HasPrivateItems; 1430b57cec5SDimitry Andric if (hasNonScalarOrMask()) 1440b57cec5SDimitry Andric result |= HasNonScalarItems; 1450b57cec5SDimitry Andric return result; 1460b57cec5SDimitry Andric } 1470b57cec5SDimitry Andric getNumArgsByte()1480b57cec5SDimitry Andric unsigned char getNumArgsByte() const { return Items.size(); } 1490b57cec5SDimitry Andric }; 1500b57cec5SDimitry Andric 1510b57cec5SDimitry Andric // Given a call 'E' to one of the builtins __builtin_os_log_format() or 1520b57cec5SDimitry Andric // __builtin_os_log_format_buffer_size(), compute the layout of the buffer that 1530b57cec5SDimitry Andric // the call will write into and store it in 'layout'. Returns 'false' if there 1540b57cec5SDimitry Andric // was some error encountered while computing the layout, and 'true' otherwise. 1550b57cec5SDimitry Andric bool computeOSLogBufferLayout(clang::ASTContext &Ctx, const clang::CallExpr *E, 1560b57cec5SDimitry Andric OSLogBufferLayout &layout); 1570b57cec5SDimitry Andric 1580b57cec5SDimitry Andric } // namespace analyze_os_log 1590b57cec5SDimitry Andric } // namespace clang 1600b57cec5SDimitry Andric #endif 161