diff options
Diffstat (limited to 'lib/Analysis/OSLog.cpp')
| -rw-r--r-- | lib/Analysis/OSLog.cpp | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/lib/Analysis/OSLog.cpp b/lib/Analysis/OSLog.cpp new file mode 100644 index 0000000000..b57e0d1d13 --- /dev/null +++ b/lib/Analysis/OSLog.cpp @@ -0,0 +1,177 @@ +// TODO: header template + +#include "clang/Analysis/Analyses/OSLog.h" +#include "clang/AST/Attr.h" +#include "clang/AST/Decl.h" +#include "clang/AST/DeclCXX.h" +#include "clang/AST/ExprObjC.h" +#include "clang/Analysis/Analyses/FormatString.h" +#include "clang/Basic/Builtins.h" +#include "llvm/ADT/SmallBitVector.h" + +using namespace clang; +using llvm::APInt; + +using clang::analyze_os_log::OSLogBufferItem; +using clang::analyze_os_log::OSLogBufferLayout; + +class OSLogFormatStringHandler + : public analyze_format_string::FormatStringHandler { +private: + struct ArgData { + const Expr *E = nullptr; + Optional<OSLogBufferItem::Kind> Kind; + Optional<unsigned> Size; + unsigned char Flags = 0; + }; + SmallVector<ArgData, 4> ArgsData; + ArrayRef<const Expr *> Args; + + OSLogBufferItem::Kind + getKind(analyze_format_string::ConversionSpecifier::Kind K) { + switch (K) { + case clang::analyze_format_string::ConversionSpecifier::sArg: // "%s" + return OSLogBufferItem::StringKind; + case clang::analyze_format_string::ConversionSpecifier::SArg: // "%S" + return OSLogBufferItem::WideStringKind; + case clang::analyze_format_string::ConversionSpecifier::PArg: { // "%P" + return OSLogBufferItem::PointerKind; + case clang::analyze_format_string::ConversionSpecifier::ObjCObjArg: // "%@" + return OSLogBufferItem::ObjCObjKind; + case clang::analyze_format_string::ConversionSpecifier::PrintErrno: // "%m" + return OSLogBufferItem::ErrnoKind; + default: + return OSLogBufferItem::ScalarKind; + } + } + } + +public: + OSLogFormatStringHandler(ArrayRef<const Expr *> Args) : Args(Args) { + ArgsData.reserve(Args.size()); + } + + virtual bool HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier &FS, + const char *StartSpecifier, + unsigned SpecifierLen) { + if (!FS.consumesDataArgument() && + FS.getConversionSpecifier().getKind() != + clang::analyze_format_string::ConversionSpecifier::PrintErrno) + return false; + + ArgsData.emplace_back(); + unsigned ArgIndex = FS.getArgIndex(); + if (ArgIndex < Args.size()) + ArgsData.back().E = Args[ArgIndex]; + + // First get the Kind + ArgsData.back().Kind = getKind(FS.getConversionSpecifier().getKind()); + if (ArgsData.back().Kind != OSLogBufferItem::ErrnoKind && + !ArgsData.back().E) { + // missing argument + ArgsData.pop_back(); + return false; + } + + switch (FS.getConversionSpecifier().getKind()) { + case clang::analyze_format_string::ConversionSpecifier::sArg: // "%s" + case clang::analyze_format_string::ConversionSpecifier::SArg: { // "%S" + auto &precision = FS.getPrecision(); + switch (precision.getHowSpecified()) { + case clang::analyze_format_string::OptionalAmount::NotSpecified: // "%s" + break; + case clang::analyze_format_string::OptionalAmount::Constant: // "%.16s" + ArgsData.back().Size = precision.getConstantAmount(); + break; + case clang::analyze_format_string::OptionalAmount::Arg: // "%.*s" + ArgsData.back().Kind = OSLogBufferItem::CountKind; + break; + case clang::analyze_format_string::OptionalAmount::Invalid: + return false; + } + break; + } + case clang::analyze_format_string::ConversionSpecifier::PArg: { // "%P" + auto &precision = FS.getPrecision(); + switch (precision.getHowSpecified()) { + case clang::analyze_format_string::OptionalAmount::NotSpecified: // "%P" + return false; // length must be supplied with pointer format specifier + case clang::analyze_format_string::OptionalAmount::Constant: // "%.16P" + ArgsData.back().Size = precision.getConstantAmount(); + break; + case clang::analyze_format_string::OptionalAmount::Arg: // "%.*P" + ArgsData.back().Kind = OSLogBufferItem::CountKind; + break; + case clang::analyze_format_string::OptionalAmount::Invalid: + return false; + } + break; + } + default: + break; + } + + if (FS.isPrivate()) { + ArgsData.back().Flags |= OSLogBufferItem::IsPrivate; + } + if (FS.isPublic()) { + ArgsData.back().Flags |= OSLogBufferItem::IsPublic; + } + return true; + } + + void computeLayout(ASTContext &Ctx, OSLogBufferLayout &Layout) const { + Layout.Items.clear(); + for (auto &Data : ArgsData) { + if (Data.Size) + Layout.Items.emplace_back(Ctx, CharUnits::fromQuantity(*Data.Size), + Data.Flags); + if (Data.Kind) { + CharUnits Size; + if (*Data.Kind == OSLogBufferItem::ErrnoKind) + Size = CharUnits::Zero(); + else + Size = Ctx.getTypeSizeInChars(Data.E->getType()); + Layout.Items.emplace_back(*Data.Kind, Data.E, Size, Data.Flags); + } else { + auto Size = Ctx.getTypeSizeInChars(Data.E->getType()); + Layout.Items.emplace_back(OSLogBufferItem::ScalarKind, Data.E, Size, + Data.Flags); + } + } + } +}; + +bool clang::analyze_os_log::computeOSLogBufferLayout( + ASTContext &Ctx, const CallExpr *E, OSLogBufferLayout &Layout) { + ArrayRef<const Expr *> Args(E->getArgs(), E->getArgs() + E->getNumArgs()); + + const Expr *StringArg; + ArrayRef<const Expr *> VarArgs; + switch (E->getBuiltinCallee()) { + case Builtin::BI__builtin_os_log_format_buffer_size: + assert(E->getNumArgs() >= 1 && + "__builtin_os_log_format_buffer_size takes at least 1 argument"); + StringArg = E->getArg(0); + VarArgs = Args.slice(1); + break; + case Builtin::BI__builtin_os_log_format: + assert(E->getNumArgs() >= 2 && + "__builtin_os_log_format takes at least 2 arguments"); + StringArg = E->getArg(1); + VarArgs = Args.slice(2); + break; + default: + llvm_unreachable("non-os_log builtin passed to computeOSLogBufferLayout"); + } + + const StringLiteral *Lit = cast<StringLiteral>(StringArg->IgnoreParenCasts()); + assert(Lit && (Lit->isAscii() || Lit->isUTF8())); + StringRef Data = Lit->getString(); + OSLogFormatStringHandler H(VarArgs); + ParsePrintfString(H, Data.begin(), Data.end(), Ctx.getLangOpts(), + Ctx.getTargetInfo(), /*isFreeBSDKPrintf*/ false); + + H.computeLayout(Ctx, Layout); + return true; +} |