Author: filcab Date: Thu May 12 11:51:36 2016 New Revision: 269309 URL: http://llvm.org/viewvc/llvm-project?rev=269309&view=rev Log: [ubsan] Add -fsanitize-undefined-strip-path-components=N
Summary: This option allows the user to control how much of the file name is emitted by UBSan. Tuning this option allows one to save space in the resulting binary, which is helpful for restricted execution environments. With a positive N, UBSan skips the first N path components. With a negative N, UBSan only keeps the last N path components. Reviewers: rsmith Subscribers: cfe-commits Differential Revision: http://reviews.llvm.org/D19666 Added: cfe/trunk/test/CodeGen/ubsan-strip-path-components.cpp cfe/trunk/test/Driver/fubsan-strip-path-components.cpp Modified: cfe/trunk/docs/UndefinedBehaviorSanitizer.rst cfe/trunk/include/clang/Driver/Options.td cfe/trunk/include/clang/Frontend/CodeGenOptions.def cfe/trunk/lib/CodeGen/CGExpr.cpp cfe/trunk/lib/Driver/Tools.cpp cfe/trunk/lib/Frontend/CompilerInvocation.cpp Modified: cfe/trunk/docs/UndefinedBehaviorSanitizer.rst URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/docs/UndefinedBehaviorSanitizer.rst?rev=269309&r1=269308&r2=269309&view=diff ============================================================================== --- cfe/trunk/docs/UndefinedBehaviorSanitizer.rst (original) +++ cfe/trunk/docs/UndefinedBehaviorSanitizer.rst Thu May 12 11:51:36 2016 @@ -228,6 +228,26 @@ UndefinedBehaviorSanitizer is available 3.3. The test suite is integrated into the CMake build and can be run with ``check-ubsan`` command. +Additional Configuration +======================== + +UndefinedBehaviorSanitizer adds static check data for each check unless it is +in trap mode. This check data includes the full file name. The option +``-fsanitize-undefined-strip-path-components=N`` can be used to trim this +information. If ``N`` is positive, file information emitted by +UndefinedBehaviorSanitizer will drop the first ``N`` components from the file +path. If ``N`` is negative, the last ``N`` components will be kept. + +Example +------- + +For a file called ``/code/library/file.cpp``, here is what would be emitted: +* Default (No flag, or ``-fsanitize-undefined-strip-path-components=0``): ``/code/library/file.cpp`` +* ``-fsanitize-undefined-strip-path-components=1``: ``code/library/file.cpp`` +* ``-fsanitize-undefined-strip-path-components=2``: ``library/file.cpp`` +* ``-fsanitize-undefined-strip-path-components=-1``: ``file.cpp`` +* ``-fsanitize-undefined-strip-path-components=-2``: ``library/file.cpp`` + More Information ================ Modified: cfe/trunk/include/clang/Driver/Options.td URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/Options.td?rev=269309&r1=269308&r2=269309&view=diff ============================================================================== --- cfe/trunk/include/clang/Driver/Options.td (original) +++ cfe/trunk/include/clang/Driver/Options.td Thu May 12 11:51:36 2016 @@ -677,6 +677,10 @@ def fsanitize_stats : Flag<["-"], "fsani def fno_sanitize_stats : Flag<["-"], "fno-sanitize-stats">, Group<f_clang_Group>, Flags<[CC1Option]>, HelpText<"Disable sanitizer statistics gathering.">; +def fsanitize_undefined_strip_path_components_EQ : Joined<["-"], "fsanitize-undefined-strip-path-components=">, + Group<f_clang_Group>, Flags<[CC1Option]>, MetaVarName<"<number>">, + HelpText<"Strip (or keep only, if negative) a given number of path components " + "when emitting check metadata.">; def funsafe_math_optimizations : Flag<["-"], "funsafe-math-optimizations">, Group<f_Group>; def fno_unsafe_math_optimizations : Flag<["-"], "fno-unsafe-math-optimizations">, Modified: cfe/trunk/include/clang/Frontend/CodeGenOptions.def URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Frontend/CodeGenOptions.def?rev=269309&r1=269308&r2=269309&view=diff ============================================================================== --- cfe/trunk/include/clang/Frontend/CodeGenOptions.def (original) +++ cfe/trunk/include/clang/Frontend/CodeGenOptions.def Thu May 12 11:51:36 2016 @@ -225,6 +225,10 @@ ENUM_CODEGENOPT(VecLib, VectorLibrary, 1 /// The default TLS model to use. ENUM_CODEGENOPT(DefaultTLSModel, TLSModel, 2, GeneralDynamicTLSModel) +/// Number of path components to strip when emitting checks. (0 == full +/// filename) +VALUE_CODEGENOPT(EmitCheckPathComponentsToStrip, 32, 0) + #undef CODEGENOPT #undef ENUM_CODEGENOPT #undef VALUE_CODEGENOPT Modified: cfe/trunk/lib/CodeGen/CGExpr.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExpr.cpp?rev=269309&r1=269308&r2=269309&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/CGExpr.cpp (original) +++ cfe/trunk/lib/CodeGen/CGExpr.cpp Thu May 12 11:51:36 2016 @@ -32,6 +32,7 @@ #include "llvm/IR/MDBuilder.h" #include "llvm/Support/ConvertUTF.h" #include "llvm/Support/MathExtras.h" +#include "llvm/Support/Path.h" #include "llvm/Transforms/Utils/SanitizerStats.h" using namespace clang; @@ -2367,7 +2368,33 @@ llvm::Constant *CodeGenFunction::EmitChe PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc); if (PLoc.isValid()) { - auto FilenameGV = CGM.GetAddrOfConstantCString(PLoc.getFilename(), ".src"); + StringRef FilenameString = PLoc.getFilename(); + + int PathComponentsToStrip = + CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip; + if (PathComponentsToStrip < 0) { + assert(PathComponentsToStrip != INT_MIN); + int PathComponentsToKeep = -PathComponentsToStrip; + auto I = llvm::sys::path::rbegin(FilenameString); + auto E = llvm::sys::path::rend(FilenameString); + while (I != E && --PathComponentsToKeep) + ++I; + + FilenameString = FilenameString.substr(I - E); + } else if (PathComponentsToStrip > 0) { + auto I = llvm::sys::path::begin(FilenameString); + auto E = llvm::sys::path::end(FilenameString); + while (I != E && PathComponentsToStrip--) + ++I; + + if (I != E) + FilenameString = + FilenameString.substr(I - llvm::sys::path::begin(FilenameString)); + else + FilenameString = llvm::sys::path::filename(FilenameString); + } + + auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src"); CGM.getSanitizerMetadata()->disableSanitizerForGlobal( cast<llvm::GlobalVariable>(FilenameGV.getPointer())); Filename = FilenameGV.getPointer(); Modified: cfe/trunk/lib/Driver/Tools.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=269309&r1=269308&r2=269309&view=diff ============================================================================== --- cfe/trunk/lib/Driver/Tools.cpp (original) +++ cfe/trunk/lib/Driver/Tools.cpp Thu May 12 11:51:36 2016 @@ -5607,6 +5607,10 @@ void Clang::ConstructJob(Compilation &C, if (Arg *A = Args.getLastArg(options::OPT_fshow_overloads_EQ)) A->render(Args, CmdArgs); + if (Arg *A = Args.getLastArg( + options::OPT_fsanitize_undefined_strip_path_components_EQ)) + A->render(Args, CmdArgs); + // -fdollars-in-identifiers default varies depending on platform and // language; only pass if specified. if (Arg *A = Args.getLastArg(options::OPT_fdollars_in_identifiers, Modified: cfe/trunk/lib/Frontend/CompilerInvocation.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/CompilerInvocation.cpp?rev=269309&r1=269308&r2=269309&view=diff ============================================================================== --- cfe/trunk/lib/Frontend/CompilerInvocation.cpp (original) +++ cfe/trunk/lib/Frontend/CompilerInvocation.cpp Thu May 12 11:51:36 2016 @@ -823,6 +823,9 @@ static bool ParseCodeGenArgs(CodeGenOpti Opts.Backchain = Args.hasArg(OPT_mbackchain); + Opts.EmitCheckPathComponentsToStrip = getLastArgIntValue( + Args, OPT_fsanitize_undefined_strip_path_components_EQ, 0, Diags); + return Success; } Added: cfe/trunk/test/CodeGen/ubsan-strip-path-components.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/ubsan-strip-path-components.cpp?rev=269309&view=auto ============================================================================== --- cfe/trunk/test/CodeGen/ubsan-strip-path-components.cpp (added) +++ cfe/trunk/test/CodeGen/ubsan-strip-path-components.cpp Thu May 12 11:51:36 2016 @@ -0,0 +1,29 @@ +// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -emit-llvm -fsanitize=unreachable -o - | FileCheck %s -check-prefix=REGULAR -check-prefix=CHECK +// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -emit-llvm -fsanitize=unreachable -o - -fsanitize-undefined-strip-path-components=0 | FileCheck %s -check-prefix=REGULAR -check-prefix=CHECK +// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -emit-llvm -fsanitize=unreachable -o - -fsanitize-undefined-strip-path-components=2 | FileCheck %s -check-prefix=REMOVE-FIRST-TWO -check-prefix=CHECK + +// Try to strip too much: +// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -emit-llvm -fsanitize=unreachable -o - -fsanitize-undefined-strip-path-components=-99999 | FileCheck %s -check-prefix=REGULAR +// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -emit-llvm -fsanitize=unreachable -o - -fsanitize-undefined-strip-path-components=99999 | FileCheck %s -check-prefix=LAST-ONLY + +// Check stripping from the file name +// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -emit-llvm -fsanitize=unreachable -o - -fsanitize-undefined-strip-path-components=-2 | FileCheck %s -check-prefix=LAST-TWO +// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -emit-llvm -fsanitize=unreachable -o - -fsanitize-undefined-strip-path-components=-1 | FileCheck %s -check-prefix=LAST-ONLY + +// REGULAR: @[[SRC:[0-9.a-zA-Z_]+]] = private unnamed_addr constant [{{.*}} x i8] c"{{.*test(.|\\5C)CodeGen(.|\\5C)ubsan-strip-path-components\.cpp}}\00", align 1 + +// First path component: "/" or "$drive_letter:", then a name, or '\5C' on Windows +// REMOVE-FIRST-TWO: @[[STR:[0-9.a-zA-Z_]+]] = private unnamed_addr constant [{{.*}} x i8] c"{{(.:|/)([^\\/]*(/|\\5C))}}[[REST:.*ubsan-strip-path-components\.cpp]]\00", align 1 +// REMOVE-FIRST-TWO: @[[SRC:[0-9.a-zA-Z_]+]] = private unnamed_addr constant [{{.*}} x i8] c"[[REST]]\00", align 1 + +// LAST-TWO: @[[SRC:[0-9.a-zA-Z_]+]] = private unnamed_addr constant [{{.*}} x i8] c"CodeGen{{/|\\5C}}ubsan-strip-path-components.cpp\00", align 1 +// LAST-ONLY: @[[SRC:[0-9.a-zA-Z_]+]] = private unnamed_addr constant [{{.*}} x i8] c"ubsan-strip-path-components.cpp\00", align 1 + +// CHECK: @[[STATIC_DATA:[0-9.a-zA-Z_]+]] = private unnamed_addr global { { [{{.*}} x i8]*, i32, i32 } } { { [{{.*}} x i8]*, i32, i32 } { [{{.*}} x i8]* @[[SRC]], i32 [[@LINE+6]], i32 3 } } +void g(const char *); +void f() { + // CHECK-LABEL: @_Z1fv( + g(__FILE__); + // CHECK: call void @__ubsan_handle_builtin_unreachable(i8* bitcast ({ { [{{.*}} x i8]*, i32, i32 } }* @[[STATIC_DATA]] to i8*)) {{.*}}, !nosanitize + __builtin_unreachable(); +} Added: cfe/trunk/test/Driver/fubsan-strip-path-components.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/fubsan-strip-path-components.cpp?rev=269309&view=auto ============================================================================== --- cfe/trunk/test/Driver/fubsan-strip-path-components.cpp (added) +++ cfe/trunk/test/Driver/fubsan-strip-path-components.cpp Thu May 12 11:51:36 2016 @@ -0,0 +1,2 @@ +// RUN: %clang %s -### -o %t.o -fsanitize-undefined-strip-path-components=42 2>&1 | FileCheck %s +// CHECK: "-fsanitize-undefined-strip-path-components=42" _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
