r269309 - [ubsan] Add -fsanitize-undefined-strip-path-components=N
Filipe Cabecinhas via cfe-commits
cfe-commits at lists.llvm.org
Thu May 12 09:51:37 PDT 2016
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"
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