From cb034d1d6e6c6787c61e37d6f7c4f426c7c11d75 Mon Sep 17 00:00:00 2001
From: Ed Schouten <ed@nuxi.nl>
Date: Tue, 29 Mar 2016 21:13:53 +0000
Subject: [PATCH] Enable the SafeStack sanitizer on CloudABI by default.

Over the last month we've been testing SafeStack extensively. As far as
we know, it works perfectly fine. That why I'd like to see us having
this enabled by default for CloudABI.

This change introduces a getDefaultSanitizers() function that toolchains
can use to specify which sanitizers are enabled by default. Once all
flags are processed, only flags that had no -fno-sanitize overrides are
enabled.

Extend the thests for CloudABI to test both the default case and the
case in which we want to explicitly disable SafeStack.

Reviewed by:	eugenis, pcc
Differential Revision:	http://reviews.llvm.org/D18505


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@264787 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/clang/Driver/ToolChain.h |  3 +++
 lib/Driver/SanitizerArgs.cpp     |  3 +++
 lib/Driver/ToolChains.cpp        |  4 ++++
 lib/Driver/ToolChains.h          |  1 +
 test/Driver/cloudabi.c           | 11 ++++++++---
 test/Driver/cloudabi.cpp         | 11 ++++++++---
 6 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/include/clang/Driver/ToolChain.h b/include/clang/Driver/ToolChain.h
index e093f63316..d671d75069 100644
--- a/include/clang/Driver/ToolChain.h
+++ b/include/clang/Driver/ToolChain.h
@@ -419,6 +419,9 @@ public:
 
   /// \brief Return sanitizers which are available in this toolchain.
   virtual SanitizerMask getSupportedSanitizers() const;
+
+  /// \brief Return sanitizers which are enabled by default.
+  virtual SanitizerMask getDefaultSanitizers() const { return 0; }
 };
 
 } // end namespace driver
diff --git a/lib/Driver/SanitizerArgs.cpp b/lib/Driver/SanitizerArgs.cpp
index e4e6c02767..17037108ab 100644
--- a/lib/Driver/SanitizerArgs.cpp
+++ b/lib/Driver/SanitizerArgs.cpp
@@ -268,6 +268,9 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
     }
   }
 
+  // Enable toolchain specific default sanitizers if not explicitly disabled.
+  Kinds |= TC.getDefaultSanitizers() & ~AllRemove;
+
   // We disable the vptr sanitizer if it was enabled by group expansion but RTTI
   // is disabled.
   if ((Kinds & Vptr) &&
diff --git a/lib/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index fd69ca87c2..11ded7cd5e 100644
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -2988,6 +2988,10 @@ SanitizerMask CloudABI::getSupportedSanitizers() const {
   return Res;
 }
 
+SanitizerMask CloudABI::getDefaultSanitizers() const {
+  return SanitizerKind::SafeStack;
+}
+
 /// OpenBSD - OpenBSD tool chain which can call as(1) and ld(1) directly.
 
 OpenBSD::OpenBSD(const Driver &D, const llvm::Triple &Triple,
diff --git a/lib/Driver/ToolChains.h b/lib/Driver/ToolChains.h
index 49283a9c20..d0418349bf 100644
--- a/lib/Driver/ToolChains.h
+++ b/lib/Driver/ToolChains.h
@@ -620,6 +620,7 @@ public:
   bool isPIEDefault() const override { return false; }
 
   SanitizerMask getSupportedSanitizers() const override;
+  SanitizerMask getDefaultSanitizers() const override;
 
 protected:
   Tool *buildLinker() const override;
diff --git a/test/Driver/cloudabi.c b/test/Driver/cloudabi.c
index 99a2bc24f6..2f1f9852b0 100644
--- a/test/Driver/cloudabi.c
+++ b/test/Driver/cloudabi.c
@@ -1,3 +1,8 @@
-// RUN: %clang %s -### -target x86_64-unknown-cloudabi 2>&1 | FileCheck %s
-// CHECK: "-cc1" "-triple" "x86_64-unknown-cloudabi" {{.*}} "-ffunction-sections" "-fdata-sections"
-// CHECK: "-Bstatic" "--eh-frame-hdr" "--gc-sections" "-o" "a.out" "crt0.o" "crtbegin.o" "{{.*}}" "{{.*}}" "-lc" "-lcompiler_rt" "crtend.o"
+// RUN: %clang %s -### -target x86_64-unknown-cloudabi 2>&1 | FileCheck %s -check-prefix=SAFESTACK
+// SAFESTACK: "-cc1" "-triple" "x86_64-unknown-cloudabi" {{.*}} "-ffunction-sections" "-fdata-sections" {{.*}} "-fsanitize=safe-stack"
+// SAFESTACK: "-Bstatic" "--eh-frame-hdr" "--gc-sections" "-o" "a.out" "crt0.o" "crtbegin.o" "{{.*}}" "{{.*}}" "-lc" "-lcompiler_rt" "crtend.o"
+
+// RUN: %clang %s -### -target x86_64-unknown-cloudabi -fno-sanitize=safe-stack 2>&1 | FileCheck %s -check-prefix=NOSAFESTACK
+// NOSAFESTACK: "-cc1" "-triple" "x86_64-unknown-cloudabi" {{.*}} "-ffunction-sections" "-fdata-sections"
+// NOSAFESTACK-NOT: "-fsanitize=safe-stack"
+// NOSAFESTACK: "-Bstatic" "--eh-frame-hdr" "--gc-sections" "-o" "a.out" "crt0.o" "crtbegin.o" "{{.*}}" "{{.*}}" "-lc" "-lcompiler_rt" "crtend.o"
diff --git a/test/Driver/cloudabi.cpp b/test/Driver/cloudabi.cpp
index c3b68ae880..9c1b6d091c 100644
--- a/test/Driver/cloudabi.cpp
+++ b/test/Driver/cloudabi.cpp
@@ -1,3 +1,8 @@
-// RUN: %clangxx %s -### -target x86_64-unknown-cloudabi 2>&1 | FileCheck %s
-// CHECK: "-cc1" "-triple" "x86_64-unknown-cloudabi" {{.*}} "-ffunction-sections" "-fdata-sections"
-// CHECK: "-Bstatic" "--eh-frame-hdr" "--gc-sections" "-o" "a.out" "crt0.o" "crtbegin.o" "{{.*}}" "{{.*}}" "-lc++" "-lc++abi" "-lunwind" "-lc" "-lcompiler_rt" "crtend.o"
+// RUN: %clangxx %s -### -target x86_64-unknown-cloudabi 2>&1 | FileCheck %s -check-prefix=SAFESTACK
+// SAFESTACK: "-cc1" "-triple" "x86_64-unknown-cloudabi" {{.*}} "-ffunction-sections" "-fdata-sections" {{.*}} "-fsanitize=safe-stack"
+// SAFESTACK: "-Bstatic" "--eh-frame-hdr" "--gc-sections" "-o" "a.out" "crt0.o" "crtbegin.o" "{{.*}}" "{{.*}}" "-lc++" "-lc++abi" "-lunwind" "-lc" "-lcompiler_rt" "crtend.o"
+
+// RUN: %clangxx %s -### -target x86_64-unknown-cloudabi -fno-sanitize=safe-stack 2>&1 | FileCheck %s -check-prefix=NOSAFESTACk
+// NOSAFESTACK: "-cc1" "-triple" "x86_64-unknown-cloudabi" {{.*}} "-ffunction-sections" "-fdata-sections"
+// NOSAFESTACK-NOT: "-fsanitize=safe-stack"
+// NOSAFESTACk: "-Bstatic" "--eh-frame-hdr" "--gc-sections" "-o" "a.out" "crt0.o" "crtbegin.o" "{{.*}}" "{{.*}}" "-lc++" "-lc++abi" "-lunwind" "-lc" "-lcompiler_rt" "crtend.o"
-- 
2.40.0