From 20a4fe392e8dfaaba1dd1a2be7ddd5dbc76190e3 Mon Sep 17 00:00:00 2001
From: Evgeniy Stepanov <eugeni.stepanov@gmail.com>
Date: Wed, 21 Oct 2015 21:28:49 +0000
Subject: [PATCH] MemorySanitizer does not require PIE.

Since r249754 MemorySanitizer should work equally well for PIE and
non-PIE executables on Linux/x86_64.

Beware, with this change -fsanitize=memory no longer adds implicit
-fPIE -pie compiler/linker flags on Linux/x86_64.

This is a re-land of r250941, limited to Linux/x86_64 + a very minor
refactoring in SanitizerArgs.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@250949 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/clang/Driver/SanitizerArgs.h |  2 +-
 lib/Driver/SanitizerArgs.cpp         | 14 ++++++++------
 test/Driver/fsanitize.c              | 24 ++++++++++++++----------
 3 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/include/clang/Driver/SanitizerArgs.h b/include/clang/Driver/SanitizerArgs.h
index 743e09dea4..d088cc0855 100644
--- a/include/clang/Driver/SanitizerArgs.h
+++ b/include/clang/Driver/SanitizerArgs.h
@@ -32,9 +32,9 @@ class SanitizerArgs {
   int MsanTrackOrigins;
   bool MsanUseAfterDtor;
   int AsanFieldPadding;
-  bool AsanZeroBaseShadow;
   bool AsanSharedRuntime;
   bool LinkCXXRuntimes;
+  bool NeedPIE;
 
  public:
   /// Parses the sanitizer arguments from an argument list.
diff --git a/lib/Driver/SanitizerArgs.cpp b/lib/Driver/SanitizerArgs.cpp
index 8c417ef432..3f1b99cac5 100644
--- a/lib/Driver/SanitizerArgs.cpp
+++ b/lib/Driver/SanitizerArgs.cpp
@@ -29,7 +29,7 @@ enum : SanitizerMask {
   NeedsUbsanRt = Undefined | Integer | CFI,
   NeedsUbsanCxxRt = Vptr | CFI,
   NotAllowedWithTrap = Vptr,
-  RequiresPIE = Memory | DataFlow,
+  RequiresPIE = DataFlow,
   NeedsUnwindTables = Address | Thread | Memory | DataFlow,
   SupportsCoverage = Address | Memory | Leak | Undefined | Integer | DataFlow,
   RecoverableByDefault = Undefined | Integer,
@@ -164,7 +164,7 @@ bool SanitizerArgs::needsUbsanRt() const {
 }
 
 bool SanitizerArgs::requiresPIE() const {
-  return AsanZeroBaseShadow || (Sanitizers.Mask & RequiresPIE);
+  return NeedPIE || (Sanitizers.Mask & RequiresPIE);
 }
 
 bool SanitizerArgs::needsUnwindTables() const {
@@ -180,8 +180,8 @@ void SanitizerArgs::clear() {
   CoverageFeatures = 0;
   MsanTrackOrigins = 0;
   MsanUseAfterDtor = false;
+  NeedPIE = false;
   AsanFieldPadding = 0;
-  AsanZeroBaseShadow = false;
   AsanSharedRuntime = false;
   LinkCXXRuntimes = false;
 }
@@ -424,8 +424,10 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
         }
       }
     }
-    MsanUseAfterDtor = 
-      Args.hasArg(options::OPT_fsanitize_memory_use_after_dtor);
+    MsanUseAfterDtor =
+        Args.hasArg(options::OPT_fsanitize_memory_use_after_dtor);
+    NeedPIE |= !(TC.getTriple().isOSLinux() &&
+                 TC.getTriple().getArch() == llvm::Triple::x86_64);
   }
 
   // Parse -f(no-)?sanitize-coverage flags if coverage is supported by the
@@ -496,7 +498,7 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
   if (AllAddedKinds & Address) {
     AsanSharedRuntime =
         Args.hasArg(options::OPT_shared_libasan) || TC.getTriple().isAndroid();
-    AsanZeroBaseShadow = TC.getTriple().isAndroid();
+    NeedPIE |= TC.getTriple().isAndroid();
     if (Arg *A =
             Args.getLastArg(options::OPT_fsanitize_address_field_padding)) {
         StringRef S = A->getValue();
diff --git a/test/Driver/fsanitize.c b/test/Driver/fsanitize.c
index b9e525239d..499485d4b2 100644
--- a/test/Driver/fsanitize.c
+++ b/test/Driver/fsanitize.c
@@ -142,16 +142,20 @@
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=vptr -fno-sanitize=vptr -fsanitize=undefined,address %s -### 2>&1
 // OK
 
-// RUN: %clang -target x86_64-linux-gnu -fsanitize=thread %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-TSAN-NO-PIE
-// CHECK-TSAN-NO-PIE: "-mrelocation-model" "static"
-
-// RUN: %clang -target x86_64-linux-gnu -fsanitize=memory %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-MSAN-NO-PIE
-// CHECK-MSAN-NO-PIE: "-mrelocation-model" "pic" "-pic-level" "2" "-pie-level" "2"
-// CHECK-MSAN-NO-PIE: "-pie"
-
-// RUN: %clang -target arm-linux-androideabi -fsanitize=address %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ANDROID-ASAN-NO-PIE
-// CHECK-ANDROID-ASAN-NO-PIE: "-mrelocation-model" "pic" "-pic-level" "2" "-pie-level" "2"
-// CHECK-ANDROID-ASAN-NO-PIE: "-pie"
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=thread %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-PIE
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=memory %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-PIE
+// RUN: %clang -target x86_64-unknown-freebsd -fsanitize=memory %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-PIE
+// RUN: %clang -target aarch64-linux-gnu -fsanitize=memory %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-PIE
+// RUN: %clang -target arm-linux-androideabi -fsanitize=address %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-PIE
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=address %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-PIE
+// RUN: %clang -target i386-linux-gnu -fsanitize=address %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-PIE
+
+// CHECK-NO-PIE-NOT: "-pie"
+// CHECK-NO-PIE: "-mrelocation-model" "static"
+// CHECK-NO-PIE-NOT: "-pie"
+
+// CHECK-PIE: "-mrelocation-model" "pic" "-pic-level" "2" "-pie-level" "2"
+// CHECK-PIE: "-pie"
 
 // RUN: %clang -target arm-linux-androideabi %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ANDROID-NO-ASAN
 // CHECK-ANDROID-NO-ASAN: "-mrelocation-model" "pic"
-- 
2.40.0