commit 2715b2871653e8b34183d0600fd31cd9d451a0c3
author Dan Albert <danalbert@google.com> Thu Mar 28 18:08:28 2019 +0000
committer Dan Albert <danalbert@google.com> Thu Mar 28 18:08:28 2019 +0000
tree c9f76f25a5899d021f17623ea406c0ea11cfe232
parent c25c9b4d162695c3537fdd0996c92290bcd30a9e

[Driver] Default Android toolchains to noexecstack.

Android does not support executable stacks.

Reviewers: srhines, pirama

Reviewed By: pirama

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D53343

llvm-svn: 357197

clang/lib/Driver/ToolChain.cpp

diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index 5dff2b2..b53a730 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -112,6 +112,10 @@
   return ENABLE_X86_RELAX_RELOCATIONS;
 }
 
+bool ToolChain::isNoExecStackDefault() const {
+    return false;
+}
+
 const SanitizerArgs& ToolChain::getSanitizerArgs() const {
   if (!SanitizerArguments.get())
     SanitizerArguments.reset(new SanitizerArgs(*this, Args));

clang/lib/Driver/ToolChains/Clang.cpp

diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 78f186c..1f1d800 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -2053,6 +2053,7 @@
   bool TakeNextArg = false;
 
   bool UseRelaxRelocations = C.getDefaultToolChain().useRelaxRelocations();
+  bool UseNoExecStack = C.getDefaultToolChain().isNoExecStackDefault();
   const char *MipsTargetFeature = nullptr;
   for (const Arg *A :
        Args.filtered(options::OPT_Wa_COMMA, options::OPT_Xassembler)) {
@@ -2134,7 +2135,7 @@
       } else if (Value == "--fatal-warnings") {
         CmdArgs.push_back("-massembler-fatal-warnings");
       } else if (Value == "--noexecstack") {
-        CmdArgs.push_back("-mnoexecstack");
+        UseNoExecStack = true;
       } else if (Value.startswith("-compress-debug-sections") ||
                  Value.startswith("--compress-debug-sections") ||
                  Value == "-nocompress-debug-sections" ||
@@ -2197,6 +2198,8 @@
   }
   if (UseRelaxRelocations)
     CmdArgs.push_back("--mrelax-relocations");
+  if (UseNoExecStack)
+    CmdArgs.push_back("-mnoexecstack");
   if (MipsTargetFeature != nullptr) {
     CmdArgs.push_back("-target-feature");
     CmdArgs.push_back(MipsTargetFeature);

clang/lib/Driver/ToolChains/Gnu.cpp

diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp
index 178e7f7..7b2dd67 100644
--- a/clang/lib/Driver/ToolChains/Gnu.cpp
+++ b/clang/lib/Driver/ToolChains/Gnu.cpp
@@ -360,6 +360,11 @@
     CmdArgs.push_back("--no-dynamic-linker");
   }
 
+  if (ToolChain.isNoExecStackDefault()) {
+    CmdArgs.push_back("-z");
+    CmdArgs.push_back("noexecstack");
+  }
+
   if (Args.hasArg(options::OPT_rdynamic))
     CmdArgs.push_back("-export-dynamic");
 
@@ -609,6 +614,10 @@
     }
   }
 
+  if (getToolChain().isNoExecStackDefault()) {
+      CmdArgs.push_back("--noexecstack");
+  }
+
   switch (getToolChain().getArch()) {
   default:
     break;

clang/lib/Driver/ToolChains/Linux.cpp

diff --git a/clang/lib/Driver/ToolChains/Linux.cpp b/clang/lib/Driver/ToolChains/Linux.cpp
index 3c60964..697b186 100644
--- a/clang/lib/Driver/ToolChains/Linux.cpp
+++ b/clang/lib/Driver/ToolChains/Linux.cpp
@@ -971,6 +971,10 @@
           getTriple().isMusl() || getSanitizerArgs().requiresPIE();
 }
 
+bool Linux::isNoExecStackDefault() const {
+    return getTriple().isAndroid();
+}
+
 bool Linux::IsMathErrnoDefault() const {
   if (getTriple().isAndroid())
     return false;

clang/lib/Driver/ToolChains/Linux.h

diff --git a/clang/lib/Driver/ToolChains/Linux.h b/clang/lib/Driver/ToolChains/Linux.h
index f70dc5d..4c61994 100644
--- a/clang/lib/Driver/ToolChains/Linux.h
+++ b/clang/lib/Driver/ToolChains/Linux.h
@@ -38,6 +38,7 @@
                            llvm::opt::ArgStringList &CC1Args) const override;
   CXXStdlibType GetDefaultCXXStdlibType() const override;
   bool isPIEDefault() const override;
+  bool isNoExecStackDefault() const override;
   bool IsMathErrnoDefault() const override;
   SanitizerMask getSupportedSanitizers() const override;
   void addProfileRTLibs(const llvm::opt::ArgList &Args,