Revert "Driver: switch Windows to static RelocModel"

This reverts commit r290569. It caused unforeseen codegen changes for
switch jump tables described in PR31488.

llvm-svn: 290672

3 files changed, 27 insertions, 6 deletions

diff --git a/clang/lib/Driver/MSVCToolChain.cpp b/clang/lib/Driver/MSVCToolChain.cpp
index 0bbe79c3aa7..95cf056f7a7 100644
--- a/clang/lib/Driver/MSVCToolChain.cpp
+++ b/clang/lib/Driver/MSVCToolChain.cpp
@@ -82,6 +82,18 @@ bool MSVCToolChain::IsUnwindTablesDefault() const {
   return getArch() == llvm::Triple::x86_64;
 }
 
+bool MSVCToolChain::isPICDefault() const {
+  return getArch() == llvm::Triple::x86_64;
+}
+
+bool MSVCToolChain::isPIEDefault() const {
+  return false;
+}
+
+bool MSVCToolChain::isPICDefaultForced() const {
+  return getArch() == llvm::Triple::x86_64;
+}
+
 #ifdef USE_WIN32
 static bool readFullStringValue(HKEY hkey, const char *valueName,
                                 std::string &value) {
diff --git a/clang/lib/Driver/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index d831ba8adc3..968b0cb4724 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -2880,13 +2880,22 @@ bool Generic_GCC::IsUnwindTablesDefault() const {
 
 bool Generic_GCC::isPICDefault() const {
   switch (getArch()) {
-  default: return false;
+  case llvm::Triple::x86_64:
+    return getTriple().isOSWindows();
   case llvm::Triple::ppc64:
   case llvm::Triple::ppc64le:
     return !getTriple().isOSBinFormatMachO() && !getTriple().isMacOSX();
+  default:
+    return false;
   }
 }
 
+bool Generic_GCC::isPIEDefault() const { return false; }
+
+bool Generic_GCC::isPICDefaultForced() const {
+  return getArch() == llvm::Triple::x86_64 && getTriple().isOSWindows();
+}
+
 bool Generic_GCC::IsIntegratedAssemblerDefault() const {
   switch (getTriple().getArch()) {
   case llvm::Triple::x86:
diff --git a/clang/lib/Driver/ToolChains.h b/clang/lib/Driver/ToolChains.h
index c8b7931cac8..7dab08915d4 100644
--- a/clang/lib/Driver/ToolChains.h
+++ b/clang/lib/Driver/ToolChains.h
@@ -232,8 +232,8 @@ public:
 
   bool IsUnwindTablesDefault() const override;
   bool isPICDefault() const override;
-  bool isPIEDefault() const override { return false; }
-  bool isPICDefaultForced() const override { return false; }
+  bool isPIEDefault() const override;
+  bool isPICDefaultForced() const override;
   bool IsIntegratedAssemblerDefault() const override;
   llvm::opt::DerivedArgList *
   TranslateArgs(const llvm::opt::DerivedArgList &Args, StringRef BoundArch,
@@ -1136,9 +1136,9 @@ public:
 
   bool IsIntegratedAssemblerDefault() const override;
   bool IsUnwindTablesDefault() const override;
-  bool isPICDefault() const override { return false; }
-  bool isPIEDefault() const override { return false; }
-  bool isPICDefaultForced() const override { return false; }
+  bool isPICDefault() const override;
+  bool isPIEDefault() const override;
+  bool isPICDefaultForced() const override;
 
   void
   AddClangSystemIncludeArgs(const llvm::opt::ArgList &DriverArgs,