From 71ec224e27b61d4f1998f7cd3aaf0981c6f09f9e Mon Sep 17 00:00:00 2001
From: Saleem Abdulrasool <compnerd@compnerd.org>
Date: Mon, 26 Dec 2016 03:35:24 +0000
Subject: [PATCH] Driver: warn on -fPIC/-fpic/-fPIE/-fpie on Windows

Use of these flags would result in the use of ELF-style PIE/PIC code
which is incorrect on Windows.  Windows is inherently PIC by means of
the DLL slide that occurs at load.  This also mirrors the behaviour on
GCC for MinGW.  Currently, the Windows x86_64 forces the relocation
model to PIC (Level 2).  This is unchanged for now, though we should
remove any assumptions on that and change it to a static relocation
model.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@290533 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Driver/Tools.cpp        | 11 +++++++
 test/Driver/windows-pic.cpp | 59 +++++++++++++++++++++++++++++++++++++
 2 files changed, 70 insertions(+)
 create mode 100644 test/Driver/windows-pic.cpp

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 5bab0ef4a8..8ed12d72b4 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -3859,6 +3859,17 @@ ParsePICArgs(const ToolChain &ToolChain, const ArgList &Args) {
                                     options::OPT_fpic, options::OPT_fno_pic,
                                     options::OPT_fPIE, options::OPT_fno_PIE,
                                     options::OPT_fpie, options::OPT_fno_pie);
+  if (Triple.isOSWindows() && LastPICArg &&
+      LastPICArg ==
+          Args.getLastArg(options::OPT_fPIC, options::OPT_fpic,
+                          options::OPT_fPIE, options::OPT_fpie)) {
+    ToolChain.getDriver().Diag(diag::err_drv_unsupported_opt_for_target)
+        << LastPICArg->getSpelling() << Triple.str();
+    if (Triple.getArch() == llvm::Triple::x86_64)
+      return std::make_tuple(llvm::Reloc::PIC_, 2U, false);
+    return std::make_tuple(llvm::Reloc::Static, 0U, false);
+  }
+
   // Check whether the tool chain trumps the PIC-ness decision. If the PIC-ness
   // is forced, then neither PIC nor PIE flags will have no effect.
   if (!ToolChain.isPICDefaultForced()) {
diff --git a/test/Driver/windows-pic.cpp b/test/Driver/windows-pic.cpp
new file mode 100644
index 0000000000..3b77a7cc5a
--- /dev/null
+++ b/test/Driver/windows-pic.cpp
@@ -0,0 +1,59 @@
+// RUN: %clang -### -target i686-windows -fPIC %s 2>&1 | FileCheck -check-prefix CHECK-PIC-ERROR %s
+// RUN: %clang -### -target i686-windows -fpic %s 2>&1 | FileCheck -check-prefix CHECK-pic-ERROR %s
+// RUN: %clang -### -target i686-windows -fPIE %s 2>&1 | FileCheck -check-prefix CHECK-PIE-ERROR %s
+// RUN: %clang -### -target i686-windows -fpie %s 2>&1 | FileCheck -check-prefix CHECK-pie-ERROR %s
+// RUN: %clang -### -target i686-windows -fPIC -fno-pic %s
+// RUN: %clang -### -target i686-windows -Fpic -fno-pic %s
+// RUN: %clang -### -target i686-windows -fPIE -fno-pie %s
+// RUN: %clang -### -target i686-windows -fpie -fno-pie %s
+
+// RUN: %clang -### -target i686-windows-itanium -fPIC %s 2>&1 | FileCheck -check-prefix CHECK-PIC-ERROR %s
+// RUN: %clang -### -target i686-windows-itanium -fpic %s 2>&1 | FileCheck -check-prefix CHECK-pic-ERROR %s
+// RUN: %clang -### -target i686-windows-itanium -fPIE %s 2>&1 | FileCheck -check-prefix CHECK-PIE-ERROR %s
+// RUN: %clang -### -target i686-windows-itanium -fpie %s 2>&1 | FileCheck -check-prefix CHECK-pie-ERROR %s
+// RUN: %clang -### -target i686-windows-itanium -fPIC -fno-pic %s
+// RUN: %clang -### -target i686-windows-itanium -Fpic -fno-pic %s
+// RUN: %clang -### -target i686-windows-itanium -fPIE -fno-pie %s
+// RUN: %clang -### -target i686-windows-itanium -fpie -fno-pie %s
+
+// RUN: %clang -### -target i686-windows-gnu -fPIC %s 2>&1 | FileCheck -check-prefix CHECK-PIC-ERROR %s
+// RUN: %clang -### -target i686-windows-gnu -fpic %s 2>&1 | FileCheck -check-prefix CHECK-pic-ERROR %s
+// RUN: %clang -### -target i686-windows-gnu -fPIE %s 2>&1 | FileCheck -check-prefix CHECK-PIE-ERROR %s
+// RUN: %clang -### -target i686-windows-gnu -fpie %s 2>&1 | FileCheck -check-prefix CHECK-pie-ERROR %s
+// RUN: %clang -### -target i686-windows-gnu -fPIC -fno-pic %s
+// RUN: %clang -### -target i686-windows-gnu -Fpic -fno-pic %s
+// RUN: %clang -### -target i686-windows-gnu -fPIE -fno-pie %s
+// RUN: %clang -### -target i686-windows-gnu -fpie -fno-pie %s
+
+// RUN: %clang -### -target x86_64-windows -fPIC %s 2>&1 | FileCheck -check-prefix CHECK-PIC-ERROR %s
+// RUN: %clang -### -target x86_64-windows -fpic %s 2>&1 | FileCheck -check-prefix CHECK-pic-ERROR %s
+// RUN: %clang -### -target x86_64-windows -fPIE %s 2>&1 | FileCheck -check-prefix CHECK-PIE-ERROR %s
+// RUN: %clang -### -target x86_64-windows -fpie %s 2>&1 | FileCheck -check-prefix CHECK-pie-ERROR %s
+// RUN: %clang -### -target x86_64-windows -fPIC -fno-pic %s
+// RUN: %clang -### -target x86_64-windows -Fpic -fno-pic %s
+// RUN: %clang -### -target x86_64-windows -fPIE -fno-pie %s
+// RUN: %clang -### -target x86_64-windows -fpie -fno-pie %s
+
+// RUN: %clang -### -target x86_64-windows-itanium -fPIC %s 2>&1 | FileCheck -check-prefix CHECK-PIC-ERROR %s
+// RUN: %clang -### -target x86_64-windows-itanium -fpic %s 2>&1 | FileCheck -check-prefix CHECK-pic-ERROR %s
+// RUN: %clang -### -target x86_64-windows-itanium -fPIE %s 2>&1 | FileCheck -check-prefix CHECK-PIE-ERROR %s
+// RUN: %clang -### -target x86_64-windows-itanium -fpie %s 2>&1 | FileCheck -check-prefix CHECK-pie-ERROR %s
+// RUN: %clang -### -target x86_64-windows-itanium -fPIC -fno-pic %s
+// RUN: %clang -### -target x86_64-windows-itanium -Fpic -fno-pic %s
+// RUN: %clang -### -target x86_64-windows-itanium -fPIE -fno-pie %s
+// RUN: %clang -### -target x86_64-windows-itanium -fpie -fno-pie %s
+
+// RUN: %clang -### -target x86_64-windows-gnu -fPIC %s 2>&1 | FileCheck -check-prefix CHECK-PIC-ERROR %s
+// RUN: %clang -### -target x86_64-windows-gnu -fpic %s 2>&1 | FileCheck -check-prefix CHECK-pic-ERROR %s
+// RUN: %clang -### -target x86_64-windows-gnu -fPIE %s 2>&1 | FileCheck -check-prefix CHECK-PIE-ERROR %s
+// RUN: %clang -### -target x86_64-windows-gnu -fpie %s 2>&1 | FileCheck -check-prefix CHECK-pie-ERROR %s
+// RUN: %clang -### -target x86_64-windows-gnu -fPIC -fno-pic %s
+// RUN: %clang -### -target x86_64-windows-gnu -Fpic -fno-pic %s
+// RUN: %clang -### -target x86_64-windows-gnu -fPIE -fno-pie %s
+// RUN: %clang -### -target x86_64-windows-gnu -fpie -fno-pie %s
+
+// CHECK-PIC-ERROR: unsupported option '-fPIC' for target '{{.*}}
+// CHECK-pic-ERROR: unsupported option '-fpic' for target '{{.*}}
+// CHECK-PIE-ERROR: unsupported option '-fPIE' for target '{{.*}}
+// CHECK-pie-ERROR: unsupported option '-fpie' for target '{{.*}}
+
-- 
2.40.0