CodeGen: create a WindowsARMTargetCodeGenInfo

Create a new TargetCodeGenInfo for Windows on ARM to permit annotating the
functions with stack-probe-size (for /Gs and -mstack-probe-support) for
generating the stack probe necessary for Windows targets.  This will be used by
the backend when lowering the frame to generate the stack probe appropriately.

llvm-svn: 227641

1 files changed, 34 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index ebac376d7c2..d0678214190 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -4462,9 +4462,37 @@ public:
                                               llvm::AttributeSet::FunctionIndex,
                                               B));
   }
+};
+
+class WindowsARMTargetCodeGenInfo : public ARMTargetCodeGenInfo {
+  void addStackProbeSizeTargetAttribute(const Decl *D, llvm::GlobalValue *GV,
+                                        CodeGen::CodeGenModule &CGM) const;
+
+public:
+  WindowsARMTargetCodeGenInfo(CodeGenTypes &CGT, ARMABIInfo::ABIKind K)
+      : ARMTargetCodeGenInfo(CGT, K) {}
 
+  void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
+                           CodeGen::CodeGenModule &CGM) const override;
 };
 
+void WindowsARMTargetCodeGenInfo::addStackProbeSizeTargetAttribute(
+    const Decl *D, llvm::GlobalValue *GV, CodeGen::CodeGenModule &CGM) const {
+  if (!isa<FunctionDecl>(D))
+    return;
+  if (CGM.getCodeGenOpts().StackProbeSize == 4096)
+    return;
+
+  llvm::Function *F = cast<llvm::Function>(GV);
+  F->addFnAttr("stack-probe-size",
+               llvm::utostr(CGM.getCodeGenOpts().StackProbeSize));
+}
+
+void WindowsARMTargetCodeGenInfo::SetTargetAttributes(
+    const Decl *D, llvm::GlobalValue *GV, CodeGen::CodeGenModule &CGM) const {
+  ARMTargetCodeGenInfo::SetTargetAttributes(D, GV, CGM);
+  addStackProbeSizeTargetAttribute(D, GV, CGM);
+}
 }
 
 void ARMABIInfo::computeInfo(CGFunctionInfo &FI) const {
@@ -7075,6 +7103,12 @@ const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() {
   case llvm::Triple::thumb:
   case llvm::Triple::thumbeb:
     {
+      if (Triple.getOS() == llvm::Triple::Win32) {
+        TheTargetCodeGenInfo =
+            new WindowsARMTargetCodeGenInfo(Types, ARMABIInfo::AAPCS_VFP);
+        return *TheTargetCodeGenInfo;
+      }
+
       ARMABIInfo::ABIKind Kind = ARMABIInfo::AAPCS;
       if (getTarget().getABI() == "apcs-gnu")
         Kind = ARMABIInfo::APCS;