Targets: Allow CreateTargetInfo to mutate the target features.

 - In particular, it can claim features for itself instead of always passing them on to LLVM.
 - This allows using the target features as a generic mechanism for passing target specific options to the TargetInfo instance, which may need them for initializing preprocessor defines, etc.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@91753 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/TargetInfo.h b/include/clang/Basic/TargetInfo.h
index 1dd01c7338bf0c653b99aadf85443045680cf81f..0d95e6a603235471d307d655aa6004f8285aa223 100644 (file)
--- a/include/clang/Basic/TargetInfo.h
+++ b/include/clang/Basic/TargetInfo.h
@@ -61,8 +61,11 @@ protected:
 
 public:
   /// CreateTargetInfo - Construct a target for the given options.
-  static TargetInfo* CreateTargetInfo(Diagnostic &Diags,
-                                      const TargetOptions &Opts);
+  ///
+  /// \param Opts - The options to use to initialize the target. The target may
+  /// modify the options to canonicalize the target feature information to match
+  /// what the backend expects.
+  static TargetInfo* CreateTargetInfo(Diagnostic &Diags, TargetOptions &Opts);
 
   virtual ~TargetInfo();
 
@@ -389,7 +392,10 @@ public:
   /// HandleTargetOptions - Perform initialization based on the user configured
   /// set of features (e.g., +sse4). The list is guaranteed to have at most one
   /// entry per feature.
-  virtual void HandleTargetFeatures(const std::vector<std::string> &Features) {
+  ///
+  /// The target may modify the features list, to change which options are
+  /// passed onwards to the backend.
+  virtual void HandleTargetFeatures(std::vector<std::string> &Features) {
   }
 
   // getRegParmMax - Returns maximal number of args passed in registers.

diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index 059d4d3023a9bfcc78e6e29f3162825e0533316e..7cc9f73b6cd0765cb6c41260cfcf12822e463ee4 100644 (file)
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -688,7 +688,7 @@ public:
                                  bool Enabled) const;
   virtual void getDefaultFeatures(const std::string &CPU,
                                   llvm::StringMap<bool> &Features) const;
-  virtual void HandleTargetFeatures(const std::vector<std::string> &Features);
+  virtual void HandleTargetFeatures(std::vector<std::string> &Features);
 };
 
 void X86TargetInfo::getDefaultFeatures(const std::string &CPU,
@@ -805,8 +805,7 @@ bool X86TargetInfo::setFeatureEnabled(llvm::StringMap<bool> &Features,
 
 /// HandleTargetOptions - Perform initialization based on the user
 /// configured set of features.
-void
-X86TargetInfo::HandleTargetFeatures(const std::vector<std::string> &Features) {
+void X86TargetInfo::HandleTargetFeatures(std::vector<std::string> &Features) {
   // Remember the maximum enabled sselevel.
   for (unsigned i = 0, e = Features.size(); i !=e; ++i) {
     // Ignore disabled features.
@@ -2112,7 +2111,7 @@ static TargetInfo *AllocateTarget(const std::string &T) {
 /// CreateTargetInfo - Return the target info object for the specified target
 /// triple.
 TargetInfo *TargetInfo::CreateTargetInfo(Diagnostic &Diags,
-                                         const TargetOptions &Opts) {
+                                         TargetOptions &Opts) {
   llvm::Triple Triple(Opts.Triple);
 
   // Construct the target
@@ -2156,11 +2155,11 @@ TargetInfo *TargetInfo::CreateTargetInfo(Diagnostic &Diags,
   //
   // FIXME: If we are completely confident that we have the right set, we only
   // need to pass the minuses.
-  std::vector<std::string> StrFeatures;
+  Opts.Features.clear();
   for (llvm::StringMap<bool>::const_iterator it = Features.begin(),
          ie = Features.end(); it != ie; ++it)
-    StrFeatures.push_back(std::string(it->second ? "+" : "-") + it->first());
-  Target->HandleTargetFeatures(StrFeatures);
+    Opts.Features.push_back(std::string(it->second ? "+" : "-") + it->first());
+  Target->HandleTargetFeatures(Opts.Features);
 
   return Target.take();
 }