Merge pull request hfinkel#1 from tpops/pull-request-syntax-plugin

Updating plugin interface to allow inserting entities prior to the function being replaced.

Author: Hal Finkel

clang/examples/PrintTokensSyntax/PrintTokensSyntax.cpp

@@ -23,11 +23,17 @@ class PrintTokensHandler : public SyntaxHandler {
   void GetReplacement(Preprocessor &PP, Declarator &D,
                       CachedTokens &Toks,
                       llvm::raw_string_ostream &OS) override {
+    
+    OS << "static const char* tokens = \"";
     for (auto &Tok : Toks) {
-      OS << "printf(\"%s\\n\", \"";
+      OS << " ";
       OS.write_escaped(PP.getSpelling(Tok));
-      OS << "\");\n";
     }
+    OS << "\";\n";
+    // Rewrite syntax original function.
+    OS << getDeclText(PP,D) << "{\n";
+    OS << "printf(\"%s\",tokens);\n";
+    OS <<"}\n";
   }
 
   void AddToPredefines(llvm::raw_string_ostream &OS) override {

clang/include/clang/Parse/Parser.h

@@ -3117,7 +3117,6 @@ class SyntaxHandler {
   std::string Name;
 
   virtual void anchor();
-
 public:
   SyntaxHandler() = default;
   explicit SyntaxHandler(StringRef name) : Name(name) {}
@@ -3128,6 +3127,8 @@ class SyntaxHandler {
                               CachedTokens &Toks,
                               llvm::raw_string_ostream &OS) = 0;
   virtual void AddToPredefines(llvm::raw_string_ostream &OS) = 0;
+  /// Utility function returns actual text of a declarator.
+  StringRef getDeclText(Preprocessor &PP,Declarator &D);
 };
 
 /// Registry of syntax handlers added by plugins

clang/lib/Parse/Parser.cpp

@@ -25,7 +25,14 @@ using namespace clang;
 LLVM_INSTANTIATE_REGISTRY(SyntaxHandlerRegistry)
 
 void SyntaxHandler::anchor() {}
-
+// Utility function returning actual text for a declarator.
+llvm::StringRef SyntaxHandler::getDeclText(Preprocessor &PP,Declarator &D){
+  auto DeclCharRange = Lexer::getAsCharRange (D.getSourceRange(), 
+		  PP.getSourceManager(), PP.getLangOpts());
+  auto DeclText= Lexer::getSourceText (DeclCharRange,
+		  PP.getSourceManager(), PP.getLangOpts());
+  return DeclText;
+}
 namespace {
 /// A comment handler that passes comments found by the preprocessor
 /// to the parser action.
@@ -1190,15 +1197,27 @@ void Parser::ProcessPluginSyntax(ParsingDeclarator &D) {
     return;
   }
 
-  // Provide the token stream to the plugin and get back the replacement text.
 
   std::string Replacement;
   llvm::raw_string_ostream ReplacementOS(Replacement);
-
   ReplacementOS << "\n{\n";
-  SHI->second->GetReplacement(PP, D, Toks, ReplacementOS);
+  // Place __builtin_unreachable(); in the forgoten function. This 
+  // is done to avoid warnings from the compiler.
+  ReplacementOS << "__builtin_unreachable();\n";
   ReplacementOS << "\n}\n";
+
+  // Provide the token stream to the plugin and get back the replacement text.
+  SHI->second->GetReplacement(PP, D, Toks, ReplacementOS);
   ReplacementOS.flush();
+  
+  // Change the identifier name in the declarator to forget
+  // the original function.
+  
+  std::string NewName;
+  NewName ="__"+ D.getIdentifier()->getName().str();
+ 
+  IdentifierInfo &VariantII = Actions.Context.Idents.get(NewName);
+  D.SetIdentifier(&VariantII, D.getBeginLoc()); 
 
   // Now we have a replacement text buffer from the plugin, enter it for
   // lexing. After we're done with that, we'll resume parsing the original

clang/test/Frontend/plugin-syntax-print-tokens.cpp

@@ -5,26 +5,27 @@
   This is a test with a "string".
 }
 
-// CHECK: [[STR_VAR:@.+]] = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
-// CHECK-NEXT: [[STR_VAR1:@.+]] = private unnamed_addr constant [5 x i8] c"This\00", align 1
-// CHECK-NEXT: [[STR_VAR2:@.+]] = private unnamed_addr constant [3 x i8] c"is\00", align 1
-// CHECK-NEXT: [[STR_VAR3:@.+]] = private unnamed_addr constant [2 x i8] c"a\00", align 1
-// CHECK-NEXT: [[STR_VAR4:@.+]] = private unnamed_addr constant [5 x i8] c"test\00", align 1
-// CHECK-NEXT: [[STR_VAR5:@.+]] = private unnamed_addr constant [5 x i8] c"with\00", align 1
-// CHECK-NEXT: [[STR_VAR6:@.+]] = private unnamed_addr constant [9 x i8] c"\22string\22\00", align 1
-// CHECK-NEXT: [[STR_VAR7:@.+]] = private unnamed_addr constant [2 x i8] c".\00", align 1
-
-// CHECK: define dso_local void @_Z3fn1v() #0 {
-// CHECK-NEXT: entry:
-// CHECK-NEXT:   %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* [[STR_VAR]], {{.*}}), i8* getelementptr inbounds ([5 x i8], [5 x i8]* [[STR_VAR1]], {{.*}}))
-// CHECK-NEXT:   %call1 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* [[STR_VAR]], {{.*}}), i8* getelementptr inbounds ([3 x i8], [3 x i8]* [[STR_VAR2]], {{.*}}))
-// CHECK-NEXT:   %call2 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* [[STR_VAR]], {{.*}}), i8* getelementptr inbounds ([2 x i8], [2 x i8]* [[STR_VAR3]], {{.*}}))
-// CHECK-NEXT:   %call3 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* [[STR_VAR]], {{.*}}), i8* getelementptr inbounds ([5 x i8], [5 x i8]* [[STR_VAR4]], {{.*}}))
-// CHECK-NEXT:   %call4 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* [[STR_VAR]], {{.*}}), i8* getelementptr inbounds ([5 x i8], [5 x i8]* [[STR_VAR5]], {{.*}}))
-// CHECK-NEXT:   %call5 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* [[STR_VAR]], {{.*}}), i8* getelementptr inbounds ([2 x i8], [2 x i8]* [[STR_VAR3]], {{.*}}))
-// CHECK-NEXT:   %call6 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* [[STR_VAR]], {{.*}}), i8* getelementptr inbounds ([9 x i8], [9 x i8]* [[STR_VAR6]], {{.*}}))
-// CHECK-NEXT:   %call7 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* [[STR_VAR]], {{.*}}), i8* getelementptr inbounds ([2 x i8], [2 x i8]* [[STR_VAR7]], {{.*}}))
-// CHECK-NEXT:   ret void
-// CHECK-NEXT: }
+//CHECK: [[STR_VAR:@.+]] = private unnamed_addr constant [3 x i8] c"%s\00", align 1
+//CHECK-NEXT:@_ZL6tokens = internal global i8* getelementptr inbounds ([34 x i8], [34 x i8]* @.str.1, i32 0, i32 0), align 8
+//CHECK-NEXT: [[STR_VAR:@.+]] = private unnamed_addr constant [34 x i8] c" This is a test with a \22string\22 .\00", align 1
+
+
+
+//CHECK: define dso_local void @_Z5__fn1v() #0 {
+//CHECK-NEXT: entry:
+//CHECK-NEXT:  unreachable
+//CHECK-NEXT: }
+
+
+
+//CHECK: define dso_local void @_Z3fn1v() #1 {
+//CHECK-NEXT: entry:
+//CHECK-NEXT:   %0 = load i8*, i8** @_ZL6tokens, align 8
+//CHECK-NEXT:   %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i8* %0)
+//CHECK-NEXT:   ret void
+//CHECK-NEXT: }
+
+
+