static FrontendPluginRegistry::Add<MyPlugin> X("my-plugin-name", "my plugin description");
+Defining pragmas
+================
+
+Plugins can also define pragmas by declaring a ``PragmaHandler`` and
+registering it using ``PragmaHandlerRegistry::Add<>``:
+
+.. code-block:: c++
+
+ // Define a pragma handler for #pragma example_pragma
+ class ExamplePragmaHandler : public PragmaHandler {
+ public:
+ ExamplePragmaHandler() : PragmaHandler("example_pragma") { }
+ void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
+ Token &PragmaTok) {
+ // Handle the pragma
+ }
+ };
+
+ static PragmaHandlerRegistry::Add<ExamplePragmaHandler> Y("example_pragma","example pragma description");
+
Putting it all together
=======================
//
//===----------------------------------------------------------------------===//
//
-// Example clang plugin which adds an annotation to every function.
+// Example clang plugin which adds an annotation to every function in
+// translation units that start with #pragma enable_annotate.
//
//===----------------------------------------------------------------------===//
#include "clang/Frontend/FrontendPluginRegistry.h"
#include "clang/AST/AST.h"
#include "clang/AST/ASTConsumer.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Lex/LexDiagnostic.h"
using namespace clang;
namespace {
+static bool EnableAnnotate = false;
+static bool HandledDecl = false;
+
class AnnotateFunctionsConsumer : public ASTConsumer {
public:
bool HandleTopLevelDecl(DeclGroupRef DG) override {
+ HandledDecl = true;
+ if (!EnableAnnotate)
+ return true;
for (auto D : DG)
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
FD->addAttr(AnnotateAttr::CreateImplicit(FD->getASTContext(),
}
};
+class PragmaAnnotateHandler : public PragmaHandler {
+public:
+ PragmaAnnotateHandler() : PragmaHandler("enable_annotate") { }
+
+ void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
+ Token &PragmaTok) override {
+
+ Token Tok;
+ PP.LexUnexpandedToken(Tok);
+ if (Tok.isNot(tok::eod))
+ PP.Diag(Tok, diag::ext_pp_extra_tokens_at_eol) << "pragma";
+
+ if (HandledDecl) {
+ DiagnosticsEngine &D = PP.getDiagnostics();
+ unsigned ID = D.getCustomDiagID(
+ DiagnosticsEngine::Error,
+ "#pragma enable_annotate not allowed after declarations");
+ D.Report(PragmaTok.getLocation(), ID);
+ }
+
+ EnableAnnotate = true;
+ }
+};
+
}
static FrontendPluginRegistry::Add<AnnotateFunctionsAction>
X("annotate-fns", "annotate functions");
+
+static PragmaHandlerRegistry::Add<PragmaAnnotateHandler>
+Y("enable_annotate","enable annotation");
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/TinyPtrVector.h"
#include "llvm/Support/Allocator.h"
+#include "llvm/Support/Registry.h"
#include <memory>
#include <vector>
virtual bool HandleComment(Preprocessor &PP, SourceRange Comment) = 0;
};
+/// \brief Registry of pragma handlers added by plugins
+typedef llvm::Registry<PragmaHandler> PragmaHandlerRegistry;
+
} // end namespace clang
#endif
AddPragmaHandler(new PragmaRegionHandler("region"));
AddPragmaHandler(new PragmaRegionHandler("endregion"));
}
+
+ // Pragmas added by plugins
+ for (PragmaHandlerRegistry::iterator it = PragmaHandlerRegistry::begin(),
+ ie = PragmaHandlerRegistry::end();
+ it != ie; ++it) {
+ AddPragmaHandler(it->instantiate().release());
+ }
}
/// Ignore all pragmas, useful for modes such as -Eonly which would otherwise
-// RUN: %clang -fplugin=%llvmshlibdir/AnnotateFunctions%pluginext -emit-llvm -S %s -o - | FileCheck %s
+// RUN: %clang -fplugin=%llvmshlibdir/AnnotateFunctions%pluginext -emit-llvm -DPRAGMA_ON -S %s -o - | FileCheck %s --check-prefix=PRAGMA
+// RUN: %clang -fplugin=%llvmshlibdir/AnnotateFunctions%pluginext -emit-llvm -S %s -o - | FileCheck %s --check-prefix=NOPRAGMA
+// RUN: not %clang -fplugin=%llvmshlibdir/AnnotateFunctions%pluginext -emit-llvm -DBAD_PRAGMA -S %s -o - 2>&1 | FileCheck %s --check-prefix=BADPRAGMA
// REQUIRES: plugins, examples
-// CHECK: [[STR_VAR:@.+]] = private unnamed_addr constant [19 x i8] c"example_annotation\00"
-// CHECK: @llvm.global.annotations = {{.*}}@fn1{{.*}}[[STR_VAR]]{{.*}}@fn2{{.*}}[[STR_VAR]]
+#ifdef PRAGMA_ON
+#pragma enable_annotate
+#endif
+
+// BADPRAGMA: warning: extra tokens at end of #pragma directive
+#ifdef BAD_PRAGMA
+#pragma enable_annotate something
+#endif
+
+// PRAGMA: [[STR_VAR:@.+]] = private unnamed_addr constant [19 x i8] c"example_annotation\00"
+// PRAGMA: @llvm.global.annotations = {{.*}}@fn1{{.*}}[[STR_VAR]]{{.*}}@fn2{{.*}}[[STR_VAR]]
+// NOPRAGMA-NOT: [[STR_VAR:@.+]] = private unnamed_addr constant [19 x i8] c"example_annotation\00"
+// NOPRAGMA-NOT: @llvm.global.annotations = {{.*}}@fn1{{.*}}[[STR_VAR]]{{.*}}@fn2{{.*}}[[STR_VAR]]
void fn1() { }
void fn2() { }
+
+// BADPRAGMA: error: #pragma enable_annotate not allowed after declarations
+#ifdef BAD_PRAGMA
+#pragma enable_annotate
+#endif