[llvm-branch-commits] [cfe-branch] r348012 - Merging r344100:

Tom Stellard via llvm-branch-commits llvm-branch-commits at lists.llvm.org
Fri Nov 30 10:15:48 PST 2018

Author: tstellar
Date: Fri Nov 30 10:15:48 2018
New Revision: 348012

URL: http://llvm.org/viewvc/llvm-project?rev=348012&view=rev
Merging r344100:

r344100 | emaste | 2018-10-09 17:34:17 -0700 (Tue, 09 Oct 2018) | 16 lines

clang: Allow ifunc resolvers to accept arguments

When ifunc support was added to Clang (r265917) it did not allow
resolvers to take function arguments.  This was based on GCC's
documentation, which states resolvers return a pointer and take no

However, GCC actually allows resolvers to take arguments, and glibc (on
non-x86 platforms) and FreeBSD (on x86 and arm64) pass some CPU
identification information as arguments to ifunc resolvers.  I believe
GCC's documentation is simply incorrect / out-of-date.

FreeBSD already removed the prohibition in their in-tree Clang copy.

Differential Revision:	https://reviews.llvm.org/D52703



Modified: cfe/branches/release_70/include/clang/Basic/AttrDocs.td
URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_70/include/clang/Basic/AttrDocs.td?rev=348012&r1=348011&r2=348012&view=diff
--- cfe/branches/release_70/include/clang/Basic/AttrDocs.td (original)
+++ cfe/branches/release_70/include/clang/Basic/AttrDocs.td Fri Nov 30 10:15:48 2018
@@ -3364,7 +3364,7 @@ def IFuncDocs : Documentation {
   let Content = [{
 ``__attribute__((ifunc("resolver")))`` is used to mark that the address of a declaration should be resolved at runtime by calling a resolver function.
-The symbol name of the resolver function is given in quotes.  A function with this name (after mangling) must be defined in the current translation unit; it may be ``static``.  The resolver function should take no arguments and return a pointer.
+The symbol name of the resolver function is given in quotes.  A function with this name (after mangling) must be defined in the current translation unit; it may be ``static``.  The resolver function should return a pointer.
 The ``ifunc`` attribute may only be used on a function declaration.  A function declaration with an ``ifunc`` attribute is considered to be a definition of the declared entity.  The entity must not have weak linkage; for example, in C++, it cannot be applied to a declaration if a definition at that location would be considered inline.

Modified: cfe/branches/release_70/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_70/include/clang/Basic/DiagnosticSemaKinds.td?rev=348012&r1=348011&r2=348012&view=diff
--- cfe/branches/release_70/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/branches/release_70/include/clang/Basic/DiagnosticSemaKinds.td Fri Nov 30 10:15:48 2018
@@ -2857,8 +2857,6 @@ def err_cyclic_alias : Error<
   "%select{alias|ifunc}0 definition is part of a cycle">;
 def err_ifunc_resolver_return : Error<
   "ifunc resolver function must return a pointer">;
-def err_ifunc_resolver_params : Error<
-  "ifunc resolver function must have no parameters">;
 def warn_attribute_wrong_decl_type_str : Warning<
   "%0 attribute only applies to %1">, InGroup<IgnoredAttributes>;
 def err_attribute_wrong_decl_type_str : Error<

Modified: cfe/branches/release_70/lib/CodeGen/CodeGenModule.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_70/lib/CodeGen/CodeGenModule.cpp?rev=348012&r1=348011&r2=348012&view=diff
--- cfe/branches/release_70/lib/CodeGen/CodeGenModule.cpp (original)
+++ cfe/branches/release_70/lib/CodeGen/CodeGenModule.cpp Fri Nov 30 10:15:48 2018
@@ -320,8 +320,6 @@ void CodeGenModule::checkAliases() {
       if (!FTy->getReturnType()->isPointerTy())
         Diags.Report(Location, diag::err_ifunc_resolver_return);
-      if (FTy->getNumParams())
-        Diags.Report(Location, diag::err_ifunc_resolver_params);
     llvm::Constant *Aliasee = Alias->getIndirectSymbol();

Modified: cfe/branches/release_70/test/Sema/attr-ifunc.c
URL: http://llvm.org/viewvc/llvm-project/cfe/branches/release_70/test/Sema/attr-ifunc.c?rev=348012&r1=348011&r2=348012&view=diff
--- cfe/branches/release_70/test/Sema/attr-ifunc.c (original)
+++ cfe/branches/release_70/test/Sema/attr-ifunc.c Fri Nov 30 10:15:48 2018
@@ -27,10 +27,6 @@ void f4_ifunc() {}
 void f4() __attribute__((ifunc("f4_ifunc")));
 //expected-error at -1 {{ifunc resolver function must return a pointer}}
-void* f5_ifunc(int i) { return 0; }
-void f5() __attribute__((ifunc("f5_ifunc")));
-//expected-error at -1 {{ifunc resolver function must have no parameters}}
 void f1a() __asm("f1");
 void f1a() {}

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