Author: serge-sans-paille Date: 2020-01-17T09:58:32+01:00 New Revision: d293417931d3a9d46799b42795988ca3b5cfd766
URL: https://github.com/llvm/llvm-project/commit/d293417931d3a9d46799b42795988ca3b5cfd766 DIFF: https://github.com/llvm/llvm-project/commit/d293417931d3a9d46799b42795988ca3b5cfd766.diff LOG: Add __warn_memset_zero_len builtin as a workaround for glibc issue Glibc issue: https://sourceware.org/bugzilla/show_bug.cgi?id=25399 The fix consist in considering the missing function as a builtin lowered to a nop. Differential Revision: https://reviews.llvm.org/D72869 Added: Modified: clang/include/clang/Basic/Builtins.def clang/lib/CodeGen/CGBuiltin.cpp clang/test/CodeGen/builtins.c Removed: ################################################################################ diff --git a/clang/include/clang/Basic/Builtins.def b/clang/include/clang/Basic/Builtins.def index d388afe7fae6..1a6c85ce2dd3 100644 --- a/clang/include/clang/Basic/Builtins.def +++ b/clang/include/clang/Basic/Builtins.def @@ -788,6 +788,9 @@ BUILTIN(__builtin_abort, "v", "Fnr") BUILTIN(__builtin_index, "c*cC*i", "Fn") BUILTIN(__builtin_rindex, "c*cC*i", "Fn") +// ignored glibc builtin, see https://sourceware.org/bugzilla/show_bug.cgi?id=25399 +BUILTIN(__warn_memset_zero_len, "v", "nU") + // Microsoft builtins. These are only active with -fms-extensions. LANGBUILTIN(_alloca, "v*z", "n", ALL_MS_LANGUAGES) LANGBUILTIN(__annotation, "wC*.","n", ALL_MS_LANGUAGES) diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp index 4decaa593a59..9986ea4cb94c 100644 --- a/clang/lib/CodeGen/CGBuiltin.cpp +++ b/clang/lib/CodeGen/CGBuiltin.cpp @@ -3222,6 +3222,8 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID, Builder.CreateZExt(EmitSignBit(*this, EmitScalarExpr(E->getArg(0))), ConvertType(E->getType()))); } + case Builtin::BI__warn_memset_zero_len: + return RValue::getIgnored(); case Builtin::BI__annotation: { // Re-encode each wide string to UTF8 and make an MDString. SmallVector<Metadata *, 1> Strings; diff --git a/clang/test/CodeGen/builtins.c b/clang/test/CodeGen/builtins.c index 591416d00cc7..9f2a74f6c873 100644 --- a/clang/test/CodeGen/builtins.c +++ b/clang/test/CodeGen/builtins.c @@ -453,6 +453,13 @@ void test_builtin_launder(int *p) { int *d = __builtin_launder(p); } +// __warn_memset_zero_len should be NOP, see https://sourceware.org/bugzilla/show_bug.cgi?id=25399 +// CHECK-LABEL: define void @test___warn_memset_zero_len +void test___warn_memset_zero_len() { + // CHECK-NOT: @__warn_memset_zero_len + __warn_memset_zero_len(); +} + // Behavior of __builtin_os_log diff ers between platforms, so only test on X86 #ifdef __x86_64__ _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
