From 3be25e79477db2d31ac46493d97eca8c20592b07 Mon Sep 17 00:00:00 2001 From: Johannes Doerfert Date: Wed, 31 Jul 2019 05:16:38 +0000 Subject: [Fix] Customize warnings for missing built-in types If we detect a built-in declaration for which we cannot derive a type matching the pattern in the Builtins.def file, we currently emit a warning that the respective header is needed. However, this is not necessarily the behavior we want as it has no connection to the location of the declaration (which can actually be in the header in question). Instead, this warning is generated - if we could not build the type for the pattern on file (for some reason). Here we should make the reason explicit. The actual problem is otherwise circumvented as the warning is misleading, see [0] for an example. - if we could not build the type for the pattern because we do not have a type on record, possible since D55483, we should not emit any warning. See [1] for a legitimate problem. This patch address both cases. For the "setjmp" family a new warning is introduced and for built-ins without type on record, so far "pthread_create", we do not emit the warning anymore. Also see: PR40692 [0] https://lkml.org/lkml/2019/1/11/718 [1] https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=235583 Differential Revision: https://reviews.llvm.org/D58091 llvm-svn: 367387 --- clang/lib/Sema/SemaDecl.cpp | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) (limited to 'clang/lib') diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp index ced24805ed8..74c6316da6a 100644 --- a/clang/lib/Sema/SemaDecl.cpp +++ b/clang/lib/Sema/SemaDecl.cpp @@ -1983,10 +1983,27 @@ NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID, ASTContext::GetBuiltinTypeError Error; QualType R = Context.GetBuiltinType(ID, Error); if (Error) { - if (ForRedeclaration) - Diag(Loc, diag::warn_implicit_decl_requires_sysheader) - << getHeaderName(Context.BuiltinInfo, ID, Error) + if (!ForRedeclaration) + return nullptr; + + // If we have a builtin without an associated type we should not emit a + // warning when we were not able to find a type for it. + if (Error == ASTContext::GE_Missing_type) + return nullptr; + + // If we could not find a type for setjmp it is because the jmp_buf type was + // not defined prior to the setjmp declaration. + if (Error == ASTContext::GE_Missing_setjmp) { + Diag(Loc, diag::warn_implicit_decl_no_jmp_buf) << Context.BuiltinInfo.getName(ID); + return nullptr; + } + + // Generally, we emit a warning that the declaration requires the + // appropriate header. + Diag(Loc, diag::warn_implicit_decl_requires_sysheader) + << getHeaderName(Context.BuiltinInfo, ID, Error) + << Context.BuiltinInfo.getName(ID); return nullptr; } -- cgit v1.2.3