From 3be25e79477db2d31ac46493d97eca8c20592b07 Mon Sep 17 00:00:00 2001 From: Johannes Doerfert Date: Wed, 31 Jul 2019 05:16:38 +0000 Subject: [PATCH] [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/include/clang/Basic/DiagnosticSemaKinds.td | 4 ++++ clang/lib/Sema/SemaDecl.cpp | 23 ++++++++++++++++++++--- clang/test/Analysis/retain-release.m | 4 ++-- clang/test/Sema/builtin-setjmp.c | 10 ++++++++++ clang/test/Sema/implicit-builtin-decl.c | 9 ++++++--- 5 files changed, 42 insertions(+), 8 deletions(-) create mode 100644 clang/test/Sema/builtin-setjmp.c diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 4cf1b34..28e407a 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -598,6 +598,10 @@ def ext_implicit_lib_function_decl : ExtWarn< def note_include_header_or_declare : Note< "include the header <%0> or explicitly provide a declaration for '%1'">; def note_previous_builtin_declaration : Note<"%0 is a builtin with type %1">; +def warn_implicit_decl_no_jmp_buf + : Warning<"declaration of built-in function '%0' requires the declaration" + " of the 'jmp_buf' type, commonly provided in the header .">, + InGroup>; def warn_implicit_decl_requires_sysheader : Warning< "declaration of built-in function '%1' requires inclusion of the header <%0>">, InGroup; diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp index ced2480..74c6316 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; } diff --git a/clang/test/Analysis/retain-release.m b/clang/test/Analysis/retain-release.m index ad79d72..e459fb7 100644 --- a/clang/test/Analysis/retain-release.m +++ b/clang/test/Analysis/retain-release.m @@ -2,7 +2,7 @@ // RUN: %clang_analyze_cc1 -triple x86_64-apple-darwin10\ // RUN: -analyzer-checker=core,osx.coreFoundation.CFRetainRelease\ // RUN: -analyzer-checker=osx.cocoa.ClassRelease,osx.cocoa.RetainCount\ -// RUN: -analyzer-checker=debug.ExprInspection -fblocks -verify=expected,C %s\ +// RUN: -analyzer-checker=debug.ExprInspection -fblocks -verify %s\ // RUN: -Wno-objc-root-class -analyzer-output=plist -o %t.objc.plist // RUN: %clang_analyze_cc1 -triple x86_64-apple-darwin10\ // RUN: -analyzer-checker=core,osx.coreFoundation.CFRetainRelease\ @@ -1231,7 +1231,7 @@ typedef __darwin_pthread_attr_t pthread_attr_t; typedef unsigned long __darwin_pthread_key_t; typedef __darwin_pthread_key_t pthread_key_t; -int pthread_create(pthread_t *, const pthread_attr_t *, // C-warning{{declaration of built-in function 'pthread_create' requires inclusion of the header }} +int pthread_create(pthread_t *, const pthread_attr_t *, void *(*)(void *), void *); int pthread_setspecific(pthread_key_t key, const void *value); diff --git a/clang/test/Sema/builtin-setjmp.c b/clang/test/Sema/builtin-setjmp.c new file mode 100644 index 0000000..f8770d8 --- /dev/null +++ b/clang/test/Sema/builtin-setjmp.c @@ -0,0 +1,10 @@ +// RUN: %clang_cc1 -triple x86_64-unknown-unknown -fsyntax-only -verify -DNO_JMP_BUF %s +// RUN: %clang_cc1 -triple x86_64-unknown-unknown -fsyntax-only -verify %s + +#ifdef NO_JMP_BUF +extern long setjmp(long *); // expected-warning {{declaration of built-in function 'setjmp' requires the declaration of the 'jmp_buf' type, commonly provided in the header .}} +#else +typedef long jmp_buf; +extern int setjmp(char); // expected-warning@8 {{incompatible redeclaration of library function 'setjmp'}} + // expected-note@8 {{'setjmp' is a builtin with type 'int (jmp_buf)' (aka 'int (long)')}} +#endif diff --git a/clang/test/Sema/implicit-builtin-decl.c b/clang/test/Sema/implicit-builtin-decl.c index 3c2ff94..3a3dfa9 100644 --- a/clang/test/Sema/implicit-builtin-decl.c +++ b/clang/test/Sema/implicit-builtin-decl.c @@ -55,14 +55,17 @@ main(int argc, char *argv[]) void snprintf() { } -// PR8316 -void longjmp(); // expected-warning{{declaration of built-in function 'longjmp' requires inclusion of the header }} +// PR8316 & PR40692 +void longjmp(); // expected-warning{{declaration of built-in function 'longjmp' requires the declaration of the 'jmp_buf' type, commonly provided in the header .}} extern float fmaxf(float, float); struct __jmp_buf_tag {}; -void sigsetjmp(struct __jmp_buf_tag[1], int); // expected-warning{{declaration of built-in function 'sigsetjmp' requires inclusion of the header }} +void sigsetjmp(struct __jmp_buf_tag[1], int); // expected-warning{{declaration of built-in function 'sigsetjmp' requires the declaration of the 'jmp_buf' type, commonly provided in the header .}} // CHECK: FunctionDecl {{.*}} col:6 sigsetjmp ' // CHECK-NOT: FunctionDecl // CHECK: ReturnsTwiceAttr {{.*}} <{{.*}}> Implicit + +// PR40692 +void pthread_create(); // no warning expected -- 2.7.4