jdoerfert created this revision.
jdoerfert added reviewers: jyknight, lebedev.ri, aaron.ballman, bcain.
Herald added subscribers: jfb, bollu, krytarowski, emaste.
Herald added a project: clang.
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 <https://reviews.llvm.org/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
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D58091
Files:
clang/include/clang/Basic/DiagnosticSemaKinds.td
clang/lib/Sema/SemaDecl.cpp
clang/test/Analysis/retain-release.m
clang/test/Sema/builtin-setjmp.c
clang/test/Sema/implicit-builtin-decl.c
Index: clang/test/Sema/implicit-builtin-decl.c
===================================================================
--- clang/test/Sema/implicit-builtin-decl.c
+++ clang/test/Sema/implicit-builtin-decl.c
@@ -55,14 +55,17 @@
void snprintf() { }
-// PR8316
-void longjmp(); // expected-warning{{declaration of built-in function 'longjmp' requires inclusion of the header <setjmp.h>}}
+// PR8316 & PR40692
+void longjmp(); // expected-warning{{declaration of built-in 'longjmp' requires the definition of the 'jmp_buf' type}}
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 <setjmp.h>}}
+void sigsetjmp(struct __jmp_buf_tag[1], int); // expected-warning{{declaration of built-in 'sigsetjmp' requires the definition of the 'jmp_buf' type}}
// CHECK: FunctionDecl {{.*}} <line:[[@LINE-2]]:1, col:44> col:6 sigsetjmp '
// CHECK-NOT: FunctionDecl
// CHECK: ReturnsTwiceAttr {{.*}} <{{.*}}> Implicit
+
+// PR40692
+void pthread_create(); // no warning expected
Index: clang/test/Sema/builtin-setjmp.c
===================================================================
--- /dev/null
+++ clang/test/Sema/builtin-setjmp.c
@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -fsyntax-only -verify=no_jmp_buf -DNO_JMP_BUF %s
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -fsyntax-only -verify=redecl %s
+
+#ifdef NO_JMP_BUF
+extern long setjmp(long *); // no_jmp_buf-warning {{declaration of built-in 'setjmp' requires the definition of the 'jmp_buf' type}}
+#else
+typedef long jmp_buf;
+extern int setjmp(char); // redecl-warning@8 {{incompatible redeclaration of library function 'setjmp'}}
+ // redecl-note@8 {{'setjmp' is a builtin with type 'int (jmp_buf)' (aka 'int (long)')}}
+#endif
Index: clang/test/Analysis/retain-release.m
===================================================================
--- clang/test/Analysis/retain-release.m
+++ 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 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 <pthread.h>}}
+int pthread_create(pthread_t *, const pthread_attr_t *,
void *(*)(void *), void *);
int pthread_setspecific(pthread_key_t key, const void *value);
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -1955,10 +1955,27 @@
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;
}
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -587,6 +587,10 @@
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 '%0' requires the definition of the "
+ "'jmp_buf' type">,
+ InGroup<DiagGroup<"incomplete-setjmp-declaration">>;
def warn_implicit_decl_requires_sysheader : Warning<
"declaration of built-in function '%1' requires inclusion of the header <%0>">,
InGroup<BuiltinRequiresHeader>;
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