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Catch a few more cases of illegal comparisons. 

llvm-svn: 79793
This commit is contained in:
Eli Friedman 2009-08-23 00:27:47 +00:00
parent 79ba8f2edc
commit 16c209610c
3 changed files with 31 additions and 31 deletions
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2
clang/include/clang/Basic/DiagnosticSemaKinds.td
View File

@ -1352,6 +1352,8 @@ def ext_typecheck_ordered_comparison_of_pointer_and_zero : Extension<
"ordered comparison between pointer and zero (%0 and %1) is an extension">;
def ext_typecheck_ordered_comparison_of_function_pointers : ExtWarn<
"ordered comparison of function pointers (%0 and %1)">;
def ext_typecheck_comparison_of_fptr_to_void : Extension<
"equality comparison between function pointer and void pointer (%0 and %1)">;
def ext_typecheck_comparison_of_pointer_integer : ExtWarn<
"comparison between pointer and integer (%0 and %1)">;
def ext_typecheck_comparison_of_distinct_pointers : ExtWarn<

50
clang/lib/Sema/SemaExpr.cpp
View File

@ -4237,28 +4237,10 @@ QualType Sema::CheckCompareOperands(Expr *&lex, Expr *&rex, SourceLocation Loc,
QualType RCanPointeeTy =
Context.getCanonicalType(rType->getAs<PointerType>()->getPointeeType());
if (isRelational) {
if (lType->isFunctionPointerType() || rType->isFunctionPointerType()) {
Diag(Loc, diag::ext_typecheck_ordered_comparison_of_function_pointers)
<< lType << rType << lex->getSourceRange() << rex->getSourceRange();
}
if (LCanPointeeTy->isVoidType() != RCanPointeeTy->isVoidType()) {
Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers)
<< lType << rType << lex->getSourceRange() << rex->getSourceRange();
}
} else {
if (lType->isFunctionPointerType() != rType->isFunctionPointerType()) {
if (!LHSIsNull && !RHSIsNull)
Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers)
<< lType << rType << lex->getSourceRange() << rex->getSourceRange();
}
}
// Simple check: if the pointee types are identical, we're done.
if (LCanPointeeTy == RCanPointeeTy)
return ResultTy;
if (getLangOptions().CPlusPlus) {
if (LCanPointeeTy == RCanPointeeTy)
return ResultTy;
// C++ [expr.rel]p2:
// [...] Pointer conversions (4.10) and qualification
// conversions (4.4) are performed on pointer operands (or on
@ -4278,15 +4260,29 @@ QualType Sema::CheckCompareOperands(Expr *&lex, Expr *&rex, SourceLocation Loc,
ImpCastExprToType(rex, T);
return ResultTy;
}
if (!LHSIsNull && !RHSIsNull && // C99 6.5.9p2
!LCanPointeeTy->isVoidType() && !RCanPointeeTy->isVoidType() &&
!Context.typesAreCompatible(LCanPointeeTy.getUnqualifiedType(),
RCanPointeeTy.getUnqualifiedType())) {
// C99 6.5.9p2 and C99 6.5.8p2
if (Context.typesAreCompatible(LCanPointeeTy.getUnqualifiedType(),
RCanPointeeTy.getUnqualifiedType())) {
// Valid unless a relational comparison of function pointers
if (isRelational && LCanPointeeTy->isFunctionType()) {
Diag(Loc, diag::ext_typecheck_ordered_comparison_of_function_pointers)
<< lType << rType << lex->getSourceRange() << rex->getSourceRange();
}
} else if (!isRelational &&
(LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) {
// Valid unless comparison between non-null pointer and function pointer
if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType())
&& !LHSIsNull && !RHSIsNull) {
Diag(Loc, diag::ext_typecheck_comparison_of_fptr_to_void)
<< lType << rType << lex->getSourceRange() << rex->getSourceRange();
}
} else {
// Invalid
Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers)
<< lType << rType << lex->getSourceRange() << rex->getSourceRange();
}
ImpCastExprToType(rex, lType); // promote the pointer to pointer
if (LCanPointeeTy != RCanPointeeTy)
ImpCastExprToType(rex, lType); // promote the pointer to pointer
return ResultTy;
}
// C++ allows comparison of pointers with null pointer constants.

10
clang/test/Sema/compare.c
View File

@ -24,13 +24,15 @@ int pointers(int *a) {
return a > (void *)0; // expected-warning {{comparison of distinct pointer types}}
}
int function_pointers(int (*a)(int), int (*b)(int)) {
int function_pointers(int (*a)(int), int (*b)(int), void (*c)(int)) {
return a > b; // expected-warning {{ordered comparison of function pointers}}
return function_pointers > function_pointers; // expected-warning {{ordered comparison of function pointers}}
return a > c; // expected-warning {{comparison of distinct pointer types}}
return a == (void *) 0;
return a == (void *) 1; // expected-warning {{comparison of distinct pointer types}}
return a == (void *) 1; // expected-warning {{equality comparison between function pointer and void pointer}}
}
int void_pointers(void *foo) {
return foo == NULL;
int void_pointers(void* foo) {
return foo == (void*) 0;
return foo == (void*) 1;
}