mirrors/llvm-project
0
0
Fork 0
mirror of https://github.com/llvm/llvm-project.git synced 2025-04-29 03:26:06 +00:00
Code Issues Projects Releases Wiki Activity

Fix for PR4074: allow subscripting non-lvalue arrays in C90 mode.

Browse Source 
I wasn't originally going to use this approach, but cases like 
test/Sema/expr-comma.c make things difficult.

llvm-svn: 70096
This commit is contained in:
Eli Friedman 2009-04-25 23:46:54 +00:00
parent 0dedefe4f2
commit ab2784f2c1
3 changed files with 37 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
clang/include/clang/Basic/DiagnosticSemaKinds.td
View File

@ -945,6 +945,8 @@ def err_arithmetic_nonfragile_interface : Error<
"non-fragile ABI">;
def ext_subscript_non_lvalue : Extension<
"ISO C90 does not allow subscripting non-lvalue array">;
def err_typecheck_subscript_value : Error<
"subscripted value is not an array, pointer, or vector">;
def err_typecheck_subscript_not_integer : Error<

26
clang/lib/Sema/SemaExpr.cpp
View File

@ -1621,13 +1621,11 @@ Sema::ActOnArraySubscriptExpr(Scope *S, ExprArg Base, SourceLocation LLoc,
} else if (const PointerType *PTy = LHSTy->getAsPointerType()) {
BaseExpr = LHSExp;
IndexExpr = RHSExp;
// FIXME: need to deal with const...
ResultType = PTy->getPointeeType();
} else if (const PointerType *PTy = RHSTy->getAsPointerType()) {
// Handle the uncommon case of "123[Ptr]".
BaseExpr = RHSExp;
IndexExpr = LHSExp;
// FIXME: need to deal with const...
ResultType = PTy->getPointeeType();
} else if (const VectorType *VTy = LHSTy->getAsVectorType()) {
BaseExpr = LHSExp; // vectors: V[123]
@ -1635,6 +1633,30 @@ Sema::ActOnArraySubscriptExpr(Scope *S, ExprArg Base, SourceLocation LLoc,
// FIXME: need to deal with const...
ResultType = VTy->getElementType();
} else if (LHSTy->isArrayType()) {
// If we see an array that wasn't promoted by
// DefaultFunctionArrayConversion, it must be an array that
// wasn't promoted because of the C90 rule that doesn't
// allow promoting non-lvalue arrays. Warn, then
// force the promotion here.
Diag(LHSExp->getLocStart(), diag::ext_subscript_non_lvalue) <<
LHSExp->getSourceRange();
ImpCastExprToType(LHSExp, Context.getArrayDecayedType(LHSTy));
LHSTy = LHSExp->getType();
BaseExpr = LHSExp;
IndexExpr = RHSExp;
ResultType = LHSTy->getAsPointerType()->getPointeeType();
} else if (RHSTy->isArrayType()) {
// Same as previous, except for 123[f().a] case
Diag(RHSExp->getLocStart(), diag::ext_subscript_non_lvalue) <<
RHSExp->getSourceRange();
ImpCastExprToType(RHSExp, Context.getArrayDecayedType(RHSTy));
RHSTy = RHSExp->getType();
BaseExpr = RHSExp;
IndexExpr = LHSExp;
ResultType = RHSTy->getAsPointerType()->getPointeeType();
} else {
return ExprError(Diag(LLoc, diag::err_typecheck_subscript_value)
<< LHSExp->getSourceRange() << RHSExp->getSourceRange());

11
clang/test/Sema/c89.c
View File

@ -67,3 +67,14 @@ void test11 (int x[static 4]); /* expected-warning {{use of C99-specific array f
void test12 (int x[const 4]) { /* expected-warning {{use of C99-specific array features}} */
int Y[x[1]]; /* expected-warning {{variable length arrays are a C99 feature, accepted as an extension}} */
}
/* PR4074 */
struct test13 {
int X[23];
} test13a();
void test13b() {
int a = test13a().X[1]; /* expected-warning {{ISO C90 does not allow subscripting non-lvalue array}} */
int b = 1[test13a().X]; /* expected-warning {{ISO C90 does not allow subscripting non-lvalue array}} */
}