Declaring nt_checked array of size 0 should be illegal

[secure-sw-dev-bot]

This issue was copied from checkedc/checkedc-clang#1138

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We have the following code in test/CheckedC/inferred-bounds/bounds-context.c:

void f(char p nt_checked[0] : count(len), unsigned len) {}

The compiler currently allows this because p has a declared bounds of count(len). But this declaration conflicts with the empty size declaration which is illegal.

Also if we remove the declared bounds then the compiler asserts.

void f(char p nt_checked[0]) {}

clang: /usr/magrang/master/src/clang/lib/Sema/BoundsUtils.cpp:57: 
static clang::BoundsExpr* clang::BoundsUtil::CreateBoundsForArrayType(clang::Sema&, clang::QualType, bool):
Assertion `size.uge(1) && "must have at least one element"' failed.

[secure-sw-dev-bot]

Comment from @mattmccutchen-cci:

We have the following code in test/CheckedC/inferred-bounds/bounds-context.c:

void f(char p nt_checked[0] : count(len), unsigned len) {}

The compiler currently allows this because p has a declared bounds of count(len). But this declaration conflicts with the empty size declaration which is illegal.

Duplicate of #1071?

Also if we remove the declared bounds then the compiler asserts.

void f(char p nt_checked[0]) {}

clang: /usr/magrang/master/src/clang/lib/Sema/BoundsUtils.cpp:57: 
static clang::BoundsExpr* clang::BoundsUtil::CreateBoundsForArrayType(clang::Sema&, clang::QualType, bool):
Assertion `size.uge(1) && "must have at least one element"' failed.

Duplicate of #1130?

If indeed both parts of this issue are duplicates, maybe it can be closed.