llvm-project/clang/test/Preprocessor/undef-error.c

// RUN: %clang_cc1 %s -pedantic-errors -Wno-empty-translation-unit -verify 
// PR2045

#define b
/* expected-error {{extra tokens at end of #undef directive}} */ #undef a b
Add pedantic warning -Wempty-translation-unit (C11 6.9p1). In standard C since C89, a 'translation-unit' is syntactically defined to have at least one "external-declaration", which is either a decl or a function definition. In Clang the latter gives us a declaration as well. The tricky bit about this warning is that our predefines can contain external declarations (__builtin_va_list and the 128-bit integer types). Therefore our AST parser now makes sure we have at least one declaration that doesn't come from the predefines buffer. Also, remove bogus warning about empty source files. This doesn't catch source files that only contain comments, and never fired anyway because of our predefines. PR12665 and <rdar://problem/9165548> llvm-svn: 158085 2012-06-07 01:25:21 +08:00			`// RUN: %clang_cc1 %s -pedantic-errors -Wno-empty-translation-unit -verify`
Fix CheckEndOfDirective to diagnose lines that contain macros that expand to zero tokens. This fixes PR2045, thanks to Neil for finding another incredibly subtle corner case :) llvm-svn: 47203 2008-02-16 09:20:36 +08:00			`// PR2045`

			`#define b`
switch to using -verify llvm-svn: 57068 2008-10-05 03:43:25 +08:00			`/* expected-error {{extra tokens at end of #undef directive}} */ #undef a b`