#__include_macros) in the arguments of a function-style macro. Directives in the
arguments of such macros have undefined behaviour, and GCC does not correctly
support these cases. In some situations, this can lead to better diagnostics.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146765
91177308-0d34-0410-b5e6-
96231b3b80d8
InGroup<CXX98CompatPedantic>, DefaultIgnore;
def ext_named_variadic_macro : Extension<
"named variadic macros are a GNU extension">, InGroup<VariadicMacros>;
+def err_embedded_include : Error<
+ "embedding a #%0 directive within macro arguments is not supported">;
def ext_embedded_directive : Extension<
- "embedding a directive within macro arguments is not portable">,
+ "embedding a directive within macro arguments has undefined behavior">,
InGroup<DiagGroup<"embedded-directive">>;
def ext_missing_varargs_arg : Extension<
"varargs argument missing, but tolerated as an extension">;
// A(abc
// #warning blah
// def)
- // If so, the user is relying on non-portable behavior, emit a diagnostic.
- if (InMacroArgs)
+ // If so, the user is relying on undefined behavior, emit a diagnostic. Do
+ // not support this for #include-like directives, since that can result in
+ // terrible diagnostics, and does not work in GCC.
+ if (InMacroArgs) {
+ if (IdentifierInfo *II = Result.getIdentifierInfo()) {
+ switch (II->getPPKeywordID()) {
+ case tok::pp_include:
+ case tok::pp_import:
+ case tok::pp_include_next:
+ case tok::pp___include_macros:
+ Diag(Result, diag::err_embedded_include) << II->getName();
+ DiscardUntilEndOfDirective();
+ return;
+ default:
+ break;
+ }
+ }
Diag(Result, diag::ext_embedded_directive);
+ }
TryAgain:
switch (Result.getKind()) {
--- /dev/null
+// RUN: %clang_cc1 %s -fsyntax-only -verify
+
+// header1.h
+void fail(const char *);
+#define MUNCH(...) \
+ ({ int result = 0; __VA_ARGS__; if (!result) { fail(#__VA_ARGS__); }; result })
+
+static inline int f(int k) {
+ return MUNCH( // expected-error {{expected ')'}} expected-note {{to match this '('}} expected-error {{returning 'void'}}
+ if (k < 3)
+ result = 24;
+ else if (k > 4)
+ result = k - 4;
+}
+
+#include "macro_arg_directive.h" // expected-error {{embedding a #include directive within macro arguments is not supported}}
+
+int g(int k) {
+ return f(k) + f(k-1));
+}
--- /dev/null
+// Support header for macro_arg_directive.c
+
+int n;
+
+struct S {
+ int k;
+};
+
+void g(int);