Hi!
And here is the last part of the paper. Contrary what the paper claims
(clearly they haven't tried -pedantic nor -pedantic-errors), I think we
already diagnose everything we should.
Tested on x86_64-linux and i686-linux, ok for trunk?
2025-08-06 Jakub Jelinek <ja...@redhat.com>
PR preprocessor/120778
* g++.dg/DRs/dr2577-1.C: New test.
* g++.dg/DRs/dr2577-2.C: New test.
* g++.dg/DRs/dr2577-2.h: New file.
* g++.dg/DRs/dr2577-3.C: New test.
* g++.dg/DRs/dr2577-2.h: New file.
--- gcc/testsuite/g++.dg/DRs/dr2577-1.C.jj 2025-08-06 15:12:24.640033269
+0200
+++ gcc/testsuite/g++.dg/DRs/dr2577-1.C 2025-08-06 16:05:12.134023501 +0200
@@ -0,0 +1,40 @@
+// DR 2577 - Undefined behavior for preprocessing directives in macro arguments
+// { dg-do preprocess }
+// { dg-options "-pedantic-errors" }
+
+#define A(x)
+#define B(x, y)
+A(
+#if 1 // { dg-error "embedding a directive within
macro arguments is not portable" }
+1
+#else // { dg-error "embedding a directive within
macro arguments is not portable" }
+2
+#endif // { dg-error "embedding a directive within
macro arguments is not portable" }
+)
+B(1,
+#line 234 // { dg-error "embedding a directive within
macro arguments is not portable" }
+)
+#line 18
+A(
+#define C 1 // { dg-error "embedding a directive within
macro arguments is not portable" }
+)
+A(
+#undef C // { dg-error "embedding a directive within
macro arguments is not portable" }
+)
+B(42,
+# 234 "dr2577-1.C" // { dg-error "embedding a directive within
macro arguments is not portable" }
+) // { dg-error "style of line directive is a GCC
extension" "" { target *-*-* } .-1 }
+#line 28 "dr2577-1.C"
+B(
+#warning "foobar" // { dg-error "embedding a directive within
macro arguments is not portable" }
+, 12) // { dg-error "'#warning' before C\\\+\\\+23 is
a GCC extension" "" { target c++20_down } .-1 }
+ // { dg-warning "#warning \"foobar\"" "" {
target *-*-* } .-2 }
+A(
+#pragma GCC diagnostics push // { dg-error "embedding a directive within
macro arguments is not portable" }
+)
+B(5,
+#pragma GCC diagnostics pop // { dg-error "embedding a directive within
macro arguments is not portable" }
+)
+A(
+#error foobar // { dg-error "embedding a directive within
macro arguments is not portable" }
+) // { dg-error "#error foobar" "" { target *-*-*
} .-1 }
--- gcc/testsuite/g++.dg/DRs/dr2577-2.C.jj 2025-08-06 16:05:35.129718707
+0200
+++ gcc/testsuite/g++.dg/DRs/dr2577-2.C 2025-08-06 16:14:20.033765879 +0200
@@ -0,0 +1,13 @@
+// DR 2577 - Undefined behavior for preprocessing directives in macro arguments
+// { dg-do preprocess }
+// { dg-options "-pedantic-errors" }
+
+#define A(x, y, z) x + y + z
+int a = A(
+#include "dr2577-2.h" // { dg-error "embedding a directive within
macro arguments is not portable" }
+,
+#include "dr2577-2.h"
+,
+#include "dr2577-2.h"
+);
+// { dg-error "unterminated argument list invoking macro 'A'" "" { target
*-*-* } 0 }
--- gcc/testsuite/g++.dg/DRs/dr2577-2.h.jj 2025-08-06 16:06:20.305119929
+0200
+++ gcc/testsuite/g++.dg/DRs/dr2577-2.h 2025-08-06 16:06:44.572798276 +0200
@@ -0,0 +1 @@
+1
--- gcc/testsuite/g++.dg/DRs/dr2577-3.C.jj 2025-08-06 16:11:09.729286055
+0200
+++ gcc/testsuite/g++.dg/DRs/dr2577-3.C 2025-08-06 16:15:12.931065370 +0200
@@ -0,0 +1,7 @@
+// DR 2577 - Undefined behavior for preprocessing directives in macro arguments
+// { dg-do preprocess }
+// { dg-options "-pedantic-errors" }
+
+#define A(x) x
+int a = A(
+#include "dr2577-3.h" // { dg-error "embedding a directive within
macro arguments is not portable" }
--- gcc/testsuite/g++.dg/DRs/dr2577-3.h.jj 2025-08-06 16:11:43.266841918
+0200
+++ gcc/testsuite/g++.dg/DRs/dr2577-3.h 2025-08-06 16:11:48.553771904 +0200
@@ -0,0 +1 @@
+1)
Jakub
