From 425ed781f7a27bc415e13a1901899e2c7b11e4c8 Mon Sep 17 00:00:00 2001
From: Nick Bowler <nbowler@draconx.ca>
Date: Tue, 28 Aug 2012 20:44:09 -0400
Subject: [PATCH] Don't allow restrict-qualified pointers to functions.

Such pointers are prohibited by the C language, so we must reject them.
---
 src/parse-decl.c           | 27 ++++++++++++++++++++++++++-
 test/declgen.c             |  6 ++++++
 tests/cdecl99-c-invalid.sh |  4 ++++
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/src/parse-decl.c b/src/parse-decl.c
index 45cf67f..4489532 100644
--- a/src/parse-decl.c
+++ b/src/parse-decl.c
@@ -1,6 +1,6 @@
 /*
  *  Parse and validate C declarations.
- *  Copyright © 2011 Nick Bowler
+ *  Copyright © 2011-2012 Nick Bowler
  *
  *  This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -364,6 +364,27 @@ normalize_specs(struct cdecl_declarator **p, struct cdecl_declarator *d)
 	return 0;
 }
 
+static int
+check_qualifiers(struct cdecl_declarator **p, struct cdecl_declarator *d)
+{
+	struct cdecl_declspec *spec;
+	struct cdecl_pointer *ptr;
+
+	if (!d->child || d->child->type != CDECL_DECL_POINTER)
+		return 0;
+
+	ptr = &d->child->u.pointer;
+	for (spec = ptr->qualifiers; spec; spec = spec->next) {
+		if (spec->type == CDECL_QUAL_RESTRICT
+		    && d->type == CDECL_DECL_FUNCTION) {
+			fprintf(stderr, "function pointers cannot be restrict-qualified\n");
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
 /*
  * Traverse the parse tree, calling a function on every declarator in a
  * depth-first preorder traversal.  The function is given a pointer to the
@@ -445,6 +466,8 @@ struct cdecl *cdecl_parse_decl(const char *declstr)
 			goto err;
 		if (!forall_declarators(i, normalize_specs))
 			goto err;
+		if (!forall_declarators(i, check_qualifiers))
+			goto err;
 
 		if (!valid_declspecs(i, true))
 			goto err;
@@ -494,6 +517,8 @@ struct cdecl *cdecl_parse_english(const char *english)
 			goto err;
 		if (!forall_declarators(i, normalize_specs))
 			goto err;
+		if (!forall_declarators(i, check_qualifiers))
+			goto err;
 
 		if (!valid_declspecs(i, true))
 			goto err;
diff --git a/test/declgen.c b/test/declgen.c
index 3f4c394..4fb39cb 100644
--- a/test/declgen.c
+++ b/test/declgen.c
@@ -402,6 +402,12 @@ struct cdecl_declarator *gen_declarators(struct gen_rng *rng)
 			break;
 		case 2:
 			gen_function(rng, d);
+			if (p && p->type == CDECL_DECL_POINTER) {
+				struct cdecl_pointer *ptr = &p->u.pointer;
+
+				gen_free_declspecs(ptr->qualifiers);
+				ptr->qualifiers = gen_qualifiers(rng, false);
+			}
 			limit = 1;
 			break;
 		default:
diff --git a/tests/cdecl99-c-invalid.sh b/tests/cdecl99-c-invalid.sh
index 5ffb3b3..4370e58 100755
--- a/tests/cdecl99-c-invalid.sh
+++ b/tests/cdecl99-c-invalid.sh
@@ -30,8 +30,12 @@ test_decl explain 'long long long x'
 test_decl declare 'x as long long long'
 test_decl explain 'inline int x'
 test_decl declare 'x as inline int'
+# C99§6.7.3#2: Types other than opinter types derived from object or incomplete
+# types shall not be restrict-qualified.
 test_decl explain 'restrict int x'
 test_decl declare 'x as restrict int'
+test_decl explain 'int (*restrict f)(void)'
+test_decl declare 'f as restrict pointer to function (void) returning int'
 test_decl explain 'static auto int x'
 test_decl declare 'x as static auto int'
 test_decl explain 'auto x'
-- 
2.43.0