c, analyzer: fix ICE with -fanalyzer and -Wunused-macros [PR107711]
PR analyzer/107711 reports an ICE since r13-4073-gd8aba860b34203 with
the combination of -fanalyzer and -Wunused-macros.
The issue is that in c_translation_unit::consider_macro's call to
cpp_create_reader I was passing "ident_hash" for use by the the new
reader, but that takes ownership of that hash_table, so that ident_hash
erroneously gets freed when c_translation_unit::consider_macro calls
cpp_destroy, leading to a use-after-free in -Wunused-macros, where:
(gdb) p pfile->hash_table->pfile == pfile
$23 = false
and it's instead pointing at the freed reader from consider_macro,
leading to a use-after-free ICE.
Fixed thusly.
gcc/c/ChangeLog:
PR analyzer/107711
* c-parser.cc (ana::c_translation_unit::consider_macro): Pass NULL
to cpp_create_reader, rather than ident_hash, so that the new
reader gets its own hash table.
gcc/testsuite/ChangeLog:
PR analyzer/107711
* gcc.dg/analyzer/named-constants-Wunused-macros.c: New test.
Signed-off-by: David Malcolm <dmalcolm@redhat.com>
diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index f3c7999..1bbb39f 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -1717,7 +1717,7 @@
return NULL_TREE;
cpp_reader *old_parse_in = parse_in;
- parse_in = cpp_create_reader (CLK_GNUC89, ident_hash, line_table);
+ parse_in = cpp_create_reader (CLK_GNUC89, NULL, line_table);
pretty_printer pp;
pp_string (&pp, (const char *) tok.val.str.text);
diff --git a/gcc/testsuite/gcc.dg/analyzer/named-constants-Wunused-macros.c b/gcc/testsuite/gcc.dg/analyzer/named-constants-Wunused-macros.c
new file mode 100644
index 0000000..0b31cc4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/analyzer/named-constants-Wunused-macros.c
@@ -0,0 +1,19 @@
+/* Regression test for interaction of named constants in -fanalyzer with
+ -Wunused-macros (PR analyzer/107711). */
+
+/* { dg-additional-options "-Wunused-macros" } */
+
+#include "analyzer-decls.h"
+
+/* Various constants used by the fd state machine. */
+
+#define O_ACCMODE 42 /* { dg-warning "-: macro \"O_ACCMODE\" is not used" } */
+#define O_RDONLY 0x1 /* { dg-warning "-: macro \"O_RDONLY\" is not used" } */
+#define O_WRONLY 010 /* { dg-warning "-: macro \"O_WRONLY\" is not used" } */
+
+void test_sm_fd_constants (void)
+{
+ __analyzer_dump_named_constant ("O_ACCMODE"); /* { dg-warning "named constant 'O_ACCMODE' has value '42'" } */
+ __analyzer_dump_named_constant ("O_RDONLY"); /* { dg-warning "named constant 'O_RDONLY' has value '1'" } */
+ __analyzer_dump_named_constant ("O_WRONLY"); /* { dg-warning "named constant 'O_WRONLY' has value '8'" } */
+}
