https://gcc.gnu.org/g:0f26f4f76961cdc7ebf7f07bec0b370fd1a04972
commit r14-10956-g0f26f4f76961cdc7ebf7f07bec0b370fd1a04972
Author: David Malcolm <dmalc...@redhat.com>
Date: Thu Jul 4 14:44:51 2024 -0400
analyzer: handle <error.h> at -O0 [PR115724]
At -O0, glibc's:
__extern_always_inline void
error (int __status, int __errnum, const char *__format, ...)
{
if (__builtin_constant_p (__status) && __status != 0)
__error_noreturn (__status, __errnum, __format, __builtin_va_arg_pack
());
else
__error_alias (__status, __errnum, __format, __builtin_va_arg_pack ());
}
becomes just:
__extern_always_inline void
error (int __status, int __errnum, const char *__format, ...)
{
if (0)
__error_noreturn (__status, __errnum, __format, __builtin_va_arg_pack
());
else
__error_alias (__status, __errnum, __format, __builtin_va_arg_pack ());
}
and thus calls to "error" are calls to "__error_alias" by the
time -fanalyzer "sees" them.
Handle them with more special-casing in kf.cc.
gcc/analyzer/ChangeLog:
PR analyzer/115724
* kf.cc (register_known_functions): Add __error_alias and
__error_at_line_alias.
gcc/testsuite/ChangeLog:
PR analyzer/115724
* c-c++-common/analyzer/error-pr115724.c: New test.
Signed-off-by: David Malcolm <dmalc...@redhat.com>
(cherry picked from commit a6fdb1a2a2906103afd70fa68cf7c45e896b8fbb)
Diff:
---
gcc/analyzer/kf.cc | 4 +
.../c-c++-common/analyzer/error-pr115724.c | 86 ++++++++++++++++++++++
2 files changed, 90 insertions(+)
diff --git a/gcc/analyzer/kf.cc b/gcc/analyzer/kf.cc
index c60e220dd1b9..e47786d0bcbf 100644
--- a/gcc/analyzer/kf.cc
+++ b/gcc/analyzer/kf.cc
@@ -2324,6 +2324,10 @@ register_known_functions (known_function_manager &kfm,
kfm.add ("__errno_location", make_unique<kf_errno_location> ());
kfm.add ("error", make_unique<kf_error> (3));
kfm.add ("error_at_line", make_unique<kf_error> (5));
+ /* Variants of "error" and "error_at_line" seen by the
+ analyzer at -O0 (PR analyzer/115724). */
+ kfm.add ("__error_alias", make_unique<kf_error> (3));
+ kfm.add ("__error_at_line_alias", make_unique<kf_error> (5));
}
/* Other implementations of C standard library. */
diff --git a/gcc/testsuite/c-c++-common/analyzer/error-pr115724.c
b/gcc/testsuite/c-c++-common/analyzer/error-pr115724.c
new file mode 100644
index 000000000000..ae606ad89d6a
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/analyzer/error-pr115724.c
@@ -0,0 +1,86 @@
+/* Verify that the analyzer handles the no-optimization case in
+ glibc's <error.h> when error,error_at_line calls become
+ __error_alias and __error_at_line_alias. */
+
+typedef __SIZE_TYPE__ size_t;
+#define EXIT_FAILURE 1
+#define __extern_always_inline extern inline __attribute__
((__always_inline__)) __attribute__ ((__gnu_inline__))
+
+int errno;
+
+/* Adapted from glibc's bits/error.h. */
+
+extern void __error_alias (int __status, int __errnum,
+ const char *__format, ...)
+ __attribute__ ((__format__ (__printf__, 3, 4)));
+extern void __error_noreturn (int __status, int __errnum,
+ const char *__format, ...)
+ __attribute__ ((__noreturn__, __format__ (__printf__, 3, 4)));
+
+/* If we know the function will never return make sure the compiler
+ realizes that, too. */
+__extern_always_inline void
+error (int __status, int __errnum, const char *__format, ...)
+{
+ if (__builtin_constant_p (__status) && __status != 0)
+ __error_noreturn (__status, __errnum, __format, __builtin_va_arg_pack ());
+ else
+ __error_alias (__status, __errnum, __format, __builtin_va_arg_pack ());
+}
+
+extern void __error_at_line_alias (int __status, int __errnum,
+ const char *__fname,
+ unsigned int __line,
+ const char *__format, ...)
+ __attribute__ ((__format__ (__printf__, 5, 6)));
+extern void __error_at_line_noreturn (int __status, int __errnum,
+ const char *__fname,
+ unsigned int __line,
+ const char *__format,
+ ...)
+ __attribute__ ((__noreturn__, __format__ (__printf__, 5, 6)));
+
+/* If we know the function will never return make sure the compiler
+ realizes that, too. */
+__extern_always_inline void
+error_at_line (int __status, int __errnum, const char *__fname,
+ unsigned int __line, const char *__format, ...)
+{
+ if (__builtin_constant_p (__status) && __status != 0)
+ __error_at_line_noreturn (__status, __errnum, __fname, __line, __format,
+ __builtin_va_arg_pack ());
+ else
+ __error_at_line_alias (__status, __errnum, __fname, __line,
+ __format, __builtin_va_arg_pack ());
+}
+
+
+struct list {
+ size_t size;
+ void (*destroy)(void *data);
+ struct list_node *head;
+ struct list_node *tail;
+};
+
+struct list *list_create(void (*destroy)(void *data))
+{
+ struct list *result = (struct list *)__builtin_calloc(1,
sizeof(*result));
+ if (!result)
+ error(EXIT_FAILURE,errno,"%s:%d
%s()",__FILE__,__LINE__,__func__);
+
+ result->destroy = destroy; /* { dg-bogus "dereference of NULL
'result'" } */
+
+ return result;
+}
+
+struct list *list_create_using_at_line(void (*destroy)(void *data))
+{
+ struct list *result = (struct list *)__builtin_calloc(1,
sizeof(*result));
+ if (!result)
+ error_at_line(EXIT_FAILURE,errno,__FILE__,__LINE__,
+ "%s()", __func__);
+
+ result->destroy = destroy; /* { dg-bogus "dereference of NULL
'result'" } */
+
+ return result;
+}
