On Sun, May 16, 2021 at 07:01:45PM +0200, Bruno Haible wrote:
[...]
> To fix this problem, I'm adding a module 'sigsegv'.
I've tried to rebuild the latest GNU grep with the latest gnulib
and got a few build issues:
sigsegv.c: In function 'sigsegv_handler':
sigsegv.c:1059:36: error: declaration of 'sig' shadows a parameter
[-Werror=shadow]
1059 | SIGSEGV_FOR_ALL_SIGNALS (sig, signal (sig, SIG_DFL);)
| ^~~
sigsegv.c:738:11: note: in definition of macro 'SIGSEGV_FOR_ALL_SIGNALS'
738 | { int var; var = SIGSEGV; { body } }
| ^~~
sigsegv.c:64:45: note: shadowed declaration is here
64 | # define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, siginfo_t *sip, void
*ucp
| ~~~~^~~
sigsegv.c:915:18: note: in expansion of macro 'SIGSEGV_FAULT_HANDLER_ARGLIST'
915 | sigsegv_handler (SIGSEGV_FAULT_HANDLER_ARGLIST)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test-sigsegv-catch-segv1.c:42:1: error: no previous prototype for 'handler'
[-Werror=missing-prototypes]
42 | handler (void *fault_address, int serious)
| ^~~~~~~
test-sigsegv-catch-segv1.c:56:1: error: no previous prototype for 'crasher'
[-Werror=missing-prototypes]
56 | crasher (uintptr_t p)
| ^~~~~~~
test-sigsegv-catch-segv2.c:61:1: error: no previous prototype for 'handler'
[-Werror=missing-prototypes]
61 | handler (void *fault_address, int serious)
| ^~~~~~~
test-sigsegv-catch-segv2.c:76:1: error: no previous prototype for 'crasher'
[-Werror=missing-prototypes]
76 | crasher (uintptr_t p)
| ^~~~~~~
test-sigsegv-catch-stackoverflow1.c:62:1: error: no previous prototype for
'stackoverflow_handler' [-Werror=missing-prototypes]
62 | stackoverflow_handler (int emergency, stackoverflow_context_t scp)
| ^~~~~~~~~~~~~~~~~~~~~
test-sigsegv-catch-stackoverflow1.c:76:1: error: no previous prototype for
'recurse_1' [-Werror=missing-prototypes]
76 | recurse_1 (int n, volatile int *p)
| ^~~~~~~~~
test-sigsegv-catch-stackoverflow1.c:84:1: error: no previous prototype for
'recurse' [-Werror=missing-prototypes]
84 | recurse (volatile int n)
| ^~~~~~~
test-sigsegv-catch-stackoverflow2.c:62:1: error: no previous prototype for
'stackoverflow_handler' [-Werror=missing-prototypes]
62 | stackoverflow_handler (int emergency, stackoverflow_context_t scp)
| ^~~~~~~~~~~~~~~~~~~~~
test-sigsegv-catch-stackoverflow2.c:78:1: error: no previous prototype for
'sigsegv_handler' [-Werror=missing-prototypes]
78 | sigsegv_handler (void *address, int emergency)
| ^~~~~~~~~~~~~~~
test-sigsegv-catch-stackoverflow2.c:98:1: error: no previous prototype for
'recurse_1' [-Werror=missing-prototypes]
98 | recurse_1 (int n, volatile int *p)
| ^~~~~~~~~
test-sigsegv-catch-stackoverflow2.c:106:1: error: no previous prototype for
'recurse' [-Werror=missing-prototypes]
106 | recurse (volatile int n)
| ^~~~~~~
test-sigsegv-catch-stackoverflow2.c: In function 'main':
test-sigsegv-catch-stackoverflow2.c:186:27: error: null pointer dereference
[-Werror=null-dereference]
186 | *(volatile int *) 0 = 42;
| ~~~~~~~~~~~~~~~~~~~~^~~~
The following gnulib patch makes the compiler happy again:
diff --git a/lib/sigsegv.c b/lib/sigsegv.c
index 312f132b8..b0b406685 100644
--- a/lib/sigsegv.c
+++ b/lib/sigsegv.c
@@ -1056,7 +1056,7 @@ sigsegv_handler (SIGSEGV_FAULT_HANDLER_ARGLIST)
/* Handler declined responsibility for real. */
/* Remove ourselves and dump core. */
- SIGSEGV_FOR_ALL_SIGNALS (sig, signal (sig, SIG_DFL);)
+ SIGSEGV_FOR_ALL_SIGNALS (signo, signal (signo, SIG_DFL);)
}
# if HAVE_STACK_OVERFLOW_RECOVERY
diff --git a/tests/test-sigsegv-catch-segv1.c b/tests/test-sigsegv-catch-segv1.c
index 62eef69c8..741a37878 100644
--- a/tests/test-sigsegv-catch-segv1.c
+++ b/tests/test-sigsegv-catch-segv1.c
@@ -38,7 +38,7 @@ uintptr_t page;
volatile int handler_called = 0;
-int
+static int
handler (void *fault_address, int serious)
{
handler_called++;
@@ -52,7 +52,7 @@ handler (void *fault_address, int serious)
return 0;
}
-void
+static void
crasher (uintptr_t p)
{
*(volatile int *) (p + 0x678) = 42;
diff --git a/tests/test-sigsegv-catch-segv2.c b/tests/test-sigsegv-catch-segv2.c
index dd28517f9..f28cb0a8e 100644
--- a/tests/test-sigsegv-catch-segv2.c
+++ b/tests/test-sigsegv-catch-segv2.c
@@ -57,7 +57,7 @@ handler_continuation (void *arg1, void *arg2, void *arg3)
longjmp (mainloop, pass);
}
-int
+static int
handler (void *fault_address, int serious)
{
handler_called++;
@@ -72,7 +72,7 @@ handler (void *fault_address, int serious)
return sigsegv_leave_handler (handler_continuation, NULL, NULL, NULL);
}
-void
+static void
crasher (uintptr_t p)
{
*(volatile int *) (p + 0x678 + 8 * pass) = 42;
diff --git a/tests/test-sigsegv-catch-stackoverflow1.c
b/tests/test-sigsegv-catch-stackoverflow1.c
index c828ed282..bfa04ae8b 100644
--- a/tests/test-sigsegv-catch-stackoverflow1.c
+++ b/tests/test-sigsegv-catch-stackoverflow1.c
@@ -58,7 +58,7 @@ stackoverflow_handler_continuation (void *arg1, void *arg2,
void *arg3)
longjmp (mainloop, arg);
}
-void
+static void
stackoverflow_handler (int emergency, stackoverflow_context_t scp)
{
char dummy;
@@ -72,7 +72,7 @@ stackoverflow_handler (int emergency, stackoverflow_context_t
scp)
(void *) (long) (emergency ? -1 : pass), NULL, NULL);
}
-volatile int *
+static volatile int *
recurse_1 (int n, volatile int *p)
{
if (n < INT_MAX)
@@ -80,7 +80,7 @@ recurse_1 (int n, volatile int *p)
return p;
}
-int
+static int
recurse (volatile int n)
{
return *recurse_1 (n, &n);
diff --git a/tests/test-sigsegv-catch-stackoverflow2.c
b/tests/test-sigsegv-catch-stackoverflow2.c
index b94d1310b..f7fd191a6 100644
--- a/tests/test-sigsegv-catch-stackoverflow2.c
+++ b/tests/test-sigsegv-catch-stackoverflow2.c
@@ -58,7 +58,7 @@ stackoverflow_handler_continuation (void *arg1, void *arg2,
void *arg3)
longjmp (mainloop, arg);
}
-void
+static void
stackoverflow_handler (int emergency, stackoverflow_context_t scp)
{
pass++;
@@ -74,7 +74,7 @@ stackoverflow_handler (int emergency, stackoverflow_context_t
scp)
(void *) (long) (emergency ? -1 : pass), NULL, NULL);
}
-int
+static int
sigsegv_handler (void *address, int emergency)
{
/* This test is necessary to distinguish stack overflow and SIGSEGV. */
@@ -94,7 +94,7 @@ sigsegv_handler (void *address, int emergency)
(void *) (long) pass, NULL, NULL);
}
-volatile int *
+static volatile int *
recurse_1 (int n, volatile int *p)
{
if (n < INT_MAX)
@@ -102,7 +102,7 @@ recurse_1 (int n, volatile int *p)
return p;
}
-int
+static int
recurse (volatile int n)
{
return *recurse_1 (n, &n);
@@ -183,6 +183,9 @@ main ()
*(volatile int *) (page + 0x678) = 42;
break;
case 3:
+#if 6 < __GNUC__
+# pragma GCC diagnostic ignored "-Wnull-dereference"
+#endif
*(volatile int *) 0 = 42;
break;
case 4:
--
ldv
