checkasm/riscv: report an error upon SIGILL

Terminating the whole checkasm process is not very helpful. This will
report if an illegal instruction occurs while executing a tested
function. This is a common occurrence whilst developping RISC-V
assembler, due to the compatibility between vector configuration and
instruction done at run-time.

tests/checkasm/checkasm.c

@@ -27,6 +27,7 @@
 # define _GNU_SOURCE // for syscall (performance monitoring API), strsignal()
 #endif
 
+#include <signal.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -734,6 +735,14 @@ int main(int argc, char *argv[])
     if (have_vfp(av_get_cpu_flags()) || have_neon(av_get_cpu_flags()))
         checkasm_checked_call = checkasm_checked_call_vfp;
 #endif
+#if ARCH_RISCV
+    struct sigaction act = {
+        .sa_handler = checkasm_handle_signal,
+        .sa_flags = 0,
+    };
+
+    sigaction(SIGILL, &act, NULL);
+#endif
 
     if (!tests[0].func || !cpus[0].flag) {
         fprintf(stderr, "checkasm: no tests to perform\n");

tests/checkasm/checkasm.h

@@ -23,6 +23,7 @@
 #ifndef TESTS_CHECKASM_CHECKASM_H
 #define TESTS_CHECKASM_CHECKASM_H
 
+#include <setjmp.h>
 #include <stdint.h>
 #include "config.h"
 
@@ -211,14 +212,20 @@ void checkasm_checked_call(void *func, ...);
                       checked_call(func_new, 0, 0, 0, 0, 0, 0, 0, __VA_ARGS__,\
                                    7, 6, 5, 4, 3, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0))
 #elif ARCH_RISCV
-void checkasm_set_function(void *);
+void checkasm_set_function(void *, sigjmp_buf);
 void *checkasm_get_wrapper(void);
+void checkasm_handle_signal(int signum);
 
 #if (__riscv_xlen == 64) && defined (__riscv_d)
 #define declare_new(ret, ...) \
+    int checked_call_signum = 0; \
+    sigjmp_buf checked_call_jb; \
     ret (*checked_call)(__VA_ARGS__) = checkasm_get_wrapper();
 #define call_new(...) \
-    (checkasm_set_function(func_new), checked_call(__VA_ARGS__))
+    (checkasm_set_function(func_new, checked_call_jb), \
+     (checked_call_signum = sigsetjmp(checked_call_jb, 1)) == 0 \
+        ? checked_call(__VA_ARGS__) \
+        : (checkasm_fail_signal(checked_call_signum), 0))
 #endif
 #else
 #define declare_new(ret, ...)

tests/checkasm/riscv/checkasm.S

@@ -41,6 +41,7 @@ endconst
 
 checked_func:
         .quad   0
+        .quad   0
 
 saved_regs:
         /* Space to spill RA, SP, GP, TP, S0-S11 and FS0-FS11 */
@@ -52,6 +53,7 @@ func checkasm_set_function
         la.tls.ie t0, checked_func
         add     t0, tp, t0
         sd      a0, (t0)
+        sd      a1, 8(t0)
         ret
 endfunc
 
@@ -175,4 +177,14 @@ func checkasm_get_wrapper, v
         call    checkasm_fail_func
         j       4b
 endfunc
+
+func checkasm_handle_signal
+        mv      a1, a0
+        la.tls.ie a0, checked_func
+        add     a0, tp, a0
+        ld      a0, 8(a0)
+        beqz    a0, 8f
+        tail    siglongjmp
+8:      tail    abort /* No jump buffer to go to */
+endfunc
 #endif