Add a basic testcase for emulated signals.

tests/general/signals.c

@@ -0,0 +1,88 @@
+#include <signal.h>
+#include <string.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+
+// Check for C-standard macros.
+#ifndef SIGABRT
+#error SIGABRT not defined
+#endif
+#ifndef SIGFPE
+#error SIGFPE not defined
+#endif
+#ifndef SIGILL
+#error SIGILL not defined
+#endif
+#ifndef SIGINT
+#error SIGINT not defined
+#endif
+#ifndef SIGSEGV
+#error SIGSEGV not defined
+#endif
+#ifndef SIGTERM
+#error SIGTERM not defined
+#endif
+
+// Make sure this exists.
+#include <sys/signal.h>
+
+volatile sig_atomic_t flag = 0;
+
+static void handler(int n) {
+    // This is undefined behavior by the spec, but this is just a testcase.
+    fflush(stdout);
+    printf("handler for signal %s\n", strsignal(n));
+    fflush(stdout);
+    flag = 1;
+}
+
+int main(void) {
+    // Test various raise cases that don't abort.
+    assert(raise(SIGCHLD) == 0);
+#ifdef SIGCLD
+    assert(raise(SIGCLD) == 0);
+#endif
+    assert(raise(SIGURG) == 0);
+    assert(raise(SIGWINCH) == 0);
+
+    errno = 0;
+    assert(raise(_NSIG) == -1 && errno == EINVAL);
+
+    // Test psignal.
+    psignal(SIGINT, "psignal message for SIGINT");
+
+    // Test strsignal.
+    printf("strsignal for SIGHUP: '%s'\n", strsignal(SIGHUP));
+
+    // Some signals can't be ignored.
+    errno = 0;
+    assert(signal(SIGKILL, SIG_IGN) == SIG_ERR && errno == EINVAL);
+    errno = 0;
+    assert(signal(SIGSTOP, SIG_IGN) == SIG_ERR && errno == EINVAL);
+
+    // Test SIG_IGN.
+    assert(signal(SIGINT, SIG_IGN) == SIG_DFL);
+    raise(SIGINT);
+    assert(signal(SIGINT, SIG_DFL) == SIG_IGN);
+
+    // Install a handler and invoke it.
+    printf("beginning handler test:\n");
+    assert(signal(SIGWINCH, handler) == SIG_DFL);
+    fflush(stdout);
+    assert(raise(SIGWINCH) == 0);
+    fflush(stdout);
+    assert(flag == 1);
+    printf("finished handler test\n");
+
+    // Check various API invariants.
+    assert(signal(SIGWINCH, SIG_IGN) == handler);
+    assert(raise(SIGWINCH) == 0);
+    assert(signal(SIGWINCH, SIG_DFL) == SIG_IGN);
+    assert(raise(SIGWINCH) == 0);
+    assert(signal(SIGWINCH, SIG_DFL) == SIG_DFL);
+    assert(raise(SIGWINCH) == 0);
+
+    return EXIT_SUCCESS;
+}

tests/general/signals.c.options

@@ -0,0 +1 @@
+-D_WASI_EMULATED_SIGNAL -lwasi-emulated-signal

tests/general/signals.c.stderr.expected

@@ -0,0 +1 @@
+psignal message for SIGINT: Interrupt

tests/general/signals.c.stdout.expected

@@ -0,0 +1,4 @@
+strsignal for SIGHUP: 'Hangup'
+beginning handler test:
+handler for signal Window changed
+finished handler test