wasm2c runtime: fix mis-nesting of def'n of os_has_altstack_installed (#2346)

Also adds an RLBox-like CI test where the embedder takes responsibility for signal handling

Co-authored-by: wrv <wrv@utexas.edu>

2 files changed, 20 insertions, 15 deletions

diff --git a/wasm2c/wasm-rt-impl.c b/wasm2c/wasm-rt-impl.c
index 72e4d66e..5f22d3bf 100644
--- a/wasm2c/wasm-rt-impl.c
+++ b/wasm2c/wasm-rt-impl.c
@@ -25,7 +25,8 @@
 #include <stdlib.h>
 #include <string.h>
 
-#if WASM_RT_INSTALL_SIGNAL_HANDLER && !defined(_WIN32)
+#if (WASM_RT_INSTALL_SIGNAL_HANDLER || !WASM_RT_USE_STACK_DEPTH_COUNT) && \
+    !defined(_WIN32)
 #include <signal.h>
 #include <unistd.h>
 #endif
@@ -163,17 +164,7 @@ static void os_print_last_error(const char* msg) {
   perror(msg);
 }
 
-#if WASM_RT_INSTALL_SIGNAL_HANDLER
-static void os_signal_handler(int sig, siginfo_t* si, void* unused) {
-  if (si->si_code == SEGV_ACCERR) {
-    wasm_rt_trap(WASM_RT_TRAP_OOB);
-  } else {
-    wasm_rt_trap(WASM_RT_TRAP_EXHAUSTION);
-  }
-}
-
 #if !WASM_RT_USE_STACK_DEPTH_COUNT
-/* These routines set up an altstack to handle SIGSEGV from stack overflow. */
 static bool os_has_altstack_installed() {
   /* check for altstack already in place */
   stack_t ss;
@@ -184,7 +175,19 @@ static bool os_has_altstack_installed() {
 
   return !(ss.ss_flags & SS_DISABLE);
 }
+#endif
+
+#if WASM_RT_INSTALL_SIGNAL_HANDLER
+static void os_signal_handler(int sig, siginfo_t* si, void* unused) {
+  if (si->si_code == SEGV_ACCERR) {
+    wasm_rt_trap(WASM_RT_TRAP_OOB);
+  } else {
+    wasm_rt_trap(WASM_RT_TRAP_EXHAUSTION);
+  }
+}
 
+#if !WASM_RT_USE_STACK_DEPTH_COUNT
+/* These routines set up an altstack to handle SIGSEGV from stack overflow. */
 static void os_allocate_and_install_altstack(void) {
   /* verify altstack not already allocated */
   assert(!g_alt_stack &&
diff --git a/wasm2c/wasm-rt.h b/wasm2c/wasm-rt.h
index a79271e3..fe68aa1d 100644
--- a/wasm2c/wasm-rt.h
+++ b/wasm2c/wasm-rt.h
@@ -202,7 +202,7 @@ extern WASM_RT_THREAD_LOCAL uint32_t wasm_rt_call_stack_depth;
 #define WASM_RT_NO_RETURN __attribute__((noreturn))
 #endif
 
-#if defined(__APPLE__) && WASM_RT_INSTALL_SIGNAL_HANDLER
+#if defined(__APPLE__) && !WASM_RT_USE_STACK_DEPTH_COUNT
 #define WASM_RT_MERGED_OOB_AND_EXHAUSTION_TRAPS 1
 #else
 #define WASM_RT_MERGED_OOB_AND_EXHAUSTION_TRAPS 0
@@ -218,7 +218,7 @@ typedef enum {
   WASM_RT_TRAP_UNREACHABLE,        /** Unreachable instruction executed. */
   WASM_RT_TRAP_CALL_INDIRECT,      /** Invalid call_indirect, for any reason. */
   WASM_RT_TRAP_UNCAUGHT_EXCEPTION, /* Exception thrown and not caught. */
-  WASM_RT_TRAP_UNALIGNED, /** Unaligned atomic instruction executed. */
+  WASM_RT_TRAP_UNALIGNED,          /** Unaligned atomic instruction executed. */
 #if WASM_RT_MERGED_OOB_AND_EXHAUSTION_TRAPS
   WASM_RT_TRAP_EXHAUSTION = WASM_RT_TRAP_OOB,
 #else
@@ -354,7 +354,8 @@ typedef struct {
   jmp_buf buffer;
 } wasm_rt_jmp_buf;
 
-#if WASM_RT_INSTALL_SIGNAL_HANDLER && !defined(_WIN32)
+#if (WASM_RT_INSTALL_SIGNAL_HANDLER || (!WASM_RT_USE_STACK_DEPTH_COUNT)) && \
+    !defined(_WIN32)
 #define WASM_RT_SETJMP_SETBUF(buf) sigsetjmp(buf, 1)
 #else
 #define WASM_RT_SETJMP_SETBUF(buf) setjmp(buf)
@@ -363,7 +364,8 @@ typedef struct {
 #define WASM_RT_SETJMP(buf) \
   ((buf).initialized = true, WASM_RT_SETJMP_SETBUF((buf).buffer))
 
-#if WASM_RT_INSTALL_SIGNAL_HANDLER && !defined(_WIN32)
+#if (WASM_RT_INSTALL_SIGNAL_HANDLER || (!WASM_RT_USE_STACK_DEPTH_COUNT)) && \
+    !defined(_WIN32)
 #define WASM_RT_LONGJMP_UNCHECKED(buf, val) siglongjmp(buf, val)
 #else
 #define WASM_RT_LONGJMP_UNCHECKED(buf, val) longjmp(buf, val)