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-rw-r--r--wasm2c/examples/fac/fac.c2
-rw-r--r--wasm2c/wasm-rt-impl.c107
-rw-r--r--wasm2c/wasm-rt-impl.h2
-rw-r--r--wasm2c/wasm-rt.h48
4 files changed, 92 insertions, 67 deletions
diff --git a/wasm2c/examples/fac/fac.c b/wasm2c/examples/fac/fac.c
index 33151cdd..bd4ccb58 100644
--- a/wasm2c/examples/fac/fac.c
+++ b/wasm2c/examples/fac/fac.c
@@ -20,7 +20,7 @@
#define TRAP(x) (wasm_rt_trap(WASM_RT_TRAP_##x), 0)
-#if WASM_RT_USE_STACK_DEPTH_COUNT
+#if WASM_RT_STACK_DEPTH_COUNT
#define FUNC_PROLOGUE \
if (++wasm_rt_call_stack_depth > WASM_RT_MAX_CALL_STACK_DEPTH) \
TRAP(EXHAUSTION);
diff --git a/wasm2c/wasm-rt-impl.c b/wasm2c/wasm-rt-impl.c
index 5f22d3bf..09a28726 100644
--- a/wasm2c/wasm-rt-impl.c
+++ b/wasm2c/wasm-rt-impl.c
@@ -25,8 +25,7 @@
#include <stdlib.h>
#include <string.h>
-#if (WASM_RT_INSTALL_SIGNAL_HANDLER || !WASM_RT_USE_STACK_DEPTH_COUNT) && \
- !defined(_WIN32)
+#if WASM_RT_INSTALL_SIGNAL_HANDLER && !defined(_WIN32)
#include <signal.h>
#include <unistd.h>
#endif
@@ -39,6 +38,12 @@
#define PAGE_SIZE 65536
+#ifndef NDEBUG
+#define DEBUG_PRINTF(...) fprintf(stderr, __VA_ARGS__);
+#else
+#define DEBUG_PRINTF(...)
+#endif
+
#if WASM_RT_INSTALL_SIGNAL_HANDLER
static bool g_signal_handler_installed = false;
#ifdef _WIN32
@@ -46,10 +51,10 @@ static void* g_sig_handler_handle = 0;
#endif
#endif
-#if WASM_RT_USE_STACK_DEPTH_COUNT
+#if WASM_RT_STACK_DEPTH_COUNT
WASM_RT_THREAD_LOCAL uint32_t wasm_rt_call_stack_depth;
WASM_RT_THREAD_LOCAL uint32_t wasm_rt_saved_call_stack_depth;
-#elif WASM_RT_INSTALL_SIGNAL_HANDLER
+#elif WASM_RT_STACK_EXHAUSTION_HANDLER
static WASM_RT_THREAD_LOCAL void* g_alt_stack = NULL;
#endif
@@ -65,7 +70,7 @@ extern void WASM_RT_GROW_FAILED_HANDLER();
void wasm_rt_trap(wasm_rt_trap_t code) {
assert(code != WASM_RT_TRAP_NONE);
-#if WASM_RT_USE_STACK_DEPTH_COUNT
+#if WASM_RT_STACK_DEPTH_COUNT
wasm_rt_call_stack_depth = wasm_rt_saved_call_stack_depth;
#endif
@@ -164,7 +169,45 @@ static void os_print_last_error(const char* msg) {
perror(msg);
}
-#if !WASM_RT_USE_STACK_DEPTH_COUNT
+#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);
+ }
+}
+
+static void os_install_signal_handler(void) {
+ struct sigaction sa;
+ memset(&sa, '\0', sizeof(sa));
+ sa.sa_flags = SA_SIGINFO;
+#if WASM_RT_STACK_EXHAUSTION_HANDLER
+ sa.sa_flags |= SA_ONSTACK;
+#endif
+ sigemptyset(&sa.sa_mask);
+ sa.sa_sigaction = os_signal_handler;
+
+ /* Install SIGSEGV and SIGBUS handlers, since macOS seems to use SIGBUS. */
+ if (sigaction(SIGSEGV, &sa, NULL) != 0 || sigaction(SIGBUS, &sa, NULL) != 0) {
+ perror("sigaction failed");
+ abort();
+ }
+}
+
+static void os_cleanup_signal_handler(void) {
+ /* Undo what was done in os_install_signal_handler */
+ struct sigaction sa;
+ memset(&sa, '\0', sizeof(sa));
+ sa.sa_handler = SIG_DFL;
+ if (sigaction(SIGSEGV, &sa, NULL) != 0 || sigaction(SIGBUS, &sa, NULL)) {
+ perror("sigaction failed");
+ abort();
+ }
+}
+#endif
+
+#if WASM_RT_STACK_EXHAUSTION_HANDLER
static bool os_has_altstack_installed() {
/* check for altstack already in place */
stack_t ss;
@@ -175,18 +218,7 @@ 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 */
@@ -229,10 +261,8 @@ static void os_disable_and_deallocate_altstack(void) {
if ((!g_alt_stack) || (ss.ss_flags & SS_DISABLE) ||
(ss.ss_sp != g_alt_stack) || (ss.ss_size != SIGSTKSZ)) {
-#ifndef NDEBUG
- fprintf(stderr,
- "wasm-rt warning: alternate stack was modified unexpectedly\n");
-#endif
+ DEBUG_PRINTF(
+ "wasm-rt warning: alternate stack was modified unexpectedly\n");
return;
}
@@ -247,35 +277,6 @@ static void os_disable_and_deallocate_altstack(void) {
}
#endif
-static void os_install_signal_handler(void) {
- struct sigaction sa;
- memset(&sa, '\0', sizeof(sa));
- sa.sa_flags = SA_SIGINFO;
-#if !WASM_RT_USE_STACK_DEPTH_COUNT
- sa.sa_flags |= SA_ONSTACK;
-#endif
- sigemptyset(&sa.sa_mask);
- sa.sa_sigaction = os_signal_handler;
-
- /* Install SIGSEGV and SIGBUS handlers, since macOS seems to use SIGBUS. */
- if (sigaction(SIGSEGV, &sa, NULL) != 0 || sigaction(SIGBUS, &sa, NULL) != 0) {
- perror("sigaction failed");
- abort();
- }
-}
-
-static void os_cleanup_signal_handler(void) {
- /* Undo what was done in os_install_signal_handler */
- struct sigaction sa;
- memset(&sa, '\0', sizeof(sa));
- sa.sa_handler = SIG_DFL;
- if (sigaction(SIGSEGV, &sa, NULL) != 0 || sigaction(SIGBUS, &sa, NULL)) {
- perror("sigaction failed");
- abort();
- }
-}
-#endif
-
#endif
void wasm_rt_init(void) {
@@ -290,7 +291,7 @@ void wasm_rt_init(void) {
}
bool wasm_rt_is_initialized(void) {
-#if !WASM_RT_USE_STACK_DEPTH_COUNT
+#if WASM_RT_STACK_EXHAUSTION_HANDLER
if (!os_has_altstack_installed()) {
return false;
}
@@ -312,13 +313,13 @@ void wasm_rt_free(void) {
}
void wasm_rt_init_thread(void) {
-#if WASM_RT_INSTALL_SIGNAL_HANDLER && !WASM_RT_USE_STACK_DEPTH_COUNT
+#if WASM_RT_STACK_EXHAUSTION_HANDLER
os_allocate_and_install_altstack();
#endif
}
void wasm_rt_free_thread(void) {
-#if WASM_RT_INSTALL_SIGNAL_HANDLER && !WASM_RT_USE_STACK_DEPTH_COUNT
+#if WASM_RT_STACK_EXHAUSTION_HANDLER
os_disable_and_deallocate_altstack();
#endif
}
diff --git a/wasm2c/wasm-rt-impl.h b/wasm2c/wasm-rt-impl.h
index c7d7fdbf..aa6f46d9 100644
--- a/wasm2c/wasm-rt-impl.h
+++ b/wasm2c/wasm-rt-impl.h
@@ -30,7 +30,7 @@ extern "C" {
/** A setjmp buffer used for handling traps. */
extern WASM_RT_THREAD_LOCAL wasm_rt_jmp_buf g_wasm_rt_jmp_buf;
-#if WASM_RT_USE_STACK_DEPTH_COUNT
+#if WASM_RT_STACK_DEPTH_COUNT
/** Saved call stack depth that will be restored in case a trap occurs. */
extern WASM_RT_THREAD_LOCAL uint32_t wasm_rt_saved_call_stack_depth;
#define WASM_RT_SAVE_STACK_DEPTH() \
diff --git a/wasm2c/wasm-rt.h b/wasm2c/wasm-rt.h
index fe68aa1d..55b3cce8 100644
--- a/wasm2c/wasm-rt.h
+++ b/wasm2c/wasm-rt.h
@@ -166,17 +166,42 @@ extern "C" {
#define WASM_RT_INSTALL_SIGNAL_HANDLER 0
#endif
-#ifndef WASM_RT_USE_STACK_DEPTH_COUNT
-/* The signal handler on POSIX can detect call stack overflows. On windows, or
- * platforms without a signal handler, we use stack depth counting. */
+/* We need to detect and trap stack overflows. If we use a signal handler on
+ * POSIX systems, this can detect call stack overflows. On windows, or platforms
+ * without a signal handler, we use stack depth counting. */
+#if !defined(WASM_RT_STACK_DEPTH_COUNT) && \
+ !defined(WASM_RT_STACK_EXHAUSTION_HANDLER)
+
#if WASM_RT_INSTALL_SIGNAL_HANDLER && !defined(_WIN32)
-#define WASM_RT_USE_STACK_DEPTH_COUNT 0
+#define WASM_RT_STACK_EXHAUSTION_HANDLER 1
#else
-#define WASM_RT_USE_STACK_DEPTH_COUNT 1
+#define WASM_RT_STACK_DEPTH_COUNT 1
+#endif
+
+#endif
+
+// Ensure the stack macros are defined
+#ifndef WASM_RT_STACK_DEPTH_COUNT
+#define WASM_RT_STACK_DEPTH_COUNT 0
+#endif
+#ifndef WASM_RT_STACK_EXHAUSTION_HANDLER
+#define WASM_RT_STACK_EXHAUSTION_HANDLER 0
#endif
+
+#if (WASM_RT_STACK_EXHAUSTION_HANDLER + WASM_RT_STACK_DEPTH_COUNT) > 1
+#error \
+ "Cannot specify multiple options from WASM_RT_STACK_EXHAUSTION_HANDLER , WASM_RT_STACK_DEPTH_COUNT"
+#elif (WASM_RT_STACK_EXHAUSTION_HANDLER + WASM_RT_STACK_DEPTH_COUNT) == 0
+#error \
+ "Must specify one of WASM_RT_STACK_EXHAUSTION_HANDLER , WASM_RT_STACK_DEPTH_COUNT"
+#endif
+
+#if WASM_RT_STACK_EXHAUSTION_HANDLER && !WASM_RT_INSTALL_SIGNAL_HANDLER
+#error \
+ "WASM_RT_STACK_EXHAUSTION_HANDLER can only be used if WASM_RT_INSTALL_SIGNAL_HANDLER is enabled"
#endif
-#if WASM_RT_USE_STACK_DEPTH_COUNT
+#if WASM_RT_STACK_DEPTH_COUNT
/**
* When the signal handler cannot be used to detect stack overflows, stack depth
* is limited explicitly. The maximum stack depth before trapping can be
@@ -202,7 +227,7 @@ 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_USE_STACK_DEPTH_COUNT
+#if defined(__APPLE__) && WASM_RT_STACK_EXHAUSTION_HANDLER
#define WASM_RT_MERGED_OOB_AND_EXHAUSTION_TRAPS 1
#else
#define WASM_RT_MERGED_OOB_AND_EXHAUSTION_TRAPS 0
@@ -279,7 +304,8 @@ typedef struct {
} wasm_rt_funcref_t;
/** Default (null) value of a funcref */
-#define wasm_rt_funcref_null_value ((wasm_rt_funcref_t){NULL, NULL, {NULL}, NULL})
+#define wasm_rt_funcref_null_value \
+ ((wasm_rt_funcref_t){NULL, NULL, {NULL}, NULL})
/** The type of an external reference (opaque to WebAssembly). */
typedef void* wasm_rt_externref_t;
@@ -354,8 +380,7 @@ typedef struct {
jmp_buf buffer;
} wasm_rt_jmp_buf;
-#if (WASM_RT_INSTALL_SIGNAL_HANDLER || (!WASM_RT_USE_STACK_DEPTH_COUNT)) && \
- !defined(_WIN32)
+#ifndef _WIN32
#define WASM_RT_SETJMP_SETBUF(buf) sigsetjmp(buf, 1)
#else
#define WASM_RT_SETJMP_SETBUF(buf) setjmp(buf)
@@ -364,8 +389,7 @@ typedef struct {
#define WASM_RT_SETJMP(buf) \
((buf).initialized = true, WASM_RT_SETJMP_SETBUF((buf).buffer))
-#if (WASM_RT_INSTALL_SIGNAL_HANDLER || (!WASM_RT_USE_STACK_DEPTH_COUNT)) && \
- !defined(_WIN32)
+#ifndef _WIN32
#define WASM_RT_LONGJMP_UNCHECKED(buf, val) siglongjmp(buf, val)
#else
#define WASM_RT_LONGJMP_UNCHECKED(buf, val) longjmp(buf, val)
generated by cgit v1.2.3 (git 2.39.1) at 2025-08-26 06:04:54 +0000