Enable to use BH_VPRINTF macro to redirect stdout output (#560)

Enable to use BH_VPRINTF macro for platform Linux/Windows/Darwin/VxWorks to redirect the stdout output from platform os_printf/os_vprintf, or the wasi output from wasm app to the vprintf like callback function specified by BH_VPRINTF macro of cmake WAMR_BH_VPRINTF variable.

Signed-off-by: Wenyong Huang <wenyong.huang@intel.com>

core/iwasm/libraries/libc-uvwasi/libc_uvwasi_wrapper.c

@@ -604,8 +604,31 @@ wasi_fd_write(wasm_exec_env_t exec_env, wasi_fd_t fd,
         ciovec->buf_len = iovec_app->buf_len;
     }
 
-    err = uvwasi_fd_write(uvwasi, fd,
-                          ciovec_begin, iovs_len, &nwritten);
+#ifndef BH_VPRINTF
+    err = uvwasi_fd_write(uvwasi, fd, ciovec_begin, iovs_len, &nwritten);
+#else
+    /* redirect stdout/stderr output to BH_VPRINTF function */
+    if (fd == 1 || fd == 2) {
+        int i;
+        const struct iovec *iov1 = (const struct iovec *)ciovec_begin;
+
+        nwritten = 0;
+        for (i = 0; i < (int)iovs_len; i++, iov1++) {
+            if (iov1->iov_len > 0 && iov1->iov_base) {
+                char format[16];
+
+                /* make up format string "%.ns" */
+                snprintf(format, sizeof(format), "%%.%ds", (int)iov1->iov_len);
+                nwritten += (uvwasi_size_t)os_printf(format, iov1->iov_base);
+            }
+        }
+        err = 0;
+    }
+    else {
+        err = uvwasi_fd_write(uvwasi, fd, ciovec_begin, iovs_len, &nwritten);
+    }
+#endif /* end of BH_VPRINTF */
+
     if (err)
         goto fail;
 

core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/posix.c

@@ -1237,7 +1237,29 @@ __wasi_errno_t wasmtime_ssp_fd_write(
   if (error != 0)
     return error;
 
+#ifndef BH_VPRINTF
   ssize_t len = writev(fd_number(fo), (const struct iovec *)iov, (int)iovcnt);
+#else
+  ssize_t len = 0;
+  /* redirect stdout/stderr output to BH_VPRINTF function */
+  if (fd_number(fo) == 1 || fd_number(fo) == 2) {
+    int i;
+    const struct iovec *iov1 = (const struct iovec *)iov;
+
+    for (i = 0; i < (int)iovcnt; i++, iov1++) {
+      if (iov1->iov_len > 0 && iov1->iov_base) {
+        char format[16];
+
+        /* make up format string "%.ns" */
+        snprintf(format, sizeof(format), "%%.%ds", (int)iov1->iov_len);
+        len += (ssize_t)os_printf(format, iov1->iov_base);
+      }
+    }
+  }
+  else {
+    len = writev(fd_number(fo), (const struct iovec *)iov, (int)iovcnt);
+  }
+#endif /* end of BH_VPRINTF */
   fd_object_release(fo);
   if (len < 0)
     return convert_errno(errno);

core/shared/platform/darwin/platform_init.c

@@ -23,7 +23,11 @@ os_printf(const char *format, ...)
     va_list ap;
 
     va_start(ap, format);
+#ifndef BH_VPRINTF
     ret += vprintf(format, ap);
+#else
+    ret += BH_VPRINTF(format, ap);
+#endif
     va_end(ap);
 
     return ret;
@@ -32,6 +36,10 @@ os_printf(const char *format, ...)
 int
 os_vprintf(const char *format, va_list ap)
 {
+#ifndef BH_VPRINTF
     return vprintf(format, ap);
+#else
+    return BH_VPRINTF(format, ap);
+#endif
 }
 

core/shared/platform/include/platform_common.h

@@ -34,13 +34,21 @@ extern "C" {
 #endif
 
 #if defined(MSVC)
-__declspec(dllimport)  void *BH_MALLOC(unsigned int size);
-__declspec(dllimport)  void BH_FREE(void *ptr);
+__declspec(dllimport) void *BH_MALLOC(unsigned int size);
+__declspec(dllimport) void BH_FREE(void *ptr);
 #else
 void *BH_MALLOC(unsigned int size);
 void BH_FREE(void *ptr);
 #endif
 
+#if defined(BH_VPRINTF)
+#if defined(MSVC)
+__declspec(dllimport) int BH_VPRINTF(const char *format, va_list ap);
+#else
+int BH_VPRINTF(const char *format, va_list ap);
+#endif
+#endif
+
 #ifndef NULL
 #define NULL (void*)0
 #endif

core/shared/platform/linux/platform_init.c

@@ -23,7 +23,11 @@ os_printf(const char *format, ...)
     va_list ap;
 
     va_start(ap, format);
+#ifndef BH_VPRINTF
     ret += vprintf(format, ap);
+#else
+    ret += BH_VPRINTF(format, ap);
+#endif
     va_end(ap);
 
     return ret;
@@ -32,6 +36,10 @@ os_printf(const char *format, ...)
 int
 os_vprintf(const char *format, va_list ap)
 {
+#ifndef BH_VPRINTF
     return vprintf(format, ap);
+#else
+    return BH_VPRINTF(format, ap);
+#endif
 }
 

core/shared/platform/vxworks/platform_init.c

@@ -23,7 +23,11 @@ os_printf(const char *format, ...)
     va_list ap;
 
     va_start(ap, format);
+#ifndef BH_VPRINTF
     ret += vprintf(format, ap);
+#else
+    ret += BH_VPRINTF(format, ap);
+#endif
     va_end(ap);
 
     return ret;
@@ -32,6 +36,10 @@ os_printf(const char *format, ...)
 int
 os_vprintf(const char *format, va_list ap)
 {
+#ifndef BH_VPRINTF
     return vprintf(format, ap);
+#else
+    return BH_VPRINTF(format, ap);
+#endif
 }
 

core/shared/platform/windows/platform_init.c

@@ -16,3 +16,30 @@ bh_platform_destroy()
 {
 }
 
+int
+os_printf(const char *format, ...)
+{
+    int ret = 0;
+    va_list ap;
+
+    va_start(ap, format);
+#ifndef BH_VPRINTF
+    ret += vprintf(format, ap);
+#else
+    ret += BH_VPRINTF(format, ap);
+#endif
+    va_end(ap);
+
+    return ret;
+}
+
+int
+os_vprintf(const char *format, va_list ap)
+{
+#ifndef BH_VPRINTF
+    return vprintf(format, ap);
+#else
+    return BH_VPRINTF(format, ap);
+#endif
+}
+

core/shared/platform/windows/platform_internal.h

@@ -49,9 +49,6 @@ typedef struct {
     unsigned int waiting_count;
 } korp_cond;
 
-#define os_printf printf
-#define os_vprintf vprintf
-
 static inline size_t
 getpagesize()
 {