From fa67b926b47620d1b14b9696294f22cf3af081ae Mon Sep 17 00:00:00 2001
From: Ivan Grokhotkov <ivan@espressif.com>
Date: Tue, 14 Aug 2018 23:20:34 +0300
Subject: [PATCH 1/4] add stubs for more exception throw calls

Fixes https://github.com/esp8266/Arduino/issues/3358
---
 cores/esp8266/abi.cpp | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/cores/esp8266/abi.cpp b/cores/esp8266/abi.cpp
index 8001c185a5..aa4d29f990 100644
--- a/cores/esp8266/abi.cpp
+++ b/cores/esp8266/abi.cpp
@@ -127,7 +127,24 @@ void __throw_out_of_range(const char* str)
     (void) str;
     panic();
 }
+
+void __throw_bad_cast(void)
+{
+    panic();
+}
+
+void __throw_ios_failure(const char* str)
+{
+    (void) str;
+    panic();
+}
+
+void __throw_runtime_error(const char* str)
+{
+    (void) str;
+    panic();
 }
+} // namespace std
 
 // TODO: rebuild windows toolchain to make this unnecessary:
 void* __dso_handle;

From 97d08065f9ee2f195756efde554497a5e449c2f0 Mon Sep 17 00:00:00 2001
From: Ivan Grokhotkov <ivan@espressif.com>
Date: Tue, 14 Aug 2018 23:22:24 +0300
Subject: [PATCH 2/4] libc: make putc_r implementation weak

newlib provides its own implementation of _putc_r, which will call
_write_r (possibly after buffering). Make our implementation weak to
allow using the one from newlib.

Fixes https://github.com/esp8266/Arduino/issues/4630
---
 cores/esp8266/libc_replacements.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/cores/esp8266/libc_replacements.c b/cores/esp8266/libc_replacements.c
index fe111ba4cb..50bb246062 100644
--- a/cores/esp8266/libc_replacements.c
+++ b/cores/esp8266/libc_replacements.c
@@ -93,6 +93,8 @@ int ICACHE_RAM_ATTR _write_r(struct _reent* r, int file, char *ptr, int len) {
     return len;
 }
 
+int ICACHE_RAM_ATTR _putc_r(struct _reent* r, int c, FILE* file) __attribute__((weak));
+
 int ICACHE_RAM_ATTR _putc_r(struct _reent* r, int c, FILE* file) {
     (void) r;
     if (file->_file == STDOUT_FILENO) {

From 074dff7fdcd70918e93958d0d7f06651bb854888 Mon Sep 17 00:00:00 2001
From: Ivan Grokhotkov <ivan@espressif.com>
Date: Tue, 14 Aug 2018 23:23:49 +0300
Subject: [PATCH 3/4] libc: fix incorrect return value of _write_r call

Should return number of bytes written, actually returned zero. This
resulted in std::cout going into failed state after the first write.
---
 cores/esp8266/libc_replacements.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/cores/esp8266/libc_replacements.c b/cores/esp8266/libc_replacements.c
index 50bb246062..fc6c2f142d 100644
--- a/cores/esp8266/libc_replacements.c
+++ b/cores/esp8266/libc_replacements.c
@@ -84,8 +84,9 @@ int ICACHE_RAM_ATTR _read_r(struct _reent* unused, int file, char *ptr, int len)
 
 int ICACHE_RAM_ATTR _write_r(struct _reent* r, int file, char *ptr, int len) {
     (void) r;
+    int pos = len;
     if (file == STDOUT_FILENO) {
-        while(len--) {
+        while(pos--) {
             ets_putc(*ptr);
             ++ptr;
         }

From 6e906b2d9deacf8015097cfce580444e8b97db66 Mon Sep 17 00:00:00 2001
From: Ivan Grokhotkov <ivan@espressif.com>
Date: Tue, 14 Aug 2018 23:40:48 +0300
Subject: [PATCH 4/4] tests: add test for output to std::cout

---
 tests/device/test_iostream/test_iostream.ino | 34 ++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 tests/device/test_iostream/test_iostream.ino

diff --git a/tests/device/test_iostream/test_iostream.ino b/tests/device/test_iostream/test_iostream.ino
new file mode 100644
index 0000000000..b644882bf2
--- /dev/null
+++ b/tests/device/test_iostream/test_iostream.ino
@@ -0,0 +1,34 @@
+#include <ESP8266WiFi.h>
+#include <BSTest.h>
+#include <sstream>
+#include <iostream>
+
+BS_ENV_DECLARE();
+
+void setup()
+{
+    Serial.begin(115200);
+    BS_RUN(Serial);
+}
+
+TEST_CASE("can print to std::cout", "[iostream]")
+{
+    std::stringstream test_stream("");
+    test_stream << "hello stream";
+
+    // empty the RX buffer, just in case
+    Serial.readString();
+
+    USC0(0) |= (1 << UCLBE);  // enable loopback
+    std::cout << test_stream.str().c_str() << std::endl;
+    delay(100);
+    USC0(0) &= ~(1 << UCLBE);  // disable loopback
+    
+    String result = Serial.readStringUntil('\n');
+
+    Serial.printf("result: '%s'\n", result.c_str());
+
+    CHECK(result == test_stream.str().c_str());
+}
+
+void loop() { }