From 457852666cb870a844df016962fac487cb5e7559 Mon Sep 17 00:00:00 2001
From: Elliott Hughes <enh@google.com>
Date: Wed, 14 Feb 2018 15:21:45 -0800
Subject: [PATCH] Add __fseterr.

Trivial, obvious counterpart to the standard ferror(3) and clearerr(3),
and lets us build bison out of the box.

Bug: http://b/64273806
Test: ran tests
Change-Id: I20affabddb71210051165c41e86adfe5ae04f77f
---
 libc/include/stdio_ext.h |  2 ++
 libc/libc.arm.map        |  1 +
 libc/libc.arm64.map      |  1 +
 libc/libc.map.txt        |  1 +
 libc/libc.mips.map       |  1 +
 libc/libc.mips64.map     |  1 +
 libc/libc.x86.map        |  1 +
 libc/libc.x86_64.map     |  1 +
 libc/stdio/stdio_ext.cpp |  4 ++++
 tests/stdio_ext_test.cpp | 16 ++++++++++++++++
 10 files changed, 29 insertions(+)

diff --git a/libc/include/stdio_ext.h b/libc/include/stdio_ext.h
index 2f0f438e0..b8aa68dbd 100644
--- a/libc/include/stdio_ext.h
+++ b/libc/include/stdio_ext.h
@@ -45,6 +45,8 @@ void __fpurge(FILE* __fp) __INTRODUCED_IN(23);
 size_t __fpending(FILE* __fp) __INTRODUCED_IN(23);
 void _flushlbf(void) __INTRODUCED_IN(23);
 
+void __fseterr(FILE* __fp) __INTRODUCED_IN(28);
+
 #define FSETLOCKING_QUERY 0
 #define FSETLOCKING_INTERNAL 1
 #define FSETLOCKING_BYCALLER 2
diff --git a/libc/libc.arm.map b/libc/libc.arm.map
index 4586fdacd..dc0eb9397 100644
--- a/libc/libc.arm.map
+++ b/libc/libc.arm.map
@@ -1322,6 +1322,7 @@ LIBC_P { # introduced=P
   global:
     __freading;
     __free_hook;
+    __fseterr;
     __fwriting;
     __malloc_hook;
     __memalign_hook;
diff --git a/libc/libc.arm64.map b/libc/libc.arm64.map
index 75436ff0c..fdae8f11f 100644
--- a/libc/libc.arm64.map
+++ b/libc/libc.arm64.map
@@ -1242,6 +1242,7 @@ LIBC_P { # introduced=P
   global:
     __freading;
     __free_hook;
+    __fseterr;
     __fwriting;
     __malloc_hook;
     __memalign_hook;
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index a8a52c302..07241d5e4 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1347,6 +1347,7 @@ LIBC_P { # introduced=P
   global:
     __freading;
     __free_hook;
+    __fseterr;
     __fwriting;
     __malloc_hook;
     __memalign_hook;
diff --git a/libc/libc.mips.map b/libc/libc.mips.map
index 584807e39..bbd599afd 100644
--- a/libc/libc.mips.map
+++ b/libc/libc.mips.map
@@ -1306,6 +1306,7 @@ LIBC_P { # introduced=P
   global:
     __freading;
     __free_hook;
+    __fseterr;
     __fwriting;
     __malloc_hook;
     __memalign_hook;
diff --git a/libc/libc.mips64.map b/libc/libc.mips64.map
index 75436ff0c..fdae8f11f 100644
--- a/libc/libc.mips64.map
+++ b/libc/libc.mips64.map
@@ -1242,6 +1242,7 @@ LIBC_P { # introduced=P
   global:
     __freading;
     __free_hook;
+    __fseterr;
     __fwriting;
     __malloc_hook;
     __memalign_hook;
diff --git a/libc/libc.x86.map b/libc/libc.x86.map
index 4498d6d21..6e9acc025 100644
--- a/libc/libc.x86.map
+++ b/libc/libc.x86.map
@@ -1304,6 +1304,7 @@ LIBC_P { # introduced=P
   global:
     __freading;
     __free_hook;
+    __fseterr;
     __fwriting;
     __malloc_hook;
     __memalign_hook;
diff --git a/libc/libc.x86_64.map b/libc/libc.x86_64.map
index 75436ff0c..fdae8f11f 100644
--- a/libc/libc.x86_64.map
+++ b/libc/libc.x86_64.map
@@ -1242,6 +1242,7 @@ LIBC_P { # introduced=P
   global:
     __freading;
     __free_hook;
+    __fseterr;
     __fwriting;
     __malloc_hook;
     __memalign_hook;
diff --git a/libc/stdio/stdio_ext.cpp b/libc/stdio/stdio_ext.cpp
index 8cf4f4b3d..e17b62a05 100644
--- a/libc/stdio/stdio_ext.cpp
+++ b/libc/stdio/stdio_ext.cpp
@@ -72,6 +72,10 @@ void _flushlbf() {
   fflush(NULL);
 }
 
+void __fseterr(FILE* fp) {
+  fp->_flags |= __SERR;
+}
+
 int __fsetlocking(FILE* fp, int type) {
   int old_state = _EXT(fp)->_caller_handles_locking ? FSETLOCKING_BYCALLER : FSETLOCKING_INTERNAL;
   if (type == FSETLOCKING_QUERY) {
diff --git a/tests/stdio_ext_test.cpp b/tests/stdio_ext_test.cpp
index 128e25558..849bf0bc1 100644
--- a/tests/stdio_ext_test.cpp
+++ b/tests/stdio_ext_test.cpp
@@ -190,6 +190,22 @@ TEST(stdio_ext, __freading__fwriting) {
   }
 }
 
+TEST(stdio_ext, __fseterr) {
+#if defined(__GLIBC__)
+  GTEST_LOG_(INFO) << "glibc doesn't have __fseterr, but gnulib will use it";
+#else
+  FILE* fp = fopen("/dev/null", "w");
+
+  ASSERT_FALSE(ferror(fp));
+  __fseterr(fp);
+  ASSERT_TRUE(ferror(fp));
+  clearerr(fp);
+  ASSERT_FALSE(ferror(fp));
+
+  fclose(fp);
+#endif
+}
+
 TEST(stdio_ext, __fsetlocking) {
   FILE* fp = fopen("/proc/version", "r");
   ASSERT_EQ(FSETLOCKING_INTERNAL, __fsetlocking(fp, FSETLOCKING_QUERY));