From ad03c82d65aa076d3a7e97ad58ceb3f8e63861f6 Mon Sep 17 00:00:00 2001
From: Dan Gohman <sunfish@mozilla.com>
Date: Mon, 22 Apr 2019 12:46:36 -0700
Subject: [PATCH] Implement reallocarray.

reallocarray is non-standard but present in GLIBC and BSDs.
---
 Makefile                                 |  9 ++++-----
 basics/{libc => crt}/crt1.c              |  0
 basics/include/__functions_malloc.h      |  4 ++++
 basics/sources/reallocarray.c            | 14 ++++++++++++++
 basics/{libc => sources}/string.c        |  0
 expected/wasm32-wasi/defined-symbols.txt |  2 ++
 6 files changed, 24 insertions(+), 5 deletions(-)
 rename basics/{libc => crt}/crt1.c (100%)
 create mode 100644 basics/sources/reallocarray.c
 rename basics/{libc => sources}/string.c (100%)

diff --git a/Makefile b/Makefile
index 800e6b9..a6f84c9 100644
--- a/Makefile
+++ b/Makefile
@@ -33,9 +33,8 @@ endif
 # directories in the source tree.
 BASICS_DIR = $(CURDIR)/basics
 BASICS_INC = $(BASICS_DIR)/include
-BASICS_LIBC_DIR = $(BASICS_DIR)/libc
-BASICS_CRT_SOURCES = $(wildcard $(BASICS_LIBC_DIR)/crt*.c)
-BASICS_LIBC_SOURCES = $(BASICS_LIBC_DIR)/string.c
+BASICS_CRT_SOURCES = $(wildcard $(BASICS_DIR)/crt/*.c)
+BASICS_SOURCES = $(wildcard $(BASICS_DIR)/sources/*.c)
 DLMALLOC_DIR = $(CURDIR)/dlmalloc
 DLMALLOC_SRC_DIR = $(DLMALLOC_DIR)/src
 DLMALLOC_SOURCES = $(DLMALLOC_SRC_DIR)/dlmalloc.c
@@ -184,11 +183,11 @@ endif
 override WASM_CFLAGS += --sysroot="$(SYSROOT)"
 
 objs = $(patsubst $(CURDIR)/%.c,$(OBJDIR)/%.o,$(1))
-override BASICS_LIBC_OBJS = $(call objs,$(BASICS_LIBC_SOURCES))
+override BASICS_OBJS = $(call objs,$(BASICS_SOURCES))
 override DLMALLOC_OBJS = $(call objs,$(DLMALLOC_SOURCES))
 override LIBC_BOTTOM_HALF_ALL_OBJS = $(call objs,$(LIBC_BOTTOM_HALF_ALL_SOURCES))
 override LIBC_TOP_HALF_ALL_OBJS = $(call objs,$(LIBC_TOP_HALF_ALL_SOURCES))
-override LIBC_OBJS := $(BASICS_LIBC_OBJS)
+override LIBC_OBJS := $(BASICS_OBJS)
 ifeq ($(BUILD_DLMALLOC),yes)
 override LIBC_OBJS += $(DLMALLOC_OBJS)
 endif
diff --git a/basics/libc/crt1.c b/basics/crt/crt1.c
similarity index 100%
rename from basics/libc/crt1.c
rename to basics/crt/crt1.c
diff --git a/basics/include/__functions_malloc.h b/basics/include/__functions_malloc.h
index 803bc11..9d4676b 100644
--- a/basics/include/__functions_malloc.h
+++ b/basics/include/__functions_malloc.h
@@ -15,6 +15,10 @@ void free(void *ptr);
 void *calloc(size_t nmemb, size_t size) __attribute__((__malloc__, __warn_unused_result__));
 void *realloc(void *ptr, size_t size) __attribute__((__warn_unused_result__));
 
+#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+void *reallocarray(void *, size_t, size_t) __attribute__((__warn_unused_result__));
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/basics/sources/reallocarray.c b/basics/sources/reallocarray.c
new file mode 100644
index 0000000..3e828cc
--- /dev/null
+++ b/basics/sources/reallocarray.c
@@ -0,0 +1,14 @@
+#include <stdlib.h>
+#include <errno.h>
+
+void *__reallocarray(void *ptr, size_t nmemb, size_t size) {
+    size_t bytes;
+    if (__builtin_umull_overflow(nmemb, size, &bytes)) {
+        errno = ENOMEM;
+        return NULL;
+    }
+    return realloc(ptr, bytes);
+}
+
+void *reallocarray(void *ptr, size_t nmemb, size_t size)
+    __attribute__((__weak__, __alias__("__reallocarray")));
diff --git a/basics/libc/string.c b/basics/sources/string.c
similarity index 100%
rename from basics/libc/string.c
rename to basics/sources/string.c
diff --git a/expected/wasm32-wasi/defined-symbols.txt b/expected/wasm32-wasi/defined-symbols.txt
index ae840ca..63a413e 100644
--- a/expected/wasm32-wasi/defined-symbols.txt
+++ b/expected/wasm32-wasi/defined-symbols.txt
@@ -163,6 +163,7 @@ __progname
 __progname_full
 __putenv
 __rand48_step
+__reallocarray
 __rem_pio2
 __rem_pio2_large
 __rem_pio2f
@@ -825,6 +826,7 @@ readlink
 readlinkat
 readv
 realloc
+reallocarray
 recv
 regcomp
 regerror
-- 
2.39.2