Merge pull request #9 from WebAssembly/dlmalloc

Add a malloc implementation using dlmalloc.

LICENSE

@@ -3,3 +3,4 @@ Please see the LICENSE file in each top-level directory for the terms applicable
 The relevant directories and licenses are:
 
 basics/      - CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
+dlmalloc/    - CC0 1.0 Universal (CC0 1.0) Public Domain Dedication

Makefile

@@ -4,13 +4,27 @@ WASM_CC = clang
 WASM_CFLAGS = -O2
 WASM_TARGET_FLAGS = --target=wasm32
 SYSROOT = sysroot
+# single or posix
+THREAD_MODEL = single
 
 # These variables describe the locations of various files and
 # directories in the source tree.
 BASICS_DIR = basics
-BASICS_INC = basics/include
+BASICS_INC = $(BASICS_DIR)/include
 BASICS_LIBC_DIR = $(BASICS_DIR)/libc
 BASICS_LIBC_SOURCES = $(BASICS_LIBC_DIR)/string.c
+DLMALLOC_DIR = dlmalloc
+DLMALLOC_SRC_DIR = $(DLMALLOC_DIR)/src
+DLMALLOC_SOURCES = $(DLMALLOC_SRC_DIR)/wrapper.c
+DLMALLOC_INC = $(DLMALLOC_DIR)/include
+
+# Configure support for threads.
+ifeq ($(THREADS), single)
+WASM_CFLAGS += -mthread-model single -DWASM_THREAD_MODEL_SINGLE
+endif
+ifeq ($(THREADS), posix)
+WASM_CFLAGS += -mthread-model posix -DWASM_THREAD_MODEL_POSIX
+endif
 
 .PHONY: $(SYSROOT)
 $(SYSROOT):
@@ -36,5 +50,14 @@ $(SYSROOT):
 	$(RM) *.o
 	"$(WASM_CC)" $(WASM_CFLAGS) $(WASM_TARGET_FLAGS) --sysroot="$(SYSROOT)" -c $(BASICS_LIBC_SOURCES)
 	mkdir -p "$(SYSROOT)/lib"
-	$(AR) crs "$(SYSROOT)/lib/libc.a" *.o
+	$(AR) crs "$(SYSROOT)/lib/libc-basics.a" *.o
+	$(RM) *.o
+
+	#
+	# Compile and install the dlmalloc source files.
+	#
+	$(RM) *.o
+	"$(WASM_CC)" $(WASM_CFLAGS) $(WASM_TARGET_FLAGS) --sysroot="$(SYSROOT)" -c $(DLMALLOC_SOURCES) -I $(DLMALLOC_INC)
+	mkdir -p "$(SYSROOT)/lib"
+	$(AR) crs "$(SYSROOT)/lib/libc-dlmalloc.a" *.o
 	$(RM) *.o

basics/include/errno.h

@@ -0,0 +1,24 @@
+#ifndef __wasm_sysroot_errno_h
+#define __wasm_sysroot_errno_h
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef WASM_THREAD_MODEL_SINGLE
+extern int errno;
+#else
+#ifdef __cplusplus
+extern thread_local int errno;
+#else
+extern _Thread_local int errno;
+#endif
+#endif
+
+#define errno errno
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

dlmalloc/LICENSE

@@ -0,0 +1,121 @@
+Creative Commons Legal Code
+
+CC0 1.0 Universal
+
+    CREATIVE COMMONS CORPORATION IS NOT A LAW FIRM AND DOES NOT PROVIDE
+    LEGAL SERVICES. DISTRIBUTION OF THIS DOCUMENT DOES NOT CREATE AN
+    ATTORNEY-CLIENT RELATIONSHIP. CREATIVE COMMONS PROVIDES THIS
+    INFORMATION ON AN "AS-IS" BASIS. CREATIVE COMMONS MAKES NO WARRANTIES
+    REGARDING THE USE OF THIS DOCUMENT OR THE INFORMATION OR WORKS
+    PROVIDED HEREUNDER, AND DISCLAIMS LIABILITY FOR DAMAGES RESULTING FROM
+    THE USE OF THIS DOCUMENT OR THE INFORMATION OR WORKS PROVIDED
+    HEREUNDER.
+
+Statement of Purpose
+
+The laws of most jurisdictions throughout the world automatically confer
+exclusive Copyright and Related Rights (defined below) upon the creator
+and subsequent owner(s) (each and all, an "owner") of an original work of
+authorship and/or a database (each, a "Work").
+
+Certain owners wish to permanently relinquish those rights to a Work for
+the purpose of contributing to a commons of creative, cultural and
+scientific works ("Commons") that the public can reliably and without fear
+of later claims of infringement build upon, modify, incorporate in other
+works, reuse and redistribute as freely as possible in any form whatsoever
+and for any purposes, including without limitation commercial purposes.
+These owners may contribute to the Commons to promote the ideal of a free
+culture and the further production of creative, cultural and scientific
+works, or to gain reputation or greater distribution for their Work in
+part through the use and efforts of others.
+
+For these and/or other purposes and motivations, and without any
+expectation of additional consideration or compensation, the person
+associating CC0 with a Work (the "Affirmer"), to the extent that he or she
+is an owner of Copyright and Related Rights in the Work, voluntarily
+elects to apply CC0 to the Work and publicly distribute the Work under its
+terms, with knowledge of his or her Copyright and Related Rights in the
+Work and the meaning and intended legal effect of CC0 on those rights.
+
+1. Copyright and Related Rights. A Work made available under CC0 may be
+protected by copyright and related or neighboring rights ("Copyright and
+Related Rights"). Copyright and Related Rights include, but are not
+limited to, the following:
+
+  i. the right to reproduce, adapt, distribute, perform, display,
+     communicate, and translate a Work;
+ ii. moral rights retained by the original author(s) and/or performer(s);
+iii. publicity and privacy rights pertaining to a person's image or
+     likeness depicted in a Work;
+ iv. rights protecting against unfair competition in regards to a Work,
+     subject to the limitations in paragraph 4(a), below;
+  v. rights protecting the extraction, dissemination, use and reuse of data
+     in a Work;
+ vi. database rights (such as those arising under Directive 96/9/EC of the
+     European Parliament and of the Council of 11 March 1996 on the legal
+     protection of databases, and under any national implementation
+     thereof, including any amended or successor version of such
+     directive); and
+vii. other similar, equivalent or corresponding rights throughout the
+     world based on applicable law or treaty, and any national
+     implementations thereof.
+
+2. Waiver. To the greatest extent permitted by, but not in contravention
+of, applicable law, Affirmer hereby overtly, fully, permanently,
+irrevocably and unconditionally waives, abandons, and surrenders all of
+Affirmer's Copyright and Related Rights and associated claims and causes
+of action, whether now known or unknown (including existing as well as
+future claims and causes of action), in the Work (i) in all territories
+worldwide, (ii) for the maximum duration provided by applicable law or
+treaty (including future time extensions), (iii) in any current or future
+medium and for any number of copies, and (iv) for any purpose whatsoever,
+including without limitation commercial, advertising or promotional
+purposes (the "Waiver"). Affirmer makes the Waiver for the benefit of each
+member of the public at large and to the detriment of Affirmer's heirs and
+successors, fully intending that such Waiver shall not be subject to
+revocation, rescission, cancellation, termination, or any other legal or
+equitable action to disrupt the quiet enjoyment of the Work by the public
+as contemplated by Affirmer's express Statement of Purpose.
+
+3. Public License Fallback. Should any part of the Waiver for any reason
+be judged legally invalid or ineffective under applicable law, then the
+Waiver shall be preserved to the maximum extent permitted taking into
+account Affirmer's express Statement of Purpose. In addition, to the
+extent the Waiver is so judged Affirmer hereby grants to each affected
+person a royalty-free, non transferable, non sublicensable, non exclusive,
+irrevocable and unconditional license to exercise Affirmer's Copyright and
+Related Rights in the Work (i) in all territories worldwide, (ii) for the
+maximum duration provided by applicable law or treaty (including future
+time extensions), (iii) in any current or future medium and for any number
+of copies, and (iv) for any purpose whatsoever, including without
+limitation commercial, advertising or promotional purposes (the
+"License"). The License shall be deemed effective as of the date CC0 was
+applied by Affirmer to the Work. Should any part of the License for any
+reason be judged legally invalid or ineffective under applicable law, such
+partial invalidity or ineffectiveness shall not invalidate the remainder
+of the License, and in such case Affirmer hereby affirms that he or she
+will not (i) exercise any of his or her remaining Copyright and Related
+Rights in the Work or (ii) assert any associated claims and causes of
+action with respect to the Work, in either case contrary to Affirmer's
+express Statement of Purpose.
+
+4. Limitations and Disclaimers.
+
+ a. No trademark or patent rights held by Affirmer are waived, abandoned,
+    surrendered, licensed or otherwise affected by this document.
+ b. Affirmer offers the Work as-is and makes no representations or
+    warranties of any kind concerning the Work, express, implied,
+    statutory or otherwise, including without limitation warranties of
+    title, merchantability, fitness for a particular purpose, non
+    infringement, or the absence of latent or other defects, accuracy, or
+    the present or absence of errors, whether or not discoverable, all to
+    the greatest extent permissible under applicable law.
+ c. Affirmer disclaims responsibility for clearing rights of other persons
+    that may apply to the Work or any use thereof, including without
+    limitation any person's Copyright and Related Rights in the Work.
+    Further, Affirmer disclaims responsibility for obtaining any necessary
+    consents, permissions or other rights required for any use of the
+    Work.
+ d. Affirmer understands and acknowledges that Creative Commons is not a
+    party to this document and has no duty or obligation with respect to
+    this CC0 or use of the Work.

dlmalloc/include/unistd.h

@@ -0,0 +1,14 @@
+/* Stub include file to support dlmalloc. */
+
+#include <stdint.h>
+
+/*
+ * The page size in WebAssembly is fixed at 64 KiB. If this ever changes,
+ * it's expected that applications will need to opt in, so we can change
+ * this.
+ */
+#define sysconf(name) 0x10000
+#define _SC_PAGESIZE
+
+/* Declare sbrk. */
+void *sbrk(intptr_t increment);

dlmalloc/src/wrapper.c

@@ -0,0 +1,63 @@
+/* Define configuration macros for dlmalloc. */
+
+/* WebAssembly doesn't have mmap-style memory allocation. */
+#define HAVE_MMAP 0
+
+/* WebAssembly doesn't support shrinking linear memory. */
+#define MORECORE_CANNOT_TRIM 1
+
+/* Disable sanity checks to reduce code size. */
+#define ABORT __builtin_unreachable()
+
+/* If threads are enabled, enable support for threads. */
+#ifndef WASM_THREAD_MODEL_SINGLE
+#define USE_LOCKS 1
+#endif
+
+/* Make malloc deterministic. */
+#define LACKS_TIME_H 1
+
+/* WebAssembly has no sched_yield or similar. */
+#define LACKS_SCHED_H
+
+/* Disable malloc statistics generation to reduce code size. */
+#define NO_MALLINFO 1
+#define NO_MALLOC_STATS 1
+
+/*
+ * Declare errno values used by dlmalloc. We define them like this to avoid
+ * putting specific errno values in the ABI.
+ */
+extern const int __ENOMEM;
+#define ENOMEM __ENOMEM
+extern const int __EINVAL;
+#define EINVAL __EINVAL
+
+/* Prefix dlmalloc's names with 'dl'. We wrap them with public names below. */
+#define USE_DL_PREFIX 1
+#define DLMALLOC_EXPORT static inline
+
+/* Include the upstream dlmalloc's malloc.c. */
+#include "malloc.c"
+
+/* Export the public names. */
+
+void *malloc(size_t size) {
+    return dlmalloc(size);
+}
+
+void free(void *ptr) {
+    return dlfree(ptr);
+}
+
+void *calloc(size_t nmemb, size_t size) {
+    return dlcalloc(nmemb, size);
+}
+
+void *realloc(void *ptr, size_t size) {
+    return dlrealloc(ptr, size);
+}
+
+int posix_memalign(void **memptr, size_t alignment, size_t size) {
+    return dlposix_memalign(memptr, alignment, size);
+}