Add initial files.

This populates the repo with a very minimal set of files. This is just
enough to set out a basic outline. Hopefully as we move forward we'll
be replacing many of these parts, but this is just something basic to
get things started.

This tree isn't really usable yet, as it doesn't yet have an easy way
to obtain a compiler-rt/libgcc build.

diff --git a/.gitignore b/.gitignore
new file mode 100644 (file)
index 0000000..dea22ea
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+sysroot

diff --git a/LICENSE b/LICENSE
new file mode 100644 (file)
index 0000000..6a9bda7
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,5 @@
+Please see the LICENSE file in each top-level directory for the terms applicable to that directory and its relative sub-directories.
+
+The relevant directories and licenses are:
+
+basics/      - CC0 1.0 Universal (CC0 1.0) Public Domain Dedication

diff --git a/Makefile b/Makefile
new file mode 100644 (file)
index 0000000..8ae722f
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,40 @@
+# These variables are specifically meant to be overridable via
+# the make command-line.
+WASM_CC = clang
+WASM_CFLAGS = -O2
+WASM_TARGET_FLAGS = --target=wasm32
+SYSROOT = sysroot
+
+# These variables describe the locations of various files and
+# directories in the source tree.
+BASICS_DIR = basics
+BASICS_INC = basics/include
+BASICS_LIBC_DIR = $(BASICS_DIR)/libc
+BASICS_LIBC_SOURCES = $(BASICS_LIBC_DIR)/string.c
+
+.PHONY: $(SYSROOT)
+$(SYSROOT):
+       $(RM) -r "$(SYSROOT)"
+       mkdir -p "$(SYSROOT)/usr"
+
+       #
+       # Install the include files.
+       #
+       cp -r  "$(BASICS_INC)" "$(SYSROOT)/usr"
+
+       #
+       # Build the C startup files.
+       #
+       $(RM) *.o
+       "$(WASM_CC)" $(WASM_CFLAGS) $(WASM_TARGET_FLAGS) --sysroot="$(SYSROOT)" -c $(BASICS_LIBC_DIR)/crt*.s
+       mkdir -p "$(SYSROOT)/lib"
+       mv *.o "$(SYSROOT)/lib"
+
+       #
+       # Compile and install the libc-subset source files.
+       #
+       $(RM) *.o
+       "$(WASM_CC)" $(WASM_CFLAGS) $(WASM_TARGET_FLAGS) --sysroot="$(SYSROOT)" -c $(BASICS_LIBC_SOURCES)
+       mkdir -p "$(SYSROOT)/lib"
+       ar crs "$(SYSROOT)/lib/libc.a" *.o
+       $(RM) *.o

diff --git a/README.md b/README.md
new file mode 100644 (file)
index 0000000..618f234
--- /dev/null
+++ b/README.md
@@ -0,0 +1,31 @@
+# WebAssembly Reference Sysroot
+
+Caution: This is currently quite experimental and not generally usable yet!
+
+## What is this?
+
+This is a "reference sysroot", which is meant to be part of a common C ABI
+that can be shared across C libraries and compilers. While it's intened to
+(eventually) be usable in its own right, we fully expect other
+implementations to be used in practice by many different systems, though
+we do hope that in those cases, this library defines a useful ABI that can
+be followed.
+
+## Usage
+
+Obtain a WebAssembly-supporting C compiler, and then run:
+
+```
+make WASM_CC=/path/to/wasm/supporting/c/compiler
+```
+
+This makes a directory called "sysroot", by default. See the top of the Makfile
+for customization options.
+
+To use the sysroot, use the `--sysroot=` option:
+
+```
+/path/to/wasm/supporting/c/compiler --sysroot=/path/to/the/newly/built/sysroot ...
+``
+
+to run the compiler using the newly built sysroot.

diff --git a/basics/LICENSE b/basics/LICENSE
new file mode 100644 (file)
index 0000000..0e259d4
--- /dev/null
+++ b/basics/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
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+    THE USE OF THIS DOCUMENT OR THE INFORMATION OR WORKS PROVIDED
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+
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+
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+1. Copyright and Related Rights. A Work made available under CC0 may be
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+be judged legally invalid or ineffective under applicable law, then the
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+person a royalty-free, non transferable, non sublicensable, non exclusive,
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+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,
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+ c. Affirmer disclaims responsibility for clearing rights of other persons
+    that may apply to the Work or any use thereof, including without
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+    consents, permissions or other rights required for any use of the
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+ 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.

diff --git a/basics/include/__typedef_clock_t.h b/basics/include/__typedef_clock_t.h
new file mode 100644 (file)
index 0000000..e7f0bbb
--- /dev/null
+++ b/basics/include/__typedef_clock_t.h
@@ -0,0 +1,2 @@
+/* Define this as a 64-bit signed integer to avoid wraparounds. */
+typedef long long clock_t;

diff --git a/basics/include/__typedef_time_t.h b/basics/include/__typedef_time_t.h
new file mode 100644 (file)
index 0000000..78763e1
--- /dev/null
+++ b/basics/include/__typedef_time_t.h
@@ -0,0 +1,2 @@
+/* Define this as a 64-bit signed integer to avoid the 2038 bug. */
+typedef long long time_t;

diff --git a/basics/include/stdlib.h b/basics/include/stdlib.h
new file mode 100644 (file)
index 0000000..ae90326
--- /dev/null
+++ b/basics/include/stdlib.h
@@ -0,0 +1,22 @@
+#ifndef __wasm_sysroot_stdlib_h
+#define __wasm_sysroot_stdlib_h
+
+#define __need_size_t
+#define __need_wchar_t
+#define __need_NULL
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void *malloc(size_t size);
+void free(void *ptr);
+void *calloc(size_t nmemb, size_t size);
+void *realloc(void *ptr, size_t size);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

diff --git a/basics/include/string.h b/basics/include/string.h
new file mode 100644 (file)
index 0000000..b218bbe
--- /dev/null
+++ b/basics/include/string.h
@@ -0,0 +1,20 @@
+#ifndef __wasm_sysroot_string_h
+#define __wasm_sysroot_string_h
+
+#define __need_size_t
+#define __need_NULL
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void *memcpy(void *dst, const void *src, size_t n);
+void *memmove(void *dst, const void *src, size_t n);
+void *memset(void *dst, int c, size_t n);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

diff --git a/basics/include/sys/types.h b/basics/include/sys/types.h
new file mode 100644 (file)
index 0000000..0241800
--- /dev/null
+++ b/basics/include/sys/types.h
@@ -0,0 +1,17 @@
+#ifndef __wasm_sysroot_sys_types_h
+#define __wasm_sysroot_sys_types_h
+
+#define __need_size_t
+#include <stddef.h>
+
+#include <__typedef_clock_t.h>
+#include <__typedef_time_t.h>
+
+/* Define these as 64-bit signed integers to support files larger than 2 GiB. */
+typedef long long blksize_t;
+typedef long long off_t;
+
+/* This is defined to be the same size as size_t. */
+typedef long ssize_t;
+
+#endif

diff --git a/basics/include/time.h b/basics/include/time.h
new file mode 100644 (file)
index 0000000..5046455
--- /dev/null
+++ b/basics/include/time.h
@@ -0,0 +1,10 @@
+#ifndef __wasm_sysroot_time_h
+#define __wasm_sysroot_time_h
+
+#define __need_size_t
+#define __need_NULL
+#include <stddef.h>
+
+#include <__typedef_time_t.h>
+
+#endif

diff --git a/basics/include/wchar.h b/basics/include/wchar.h
new file mode 100644 (file)
index 0000000..a6fe1dc
--- /dev/null
+++ b/basics/include/wchar.h
@@ -0,0 +1,9 @@
+#ifndef __wasm_sysroot_wchar_h
+#define __wasm_sysroot_wchar_h
+
+#define __need_size_t
+#define __need_wchar_t
+#define __need_NULL
+#include <stddef.h>
+
+#endif

diff --git a/basics/libc/crt1.s b/basics/libc/crt1.s
new file mode 100644 (file)
index 0000000..996cee9
--- /dev/null
+++ b/basics/libc/crt1.s
@@ -0,0 +1 @@
+# Empty.

diff --git a/basics/libc/string.c b/basics/libc/string.c
new file mode 100644 (file)
index 0000000..77d7201
--- /dev/null
+++ b/basics/libc/string.c
@@ -0,0 +1,41 @@
+#include <string.h>
+#include <stdint.h>
+
+static void *copy_forward(void *restrict dst, const void *restrict src, size_t n) {
+    char *d = (char *)dst;
+    const char *s = (const char *)src;
+    while (n-- != 0) {
+        *d++ = *s++;
+    }
+    return dst;
+}
+
+static void *copy_backward(void *restrict dst, const void *restrict src, size_t n) {
+    char *d = (char *)dst;
+    const char *s = (const char *)src;
+    d += n;
+    s += n;
+    while (n-- != 0) {
+        *--d = *--s;
+    }
+    return dst;
+}
+
+void *memcpy(void *restrict dst, const void *restrict src, size_t n) {
+    return copy_forward(dst, src, n);
+}
+
+void *memmove(void *dst, const void *src, size_t n) {
+    if ((uintptr_t)dst - (uintptr_t)src >= n) {
+        return copy_forward(dst, src, n);
+    }
+    return copy_backward(dst, src, n);
+}
+
+void *memset(void *restrict dst, int c, size_t n) {
+    char *d = (char *)dst;
+    while (n-- != 0) {
+        *d++ = c;
+    }
+    return dst;
+}