thodg/libgit2

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 750b708..baeed97 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,7 +29,7 @@ option(USE_NSEC                "Support nanosecond precision file mtimes and cti
 # Backend selection
 option(USE_SSH                 "Link with libssh2 to enable SSH support"               OFF)
 option(USE_HTTPS               "Enable HTTPS support. Can be set to a specific backend" ON)
-option(USE_SHA1                "Enable SHA1. Can be set to CollisionDetection(ON)/HTTPS/Generic" ON)
+option(USE_SHA1                "Enable SHA1. Can be set to CollisionDetection(ON)/HTTPS" ON)
 option(USE_GSSAPI              "Link with libgssapi for SPNEGO auth"      OFF)
    set(USE_HTTP_PARSER         "" CACHE STRING "Specifies the HTTP Parser implementation; either system or builtin.")
    set(REGEX_BACKEND           "" CACHE STRING "Regular expression implementation. One of regcomp_l, pcre2, pcre, regcomp, or builtin.")
diff --git a/cmake/SelectHashes.cmake b/cmake/SelectHashes.cmake
index 575ae8f..f7ca2ce 100644
--- a/cmake/SelectHashes.cmake
+++ b/cmake/SelectHashes.cmake
@@ -42,7 +42,7 @@ elseif(USE_SHA1 STREQUAL "mbedTLS")
 	list(APPEND LIBGIT2_PC_LIBS ${MBEDTLS_LIBRARIES})
 elseif(USE_SHA1 STREQUAL "Win32")
 	set(GIT_SHA1_WIN32 1)
-elseif(NOT (USE_SHA1 STREQUAL "Generic"))
+else()
 	message(FATAL_ERROR "Asked for unknown SHA1 backend: ${USE_SHA1}")
 endif()
 
diff --git a/src/util/CMakeLists.txt b/src/util/CMakeLists.txt
index b725d54..66ef67a 100644
--- a/src/util/CMakeLists.txt
+++ b/src/util/CMakeLists.txt
@@ -41,8 +41,6 @@ elseif(USE_SHA1 STREQUAL "mbedTLS")
 	file(GLOB UTIL_SRC_HASH hash/sha1/mbedtls.*)
 elseif(USE_SHA1 STREQUAL "Win32")
 	file(GLOB UTIL_SRC_HASH hash/sha1/win32.*)
-elseif(USE_SHA1 STREQUAL "Generic")
-	file(GLOB UTIL_SRC_HASH hash/sha1/generic.*)
 else()
 	message(FATAL_ERROR "Asked for unknown SHA1 backend: ${USE_SHA1}")
 endif()
diff --git a/src/util/hash/sha1.h b/src/util/hash/sha1.h
index 9d32bce..82a06d6 100644
--- a/src/util/hash/sha1.h
+++ b/src/util/hash/sha1.h
@@ -12,9 +12,7 @@
 
 typedef struct git_hash_sha1_ctx git_hash_sha1_ctx;
 
-#if defined(GIT_SHA1_COLLISIONDETECT)
-# include "sha1/collisiondetect.h"
-#elif defined(GIT_SHA1_COMMON_CRYPTO)
+#if defined(GIT_SHA1_COMMON_CRYPTO)
 # include "sha1/common_crypto.h"
 #elif defined(GIT_SHA1_OPENSSL)
 # include "sha1/openssl.h"
@@ -23,7 +21,7 @@ typedef struct git_hash_sha1_ctx git_hash_sha1_ctx;
 #elif defined(GIT_SHA1_MBEDTLS)
 # include "sha1/mbedtls.h"
 #else
-# include "sha1/generic.h"
+# include "sha1/collisiondetect.h"
 #endif
 
 #define GIT_HASH_SHA1_SIZE 20
diff --git a/src/util/hash/sha1/generic.c b/src/util/hash/sha1/generic.c
deleted file mode 100644
index 85b34c5..0000000
--- a/src/util/hash/sha1/generic.c
+++ /dev/null
@@ -1,300 +0,0 @@
-/*
- * Copyright (C) the libgit2 contributors. All rights reserved.
- *
- * This file is part of libgit2, distributed under the GNU GPL v2 with
- * a Linking Exception. For full terms see the included COPYING file.
- */
-
-#include "generic.h"
-
-#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
-
-/*
- * Force usage of rol or ror by selecting the one with the smaller constant.
- * It _can_ generate slightly smaller code (a constant of 1 is special), but
- * perhaps more importantly it's possibly faster on any uarch that does a
- * rotate with a loop.
- */
-
-#define SHA_ASM(op, x, n) (__extension__ ({ unsigned int __res; __asm__(op " %1,%0":"=r" (__res):"i" (n), "0" (x)); __res; }))
-#define SHA_ROL(x,n)	SHA_ASM("rol", x, n)
-#define SHA_ROR(x,n)	SHA_ASM("ror", x, n)
-
-#else
-
-#define SHA_ROT(X,l,r)	(((X) << (l)) | ((X) >> (r)))
-#define SHA_ROL(X,n)	SHA_ROT(X,n,32-(n))
-#define SHA_ROR(X,n)	SHA_ROT(X,32-(n),n)
-
-#endif
-
-/*
- * If you have 32 registers or more, the compiler can (and should)
- * try to change the array[] accesses into registers. However, on
- * machines with less than ~25 registers, that won't really work,
- * and at least gcc will make an unholy mess of it.
- *
- * So to avoid that mess which just slows things down, we force
- * the stores to memory to actually happen (we might be better off
- * with a 'W(t)=(val);asm("":"+m" (W(t))' there instead, as
- * suggested by Artur Skawina - that will also make gcc unable to
- * try to do the silly "optimize away loads" part because it won't
- * see what the value will be).
- *
- * Ben Herrenschmidt reports that on PPC, the C version comes close
- * to the optimized asm with this (ie on PPC you don't want that
- * 'volatile', since there are lots of registers).
- *
- * On ARM we get the best code generation by forcing a full memory barrier
- * between each SHA_ROUND, otherwise gcc happily get wild with spilling and
- * the stack frame size simply explode and performance goes down the drain.
- */
-
-#if defined(__i386__) || defined(__x86_64__)
- #define setW(x, val) (*(volatile unsigned int *)&W(x) = (val))
-#elif defined(__GNUC__) && defined(__arm__)
- #define setW(x, val) do { W(x) = (val); __asm__("":::"memory"); } while (0)
-#else
- #define setW(x, val) (W(x) = (val))
-#endif
-
-/*
- * Performance might be improved if the CPU architecture is OK with
- * unaligned 32-bit loads and a fast ntohl() is available.
- * Otherwise fall back to byte loads and shifts which is portable,
- * and is faster on architectures with memory alignment issues.
- */
-
-#if defined(__i386__) || defined(__x86_64__) || \
-	defined(_M_IX86) || defined(_M_X64) || \
-	defined(__ppc__) || defined(__ppc64__) || \
-	defined(__powerpc__) || defined(__powerpc64__) || \
-	defined(__s390__) || defined(__s390x__)
-
-#define get_be32(p)	ntohl(*(const unsigned int *)(p))
-#define put_be32(p, v)	do { *(unsigned int *)(p) = htonl(v); } while (0)
-
-#else
-
-#define get_be32(p)	( \
-	(*((const unsigned char *)(p) + 0) << 24) | \
-	(*((const unsigned char *)(p) + 1) << 16) | \
-	(*((const unsigned char *)(p) + 2) << 8) | \
-	(*((const unsigned char *)(p) + 3) << 0) )
-#define put_be32(p, v)	do { \
-	unsigned int __v = (v); \
-	*((unsigned char *)(p) + 0) = __v >> 24; \
-	*((unsigned char *)(p) + 1) = __v >> 16; \
-	*((unsigned char *)(p) + 2) = __v >> 8; \
-	*((unsigned char *)(p) + 3) = __v >> 0; } while (0)
-
-#endif
-
-/* This "rolls" over the 512-bit array */
-#define W(x) (array[(x)&15])
-
-/*
- * Where do we get the source from? The first 16 iterations get it from
- * the input data, the next mix it from the 512-bit array.
- */
-#define SHA_SRC(t) get_be32(data + t)
-#define SHA_MIX(t) SHA_ROL(W(t+13) ^ W(t+8) ^ W(t+2) ^ W(t), 1)
-
-#define SHA_ROUND(t, input, fn, constant, A, B, C, D, E) do { \
-	unsigned int TEMP = input(t); setW(t, TEMP); \
-	E += TEMP + SHA_ROL(A,5) + (fn) + (constant); \
-	B = SHA_ROR(B, 2); } while (0)
-
-#define T_0_15(t, A, B, C, D, E) SHA_ROUND(t, SHA_SRC, (((C^D)&B)^D) , 0x5a827999, A, B, C, D, E )
-#define T_16_19(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (((C^D)&B)^D) , 0x5a827999, A, B, C, D, E )
-#define T_20_39(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0x6ed9eba1, A, B, C, D, E )
-#define T_40_59(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, ((B&C)+(D&(B^C))) , 0x8f1bbcdc, A, B, C, D, E )
-#define T_60_79(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0xca62c1d6, A, B, C, D, E )
-
-static void hash__block(git_hash_sha1_ctx *ctx, const unsigned int *data)
-{
-	unsigned int A,B,C,D,E;
-	unsigned int array[16];
-
-	A = ctx->H[0];
-	B = ctx->H[1];
-	C = ctx->H[2];
-	D = ctx->H[3];
-	E = ctx->H[4];
-
-	/* Round 1 - iterations 0-16 take their input from 'data' */
-	T_0_15( 0, A, B, C, D, E);
-	T_0_15( 1, E, A, B, C, D);
-	T_0_15( 2, D, E, A, B, C);
-	T_0_15( 3, C, D, E, A, B);
-	T_0_15( 4, B, C, D, E, A);
-	T_0_15( 5, A, B, C, D, E);
-	T_0_15( 6, E, A, B, C, D);
-	T_0_15( 7, D, E, A, B, C);
-	T_0_15( 8, C, D, E, A, B);
-	T_0_15( 9, B, C, D, E, A);
-	T_0_15(10, A, B, C, D, E);
-	T_0_15(11, E, A, B, C, D);
-	T_0_15(12, D, E, A, B, C);
-	T_0_15(13, C, D, E, A, B);
-	T_0_15(14, B, C, D, E, A);
-	T_0_15(15, A, B, C, D, E);
-
-	/* Round 1 - tail. Input from 512-bit mixing array */
-	T_16_19(16, E, A, B, C, D);
-	T_16_19(17, D, E, A, B, C);
-	T_16_19(18, C, D, E, A, B);
-	T_16_19(19, B, C, D, E, A);
-
-	/* Round 2 */
-	T_20_39(20, A, B, C, D, E);
-	T_20_39(21, E, A, B, C, D);
-	T_20_39(22, D, E, A, B, C);
-	T_20_39(23, C, D, E, A, B);
-	T_20_39(24, B, C, D, E, A);
-	T_20_39(25, A, B, C, D, E);
-	T_20_39(26, E, A, B, C, D);
-	T_20_39(27, D, E, A, B, C);
-	T_20_39(28, C, D, E, A, B);
-	T_20_39(29, B, C, D, E, A);
-	T_20_39(30, A, B, C, D, E);
-	T_20_39(31, E, A, B, C, D);
-	T_20_39(32, D, E, A, B, C);
-	T_20_39(33, C, D, E, A, B);
-	T_20_39(34, B, C, D, E, A);
-	T_20_39(35, A, B, C, D, E);
-	T_20_39(36, E, A, B, C, D);
-	T_20_39(37, D, E, A, B, C);
-	T_20_39(38, C, D, E, A, B);
-	T_20_39(39, B, C, D, E, A);
-
-	/* Round 3 */
-	T_40_59(40, A, B, C, D, E);
-	T_40_59(41, E, A, B, C, D);
-	T_40_59(42, D, E, A, B, C);
-	T_40_59(43, C, D, E, A, B);
-	T_40_59(44, B, C, D, E, A);
-	T_40_59(45, A, B, C, D, E);
-	T_40_59(46, E, A, B, C, D);
-	T_40_59(47, D, E, A, B, C);
-	T_40_59(48, C, D, E, A, B);
-	T_40_59(49, B, C, D, E, A);
-	T_40_59(50, A, B, C, D, E);
-	T_40_59(51, E, A, B, C, D);
-	T_40_59(52, D, E, A, B, C);
-	T_40_59(53, C, D, E, A, B);
-	T_40_59(54, B, C, D, E, A);
-	T_40_59(55, A, B, C, D, E);
-	T_40_59(56, E, A, B, C, D);
-	T_40_59(57, D, E, A, B, C);
-	T_40_59(58, C, D, E, A, B);
-	T_40_59(59, B, C, D, E, A);
-
-	/* Round 4 */
-	T_60_79(60, A, B, C, D, E);
-	T_60_79(61, E, A, B, C, D);
-	T_60_79(62, D, E, A, B, C);
-	T_60_79(63, C, D, E, A, B);
-	T_60_79(64, B, C, D, E, A);
-	T_60_79(65, A, B, C, D, E);
-	T_60_79(66, E, A, B, C, D);
-	T_60_79(67, D, E, A, B, C);
-	T_60_79(68, C, D, E, A, B);
-	T_60_79(69, B, C, D, E, A);
-	T_60_79(70, A, B, C, D, E);
-	T_60_79(71, E, A, B, C, D);
-	T_60_79(72, D, E, A, B, C);
-	T_60_79(73, C, D, E, A, B);
-	T_60_79(74, B, C, D, E, A);
-	T_60_79(75, A, B, C, D, E);
-	T_60_79(76, E, A, B, C, D);
-	T_60_79(77, D, E, A, B, C);
-	T_60_79(78, C, D, E, A, B);
-	T_60_79(79, B, C, D, E, A);
-
-	ctx->H[0] += A;
-	ctx->H[1] += B;
-	ctx->H[2] += C;
-	ctx->H[3] += D;
-	ctx->H[4] += E;
-}
-
-int git_hash_sha1_global_init(void)
-{
-	return 0;
-}
-
-int git_hash_sha1_ctx_init(git_hash_sha1_ctx *ctx)
-{
-	return git_hash_sha1_init(ctx);
-}
-
-void git_hash_sha1_ctx_cleanup(git_hash_sha1_ctx *ctx)
-{
-	GIT_UNUSED(ctx);
-}
-
-int git_hash_sha1_init(git_hash_sha1_ctx *ctx)
-{
-	ctx->size = 0;
-
-	/* Initialize H with the magic constants (see FIPS180 for constants) */
-	ctx->H[0] = 0x67452301;
-	ctx->H[1] = 0xefcdab89;
-	ctx->H[2] = 0x98badcfe;
-	ctx->H[3] = 0x10325476;
-	ctx->H[4] = 0xc3d2e1f0;
-
-	return 0;
-}
-
-int git_hash_sha1_update(git_hash_sha1_ctx *ctx, const void *data, size_t len)
-{
-	unsigned int lenW = ctx->size & 63;
-
-	ctx->size += len;
-
-	/* Read the data into W and process blocks as they get full */
-	if (lenW) {
-		unsigned int left = 64 - lenW;
-		if (len < left)
-			left = (unsigned int)len;
-		memcpy(lenW + (char *)ctx->W, data, left);
-		lenW = (lenW + left) & 63;
-		len -= left;
-		data = ((const char *)data + left);
-		if (lenW)
-			return 0;
-		hash__block(ctx, ctx->W);
-	}
-	while (len >= 64) {
-		hash__block(ctx, data);
-		data = ((const char *)data + 64);
-		len -= 64;
-	}
-	if (len)
-		memcpy(ctx->W, data, len);
-
-	return 0;
-}
-
-int git_hash_sha1_final(unsigned char *out, git_hash_sha1_ctx *ctx)
-{
-	static const unsigned char pad[64] = { 0x80 };
-	unsigned int padlen[2];
-	int i;
-
-	/* Pad with a binary 1 (ie 0x80), then zeroes, then length */
-	padlen[0] = htonl((uint32_t)(ctx->size >> 29));
-	padlen[1] = htonl((uint32_t)(ctx->size << 3));
-
-	i = ctx->size & 63;
-	git_hash_sha1_update(ctx, pad, 1+ (63 & (55 - i)));
-	git_hash_sha1_update(ctx, padlen, 8);
-
-	/* Output hash */
-	for (i = 0; i < 5; i++)
-		put_be32(out + i*4, ctx->H[i]);
-
-	return 0;
-}
diff --git a/src/util/hash/sha1/generic.h b/src/util/hash/sha1/generic.h
deleted file mode 100644
index 53fc082..0000000
--- a/src/util/hash/sha1/generic.h
+++ /dev/null
@@ -1,19 +0,0 @@
-/*
- * Copyright (C) the libgit2 contributors. All rights reserved.
- *
- * This file is part of libgit2, distributed under the GNU GPL v2 with
- * a Linking Exception. For full terms see the included COPYING file.
- */
-
-#ifndef INCLUDE_hash_sha1_generic_h__
-#define INCLUDE_hash_sha1_generic_h__
-
-#include "hash/sha1.h"
-
-struct git_hash_sha1_ctx {
-	uint64_t size;
-	unsigned int H[5];
-	unsigned int W[16];
-};
-
-#endif