Fix a bunch of warnings

This change fixes a bunch of warnings that were discovered by compiling
with `clang -target=i386-pc-linux-gnu`. It turned out that the
intrinsics were not necessarily being used in all platforms! Especially
in GCC, since it does not support __has_builtin.

Some more warnings were gleaned from the Windows build, but I stopped
when I saw that some third-party dependencies (e.g. zlib) have warnings
of their own, so we might never be able to enable -Werror there.

src/integer.h

@@ -55,16 +55,18 @@ GIT_INLINE(bool) git__add_uint64_overflow(uint64_t *out, uint64_t one, uint64_t
 }
 
 /* Use clang/gcc compiler intrinsics whenever possible */
-#if (SIZE_MAX == ULONG_MAX) && __has_builtin(__builtin_uaddl_overflow)
+#if (SIZE_MAX == ULLONG_MAX) && (__has_builtin(__builtin_uaddl_overflow) || \
+                                 (defined(__GNUC__) && (__GNUC__ >= 5)))
 # define git__add_sizet_overflow(out, one, two) \
 	__builtin_uaddl_overflow(one, two, out)
 # define git__multiply_sizet_overflow(out, one, two) \
 	__builtin_umull_overflow(one, two, out)
-#elif (SIZE_MAX == UINT_MAX) && __has_builtin(__builtin_uadd_overflow)
+#elif (__has_builtin(__builtin_add_overflow) || \
+       (defined(__GNUC__) && (__GNUC__ >= 5)))
 # define git__add_sizet_overflow(out, one, two) \
-	__builtin_uadd_overflow(one, two, out)
+	__builtin_add_overflow(one, two, out)
 # define git__multiply_sizet_overflow(out, one, two) \
-	__builtin_umul_overflow(one, two, out)
+	__builtin_mul_overflow(one, two, out)
 #else
 
 /**

src/odb.c

@@ -95,7 +95,7 @@ int git_odb__format_object_header(
 	int hdr_max = (hdr_size > INT_MAX-2) ? (INT_MAX-2) : (int)hdr_size;
 	int len;
 
-	len = p_snprintf(hdr, hdr_max, "%s %lld", type_str, (long long)obj_len);
+	len = p_snprintf(hdr, hdr_max, "%s %"PRId64, type_str, (int64_t)obj_len);
 
 	if (len < 0 || len >= hdr_max) {
 		giterr_set(GITERR_OS, "object header creation failed");

src/streams/socket.c

@@ -38,7 +38,7 @@ static void net_set_error(const char *str)
 		giterr_set(GITERR_NET, "%s: %s", str, win32_error);
 		git__free(win32_error);
 	} else {
-		giterr_set(GITERR_NET, str);
+		giterr_set(GITERR_NET, "%s", str);
 	}
 }
 #else

src/transports/winhttp.c

@@ -329,34 +329,6 @@ static void winhttp_stream_close(winhttp_stream *s)
 	s->sent_request = 0;
 }
 
-/**
- * Extract the url and password from a URL. The outputs are pointers
- * into the input.
- */
-static int userpass_from_url(wchar_t **user, int *user_len,
-			     wchar_t **pass, int *pass_len,
-			     const wchar_t *url, int url_len)
-{
-	URL_COMPONENTS components = { 0 };
-
-	components.dwStructSize = sizeof(components);
-	/* These tell WinHttpCrackUrl that we're interested in the fields */
-	components.dwUserNameLength = 1;
-	components.dwPasswordLength = 1;
-
-	if (!WinHttpCrackUrl(url, url_len, 0, &components)) {
-		giterr_set(GITERR_OS, "failed to extract user/pass from url");
-		return -1;
-	}
-
-	*user     = components.lpszUserName;
-	*user_len = components.dwUserNameLength;
-	*pass     = components.lpszPassword;
-	*pass_len = components.dwPasswordLength;
-
-	return 0;
-}
-
 #define SCHEME_HTTP  "http://"
 #define SCHEME_HTTPS "https://"
 
@@ -659,7 +631,7 @@ static int write_chunk(HINTERNET request, const char *buffer, size_t len)
 	git_buf buf = GIT_BUF_INIT;
 
 	/* Chunk header */
-	git_buf_printf(&buf, "%X\r\n", len);
+	git_buf_printf(&buf, "%zX\r\n", len);
 
 	if (git_buf_oom(&buf))
 		return -1;
@@ -747,7 +719,7 @@ static void CALLBACK winhttp_status(
 	else if ((status & WINHTTP_CALLBACK_STATUS_FLAG_SECURITY_CHANNEL_ERROR))
 		giterr_set(GITERR_NET, "security libraries could not be loaded");
 	else
-		giterr_set(GITERR_NET, "unknown security error %d", status);
+		giterr_set(GITERR_NET, "unknown security error %lu", status);
 }
 
 static int winhttp_connect(
@@ -870,7 +842,7 @@ static int do_send_request(winhttp_stream *s, size_t len, int ignore_length)
 				len, 0);
 		}
 
-		if (success || GetLastError() != SEC_E_BUFFER_TOO_SMALL)
+		if (success || GetLastError() != (DWORD)SEC_E_BUFFER_TOO_SMALL)
 			break;
 	}
 
@@ -1170,7 +1142,7 @@ replay:
 		}
 
 		if (HTTP_STATUS_OK != status_code) {
-			giterr_set(GITERR_NET, "request failed with status code: %d", status_code);
+			giterr_set(GITERR_NET, "request failed with status code: %lu", status_code);
 			return -1;
 		}
 

src/win32/posix_w32.c

@@ -397,7 +397,6 @@ int p_readlink(const char *path, char *buf, size_t bufsiz)
 int p_symlink(const char *target, const char *path)
 {
 	git_win32_path target_w, path_w;
-	wchar_t *target_p;
 
 	if (git_win32_path_from_utf8(path_w, path) < 0 ||
 		git__utf8_to_16(target_w, MAX_PATH, target) < 0)

tests/revwalk/basic.c

@@ -512,7 +512,7 @@ void test_revwalk_basic__big_timestamp(void)
 	cl_git_pass(git_reference_peel((git_object **) &tip, head, GIT_OBJECT_COMMIT));
 
 	/* Commit with a far-ahead timestamp, we should be able to parse it in the revwalk */
-	cl_git_pass(git_signature_new(&sig, "Joe", "joe@example.com", 2399662595, 0));
+	cl_git_pass(git_signature_new(&sig, "Joe", "joe@example.com", 2399662595ll, 0));
 	cl_git_pass(git_commit_tree(&tree, tip));
 
 	cl_git_pass(git_commit_create(&id, _repo, "HEAD", sig, sig, NULL, "some message", tree, 1,