mirror of
https://gitlab.freedesktop.org/wayland/wayland.git
synced 2025-10-29 05:40:16 -04:00
8a7ecd774c
If a wl_array has size zero, wl_array_for_each computes NULL + 0 to get to the end pointer. This should be fine, and indeed it would be fine in C++. But the C specification has a mistake here and it is actually undefined behavior. See https://davidben.net/2024/01/15/empty-slices.html Clang's -fsanitize=undefined flags this. I ran into this in Chromium's build with wayland-scanner on one of our XML files. ../../third_party/wayland/src/src/scanner.c:1853:2: runtime error: applying zero offset to null pointer #0 0x55c979b8e02c in emit_code third_party/wayland/src/src/scanner.c:1853:2 #1 0x55c979b89323 in main third_party/wayland/src/src/scanner.c #2 0x7f8dfdb8c6c9 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16 #3 0x7f8dfdb8c784 in __libc_start_main csu/../csu/libc-start.c:360:3 #4 0x55c979b70f39 in _start (...) An empty XML file is sufficient to hit this case, so I've added it as a test. To reproduce, undo the fix and include only the test, then build with: CC=clang CFLAGS="-fno-sanitize-recover=undefined" meson build/ -Db_sanitize=undefined -Db_lundef=false ninja -C build test Signed-off-by: David Benjamin <davidben@google.com>
25 lines
894 B
Bash
Executable file
25 lines
894 B
Bash
Executable file
#!/bin/sh -eu
|
|
|
|
generate() {
|
|
"$WAYLAND_SCANNER" $1 < "$TEST_DATA_DIR/$2" > "$TEST_DATA_DIR/$3"
|
|
"$SED" -i -e 's/Generated by wayland-scanner [0-9.]*/SCANNER TEST/' \
|
|
"$TEST_DATA_DIR/$3"
|
|
}
|
|
|
|
generate "code" "example.xml" "example-code.c"
|
|
generate "client-header" "example.xml" "example-client.h"
|
|
generate "server-header" "example.xml" "example-server.h"
|
|
|
|
generate "code" "small.xml" "small-code.c"
|
|
generate "client-header" "small.xml" "small-client.h"
|
|
generate "server-header" "small.xml" "small-server.h"
|
|
|
|
generate "-c code" "small.xml" "small-code-core.c"
|
|
generate "-c client-header" "small.xml" "small-client-core.h"
|
|
generate "-c server-header" "small.xml" "small-server-core.h"
|
|
|
|
generate "private-code" "small.xml" "small-private-code.c"
|
|
|
|
generate "code" "empty.xml" "empty-code.c"
|
|
generate "client-header" "empty.xml" "empty-client.h"
|
|
generate "server-header" "empty.xml" "empty-server.h"
|