Happy Holiday 10.01~10.08

How to generate crash backtrace just from your serial crash log, without coredump file.

If your crash log have dump maps, user stacks, and you have symbols too,
You can try to get a backtrace via below python scripts.

[2-11624.8825] PC, LR MEMINFO
[2-11624.8825] --------------------------------------------------------------------------------------
[2-11624.8825] PC:46cbfc92, LR:46cbfc59
[2-11624.8825] --------------------------------------------------------------------------------------
[2-11624.8825] PC meminfo (0x46cc005d to 0x46cc0092)
[2-11624.8825] 0040:                                                                               
[2-11624.8825] 0060: be07e9cd 801cf8d0 f04fb085 f1010901 ea4f061b e0015707 d03142b4 f85446a3
[2-11624.8825] 0080: f0055b04 2b010303 ea4fd1f6 f8d85a15 ea4f3a14
[2-11624.8825] --------------------------------------------------------------------------------------
[2-11624.8825] LR meminfo (0x46cbf459 to 0x46cc0059)
[2-11624.8825] f440:                                                                0205ea02
[2-11624.8825] f460: bf0442a2 f8832201 d009202c f84269da 6a191020 f1016a9a ea020101 621a0201
[2-11624.8825] f480: e9ddb002 b0024500 bf004770 8000f3af 4506e96d 5413ea4f e9cd460d ea4f8e04
......
[2-11624.8831] * dump maps on pid (2548 - efl_webprocess)
[2-11624.8831] -----------------------------------------------------------
[2-11624.8831] 00010000-00011000 r-xp 00000000 b3:12 55716      /usr/lib/chromium-efl/efl_webprocess
[2-11624.8831] 00020000-00021000 r--p 00000000 b3:12 55716      /usr/lib/chromium-efl/efl_webprocess
[2-11624.8831] 00021000-00022000 rw-p 00000000 00:00 0         
[2-11624.8831] 00031000-00036000 rw-p 00001000 b3:12 55716      /usr/lib/chromium-efl/efl_webprocess
[2-11624.8831] 00036000-0007c000 rw-p 00000000 00:00 0          [heap]
[2-11624.8831] 0007c000-008ae000 rw-p 00000000 00:00 0          [heap]

[2-11624.8917] -----------------------------------------------------------
[2-11624.8917] * dump user stack
[2-11624.8917] -----------------------------------------------------------
[2-11624.8917] pid(2548) stack vma (0xbe729000 ~ 0xbe74c000)
[2-11624.8917] User Stack: (0xbe749e20 to 0xbe745f10)
[2-11624.8917] -----------------------------------------------------------

Fix up : Configurable attribute "copts" doesn't match this configuration

ERROR: /home/lenger/.cache/bazel/_bazel_lenger/e744db622218e02ee1e2cbf3b8750f17/external/nsync/BUILD:402:13: Configurable attribute "copts" doesn't match this configuration (would a default condition help?).
Conditions checked:
 @nsync//:android_arm
 @nsync//:android_arm64
 @nsync//:android_armeabi
 @nsync//:android_x86_32
 @nsync//:android_x86_64
 @nsync//:clang_macos_x86_64
 @nsync//:gcc_linux_aarch64
 @nsync//:gcc_linux_ppc64
 @nsync//:gcc_linux_x86_64_1
 @nsync//:gcc_linux_x86_64_2
 @nsync//:ios_x86_64
 @nsync//:msvc_windows_x86_64.

Solution:
vim /home/lenger/.cache/bazel/_bazel_lenger/e744db622218e02ee1e2cbf3b8750f17/external/nsync/BUILD


Add a default conditions there as marked as red line below:

NSYNC_OPTS_GENERIC = select({
    # Select the CPU architecture include directory.
    # This select() has no real effect in the C++11 build, but satisfies a
    # #include that would otherwise need a #if.
    ":gcc_linux_x86_64_1": ["-I" + pkg_path_name() + "/platform/x86_64"],
    ":gcc_linux_x86_64_2": ["-I" + pkg_path_name() + "/platform/x86_64"],
    ":gcc_linux_aarch64": ["-I" + pkg_path_name() + "/platform/aarch64"],
    ":gcc_linux_ppc64": ["-I" + pkg_path_name() + "/platform/ppc64"],
    ":clang_macos_x86_64": ["-I" + pkg_path_name() + "/platform/x86_64"],
    ":ios_x86_64": ["-I" + pkg_path_name() + "/platform/x86_64"],
    ":android_x86_32": ["-I" + pkg_path_name() + "/platform/x86_32"],
    ":android_x86_64": ["-I" + pkg_path_name() + "/platform/x86_64"],
    ":android_armeabi": ["-I" + pkg_path_name() + "/platform/arm"],
    ":android_arm": ["-I" + pkg_path_name() + "/platform/arm"],
    ":android_arm64": ["-I" + pkg_path_name() + "/platform/aarch64"],
    ":msvc_windows_x86_64": ["-I" + pkg_path_name() + "/platform/x86_64"],
    "//conditions:default": [],
}) + [
    "-I" + pkg_path_name() + "/public",
    "-I" + pkg_path_name() + "/internal",
    "-I" + pkg_path_name() + "/platform/posix",
] + select({
    ":msvc_windows_x86_64": [
    ],
    "//conditions:default": [
        "-D_POSIX_C_SOURCE=200809L",
        "-pthread",
    ],
})

Cross compile tensorflow for armv7l targets via bazel

Refer:
https://github.com/bazelbuild/bazel/wiki/Building-with-a-custom-toolchain
https://www.tensorflow.org/tutorials/image_recognition

happy weekend

何必为衣裳忧虑呢？你想野地里的百合花怎么长起来；它也不劳苦，也不纺线。  (马太福音 6:28 和合本)
“And why do you worry about clothes? See how the flowers of the field grow. They do not labor or spin. (Matthew 6:28 NIV)
然而我告诉你们，就是所罗门极荣华的时候，他所穿戴的，还不如这花一朵呢！  (马太福音 6:29 和合本)
Yet I tell you that not even Solomon in all his splendor was dressed like one of these. (Matthew 6:29 NIV)