2017-10-15 119 views
0

我.c文件代碼:爲什麼我Valgrind的不顯示錯誤行,而是其它的路徑在MacOS上Seirra

#include <stdio.h> 

/* i had made the coding wrong on purpose. */ 
int main(){ 
    int g = 10; 
    int h; 

    printf("I am %d age.\n"); 
    printf("I am %dtall.\n", h); 

    return 0; 
} 

ex4.c

我跑這個代碼:gcc -Wall -g -o ex4 ex4.c

而且在我的終端這是我得到的輸出:

ex4.c:8:17: warning: more '%' conversions than data arguments [-Wformat] 
    printf("I am %d age.\n"); 
       ~^ 
ex4.c:5:7: warning: unused variable 'g' [-Wunused-variable] 
    int g = 10; 
    ^
ex4.c:9:28: warning: variable 'h' is uninitialized when used here 
     [-Wuninitialized] 
    printf("I am %dtall.\n", h); 
         ^
ex4.c:6:8: note: initialize the variable 'h' to silence this warning 
    int h; 
    ^
     = 0 
3 warnings generated. 

My terminal

而且我開始嘗試Valgrind的檢查內存泄漏:

valgrind ./ex4 

這是我的終端上的輸出:

iPatrickMac:trying_valgrind patrick$ valgrind ./ex4 
==10836== Memcheck, a memory error detector 
==10836== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al. 
==10836== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info 
==10836== Command: ./ex4 
==10836== 
==10836== Syscall param msg->desc.port.name points to uninitialised byte(s) 
==10836== at 0x1003A834A: mach_msg_trap (in /usr/lib/system/libsystem_kernel.dylib) 
==10836== by 0x1003A7796: mach_msg (in /usr/lib/system/libsystem_kernel.dylib) 
==10836== by 0x1003A1485: task_set_special_port (in /usr/lib/system/libsystem_kernel.dylib) 
==10836== by 0x10053D10E: _os_trace_create_debug_control_port (in /usr/lib/system/libsystem_trace.dylib) 
==10836== by 0x10053D458: _libtrace_init (in /usr/lib/system/libsystem_trace.dylib) 
==10836== by 0x1000A69DF: libSystem_initializer (in /usr/lib/libSystem.B.dylib) 
==10836== by 0x100018A1A: ImageLoaderMachO::doModInitFunctions(ImageLoader::LinkContext const&) (in /usr/lib/dyld) 
==10836== by 0x100018C1D: ImageLoaderMachO::doInitialization(ImageLoader::LinkContext const&) (in /usr/lib/dyld) 
==10836== by 0x1000144A9: ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) (in /usr/lib/dyld) 
==10836== by 0x100014440: ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) (in /usr/lib/dyld) 
==10836== by 0x100013523: ImageLoader::processInitializers(ImageLoader::LinkContext const&, unsigned int, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) (in /usr/lib/dyld) 
==10836== by 0x1000135B8: ImageLoader::runInitializers(ImageLoader::LinkContext const&, ImageLoader::InitializerTimingList&) (in /usr/lib/dyld) 
==10836== Address 0x10488bdcc is on thread 1's stack 
==10836== in frame #2, created by task_set_special_port (???:) 
==10836== 
I am 76077616 age. 
==10836== Conditional jump or move depends on uninitialised value(s) 
==10836== at 0x1002A64D7: __vfprintf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002CE422: __v2printf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002A433D: vfprintf_l (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002A2247: printf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x100000F67: main (ex4.c:9) 
==10836== 
==10836== Conditional jump or move depends on uninitialised value(s) 
==10836== at 0x1002A8E87: __ultoa (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002CE422: __v2printf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002A433D: vfprintf_l (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002A2247: printf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x100000F67: main (ex4.c:9) 
==10836== 
==10836== Conditional jump or move depends on uninitialised value(s) 
==10836== at 0x10009A142: _platform_memchr$VARIANT$Haswell (in /usr/local/Cellar/valgrind/3.13.0/lib/valgrind/vgpreload_memcheck-amd64-darwin.so) 
==10836== by 0x10029E4D1: __sfvwrite (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002A8898: __vfprintf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002CE422: __v2printf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002A433D: vfprintf_l (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002A2247: printf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x100000F67: main (ex4.c:9) 
==10836== 
==10836== Syscall param write(buf) points to uninitialised byte(s) 
==10836== at 0x1003B047E: write$NOCANCEL (in /usr/lib/system/libsystem_kernel.dylib) 
==10836== by 0x1002A3200: _swrite (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x10029BD26: __sflush (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x10029E584: __sfvwrite (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002A8952: __vfprintf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002CE422: __v2printf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002A433D: vfprintf_l (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002A2247: printf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x100000F67: main (ex4.c:9) 
==10836== Address 0x100b57b85 is 5 bytes inside a block of size 4,096 alloc'd 
==10836== at 0x100098616: malloc (in /usr/local/Cellar/valgrind/3.13.0/lib/valgrind/vgpreload_memcheck-amd64-darwin.so) 
==10836== by 0x10029EFD8: __smakebuf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002B3B1D: __swsetup (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002CE1BE: __v2printf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002A433D: vfprintf_l (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x1002A2247: printf (in /usr/lib/system/libsystem_c.dylib) 
==10836== by 0x100000F53: main (ex4.c:8) 
==10836== 
I am 1tall. 
==10836== 
==10836== HEAP SUMMARY: 
==10836==  in use at exit: 22,136 bytes in 160 blocks 
==10836== total heap usage: 176 allocs, 16 frees, 28,280 bytes allocated 
==10836== 
==10836== LEAK SUMMARY: 
==10836== definitely lost: 0 bytes in 0 blocks 
==10836== indirectly lost: 0 bytes in 0 blocks 
==10836==  possibly lost: 72 bytes in 3 blocks 
==10836== still reachable: 200 bytes in 6 blocks 
==10836==   suppressed: 21,864 bytes in 151 blocks 
==10836== Rerun with --leak-check=full to see details of leaked memory 
==10836== 
==10836== For counts of detected and suppressed errors, rerun with: -v 
==10836== Use --track-origins=yes to see where uninitialised values come from 
==10836== ERROR SUMMARY: 5 errors from 5 contexts (suppressed: 4 from 4) 

我很困惑,爲什麼我的valgrind沒有按」 t顯示錯誤行並顯示其他路徑。

我的編譯有問題嗎或者在macOS sierra上valgrind有什麼問題?幫助球員):

什麼是這一切:

==5190== Use of uninitialised value of size 4 
==5190== at 0x4078B2B: _itoa_word (_itoa.c:195) 
==5190== by 0x407CE55: vfprintf (vfprintf.c:1619) 
==5190== by 0x40831DE: printf (printf.c:35) 
==5190== by 0x4052112: (below main) (libc-start.c:226) 
==5190== 
==5190== Conditional jump or move depends on uninitialised value(s) 
==5190== at 0x4078B33: _itoa_word (_itoa.c:195) 
==5190== by 0x407CE55: vfprintf (vfprintf.c:1619) 
==5190== by 0x40831DE: printf (printf.c:35) 
==5190== by 0x4052112: (below main) (libc-start.c:226) 
==5190== 
==5190== Conditional jump or move depends on uninitialised value(s) 
==5190== at 0x407CC10: vfprintf (vfprintf.c:1619) 
==5190== by 0x40831DE: printf (printf.c:35) 
==5190== by 0x4052112: (below main) (libc-start.c:226) 
==5190== 
==5190== Conditional jump or move depends on uninitialised value(s) 
==5190== at 0x407C742: vfprintf (vfprintf.c:1619) 
==5190== by 0x40831DE: printf (printf.c:35) 
==5190== by 0x4052112: (below main) (libc-start.c:226) 

我怎樣才能讓我的MacOS塞拉利昂我的valgrind顯示錯誤:一個的valgrind顯示錯誤線的

==10836== Syscall param msg->desc.port.name points to uninitialised byte(s) 
==10836== at 0x1003A834A: mach_msg_trap (in /usr/lib/system/libsystem_kernel.dylib) 
==10836== by 0x1003A7796: mach_msg (in /usr/lib/system/libsystem_kernel.dylib) 
==10836== by 0x1003A1485: task_set_special_port (in /usr/lib/system/libsystem_kernel.dylib) 
==10836== by 0x10053D10E: _os_trace_create_debug_control_port (in /usr/lib/system/libsystem_trace.dylib) 
==10836== by 0x10053D458: _libtrace_init (in /usr/lib/system/libsystem_trace.dylib) 
==10836== by 0x1000A69DF: libSystem_initializer (in /usr/lib/libSystem.B.dylib) 
==10836== by 0x100018A1A: ImageLoaderMachO::doModInitFunctions(ImageLoader::LinkContext const&) (in /usr/lib/dyld) 
==10836== by 0x100018C1D: ImageLoaderMachO::doInitialization(ImageLoader::LinkContext const&) (in /usr/lib/dyld) 
==10836== by 0x1000144A9: ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) (in /usr/lib/dyld) 
==10836== by 0x100014440: ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) (in /usr/lib/dyld) 
==10836== by 0x100013523: ImageLoader::processInitializers(ImageLoader::LinkContext const&, unsigned int, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) (in /usr/lib/dyld) 
==10836== by 0x1000135B8: ImageLoader::runInitializers(ImageLoader::LinkContext const&, ImageLoader::InitializerTimingList&) (in /usr/lib/dyld) 
==10836== Address 0x10488bdcc is on thread 1's stack 
==10836== in frame #2, created by task_set_special_port (???:) 

例子因此沒有顯示其他奇怪的路徑,我不知道它們是什麼。

回答

0

C11標準,章§7.21.6.1

[..]如果存在的格式參數不足,則該行爲是未定義的。 [..]

所以,這是件好事,因爲產生這種調用的行爲是不確定的沒有忽視這個警告。

+0

我不太確定你在說什麼): – Z133l33

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