stdlib.h：沒有這樣的文件或目錄

Question

我正在使用各種 stdlib 函數，如 srand() 等。我有這條線

#include <stdlib.h>

在我的代碼頂部。

我在命令行輸入了這個：

# find / -name stdlib.h

find: `/home/dmurvihill/.gvfs: permission denied
/usr/include/stdlib.h
/usr/include/bits/stdlib.h

所以，stdlib.h 顯然在 /usr/include 中。

我的預處理器：

# gcc -print-prog-name=cc1

/usr/libexec/gcc/x86_64-redhat-linux/4.5.1/cc1

我的預處理器的默認搜索路徑：

# /usr/libexec/gcc/x86_64-redhat-linux/4.5.1/cc1 -v

ignoring nonexistent directory "/usr/lib/gcc/x86_64-redhat-linux/4.5.1/include-fixed"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../../../x86_64-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/local/include
/usr/lib/gcc/x86_64-redhat-linux/4.5.1/include
/usr/include
End of search list.

所以，stdlib.h 顯然在 /usr/include 中，我的預處理器肯定會搜索它，但我仍然收到此錯誤！

/path/to/cpa_sample_code_main.c:15:20: fatal error: stdlib.h: No such file or directory
compilation terminated

更新

我寫的一個程序來測試這段代碼：

#include <stdio.h>
#include <stdlib.h>
#include <linux/time.h>

int main()
{
    printf("Hello, World!\n");
    printf("Getting time...\n");
    time_t seconds;
    time(&seconds);
    printf("Seeding generator...\n");
    srand((unsigned int)seconds);
    printf("Getting random number...\n");
    int value = rand();
    printf("It is %d!",value);
    printf("Goodbye, cruel world!");
    return 0;
}

命令

gcc -H -v -fsyntax-only stdlib_test.c

輸出

Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/4.5.1/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --enable-languages=c,c++,objc,obj-c++,java,fortran,ada,lto --enable-plugin --enable-java-awt=gtk --disable-dssi --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre --enable-libgcj-multifile --enable-java-maintainer-mode --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib --with-ppl --with-cloog --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux
Thread model: posix
gcc version 4.5.1 20100924 (Red Hat 4.5.1-4) (GCC) 
COLLECT_GCC_OPTIONS='-H' '-v' '-fsyntax-only' '-mtune=generic' '-march=x86-64'
 /usr/libexec/gcc/x86_64-redhat-linux/4.5.1/cc1 -quiet -v -H /CRF_Verify/stdlib_test.c -quiet -dumpbase stdlib_test.c -mtune=generic -march=x86-64 -auxbase stdlib_test -version -fsyntax-only -o /dev/null
GNU C (GCC) version 4.5.1 20100924 (Red Hat 4.5.1-4) (x86_64-redhat-linux)
    compiled by GNU C version 4.5.1 20100924 (Red Hat 4.5.1-4), GMP version 4.3.1, MPFR version 2.4.2, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "/usr/lib/gcc/x86_64-redhat-linux/4.5.1/include-fixed"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../../../x86_64-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /usr/lib/gcc/x86_64-redhat-linux/4.5.1/include
 /usr/include
End of search list.
GNU C (GCC) version 4.5.1 20100924 (Red Hat 4.5.1-4) (x86_64-redhat-linux)
    compiled by GNU C version 4.5.1 20100924 (Red Hat 4.5.1-4), GMP version 4.3.1, MPFR version 2.4.2, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: ea394b69293dd698607206e8e43d607e
. /usr/include/stdio.h
.. /usr/include/features.h
... /usr/include/sys/cdefs.h
.... /usr/include/bits/wordsize.h
... /usr/include/gnu/stubs.h
.... /usr/include/bits/wordsize.h
.... /usr/include/gnu/stubs-64.h
.. /usr/lib/gcc/x86_64-redhat-linux/4.5.1/include/stddef.h
.. /usr/include/bits/types.h
... /usr/include/bits/wordsize.h
... /usr/include/bits/typesizes.h
.. /usr/include/libio.h
... /usr/include/_G_config.h
.... /usr/lib/gcc/x86_64-redhat-linux/4.5.1/include/stddef.h
.... /usr/include/wchar.h
... /usr/lib/gcc/x86_64-redhat-linux/4.5.1/include/stdarg.h
.. /usr/include/bits/stdio_lim.h
.. /usr/include/bits/sys_errlist.h
. /usr/include/stdlib.h
.. /usr/lib/gcc/x86_64-redhat-linux/4.5.1/include/stddef.h
.. /usr/include/bits/waitflags.h
.. /usr/include/bits/waitstatus.h
... /usr/include/endian.h
.... /usr/include/bits/endian.h
.... /usr/include/bits/byteswap.h
..... /usr/include/bits/wordsize.h
.. /usr/include/sys/types.h
... /usr/include/time.h
... /usr/lib/gcc/x86_64-redhat-linux/4.5.1/include/stddef.h
... /usr/include/sys/select.h
.... /usr/include/bits/select.h
..... /usr/include/bits/wordsize.h
.... /usr/include/bits/sigset.h
.... /usr/include/time.h
.... /usr/include/bits/time.h
... /usr/include/sys/sysmacros.h
... /usr/include/bits/pthreadtypes.h
.... /usr/include/bits/wordsize.h
.. /usr/include/alloca.h
... /usr/lib/gcc/x86_64-redhat-linux/4.5.1/include/stddef.h
. /usr/include/linux/time.h
.. /usr/include/linux/types.h
... /usr/include/asm/types.h
.... /usr/include/asm-generic/types.h
..... /usr/include/asm-generic/int-ll64.h
...... /usr/include/asm/bitsperlong.h
....... /usr/include/asm-generic/bitsperlong.h
... /usr/include/linux/posix_types.h
.... /usr/include/linux/stddef.h
.... /usr/include/asm/posix_types.h
..... /usr/include/asm/posix_types_64.h
In file included from /CRF_Verify/stdlib_test.c:3:0:
/usr/include/linux/time.h:9:8: error: redefinition of ‘struct timespec’
/usr/include/time.h:120:8: note: originally defined here
/usr/include/linux/time.h:15:8: error: redefinition of ‘struct timeval’
/usr/include/bits/time.h:75:8: note: originally defined here
Multiple include guards may be useful for:
/usr/include/asm/posix_types.h
/usr/include/bits/byteswap.h
/usr/include/bits/endian.h
/usr/include/bits/select.h
/usr/include/bits/sigset.h
/usr/include/bits/stdio_lim.h
/usr/include/bits/sys_errlist.h
/usr/include/bits/time.h
/usr/include/bits/typesizes.h
/usr/include/bits/waitflags.h
/usr/include/bits/waitstatus.h
/usr/include/gnu/stubs-64.h
/usr/include/gnu/stubs.h
/usr/include/wchar.h

Answer 1

您的錯誤似乎源於在嘗試包含stdlib.h時包含linux/time.h 。 linux/time.h是內核頭文件，只能在內核代碼中使用。 stdlib.h是用戶級函數，只能在用戶程序中使用。 如果你注意到你得到的錯誤：

/usr/include/linux/time.h:12: error: redefinition of 'struct timespec'
/usr/include/linux/time.h:18: error: redefinition of 'struct timeval'

您可以看到您收到與此相關的錯誤。 正如在您的長跟蹤中所見，這是因為stdlib.h包括time.h （ /usr/include那個，而不是/usr/include/linux ）。 我想這是您看到的關於未找到 stdlib.h 的錯誤的真正原因（盡管我無法想象錯誤是如何發生的細節）。

Answer 2

對於那些試圖在 Windows 上使用Cygwin編譯 C++ 程序的人來說，我的問題是我同時擁有MingW和Cygwin 。 MingW 是作為 Cygwin 安裝程序的一部分安裝的。 我使用了 Cygwin 的setup.exe （我們稱之為包安裝程序）並刪除了 MingW 的所有實例。 之后，我的測試應用程序正確編譯。

注意：此解決方案對我有用。 有無數其他原因導致您出現相同的錯誤。

Answer 3

我在使用 g++ v6.x 時發現了另一個原因，錯誤 70129 。 我在為 Boost 包含目錄指定-isystem （通過 CMake 的SYSTEM關鍵字）時觸發了它 - 最終包含cstdlib 。