如何使用.pch与clang？

Question

我有头文件header.h:

#define TEST_VALUE 1
#define TEST_STRING "hello world"

和源文件source.cpp:

#include "header.h"
#include "stdio.h"

int main() {
    printf(TEST_STRING"\n");
}

我跟着clang pch文章并表演了:

MBA-Anton:pch asmirnov$ clang -cc1 ./header.h -emit-pch -o ./header.pch
MBA-Anton:pch asmirnov$ clang -cc1 -include-pch header.pch source.cpp -o source
error: C99 was enabled in PCH file but is currently disabled
1 error generated.
MBA-Anton:pch asmirnov$ clang -I. source.cpp -o source
MBA-Anton:pch asmirnov$ ls
header.h    header.pch  source      source.cpp
MBA-Anton:pch asmirnov$ ./source 
hello world

所以我无法与PCH链接,但我可以编译/链接源+标头.与clang文章的例子的唯一区别是我已经尝试过c ++并且它是针对c描述的.所以我试着指定c ++语言:

MBA-Anton:pch asmirnov$ clang -cc1 ./header.h -emit-pch -o ./header.pch2 -x c++
MBA-Anton:pch asmirnov$ clang -cc1 -include-pch header.pch2 source.cpp -o source2 -x c++
source.cpp:2:10: fatal error: 'stdio.h' file not found
#include "stdio.h"
         ^
1 error generated.
MBA-Anton:pch asmirnov$ ls -l
total 496
-rw-r--r--  1 asmirnov  wheel      56  5 ??? 15:31 header.h
-rw-r--r--  1 asmirnov  wheel  112564  5 ??? 15:50 header.pch
-rw-r--r--  1 asmirnov  wheel  116236  5 ??? 15:50 header.pch2
-rwxr-xr-x  1 asmirnov  wheel    8456  5 ??? 15:42 source
-rw-r--r--  1 asmirnov  wheel      80  5 ??? 15:32 source.cpp

再指一次c ++ 11的尝试:

MBA-Anton:pch asmirnov$ clang -cc1 ./header.h -emit-pch -o ./header.pch3 -x c++ -std=c++11
MBA-Anton:pch asmirnov$ clang -cc1 -include-pch header.pch3 source.cpp -o source3 -x c++ -std=c++11
source.cpp:2:10: fatal error: 'stdio.h' file not found
#include "stdio.h"
         ^
1 error generated.
MBA-Anton:pch asmirnov$ ls -l
total 728
-rw-r--r--  1 asmirnov  wheel      56  5 ??? 15:31 header.h
-rw-r--r--  1 asmirnov  wheel  112564  5 ??? 15:50 header.pch
-rw-r--r--  1 asmirnov  wheel  116236  5 ??? 15:54 header.pch2
-rw-r--r--  1 asmirnov  wheel  117132  5 ??? 15:57 header.pch3
-rwxr-xr-x  1 asmirnov  wheel    8456  5 ??? 15:42 source
-rw-r--r--  1 asmirnov  wheel      80  5 ??? 15:57 source.cpp

我不是想添加-I,因为我能够编译/链接clang -I. source.cpp -o source并且包含路径(应该)是相同的.

PS.

MBA-Anton:pch asmirnov$ clang --version
Apple LLVM version 6.0 (clang-600.0.54) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin13.3.0
Thread model: posix

Answer 1

我已经解决了:

MBA-Anton:pch asmirnov$ clang++ -x c++-header header.h -emit-pch -o header.pch
MBA-Anton:pch asmirnov$ clang++ -include-pch header.pch source.cpp -o source -x c++

顺便说一句,如果我重命名header.h并尝试链接可执行文件,我会收到错误:

MBA-Anton:pch asmirnov$ clang++ -include-pch header.pch source.cpp -o source -x c++
fatal error: malformed or corrupted AST file: 'could not find file '/tmp/pch/header.h' referenced by
      AST file'
1 error generated.

这意味着它仍然需要头文件!这是预期的行为吗？

PS2.我试图向.pch添加一个标题并失败:

MBA-Anton:pch asmirnov$ clang++ -x c++-header header.h header2.h -emit-pch -o headers.pch
clang: error: cannot specify -o when generating multiple output files

创建单独的SO问题: 如何为许多标题生成.pch？