gcc -D 选项没有做我认为的那样

Question

我正在尝试在项目中使用 AsmJit。这是我使用的makefile:

CC = g++
CFLAGS = -D ASMJIT_API -I dep/

test: src/main.cpp
        $(CC) $(CFLAGS) src/main.cpp -o test.exe

尝试此操作时遇到编译器错误，因此我取消了对行 #define ASMJIT_API 的注释。从 dep/AsmJit/Config.h，并从 makefile 中删除 -D 开关，并且所有内容都被干净地编译。我正在使用 gcc 4.5.3。有任何想法吗？

谢谢。

编辑:编译器错误

g++ -DASMJIT_API -Idep/ src/main.cpp -o test.exe
In file included from dep/AsmJit/Assembler.h:31:0,
                 from src/main.cpp:1:
dep/AsmJit/Build.h:274:1: error: expected unqualified-id before numeric constant
In file included from dep/AsmJit/AssemblerX86X64.h:36:0,
                 from dep/AsmJit/Assembler.h:51,
                 from src/main.cpp:1:
dep/AsmJit/Defs.h:408:1: error: expected unqualified-id before numeric constant
In file included from dep/AsmJit/DefsX86X64.h:36:0,
                 from dep/AsmJit/Defs.h:423,
                 from dep/AsmJit/AssemblerX86X64.h:36,
                 from dep/AsmJit/Assembler.h:51,
                 from src/main.cpp:1:
dep/AsmJit/Util.h:412:8: error: expected identifier before numeric constant
dep/AsmJit/Util.h:412:8: error: expected unqualified-id before numeric constant
src/main.cpp:6:1: error: expected ‘}’ at end of input
makefile:5: recipe for target `test' failed
make: *** [test] Error 1

Answer 1

#define ASMJIT_API之间有区别和 -DASMJIT_API .
#define语句定义 ASMJIT_API无，而 the -D flag defines the preprocessor constant as 1 .

使用 -D标志，build.h 的第 274 行扩展为

1 void assertionFailure(const char* file, int line, const char* exp);

导致编译器错误。