c - 在 Visual Studio 2015 中运行 C 项目时出现错误 LNK1120 3 无法解析的外部

Question

我正在 Visual Studio 2015 中运行 C 项目，但遇到以下错误:

Severity    Code    Description Project File    Line
Error   LNK1120 3 unresolved externals  f90toC_B    C:\Users\admin\Documents\Visual Studio 2015\Projects\f90toC_B\Debug\f90toC_B.exe    1
Error   LNK2019 unresolved external symbol _yyparse referenced in function _main    f90toC_B    C:\Users\admin\Documents\Visual Studio 2015\Projects\f90toC_B\f90toC_B\f90main.obj  1
Error   LNK2019 unresolved external symbol _finclude referenced in function _getMfile   f90toC_B    C:\Users\admin\Documents\Visual Studio 2015\Projects\f90toC_B\f90toC_B\f90mod.obj   1
Error   LNK2019 unresolved external symbol _strcasecmp referenced in function _findarg  f90toC_B    C:\Users\admin\Documents\Visual Studio 2015\Projects\f90toC_B\f90toC_B\ptree.obj    1
Error   LNK2001 unresolved external symbol _strcasecmp  f90toC_B    C:\Users\admin\Documents\Visual Studio 2015\Projects\f90toC_B\f90toC_B\symb.obj 1

我的文件树:

 C:.
│   f90.h
│   f90.lex
│   f90.y
│   f90arg.c
│   f90arg.h
│   f90arg.o
│   f90decl.c
│   f90decl.h
│   f90decl.o
│   f90main.c
│   f90main.h
│   f90main.o
│   f90mod.c
│   f90mod.h
│   f90print.c
│   File_index
│   Makefile
│   ptree.c
│   ptree.h
│   README
│   symb.c
│   symb.h
│
├───doc
│       description.txt
│
└───tests
        Makefile
        mtest1.f90
        mtest1.M.std
        mtest1.std
        test1.f90
        test1.std
        test2.f90
        test2.std
        test3.f90
        test3.std

第一个错误和代码部分:

        Severity    Code    Description Project File    Line
    Error   LNK2019 unresolved external symbol _yyparse referenced in function _main    f90toC_B    C:\Users\admin\Documents\Visual Studio 2015\Projects\f90toC_B\f90toC_B\f90main.obj  1

代码:

f90main.c


#include "f90.h"
#include "ptree.h"
#include "symb.h"
#include "f90main.h"
#include "f90decl.h"
#include "f90arg.h"

main()
{
 yyparse();
}

int lineno=1;

extern struct declist *declisthead;
extern int in_module;

第二个错误和代码部分:

Severity    Code    Description Project File    Line
Error   LNK2019 unresolved external symbol _finclude referenced in function _getMfile   f90toC_B    C:\Users\admin\Documents\Visual Studio 2015\Projects\f90toC_B\f90toC_B\f90mod.obj   1

f90mod.c

/* handles things related to modules */
#include "symb.h"
#include "ptree.h"
#include "f90mod.h"
#include <stdio.h>

struct declist *modlist=NULL;
int doing_module=0;
int in_module=0;
int in_user_type=0;
char *curr_modname=NULL;
struct declist *modsubshead=NULL;

void getMfile(char *nam)
{
        char name[35];
        modlist=newdeclist(TBLANK,nam,modlist,NULL);
        curr_modname=modlist->name;
        doing_module=1;
        strcpy(name,nam);
        strcpy(name+strlen(name),".M");
        /*fprintf(stderr,"mod name: %s\n",name);*/
        finclude(name);
}

第三个错误和代码部分:

Severity    Code    Description Project File    Line
Error   LNK2019 unresolved external symbol _strcasecmp referenced in function _findarg  f90toC_B    C:\Users\admin\Documents\Visual Studio 2015\Projects\f90toC_B\f90toC_B\ptree.obj    1

ptree.c

/* finds a keyword based argument with name "name" */
struct tree *findarg(struct tree *t, char *name)
{
           struct tree *t1;
           if (t==NULL) return(NULL);
           if (t->ntype==ALISTNODE) {
             if ( (t1=findarg(t->child1,name)) != NULL) return(t1);  
             if (t->child2->ntype == ARGKWNODE) {
               if (strcasecmp(t->child2->child1->num.s,name)==0) {
                    return (t);
                 } else {
                    return(NULL);
                 }
             }
           } else {
             fprintf(stderr,"Do I ever get here in findarg?\n");
           }
           return(NULL);
}

第四个错误和代码部分:

Severity    Code    Description Project File    Line
Error   LNK2001 unresolved external symbol _strcasecmp  f90toC_B    C:\Users\admin\Documents\Visual Studio 2015\Projects\f90toC_B\f90toC_B\symb.obj 1

symb.c

int findsymbt(struct declist *d,char *s)
{
     int f;
     if (d==NULL) return(0);
     /*printf("symb: ntype %d name %s\n",d->ntype,d->name);*/
     if (d->ntype==TSEQ) {
         if ( (f=findsymbt(d->next,s))!=0 ) {return(f);}
         f=findsymbt(d->next2,s); 
         return(f);
     } else {
      if ((f=strcasecmp(d->name,s))==0) {return (d->ntype);}
        else {return (0);}
     }
     printf("I shouldn't be here \n");
 }

那我该怎么办？

我的Makefile

CC = cc  -ggdb
OBJ = f90main.o f90decl.o f90arg.o f90.tab.o lex.yy.o symb.o ptree.o \
      f90mod.o f90print.o

.c.o:
    $(CC) -c $<

all: f90

lex.yy.c:  f90.lex
    flex -i f90.lex

f90.tab.c: f90.y f90.h
    bison -d f90.y

f90: $(OBJ) f90.h
    $(CC) -o ff90 $(OBJ)

why:
    bison -d -v f90.y
clean:
    -rm *.o lex.yy.c f90.tab.c f90.tab.h f90.output

F = f90toC
tar:
    tar -cvf f90toC-test.tar $(F)/f90.lex $(F)/f90.y $(F)/*.h $(F)/*.c $(F)/tests $(F)/doc $(F)/Makefile $(F)/README $(F)/File_index

bak:
    cp *.c backup
    cp *.h backup
    cp *.y backup
    cp *.lex backup
    cp Makefile backup

编辑2添加f90.lex的一部分

...
finclude(char *text){
   if (include_stack_ptr >= MAX_INCLUDE_BUFF) {
        fprintf(stderr,"Includes nested too deep\n");
        exit(1);
       }
   lineno_stack[include_stack_ptr] = lineno; lineno=1;
   include_stack[include_stack_ptr++] = YY_CURRENT_BUFFER;  
   yyin = fopen(text,"r");
   if (!yyin) {fprintf(stderr,"Failed to include:%s\n",text); 
               include_stack_ptr--;
               return;}
   yy_switch_to_buffer(yy_create_buffer(yyin,YY_BUF_SIZE));
}

编辑了 3 个添加 f90.y编辑了 4 个删除的 f90.y，因为与讨论无关

Answer 1

错误不在您向我们展示的代码中。这些错误要么出现在您所包含的头文件中(函数声明为 _cdecl 以外的内容，因此它们的名称不以下划线开头)，要么出现在您的 makefile/项目文件中(您只需不链接从声明您正在调用的函数的 .c 文件生成的目标文件。)