Question

我正在尝试使用bison，flex和llvm为某种语言生成代码。以下是联合和规则部分的代码的一部分（点是指与问题无关的代码）：

%union {
    Node *node;
    NBlock *block;
    NMethodCall* methodcall;
    .
    .
    .
    std::vector<NIdentifier*> idetListvec;
    std::vector<NRecordItem*> recdListvec;
    .
    .

}
.
.
type           <expr>              numeric      
%type           <expr>              CondExpression
%type           <idetListvec>       IdentifierList
%type           <recdListvec>       RecordItemList  VarDefnList FormalParmSecList   VarDefns FormalParameterList

.
.
%%
.
.

FormalParameterList :  TLPAREN FormalParmSecList  TRPAREN  {$$ = $2;}
                    ;

FormalParmSecList : FormalParmSecList  TSEMICOLON   FormalParmSec   { $1->push_back($3);}
                  | FormalParmSec                                   {$$ = new NRecordItemList(); $$->push_back($1);}
                  ;


FormalParmSec : ValueParmSpec                                       {$$ = $1;}
              | VariableParmSpec                                    {$$ = $1;}
              ;

%%

我有一个单独的文件用于所谓的抽象语法树（AST）来实现类。以下是我想问的课程：

#include <iostream>
#include <vector>
class NStatement;
.
classNRecordItem;
classModule;
.
.
typedef std::vector<NRecordItem*> NRecordItemList;
typedef std::vector<NConstantDeclaration*> NConstantDeclarationList;
typedef std::vector<NTypDefn> NTypDefnList;
typedef std::vector<Module> NModuleList;

class Node {
public:
    virtual ~Node() {}
    //virtual llvm::Value* codeGen(CodeGenContext& context) { return NULL; }
};


class NExpression : public Node {
};

class NStatement : public Node {
};

class NInteger : public NExpression {
public:
    int value;
    NInteger(int value) : value(value) { }
    //virtual llvm::Value* codeGen(CodeGenContext& context);
};
.
.
class NRecordItem : public NStatement {
public:
    const NIdentifier& type;
    NIdentifierList arguments;
    NRecordItem(NIdentifierList& arguments, const NIdentifier& type ) :
        type(type),  arguments(arguments) { }
    //virtual llvm::Value* codeGen(CodeGenContext& context);
};

运行代码时，它给出了以下错误：

parser.y:256:26: error: no match for ‘operator=’ (operand types are ‘std::vector<NRecordItem*>’ and ‘NRecordItemList* {aka int*}’)
                   | FormalParmSec         {$$ = new NRecordI
                          ^
In file included from /usr/include/c++/5/vector:69:0,
                 from node.h:2,
                 from parser.y:2:
/usr/include/c++/5/bits/vector.tcc:167:5: note: candidate: std::vector<_Tp, _Alloc>& std::vector<_Tp, _Alloc>::operator=(const std::vector<_Tp, _Alloc>&) [with _Tp = NRecordItem*; _Alloc = std::allocator<NRecordItem*>]
     vector<_Tp, _Alloc>::
     ^
/usr/include/c++/5/bits/vector.tcc:167:5: note:   no known conversion for argument 1 from ‘NRecordItemList* {aka int*}’ to ‘const std::vector<NRecordItem*>&’
In file included from /usr/include/c++/5/vector:64:0,
                 from node.h:2,
                 from parser.y:2:
/usr/include/c++/5/bits/stl_vector.h:448:7: note: candidate: std::vector<_Tp, _Alloc>& std::vector<_Tp, _Alloc>::operator=(std::vector<_Tp, _Alloc>&&) [with _Tp = NRecordItem*; _Alloc = std::allocator<NRecordItem*>]
       operator=(vector&& __x) noexcept(_Alloc_traits::_S_not
       ^
/usr/include/c++/5/bits/stl_vector.h:448:7: note:   no known conversion for argument 1 from ‘NRecordItemList* {aka int*}’ to ‘std::vector<NRecordItem*>&&’
/usr/include/c++/5/bits/stl_vector.h:470:7: note: candidate: std::vector<_Tp, _Alloc>& std::vector<_Tp, _Alloc>::operator=(std::initializer_list<_Tp>) [with _Tp = NRecordItem*; _Alloc = std::allocator<NRecordItem*>]
       operator=(initializer_list<value_type> __l)
       ^

我的问题是关于规则＆＃39; FormalParmSecList＆＃39;。我将参数的值存储在矢量类中但它给出了该错误。任何想法！

Answer 1

您正试图将std::vector个对象直接放在<{1}}中。这不会起作用，因为它们不会被正确地构造和破坏。您需要更改%union以使用指针：

%union

你已经在尝试存储指向行为中向量的指针，所以看起来你已经尝试这样做了，你只是错过了声明。

Answer 2

$$ = new NRecordItemList();

此语句创建指向NRecordItemList对象的指针，并将其分配给$$。但是，在某处您声明$$是NRecordItemList，而不是指向一个new。您需要从此语句中删除$$或更改此语法规则的类型声明，以便function ReadSecuredFile { [SecureString] $SecuredString; $SecuredString = ConvertTo-SecureString 'Testing123' -asplaintext -force; return $SecuredString; } $a = ReadSecuredFile;具有正确的类型。我在这里发布的代码中没有看到您为此特定规则声明类型的位置。您需要找到并修复它。（自从我使用野牛以来已经有一段时间了。）

Answer 3

您正在尝试为std::vector分配一个指向std::vector（又名std::vector*）的指针。

从错误行中移除new以获取{$$ = NRecordItemList(); $$->push_back($1)}

不匹配'operator * for instances

3 个答案: