我一直在做一个项目并遇到过：
下面是 if 声明的列表，除了 typeSpec 中的类型之外，我这里都有，但我们现在不必担心这些。我相当确定我理解什么是 shift/reduce 和 reduce/reduce 错误，但是（对我来说很幸运）编译器没有告诉我冲突在哪里。有人可以为我指出冲突所在的正确方向，或者给我一些关于如何找到冲突所在的提示，我将不胜感激。另外，如果我在帖子中遗漏了一些东西，那么任何事情都会非常感激！
%%
program
: declList { syntaxTree = $1; }
;
declList
: declList decl { $$ = AddSibling($1, $2); }
| decl { $$ = $1; }
;
decl
: varDecl { $$ = $1; }
| funDecl { $$ = $1; }
;
varDecl
: typeSpec varDeclList SEMICOLON { $$ = $2; SetType($2, $1, false); }
;
scopedVarDecl
: STATIC typeSpec varDeclList SEMICOLON { $$ = $3; SetType($3, $2, true); }
| typeSpec varDeclList SEMICOLON { $$ = $2; SetType($2, $1, false); }
;
varDeclList
: varDeclList COMMA varDeclInit { $$ = AddSibling($1, $3); }
| varDeclInit { $$ = $1; }
;
varDeclInit
: varDeclId { $$ = $1; }
| varDeclId COLON simpleExp { $$ = $1; AddChild($$, $3); }
;
varDeclId
: ID { $$ = NewDeclNode(VarK, UndefinedType, $1); $$->tmp = $1->idIndex; }
| ID LBRACKET NUMCONST RBRACKET{ $$ = NewDeclNode(VarK, UndefinedType, $1); $$->isArray = true; $$->aSize = $3->nvalue; $$->tmp = $1->idIndex;}
;
typeSpec
: {}
;
funDecl
: typeSpec ID LPAREN parms RPAREN compoundStmt { $$ = NewDeclNode(FuncK, $1, $2, $4, $6);$$->tmp = $2->idIndex; SetType($$, $1, true);}
| ID LPAREN parms RPAREN compoundStmt{ $$ = NewDeclNode(FuncK, Void, $1, $3, $5); $$->tmp = $1->idIndex; }
;
parms
: parmList { $$ = $1; }
| { $$ = NULL; }
;
parmList
: parmList SEMICOLON parmTypeList { $$ = AddSibling($1, $3); }
| parmTypeList { $$ = $1; }
;
parmTypeList
: typeSpec parmIdList { $$ = $2; SetType($2, $1, false); }
;
parmIdList
: parmIdList COMMA parmId { $$ = AddSibling($1, $3); }
| parmId { $$ = $1; }
;
parmId
: ID { $$ = NewDeclNode(ParamK, Void, $1); $$->tmp = $1->svalue; }
| ID LBRACKET RBRACKET { $$ = NewDeclNode(ParamK, Void, $1); $$->isArray = true; $$->tmp = $1->svalue; }
;
stmt
: matched { $$ = $1; }
| unmatched { $$ = $1; }
;
matched
: expStmt { $$ = $1; }
| compoundStmt { $$ = $1; }
| returnStmt { $$ = $1; } //
| breakStmt { $$ = $1; } //
| matchedSelectStmt { $$ = $1; }
| matchedIterStmt { $$ = $1; }
;
unmatched
: unmatchedSelectStmt{ $$ = $1; }
| unmatchedIterStmt { $$ = $1; }
;
expStmt
: exp SEMICOLON { $$ = $1; }
| SEMICOLON { $$ = NULL; }
;
compoundStmt
: BEG localDecls stmtList END { $$ = NewStmtNode(CompoundK, $1, $2, $3); }
;
localDecls
: localDecls scopedVarDecl { $$ = AddSibling($1, $2); }
| { $$ = NULL; }
;
stmtList
: stmtList stmt { $$ = AddSibling($1, $2); }
| { $$ = NULL; }
;
matchedSelectStmt : IF simpleExp THEN matched ELSE matched
{ $$ = NewStmtNode(IfK, $1, $2, $4, $6); }
;
unmatchedSelectStmt
: IF simpleExp THEN stmt { $$ = NewStmtNode(IfK, $1, $2, $4); }
| IF simpleExp THEN matched ELSE unmatched { $$ = NewStmtNode(IfK, $1, $2, $4, $6); }
;
matchedIterStmt
: WHILE simpleExp DO matched { $$ = NewStmtNode(WhileK, $1, $2, $4); }
| FOR ID ASGN iterRange DO matched { $$ = NewStmtNode(ForK, $1, NewDeclNode(VarK, Integer, $2), $4, $6); $$->tmp = $2->idIndex; }
;
unmatchedIterStmt
: WHILE simpleExp DO unmatched { $$ = NewStmtNode(WhileK, $1, $2, $4); }
| FOR ID ASGN iterRange DO unmatched { $$ = NewStmtNode(ForK, $1, NewDeclNode(VarK, Integer, $2), $4, $6); $$->tmp = $2->idIndex; }
;
iterRange
: simpleExp TO simpleExp { $$ = NewStmtNode(RangeK, $2, $1, $3);}
| simpleExp TO simpleExp BY simpleExp { $$ = NewStmtNode(RangeK, $2, $1, $3, $5); $$->tmp = $2->idIndex; }
;
returnStmt
: RETURN SEMICOLON { $$ = NewStmtNode(ReturnK, $1); }
| RETURN exp SEMICOLON { $$ = NewStmtNode(ReturnK, $1, $2); }
;
breakStmt
: BREAK SEMICOLON { $$ = NewStmtNode(BreakK, $1); }
;
exp
: mutable ASGN exp { $$ = NewExpNode(AssignK, $2, $1, $3); }
| mutable ADDASGN exp { $$ = NewExpNode(AssignK, $2, $1, $3); }
| mutable SUBASGN exp { $$ = NewExpNode(AssignK, $2, $1, $3); }
| mutable MULASGN exp { $$ = NewExpNode(AssignK, $2, $1, $3); }
| mutable DIVASGN exp { $$ = NewExpNode(AssignK, $2, $1, $3); }
| mutable INC { $$ = NewExpNode(AssignK, $2, $1); }
| mutable DEC { $$ = NewExpNode(AssignK, $2, $1); }
| simpleExp {$$ = $1; }
;
simpleExp
: simpleExp OR andExp { $$ = NewExpNode(OpK, $2, $1, $3); }
| andExp { $$ = $1; }
;
andExp
: andExp AND unaryRelExp { $$ = NewExpNode(OpK, $2, $1, $3); }
| unaryExp { $$ = $1; }
;
unaryRelExp
: NOT unaryRelExp { $$ = NewExpNode(OpK, $1, $2); }
| relExp { $$ = $1; }
;
relExp
: sumExp relop sumExp { $$ = $2; AddChild($$, $1); AddChild($$, $3); }
| sumExp { $$ = $1; }
;
relop
: GT { $$ = NewExpNode(OpK, $1); }
| GEQ { $$ = NewExpNode(OpK, $1); }
| LT { $$ = NewExpNode(OpK, $1); }
| LEQ { $$ = NewExpNode(OpK, $1); }
| EQ { $$ = NewExpNode(OpK, $1); }
| NEQ { $$ = NewExpNode(OpK, $1); }
;
sumExp
: sumExp sumop mulExp { $$ = $2; AddChild($$,$1); AddChild($$,$3); }
| mulExp { $$ = $1; }
;
sumop
: ADD { $$ = NewExpNode(OpK, $1); }
| MINUS { $$ = NewExpNode(OpK, $1); }
;
mulExp
: mulExp mulop unaryExp { $$ = $2; AddChild($$, $1); AddChild($$, $3); }
| unaryExp { $$ = $1; }
;
mulop
: STAR { $$ = NewExpNode(OpK, $1); }
| DIV { $$ = NewExpNode(OpK, $1); }
| PERCENT { $$ = NewExpNode(OpK, $1); }
;
unaryExp
: unaryop unaryExp { $$ = $1; AddChild($$, $2); }
| factor { $$ = $1; }
;
unaryop
: MINUS { $$ = NewExpNode(OpK, $1); }
| STAR { $$ = NewExpNode(OpK, $1); }
| QMARK { $$ = NewExpNode(OpK, $1); }
;
factor
: mutable { $$ = $1; }
| immutable { $$ = $1; }
mutable
: ID { $$ = NewExpNode(IdK, $1); $$->name = $1->idIndex; }
| ID LBRACKET exp RBRACKET { $$ = NewExpNode(OpK, $2, NewExpNode(IdK, $1), $3); $$->child[0]->name = $1->idIndex; }
;
immutable
: LPAREN exp RPAREN { $$ = $2; }
| call { $$ = $1; }
| constant { $$ = $1; }
;
call
: ID LPAREN args RPAREN { $$ = NewExpNode(CallK, $1, $3); $$->name = $1->idIndex; }
;
args
: argList { $$ = $1; }
| { $$ = NULL; }
;
argList
: argList COMMA exp { $$ = AddSibling($1, $3); $$->name = $2->svalue; }
| exp { $$ = $1; }
;
constant
: NUMCONST { $$ = NewExpNode(ConstantK, $1); $$->expType = Integer; $$->value = $1->nvalue; }
| CHARCONST { $$ = NewExpNode(ConstantK, $1); $$->expType = Char; $$->cvalue = $1->cvalue; }
| STRINGCONST { $$ = NewExpNode(ConstantK, $1); $$->expType = String; $$->string = $1->svalue; }
| BOOLCONST { $$ = NewExpNode(ConstantK, $1); $$->expType = Boolean; $$->value = $1->nvalue;}
;
%%