[cfe-dev] hasAncestor matching nothing

[Farzad Sadeghi via cfe-dev]

thank you for the explanation. I do realize that, but that is clearly
not the case here.

On 11/25/16, Manuel Klimek <klimek at google.com> wrote:
> On Fri, Nov 25, 2016 at 9:24 AM Farzad Sadeghi via cfe-dev <
> cfe-dev at lists.llvm.org> wrote:
>
>> for the source code below:
>> short int test16(int a, int b)
>> {
>>         short int sum;
>>         short unsigned int sumus;
>>         sum = a + b;
>>         sumus = a + b;
>>
>>         return sum;
>> }
>> with AST:
>> |-FunctionDecl 0x4e52920 <line:821:1, line:829:1> line:821:11 test16
>> 'short (int, int)'
>> | |-ParmVarDecl 0x4e527d8 <col:18, col:22> col:22 used a 'int'
>> | |-ParmVarDecl 0x4e52848 <col:25, col:29> col:29 used b 'int'
>> | `-CompoundStmt 0x4e52d60 <line:822:1, line:829:1>
>> |   |-DeclStmt 0x4e52a48 <line:823:2, col:15>
>> |   | `-VarDecl 0x4e529e8 <col:2, col:12> col:12 used sum 'short'
>> |   |-DeclStmt 0x4e52ad0 <line:824:2, col:26>
>> |   | `-VarDecl 0x4e52a70 <col:2, col:21> col:21 used sumus 'unsigned
>> short'
>> |   |-BinaryOperator 0x4e52bd0 <line:825:2, col:12> 'short' '='
>> |   | |-DeclRefExpr 0x4e52ae8 <col:2> 'short' lvalue Var 0x4e529e8 'sum'
>> 'short'
>> |   | `-ImplicitCastExpr 0x4e52bb8 <col:8, col:12> 'short' <IntegralCast>
>> |   |   `-BinaryOperator 0x4e52b90 <col:8, col:12> 'int' '+'
>> |   |     |-ImplicitCastExpr 0x4e52b60 <col:8> 'int' <LValueToRValue>
>> |   |     | `-DeclRefExpr 0x4e52b10 <col:8> 'int' lvalue ParmVar
>> 0x4e527d8 'a' 'int'
>> |   |     `-ImplicitCastExpr 0x4e52b78 <col:12> 'int' <LValueToRValue>
>> |   |       `-DeclRefExpr 0x4e52b38 <col:12> 'int' lvalue ParmVar
>> 0x4e52848 'b' 'int'
>> |   |-BinaryOperator 0x4e52ce0 <line:826:2, col:14> 'unsigned short' '='
>> |   | |-DeclRefExpr 0x4e52bf8 <col:2> 'unsigned short' lvalue Var
>> 0x4e52a70 'sumus' 'unsigned short'
>> |   | `-ImplicitCastExpr 0x4e52cc8 <col:10, col:14> 'unsigned short'
>> <IntegralCast>
>> |   |   `-BinaryOperator 0x4e52ca0 <col:10, col:14> 'int' '+'
>> |   |     |-ImplicitCastExpr 0x4e52c70 <col:10> 'int' <LValueToRValue>
>> |   |     | `-DeclRefExpr 0x4e52c20 <col:10> 'int' lvalue ParmVar
>> 0x4e527d8 'a' 'int'
>> |   |     `-ImplicitCastExpr 0x4e52c88 <col:14> 'int' <LValueToRValue>
>> |   |       `-DeclRefExpr 0x4e52c48 <col:14> 'int' lvalue ParmVar
>> 0x4e52848 'b' 'int'
>> |   `-ReturnStmt 0x4e52d48 <line:828:2, col:9>
>> |     `-ImplicitCastExpr 0x4e52d30 <col:9> 'short' <LValueToRValue>
>> |       `-DeclRefExpr 0x4e52d08 <col:9> 'short' lvalue Var 0x4e529e8
>> 'sum' 'short'
>> when i run the below matcher on clang-query:
>> match declRefExpr(hasAncestor(declRefExpr()))
>> i get no matches, while in the AST it clearly says that there are such
>
> nodes. so I was wondering what could be causing this.
>>
>
> Perhaps we can make the printing easier to read here:
> -a
> ||-b
> |`-c
> does not mean that c is a child of b, it means (if I'm not mistaken) that c
> is the last child of a, but both b and a are equally children of a.
>
>
>> --
>> Farzad Sadeghi
>> _______________________________________________
>> cfe-dev mailing list
>> cfe-dev at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>>
>


-- 
Farzad Sadeghi