Question

我对clang ast-dump outout感到困惑，线和col是什么意思？谢谢

`-FunctionDecl 0xa853e98 <line:33:1, line:44:1> line:33:5 main 'int (void)'

-CompoundStmt 0xa87f018 <line:34:1, line:44:1> |-DeclStmt 0xa87e808 <line:35:1, col:11> | - VarDecl 0xa853fb8 col：9使用了＆＃39;类Anmimal＆＃39; callinit | -CXXConstructExpr 0xa87e7d8 <col:9> 'class Anmimal' 'void (void) throw()' |-BinaryOperator 0xa87e8a0 <line:36:1, col:10> 'int' lvalue '=' | |-MemberExpr 0xa87e848 <col:1, col:4> 'int' lvalue .age 0xa8533b0 | | - DeclRefExpr 0xa87e820＆＃39; class Anmimal＆＃39;左值Var 0xa853fb8＆＃39;＆＃39; ＆＃39;类Anmimal＆＃39; | -IntegerLiteral 0xa87e880 <col:10> 'int' 100 |-CXXMemberCallExpr 0xa87e9f0 <line:38:1, col:12> 'int' | - MemberExpr 0xa87e9b8＆＃39;＆＃39; .getSize 0xa853c48 | -DeclRefExpr 0xa87e990 <col:1> 'class Anmimal' lvalue Var 0xa853fb8 'an' 'class Anmimal' |-DeclStmt 0xa87edb0 <line:40:1, col:8> | - VarDecl 0xa87ea28 col：5使用cat＆＃39; struct Cat＆＃39; callinit | -CXXConstructExpr 0xa87ed80 <col:5> 'struct Cat' 'void (void) throw()' |-BinaryOperator 0xa87ee48 <line:41:1, col:15> 'int' lvalue '=' | |-MemberExpr 0xa87edf0 <col:1, col:5> 'int' lvalue .age_cat 0xa853b38 | | - DeclRefExpr 0xa87edc8＆＃39; struct Cat＆＃39;左值Var 0xa87ea28＆＃39; cat＆＃39; ＆＃39; struct Cat＆＃39; | -IntegerLiteral 0xa87ee28 <col:15> 'int' 10 |-BinaryOperator 0xa87efb8 <line:42:1, col:16> 'int' lvalue '=' | |-MemberExpr 0xa87ef60 <col:1, col:5> 'int' lvalue .size_cat 0xa853b98 | | - DeclRefExpr 0xa87ef38＆＃39; struct Cat＆＃39;左值Var 0xa87ea28＆＃39; cat＆＃39; ＆＃39; struct Cat＆＃39; | -IntegerLiteral 0xa87ef98 <col:16> 'int' 20 - ReturnStmt 0xa87f000 `-IntegerLiteral 0xa87efe0＆＃39; int＆＃39; 0

Answer 1

它们是与AST的每个节点关联的源位置：文件，行和列。 Clang通常报告节点的开始或节点覆盖的范围。为了节省空间，当Clang与前面的节点相同时，它不会重复文件名。行号也是如此。算法是

if(filename != old_filename)
  print filename:line:column
  old_filename = filename
elseif(line != old_line)
  print line:column
  old_line = line
else
  print column

因此main()的函数声明跨越第33-44行。主要的声明似乎从col开始。第33行中的第5行。依此类推。

可以通过各种AST对象上的getLocStart()，getLocEnd()和getSourceRange()方法以编程方式访问源位置，从而允许对源代码进行精确更改。

line / col在clang ast dump中意味着什么

1 个答案: