[cfe-dev] [LibClang - C - AST] Switch-Case Statement Children

[Jacob Faibussowitsch via cfe-dev]

Hello Clang Community,

Why is the first statement after a “case” label the child of the case label, but every other statement (including the break) after that its sibling? It seems like either all should be children or all should be siblings.

Suppose you have the following code snippet (full source files for any snippets below are included with this mail).

switch(expr) {
  case 1:
    func1();
    func2();
    break;
  case 2:
    func1();
    break;
}

Which when fed to clang with 

$ clang -Xclang -ast-dump -fsyntax-only test.c

produces the following AST  (edited for clarity):

| SwitchStmt <line:7:3, line:15:3>
    | `-CompoundStmt <col:15, line:15:3>
    |   |-CaseStmt <line:8:3, line:9:11>
    |   | `-CallExpr <line:9:5, col:11> —————————— func1() here is child to case 1
    |   |-CallExpr <line:10:5, col:11> —————————— func2() here is sibling to case 1
    |   |-BreakStmt <line:11:5>
    |   |-CaseStmt <line:12:3, line:13:11>
    |   | `-CallExpr <line:13:5, col:11> ————————— func1() here again is child to case 2
    |   `-BreakStmt <line:14:5>

My clang version and install info:

Apple clang version 12.0.5 (clang-1205.0.22.9)
Target: x86_64-apple-darwin20.4.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

Best regards,

Jacob Faibussowitsch
(Jacob Fai - booss - oh - vitch)
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