Cleanup GCCAsmStmt children iterations

[cor3ntin]

GCCAsmStmt stores its arguments in separately allocated array

llvm-project/clang/include/clang/AST/Stmt.h

Lines 3305 to 3311 in b936ef1

	StringLiteral *AsmStr;
	// FIXME: If we wanted to, we could allocate all of these in one big array.
	StringLiteral **Constraints = nullptr;
	StringLiteral **Clobbers = nullptr;
	IdentifierInfo **Names = nullptr;
	unsigned NumLabels = 0;

And is not considered to have any children.

Instead, we should store all these statements (contiguously) within the Exprs of ASmStmt and make sure that's returned from children()

llvm-project/clang/include/clang/AST/Stmt.h

Line 3160 in b936ef1

Stmt **Exprs = nullptr;

However, we should also make sure that the order of the children - and therefore the order of elements
in Expr makes sense,

ie Template, OutputConstraint0, OutputExpr0, ... OutputConstraintN, OutputExprN, InputConstraint0, InputExpr0, ... InputConstraintN, InputExprN, Label0, ...

Constructors, Getter, Setters, etc of GCCAsmStmt needs to be adapted to understand this order

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: cor3ntin (cor3ntin)

`GCCAsmStmt` stores its arguments in separately allocated array

llvm-project/clang/include/clang/AST/Stmt.h

Lines 3305 to 3311 in b936ef1

	StringLiteral *AsmStr;
	// FIXME: If we wanted to, we could allocate all of these in one big array.
	StringLiteral **Constraints = nullptr;
	StringLiteral **Clobbers = nullptr;
	IdentifierInfo **Names = nullptr;
	unsigned NumLabels = 0;

And is not considered to have any children.

Instead, we should store all these statements (contiguously) within the Exprs of ASmStmt and make sure that's returned from children()

llvm-project/clang/include/clang/AST/Stmt.h

Line 3160 in b936ef1

Stmt **Exprs = nullptr;

However, we should also make sure that the order of the children - and therefore the order of elements
in Expr makes sense,

ie Template, OutputConstraint0, OutputExpr0, ... OutputConstraintN, OutputExprN, InputConstraint0, InputExpr0, ... InputConstraintN, InputExprN, Label0, ...

Constructors, Getter, Setters, etc of GCCAsmStmt needs to be adapted to understand this order

[cor3ntin]

Note that we should wait #131003 to be merged before working on this

[erichkeane]

This is perhaps a 'medium first issue' as it requires significantly modifying the AST node, but is on the easier side. Any such patch should also refactor the MSAsmStmt.

Basically, we need to spend time evaluating the three types (AsmStmt, GCCAsmStmt and MSAsmStmt) to refactor them and make them more prototypical of our struct layouts.