astgen: clean up source line calculation and management

Clarify that `astgen.advanceSourceCursor` already increments absolute
values of the line and columns numbers; i.e., `GenZir.calcLine` is thus
not only obsolete but wrong by design.

Incidentally, this clean up allows for specifying the `FnDecl` line
numbers for DWARF use correctly as relative values with respect to
the start of the parent `Decl`. This `Decl` in turn has its line number
information specified relatively to its parent `Decl`, and so on, until
we reach the global scope.
This commit is contained in:
Jakub Konka
2022-01-31 17:07:45 +01:00
committed by Andrew Kelley
parent abbcf40327
commit 627cf6ce48
5 changed files with 70 additions and 53 deletions

View File

@@ -375,6 +375,7 @@ pub const Decl = struct {
src_node: Ast.Node.Index,
/// Line number corresponding to `src_node`. Stored separately so that source files
/// do not need to be loaded into memory in order to compute debug line numbers.
/// This value is absolute.
src_line: u32,
/// Index to ZIR `extra` array to the entry in the parent's decl structure
/// (the part that says "for every decls_len"). The first item at this index is
@@ -4122,7 +4123,8 @@ fn scanDecl(iter: *ScanDeclIter, decl_sub_index: usize, flags: u4) SemaError!voi
const has_linksection_or_addrspace = (flags & 0b1000) != 0;
// zig fmt: on
const line = iter.parent_decl.relativeToLine(zir.extra[decl_sub_index + 4]);
const line_off = zir.extra[decl_sub_index + 4];
const line = iter.parent_decl.relativeToLine(line_off);
const decl_name_index = zir.extra[decl_sub_index + 5];
const decl_index = zir.extra[decl_sub_index + 6];
const decl_block_inst_data = zir.instructions.items(.data)[decl_index].pl_node;