[PATCH] D100076: [lld-macho] Support -add_ast_path

[Greg Clayton via Phabricator via llvm-commits]

clayborg added a comment.

The N_AST symbol is used to specify a file on disk that contains the one and only Swift AST blob. This blob of data will be given back to the Swift compiler that is built into LLDB. I don't think this can be specified multiple times. Inline comments ask if



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Comment at: lld/MachO/Options.td:539-542
+def add_ast_path : Separate<["-"], "add_ast_path">,
+    MetaVarName<"<path>">,
+    HelpText<"AST paths will be emitted as STABS">,
+    Group<grp_symtab>;
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Does this allow specifying this option more than once? I don't believe this is supported as there should only be one N_AST.


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Comment at: lld/MachO/SyntheticSections.cpp:683
 void SymtabSection::emitStabs() {
+  for (const std::string &s : config->astPaths) {
+    StabsEntry astStab(N_AST);
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I don't think we can have more than one N_AST values emitted. Does ld64 supports multiple?


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Comment at: lld/MachO/SyntheticSections.cpp:685
+    StabsEntry astStab(N_AST);
+    astStab.strx = stringTableSection.addString(s);
+    stabs.emplace_back(std::move(astStab));
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Does ld64 put the mod time of the AST file in the symbol table value? I can't remember, but it would be worth checking


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  https://reviews.llvm.org/D100076/new/

https://reviews.llvm.org/D100076