[PATCH] D24650: [ELF] - Linkerscript: PR30387 - cannot handle EXCLUDE_FILE in the middle of a input section description.

[George Rimar via llvm-commits]

grimar added inline comments.

================
Comment at: lld/trunk/ELF/LinkerScript.cpp:992
@@ +991,3 @@
+// Example: *(.foo.1 EXCLUDE_FILE (*a.o) .foo.2 EXCLUDE_FILE (*b.o) .foo.3)
+void ScriptParser::readSectionExcludes(InputSectionDescription *Cmd) {
+  llvm::Regex ExcludeFileRe;
----------------
ruiu wrote:
> It's not clear to me what the grammar of this thing is.
> 
>   A B EXCLUDE_FILE(C) D E
> 
> Does the above pattern mean A, B, D except those matching C, and E? Or A, B, D except those matching C, E except those matching C?
> 
> What if the pattern is this?
> 
>   A B EXCLUDE_FILE(C) EXCLUDE_FILE(D) E
> 
Example from PR30387:

sec0 EXCLUDE_FILE (zed1.o) sec1  EXCLUDE_FILE (zed2.o) sec2 )

The semantics according to bfd are:
Include sec1 from every file but zed1.o
Include sec2 from every file but zed2.o
Include sec0 from every file

So
```
A B EXCLUDE_FILE(C) D E
```

Should be all A, B sections + all D, E excluding those in file C.


Pattern of 
```
A B EXCLUDE_FILE(C) EXCLUDE_FILE(D) E
```
then should be all A, B + all E except those in file E.


Repository:
  rL LLVM

https://reviews.llvm.org/D24650