[ELF] - Linkerscript: Fall back to search paths when INCLUDE not found

[arichardson]

Summary

From https://sourceware.org/binutils/docs/ld/File-Commands.html:
The file will be searched for in the current directory, and in any
directory specified with the -L option.

[ruiu]

Just curious, are you actually using INLCUDE? If so, what application? (I was looking for a real usage of INCLUDE command.)

ELF/LinkerScript.cpp

1186–1194

Can this be

StringRef Tok = unquote(next());

?

1192

Remove {}.

[arichardson]

In D27831#624458, @ruiu wrote:

Just curious, are you actually using INLCUDE? If so, what application? (I was looking for a real usage of INCLUDE command.)

I was attempting to build FreeBSD (mips64) with lld and I get this error from the following script: https://github.com/freebsd/freebsd/blob/master/sys/boot/mips/beri/boot2/flashboot.ldscript

[arichardson]

address comments

[ruiu]

LGTM with nits. Thank you for doing this!

ELF/LinkerScript.cpp

1187–1194

Please avoid auto and use StringRef as its type is not obvious by RHS.

1193

Use Optional<StringRef> instead of auto.

[ruiu]

I'm sorry but it needs a test. Please take a look at test/ELF/linkerscript/linkerscript.s. We have one test for INCLUDE. You want to add one more for this patch.

[arichardson]

added test case

[ruiu]

LGTM

test/ELF/linkerscript/linkerscript.s

43

You don't need this readobj.

[arichardson]

remove unnecessary lllvm-readobj invocation

[ruiu]

It's still LGTM, so please submit. Thanks.

[arichardson]

I don't have commit access, could you commit for me please?

[grimar]

This patch reveals an issue we have in LLD, looks some memory corruption or we free a buffer that still using.
Alexander, I know you do not have commit permission yet. I am investigating the issue above and commit this for you after fix it.
Hope in next few hours. Thanks !

[grimar]

So D27987 was posted to fix the issue I mentioned.

ELF/LinkerScript.cpp

while (!Error && !consume(")")) {
     StringRef Tok = next();
     if (Tok == "AS_NEEDED")
       readAsNeeded();
     else
       addFile(unquote(Tok));
   }
 }
 
 void ScriptParser::readInclude() {
-  StringRef Tok = next();
-  auto MBOrErr = MemoryBuffer::getFile(unquote(Tok));
+  StringRef Tok = unquote(next());
+  // https://sourceware.org/binutils/docs/ld/File-Commands.html:
+  // The file will be searched for in the current directory, and in any
+  // directory specified with the -L option.
+  auto MBOrErr = MemoryBuffer::getFile(Tok);
+  if (!MBOrErr)
+    if (Optional<std::string> Path = findFromSearchPaths(Tok))
+      MBOrErr = MemoryBuffer::getFile(*Path);
   if (!MBOrErr) {
     setError("cannot open " + Tok);
     return;
   }
   std::unique_ptr<MemoryBuffer> &MB = *MBOrErr;
   tokenize(MB->getMemBufferRef());
   OwningMBs.push_back(std::move(MB));
 }

test/ELF/linkerscript/linkerscript.s

 # RUN: ld.lld %t.script %t
 # RUN: llvm-readobj %t.out > /dev/null
 
 # RUN: echo "INCLUDE \"%t.script2\" OUTPUT(\"%t.out\")" > %t.script1
 # RUN: echo "GROUP(\"%t\")" > %t.script2
 # RUN: ld.lld %t.script1
 # RUN: llvm-readobj %t2 > /dev/null
 
+# RUN: echo "INCLUDE \"foo.script\"" > %t.script
+# RUN: echo "OUTPUT(\"%t.out\")" > %T/foo.script
+# RUN: not ld.lld %t.script > %t.log 2>&1
+# RUN: FileCheck -check-prefix=INCLUDE_ERR %s < %t.log
+# INCLUDE_ERR: error: {{.+}}.script:1: cannot open foo.script
+# INCLUDE_ERR-NEXT: error: {{.+}}.script:1: INCLUDE "foo.script"
+# RUN: ld.lld -L %T %t.script %t
+# RUN: llvm-readobj %t.out > /dev/null
+
 # RUN: echo "FOO(BAR)" > %t.script
 # RUN: not ld.lld -o foo %t.script > %t.log 2>&1
 # RUN: FileCheck -check-prefix=ERR1 %s < %t.log
 
 # ERR1: unknown directive: FOO
 
 .globl _start, _label
 _start:
   ret
 _label:
   ret