[ELF2/LinkerScript] Support for SEARCH_DIR() directive

[davide]

Summary

Needed by FreeBSD base system.

[ruiu]

LGTM with nits.

ELF/LinkerScript.cpp

169–170

Config->InputSearchPaths.push_back(next());

test/elf2/linkerscript.s

26

You don't unquote and quote here because /lib/foo/blah does not contain any variables unlike others.

echo "SEARCH_DIR(/lib/foo/blah)" > %t.script

[ruiu]

test/elf2/linkerscript.s

26

Noticed that I misunderstood this test. Its testing double-quoted path name. Linker script doesn't distinguish them, so either

echo "SEARCH_DIR(/lib/foo/blah)" > %t.script

or

echo 'SEARCH_DIR("/lib/foo/blah")' > %t.script

is fine with me. This is not a test for the tokenizer after all. I'd just avoid using double quotes inside double quotes.

ELF/LinkerScript.cpp

private:
   StringRef next();
   bool atEOF() { return Tokens.size() == Pos; }
   void expect(StringRef Expect);
 
   void readAsNeeded();
   void readGroup();
   void readOutput();
   void readOutputFormat();
+  void readSearchDir();
 
   std::vector<StringRef> Tokens;
   size_t Pos = 0;
 };
 }
 
 void LinkerScript::run() {
   while (!atEOF()) {
     StringRef Tok = next();
     if (Tok == "GROUP") {
       readGroup();
     } else if (Tok == "OUTPUT") {
       readOutput();
     } else if (Tok == "OUTPUT_FORMAT") {
       readOutputFormat();
+    } else if (Tok == "SEARCH_DIR") {
+      readSearchDir();
     } else {
       error("unknown directive: " + Tok);
     }
   }
 }
 
 // Split S into linker script tokens.
 std::vector<StringRef> LinkerScript::tokenize(StringRef S) {

 
 void LinkerScript::readOutputFormat() {
   // Error checking only for now.
   expect("(");
   next();
   expect(")");
 }
 
+void LinkerScript::readSearchDir() {
+  expect("(");
+  StringRef Tok = next();
+  Config->InputSearchPaths.push_back(Tok);
+  expect(")");
+}
+
 // Entry point. The other functions or classes are private to this file.
 void lld::elf2::readLinkerScript(MemoryBufferRef MB) {
   LinkerScript(MB.getBuffer()).run();
 }

test/elf2/linkerscript.s

 # RUN: ld.lld2 -o %t2 %t.script
 # RUN: llvm-readobj %t2 > /dev/null
 
 # RUN: rm -f %t.out
 # RUN: echo "OUTPUT(" %t.out ")" > %t.script
 # RUN: ld.lld2 %t.script %t
 # RUN: llvm-readobj %t.out > /dev/null
 
+# RUN: echo "SEARCH_DIR(\"/lib/foo/blah\")" > %t.script
+# RUN: ld.lld2 %t.script %t
+# RUN: llvm-readobj %t.out > /dev/null
+
 # RUN: echo "FOO(BAR)" > %t.script
 # RUN: not ld.lld2 -o foo %t.script > %t.log 2>&1
 # RUN: FileCheck -check-prefix=ERR1 %s < %t.log
 
 # ERR1: unknown directive: FOO
 
 .globl _start;
 _start:
   mov $60, %rax
   mov $42, %rdi
   syscall