[LLD][ELF] ignore ".so" in search path when relocatable set

[paparodeo]

closes: #94958

fixes:

$ lld -r test.o -o test -L./libs -ltest
lld: error: attempted static link of dynamic object ./libs/libtest.so

when both libtest.a and libtest.so exist in the search path

test:

mkdir libs
echo void empty(void) { } > test.c
clang test.c -c
clang test.c --shared -o libs/libtest.so
ar rc libs/libtest.a test.o
lld -r test.o -o test -L./libs -ltest

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[llvmbot]

@llvm/pr-subscribers-lld-elf

@llvm/pr-subscribers-lld

Author: Reno Dakota (paparodeo)

Changes

closes: #94958

fixes:

$ lld -r test.o -o test -L./libs -ltest
lld: error: attempted static link of dynamic object ./libs/libtest.so

when both libtest.a and libtest.so exist in the search path

test:

echo void empty(void) { } > test.c
clang test.c -c
ar rc libs/libtest.a test.o
clang test.c --shared -o libs/libtest.so
lld -r test.o -o test -L./libs -ltest

---

Full diff: https://github.com/llvm/llvm-project/pull/94965.diff

1 Files Affected:

• (modified) lld/ELF/DriverUtils.cpp (+1-1)

diff --git a/lld/ELF/DriverUtils.cpp b/lld/ELF/DriverUtils.cpp
index ac74604408152..77214aa362459 100644
--- a/lld/ELF/DriverUtils.cpp
+++ b/lld/ELF/DriverUtils.cpp
@@ -234,7 +234,7 @@ std::optional<std::string> elf::findFromSearchPaths(StringRef path) {
 // search paths.
 std::optional<std::string> elf::searchLibraryBaseName(StringRef name) {
   for (StringRef dir : config->searchPaths) {
-    if (!config->isStatic)
+    if (!(config->isStatic || config->relocatable))
       if (std::optional<std::string> s = findFile(dir, "lib" + name + ".so"))
         return s;
     if (std::optional<std::string> s = findFile(dir, "lib" + name + ".a"))

[MaskRay]

You need to turn off the hidden email for your contribution to be accepted
https://discourse.llvm.org/t/hidden-emails-on-github-should-we-do-something-about-it/74223

The word after the tags ("[LLD][ELF]") are usually capitalized. "Ignore "

I'd not use "fixes". I'd say that GNU ld does XXXX and we decide to follow suite.
I don't think there is any bug involved here. It's just some behavior difference that we don't have a strong opinion on.
The current lld behavior is like gold.