[lld][ELF][test] Improve deplib.s

[jhenderson]

Summary

The test had a few style issues, and I noticed a hole in the coverage (namely that the search order wasn't tested). Adding cases for the hole in turn meant other cases weren't important.

The .so test case isn't important, since the code is shared code, so I've removed it. Additionally, I've modified the usage of the "bar" directive to show that an unneeded library must still be present, or the link will fail, even though it isn't linked in.

[jhenderson]

Remove unneeded test input.

[MaskRay]

lld/test/ELF/deplibs.s

2–5

Up to you, but Inputs/deplibs-lib_foo.s can also be removed. It is small and thus inlining it helps reading.

echo '.globl foo; foo:' | llvm-mc -filetype=obj -triple=x86_64 - -o %tfoo.o (most -unknown-linux are not useful)

63

One space after PLAIN-DIR-NEXT:

73

is not -> may not be

[jhenderson]

Address review comments:

• Deleted foo input file.
• Fix spacing.
• Improved comment.

[jhenderson]

Fix other test due to removal of input file.

[MaskRay]

Thanks! With one nit.

lld/test/ELF/deplibs-colon-prefix.s

4

Nit: delete -unknown-linux as this is a generic ELF behavior.

[grimar]

LGTM. Have a suggestion inlined though.

lld/test/ELF/deplibs.s

64

To me it looks a bit overcomplicated to use --check-prefixes here. The COMMON part is just a single line,
but having --check-prefixes=COMMON,CWD, --check-prefixes=COMMON,PLAIN-DIR and --check-prefixes=COMMON,LIBA-DIR
seems reads slightly harder than the following:

# RUN: ld.lld %t.o -o /dev/null -L %t.dir --trace 2>&1 | \
# RUN:   FileCheck %s -DOBJ=%t.o -DDIR=%t.dir --check-prefix=CWD \
# RUN:                --implicit-check-not=foo.a --implicit-check-not=libbar.so

# CWD:      [[OBJ]]
# CWD-NEXT: {{^foo\.a}}

# RUN: rm %t.cwd/foo.a
# RUN: ld.lld %t.o -o /dev/null -L %t.dir --trace 2>&1 | \
# RUN:   FileCheck %s -DOBJ=%t.o -DDIR=%t.dir --check-prefix=PLAIN-DIR \
# RUN:                --implicit-check-not=foo.a --implicit-check-not=libbar.so

# PLAIN-DIR:      [[OBJ]]
# PLAIN-DIR-NEXT: {{^foo\.a}}

# RUN: rm %t.dir/foo.a
# RUN: ld.lld %t.o -o /dev/null -L %t.dir --trace 2>&1 | \
# RUN:   FileCheck %s -DOBJ=%t.o -DDIR=%t.dir --check-prefix=LIBA-DIR \
# RUN:                --implicit-check-not=foo.a --implicit-check-not=libbar.so

# LIBA-DIR:      [[OBJ]]
# LIBA-DIR-NEXT: {{^foo\.a}}

Up to you probably.

[jhenderson]

Remove "-unknown-linux" and adopted @grimar's suggestion.

[grimar]

The update LG too.

lld/test/ELF/Inputs/deplibs-lib_bar.s

-        .global bar
-bar:

lld/test/ELF/Inputs/deplibs-lib_foo.s

-        .global foo
-foo:

lld/test/ELF/deplibs-colon-prefix.s

 # REQUIRES: x86
 
-# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
-# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/deplibs-lib_foo.s -o %tfoo.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t.o
+# RUN: echo ".global foo; foo:" | \
+# RUN:   llvm-mc -filetype=obj -triple=x86_64 - -o %tfoo.o
 # RUN: rm -rf %t.dir
 # RUN: mkdir -p %t.dir
 # RUN: llvm-ar rc %t.dir/foo.a %tfoo.o
 # RUN: not ld.lld %t.o -o /dev/null -L %t.dir 2>&1 | FileCheck %s -DOBJ=%t.o
 # CHECK: error: [[OBJ]]: unable to find library from dependent library specifier: :foo.a
 
         .global _start
 _start:
         call foo
     .section ".deplibs","MS",@llvm_dependent_libraries,1
         .asciz  ":foo.a"

lld/test/ELF/deplibs.s

 # REQUIRES: x86
 
-# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
-# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/deplibs-lib_foo.s -o %tfoo.o
-# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/deplibs-lib_bar.s -o %tbar.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t.o
+# RUN: echo ".global foo; foo:" | \
+# RUN:   llvm-mc -filetype=obj -triple=x86_64 - -o %tfoo.o
 # RUN: rm -rf %t.dir %t.cwd
 # RUN: mkdir -p %t.dir
 
-# error if dependent libraries cannot be found
+## Error if dependent libraries cannot be found.
 # RUN: not ld.lld %t.o -o /dev/null 2>&1 | FileCheck %s -DOBJ=%t.o --check-prefix MISSING
-# MISSING: error: [[OBJ]]: unable to find library from dependent library specifier: foo.a
+# MISSING:      error: [[OBJ]]: unable to find library from dependent library specifier: foo.a
 # MISSING-NEXT: error: [[OBJ]]: unable to find library from dependent library specifier: bar
 
-# can ignore dependent libraries
+## Can ignore dependent libraries.
 # RUN: not ld.lld %t.o -o /dev/null --no-dependent-libraries 2>&1 | FileCheck %s --check-prefix IGNORE
 # IGNORE: error: undefined symbol: foo
-# IGNORE: error: undefined symbol: bar
 
-# -r links preserve dependent libraries
+## -r links preserve dependent libraries.
 # RUN: ld.lld %t.o %t.o -r -o %t-r.o
 # RUN: not ld.lld %t-r.o -o /dev/null 2>&1 | sort | FileCheck %s -DOBJ=%t-r.o --check-prefixes MINUSR
-# MINUSR: error: [[OBJ]]: unable to find library from dependent library specifier: bar
+# MINUSR:      error: [[OBJ]]: unable to find library from dependent library specifier: bar
 # MINUSR-NEXT: error: [[OBJ]]: unable to find library from dependent library specifier: foo.a
-# MINUSR-NOT: unable to find library from dependent library specifier
+# MINUSR-NOT:  unable to find library from dependent library specifier
 
-# static archives located relative to library search paths
-# RUN: llvm-ar rc %t.dir/foo.a %tfoo.o
-# RUN: llvm-ar rc %t.dir/libbar.a %tbar.o
-# RUN: ld.lld %t.o -o /dev/null -L %t.dir
-
-# shared objects located relative to library search paths
-# RUN: rm %t.dir/libbar.a
-# RUN: ld.lld -shared -o %t.dir/libbar.so %tbar.o
-# RUN: ld.lld -Bdynamic %t.o -o /dev/null -L %t.dir
-
-# dependent libraries searched for symbols after libraries on the command line
+## Dependent libraries searched for symbols after libraries on the command line.
 # RUN: mkdir -p %t.cwd
 # RUN: cd %t.cwd
+# RUN: llvm-ar rc %t.dir/foo.a %tfoo.o
+# RUN: touch %t.dir/libbar.so
 # RUN: cp %t.dir/foo.a %t.cwd/libcmdline.a
-# RUN: ld.lld %t.o libcmdline.a -o /dev/null -L %t.dir --trace 2>&1 | FileCheck %s -DOBJ=%t.o -DSO=%t.dir --check-prefix CMDLINE --implicit-check-not foo.a
-# CMDLINE: [[OBJ]]
+# RUN: ld.lld %t.o libcmdline.a -o /dev/null -L %t.dir --trace 2>&1 | \
+# RUN:   FileCheck %s -DOBJ=%t.o -DSO=%t.dir --check-prefix CMDLINE \
+# RUN:                --implicit-check-not=foo.a --implicit-check-not=libbar.so
+# CMDLINE:      [[OBJ]]
 # CMDLINE-NEXT: {{^libcmdline\.a}}
-# CMDLINE-NEXT: [[SO]]{{[\\/]}}libbar.so
 
-# libraries can be found from specifiers as if the specifiers were listed on on the command-line.
+## LLD tries to resolve dependent library specifiers in the following order:
+##   1) The literal name in the current working directory.
+##   2) The literal name in a library search path.
+##   3) The name, prefixed with "lib" and suffixed with ".so" or ".a" in a
+##      library search path. This means that a directive of "foo.a" could lead
+##      to a library named "libfoo.a.a" being linked in.
+## When using library search paths for dependent libraries, LLD follows the same
+## rules as for libraries specified on the command line.
 # RUN: cp %t.dir/foo.a %t.cwd/foo.a
-# RUN: ld.lld %t.o -o /dev/null -L %t.dir --trace 2>&1 | FileCheck %s -DOBJ=%t.o -DSO=%t.dir --check-prefix ASIFCMDLINE --implicit-check-not foo.a
-# ASIFCMDLINE: [[OBJ]]
-# ASIFCMDLINE-NEXT: {{^foo\.a}}
-# ASIFCMDLINE-NEXT: [[SO]]{{[\\/]}}libbar.so
+# RUN: cp %t.dir/foo.a %t.dir/libfoo.a.a
+# RUN: ld.lld %t.o -o /dev/null -L %t.dir --trace 2>&1 | \
+# RUN:   FileCheck %s -DOBJ=%t.o -DDIR=%t.dir --check-prefix=CWD \
+# RUN:                --implicit-check-not=foo.a --implicit-check-not=libbar.so
+
+# CWD:      [[OBJ]]
+# CWD-NEXT: {{^foo\.a}}
+
+# RUN: rm %t.cwd/foo.a
+# RUN: ld.lld %t.o -o /dev/null -L %t.dir --trace 2>&1 | \
+# RUN:   FileCheck %s -DOBJ=%t.o -DDIR=%t.dir --check-prefix=PLAIN-DIR \
+# RUN:                --implicit-check-not=foo.a --implicit-check-not=libbar.so
+
+# PLAIN-DIR:      [[OBJ]]
+# PLAIN-DIR-NEXT: [[DIR]]{{[\\/]}}foo.a
+
+# RUN: rm %t.dir/foo.a
+# RUN: ld.lld %t.o -o /dev/null -L %t.dir --trace 2>&1 | \
+# RUN:   FileCheck %s -DOBJ=%t.o -DDIR=%t.dir --check-prefix=LIBA-DIR \
+# RUN:                --implicit-check-not=foo.a --implicit-check-not=libbar.so
+
+# LIBA-DIR:      [[OBJ]]
+# LIBA-DIR-NEXT: [[DIR]]{{[\\/]}}libfoo.a.a
 
     call foo
-    call bar
 .section ".deplibs","MS",@llvm_dependent_libraries,1
-    .asciz  "foo.a"
-    .asciz  "bar"
+    .asciz "foo.a"
+    ## Show that an unneeded archive must be present but may not be linked in.
+    .asciz "bar"