[llvm-ar] Enforce one-dash form for long options

binutils ar does not support one-dash long options (they conflict with
operation code and modifier flags).

```
% ar -help
ar: invalid option -- 'e'
...
% ar -version
ar: invalid option -- 'e'
...

% ar x --plugin=xx x.a  # ok
% ar x -plugin=xx x.a
ar: two different operation options specified
% ar -plugin=/usr/lib/gcc/x86_64-linux-gnu/10/liblto_plugin.so x x.a
ar: x: No such file or directory
```

Drop one-dash long options to simplify code and match the usual practice for
command line utilities.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D116977

5 files changed, 19 insertions, 6 deletions

diff --git a/llvm/test/Object/archive-format.test b/llvm/test/Object/archive-format.test
index fd9f0ae967bd..f24b5ad57667 100644
--- a/llvm/test/Object/archive-format.test
+++ b/llvm/test/Object/archive-format.test
@@ -89,3 +89,6 @@ RUN: cat -v %t/foo.a | FileCheck -strict-whitespace --check-prefix=SOLARIS %s
 SOLARIS:      !<arch>
 SOLARIS-NEXT: /               0           0     0     0       8         `
 SOLARIS-NEXT: ^@^@^@^@^@^@^@^@foo.o/
+
+RUN: not llvm-ar -format=gnu rc %t.a 0123456789abcde 2>&1 | FileCheck --check-prefix=ONE-DASH %s
+ONE-DASH: error: unknown option f
diff --git a/llvm/test/tools/llvm-ar/plugin.test b/llvm/test/tools/llvm-ar/plugin.test
new file mode 100644
index 000000000000..0dda3d98dde2
--- /dev/null
+++ b/llvm/test/tools/llvm-ar/plugin.test
@@ -0,0 +1,9 @@
+## Test that --plugin is ignored.
+
+# RUN: rm -f %t.a
+# RUN: touch %t.txt
+# RUN: llvm-ar rc %t.a %t.txt
+# RUN: llvm-ar --plugin ignore t %t.a | FileCheck %s
+# RUN: llvm-ar t --plugin=ignore %t.a | FileCheck %s
+
+# CHECK: {{.*}}.txt
diff --git a/llvm/test/tools/llvm-ar/response.test b/llvm/test/tools/llvm-ar/response.test
index 4e798c220103..02d9e8eec092 100644
--- a/llvm/test/tools/llvm-ar/response.test
+++ b/llvm/test/tools/llvm-ar/response.test
@@ -36,6 +36,6 @@
 # RUN:   FileCheck -DMSG=%errc_ENOENT %s --check-prefix=WIN
 # WIN: error: blah\foo: [[MSG]]
 
-# RUN: not llvm-ar -rsp-quoting posix @%t-rsp.txt 2>&1 | \
+# RUN: not llvm-ar --rsp-quoting posix @%t-rsp.txt 2>&1 | \
 # RUN:   FileCheck -DMSG=%errc_ENOENT %s --check-prefix=POSIX
 # POSIX: error: blahfoo: [[MSG]]
diff --git a/llvm/test/tools/llvm-ar/version.test b/llvm/test/tools/llvm-ar/version.test
index 555e5fdf3244..0220f2cfe559 100644
--- a/llvm/test/tools/llvm-ar/version.test
+++ b/llvm/test/tools/llvm-ar/version.test
@@ -5,7 +5,10 @@ RUN: llvm-ar V | FileCheck %s
 RUN: llvm-ar xV | FileCheck %s
 RUN: llvm-ar -V | FileCheck %s
 RUN: llvm-ar -xV | FileCheck %s
-RUN: llvm-ar -version | FileCheck %s
 RUN: llvm-ar --version | FileCheck %s
 
 CHECK: version
+
+RUN: not llvm-ar -version 2>&1 | FileCheck %s --check-prefix=ONE-DASH
+
+ONE-DASH: error: unknown option e
diff --git a/llvm/tools/llvm-ar/llvm-ar.cpp b/llvm/tools/llvm-ar/llvm-ar.cpp
index 175ec8d022c2..674f57812df4 100644
--- a/llvm/tools/llvm-ar/llvm-ar.cpp
+++ b/llvm/tools/llvm-ar/llvm-ar.cpp
@@ -1111,11 +1111,11 @@ static void runMRIScript() {
 }
 
 static bool handleGenericOption(StringRef arg) {
-  if (arg == "-help" || arg == "--help" || arg == "-h") {
+  if (arg == "--help" || arg == "-h") {
     printHelpMessage();
     return true;
   }
-  if (arg == "-version" || arg == "--version") {
+  if (arg == "--version") {
     cl::PrintVersionMessage();
     return true;
   }
@@ -1129,8 +1129,6 @@ static const char *matchFlagWithArg(StringRef Expected,
 
   if (Arg.startswith("--"))
     Arg = Arg.substr(2);
-  else if (Arg.startswith("-"))
-    Arg = Arg.substr(1);
 
   size_t len = Expected.size();
   if (Arg == Expected) {