[dv] Tweak ISS linker arg construction for Xcelium

The previous code here was a bit too hacky, so implement a solution that
directly follows the suggestion in the Cadence support article.
An example was also added to make it clear what this transformation is
achieving.

Add some more typehints, and cleanup names.

Signed-off-by: Harry Callahan <[email protected]>

dv/uvm/core_ibex/scripts/compile_tb.py

@@ -5,7 +5,9 @@
 # SPDX-License-Identifier: Apache-2.0
 
 import argparse
+from typing import List
 import os
+import shlex
 import sys
 import subprocess
 import pathlib3x as pathlib
@@ -19,23 +21,51 @@
 logger = logging.getLogger(__name__)
 
 
-def _get_iss_pkgconfig_flags(specifiers, iss_pc, simulator):
+def _get_iss_pkgconfig_flags(specifiers: List[str], iss_pc: List[str], simulator: str) -> str:
+    all_tokens = []
+
     # Seperate pkg-config calls for each specifier as combining them has been
     # observed misbehaving on CentOS 7
-    _flags = ' '.join([subprocess.check_output(
-                        args=(['pkg-config', s] + iss_pc),
-                        universal_newlines=True,).strip()
-                       for s in specifiers])
-
-    if simulator == 'xlm':
-        # See xcelium documentation for the -Wld syntax for passing
-        # flags to the linker. Passing -rpath,<path> options is tricky
-        # because commas are parsed strangely between xrun and the xmsc
-        # tool, and its easy for the options to arrive malformed. Use
-        # the following hack to get it through.
-        if '-Wl' in _flags:  # This should be in LDFLAGS only
-            _flags = "'-Xlinker {}'".format(_flags.replace('-Wl,', ''))
-    return _flags
+    # Generate a list of tokens for each call, and append it to the all_tokens variable
+    for s in specifiers:
+        cmd = ['pkg-config', s] + iss_pc
+        stdout = subprocess.check_output(cmd, universal_newlines=True).strip()
+        tokens = shlex.split(stdout)
+        logger.debug(f"pkgconfig_tokens = {tokens}")
+
+        rpath_prefix = '-Wl,-rpath,'
+        def fixup_xcelium_rpath_token(t: str) -> str:
+            """Re-format rpath flags to ensure reliable passing to Xcelium.
+
+            When passing rpath flags to xcelium through the xrun tool, we need to re-format the string
+            output by pkg-config to ensure reliability.
+            This routine detects rpath flags and reformats them according to the Cadence support site
+            article.
+            """
+            if simulator == 'xlm' and t.startswith(rpath_prefix):
+                logger.debug(f"rpath token => {t}")
+                # https://support.cadence.com/apex/ArticleAttachmentPortal?id=a1Od0000000sdF8EAI
+                # See xcelium documentation for the -Wld syntax for passing
+                # user specified arguments to the C++ linker.
+                # Passing -rpath,<path> options is tricky, so use the following workaround as
+                # suggested in the support article.
+                # INPUT:  '-Wl,-rpath,/opt/spike/lib'
+                # OUTPUT: '-Wld,-Xlinker,-rpath,-Xlinker,/opt/spike/lib',
+                rpaths = (t[len(rpath_prefix):]).split(',')
+                xlinker_rpaths_str = ','.join((f"-Xlinker,{p}" for p in rpaths))
+                rpath_token = f"-Wld,-Xlinker,-rpath,{xlinker_rpaths_str}"
+                logger.debug(f"new rpath token => {rpath_token}")
+                return rpath_token
+            else:
+                return t
+
+        tokens = map(fixup_xcelium_rpath_token, tokens)
+
+        all_tokens += tokens
+
+    flags_str = shlex.join(all_tokens)
+    logger.debug(f"flags = {flags_str}")
+    return flags_str
 
 
 def _main() -> int:

dv/uvm/core_ibex/yaml/rtl_simulation.yaml

@@ -256,7 +256,7 @@
       <ISS_LIBS>
       <ISS_CFLAGS>
       <EXTRA_COSIM_CFLAGS>
-      -Wld,<ISS_LDFLAGS>
+      <ISS_LDFLAGS>
       -lstdc++
   sim:
     cmd: