From 4e71f359bf6c19e603541c0107ffff0d90a85a9b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Chmiel?= <bchmiel@antmicro.com>
Date: Mon, 4 Nov 2024 15:06:15 +0100
Subject: [PATCH] Fix duplicate scope identifiers decoding (#5584)
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Signed-off-by: Bartłomiej Chmiel <bchmiel@antmicro.com>
Co-authored-by: Ryszard Rozak <rrozak@antmicro.com>
---
 src/V3EmitCSyms.cpp             | 13 +------------
 test_regress/t/t_vpi_escape.cpp | 10 ++++++++++
 test_regress/t/t_vpi_escape.v   |  4 ++++
 3 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/src/V3EmitCSyms.cpp b/src/V3EmitCSyms.cpp
index 14323fed6..4198eecc5 100644
--- a/src/V3EmitCSyms.cpp
+++ b/src/V3EmitCSyms.cpp
@@ -156,7 +156,6 @@ class EmitCSyms final : EmitCBaseVisitorConst {
     }
 
     static string scopeDecodeIdentifier(const string& scpname) {
-        string out = scpname;
         string::size_type pos = string::npos;
 
         // Remove hierarchy
@@ -172,17 +171,7 @@ class EmitCSyms final : EmitCBaseVisitorConst {
             }
         }
 
-        if (pos != std::string::npos) out.erase(0, pos + 1);
-
-        // Decode all escaped characters
-        while ((pos = out.find("__0")) != string::npos) {
-            unsigned int x;
-            std::stringstream ss;
-            ss << std::hex << out.substr(pos + 3, 2);
-            ss >> x;
-            out.replace(pos, 5, 1, (char)x);
-        }
-        return out;
+        return pos != string::npos ? scpname.substr(pos + 1) : scpname;
     }
 
     /// (scp, m_vpiScopeCandidates, m_scopeNames) -> m_scopeNames
diff --git a/test_regress/t/t_vpi_escape.cpp b/test_regress/t/t_vpi_escape.cpp
index 043a62a5d..7fed0d2e6 100644
--- a/test_regress/t/t_vpi_escape.cpp
+++ b/test_regress/t/t_vpi_escape.cpp
@@ -135,6 +135,16 @@ int _mon_check_iter() {
         TEST_CHECK_CSTR(p, "<null>");  // Unsupported
     }
 
+    TestVpiHandle vh_null_name = MY_VPI_HANDLE("___0_");
+    TEST_CHECK_NZ(vh_null_name);
+    p = vpi_get_str(vpiName, vh_null_name);
+    TEST_CHECK_CSTR(p, "___0_");
+
+    TestVpiHandle vh_hex_name = MY_VPI_HANDLE("___0F_");
+    TEST_CHECK_NZ(vh_hex_name);
+    p = vpi_get_str(vpiName, vh_hex_name);
+    TEST_CHECK_CSTR(p, "___0F_");
+
     TestVpiHandle vh10 = vpi_iterate(vpiReg, vh2);
     TEST_CHECK_NZ(vh10);
     TEST_CHECK_EQ(vpi_get(vpiType, vh10), vpiIterator);
diff --git a/test_regress/t/t_vpi_escape.v b/test_regress/t/t_vpi_escape.v
index b575dc199..a912c1096 100644
--- a/test_regress/t/t_vpi_escape.v
+++ b/test_regress/t/t_vpi_escape.v
@@ -63,6 +63,10 @@ extern "C" int mon_check();
 
    sub \mod.with_dot (.cyc(cyc));
 
+   // Check if scope names are not decoded twice
+   sub ___0F_ (.cyc(cyc));
+   sub ___0_ (.cyc(cyc));
+
    initial begin
 
 `ifdef VERILATOR