Verilator requires a C++14 or newer compiler

[PeterWang-dev]

Type of issue: Bug Report

Please provide the steps to reproduce the problem:

1. Install Verilator 5.021
2. Use chisel-template as a test project
3. Run mill __.test

What is the current behavior?
Verilator compile error while testing, complaining Verilator need a newer compiler above c++ 14.

What is the expected behavior?
Test should work properly.

Please tell us about your environment:

• version: 6.0
• OS: Linux ArchLinux 6.7.4-zen1-1-zen #1 ZEN SMP PREEMPT_DYNAMIC Mon, 05 Feb 2024 22:07:37 +0000 x86_64 GNU/Linux
• Verilator version: Verilator 5.021 devel rev v5.020-105-ga187a16e5 (integrated with oss-cad-suite )

Other Information

Error logs of test:

LANG=C mill __.test

[83/83] TestProject.test.test 
GCDSpec:
- Gcd should calculate proper greatest common denominator *** FAILED ***
  java.lang.Exception: make: Entering directory '/tmp/chisel3.simulator.EphemeralSimulator/357569@PeterWang-ArchLinux/workdir-default'
ls . | grep -v Makefile | grep -v execution-script.txt | xargs rm -rf
\
/opt/oss-cad-suite/bin/verilator \
        '--cc' \
        '--exe' \
        '--build' \
        '-o' \
        '../simulation' \
        '--top-module' \
        'svsimTestbench' \
        '--Mdir' \
        'verilated-sources' \
        '-CFLAGS' \
        '-std=c++11 -I/tmp/chisel3.simulator.EphemeralSimulator/357569@PeterWang-ArchLinux/workdir-default -DSVSIM_ENABLE_VERILATOR_SUPPORT' \
        '../primary-sources/DecoupledGcd.sv' 'testbench.sv' '../generated-sources/c-dpi-bridge.cpp' '../generated-sources/simulation-driver.cpp'
make[1]: Entering directory '/tmp/chisel3.simulator.EphemeralSimulator/357569@PeterWang-ArchLinux/workdir-default/verilated-sources'
g++  -I.  -MMD -I/opt/oss-cad-suite/share/verilator/include -I/opt/oss-cad-suite/share/verilator/include/vltstd -DVM_COVERAGE=0 -DVM_SC=0 -DVM_TRACE=0 -DVM_TRACE_FST=0 -DVM_TRACE_VCD=0 -faligned-new -fcf-protection=none -Wno-bool-operation -Wno-shadow -Wno-sign-compare -Wno-tautological-compare -Wno-uninitialized -Wno-unused-but-set-parameter -Wno-unused-but-set-variable -Wno-unused-parameter -Wno-unused-variable    -std=c++11 -I/tmp/chisel3.simulator.EphemeralSimulator/357569@PeterWang-ArchLinux/workdir-default -DSVSIM_ENABLE_VERILATOR_SUPPORT   -Os -c -o c-dpi-bridge.o c-dpi-bridge.cpp
g++  -I.  -MMD -I/opt/oss-cad-suite/share/verilator/include -I/opt/oss-cad-suite/share/verilator/include/vltstd -DVM_COVERAGE=0 -DVM_SC=0 -DVM_TRACE=0 -DVM_TRACE_FST=0 -DVM_TRACE_VCD=0 -faligned-new -fcf-protection=none -Wno-bool-operation -Wno-shadow -Wno-sign-compare -Wno-tautological-compare -Wno-uninitialized -Wno-unused-but-set-parameter -Wno-unused-but-set-variable -Wno-unused-parameter -Wno-unused-variable    -std=c++11 -I/tmp/chisel3.simulator.EphemeralSimulator/357569@PeterWang-ArchLinux/workdir-default -DSVSIM_ENABLE_VERILATOR_SUPPORT   -Os -c -o simulation-driver.o simulation-driver.cpp
In file included from /opt/oss-cad-suite/share/verilator/include/verilated.h:42,
                 from ./VsvsimTestbench.h:11,
                 from simulation-driver.cpp:883:
/opt/oss-cad-suite/share/verilator/include/verilatedos.h:265:3: error: #error "Verilator requires a C++14 or newer compiler"
  265 | # error "Verilator requires a C++14 or newer compiler"
      |   ^~~~~
/opt/oss-cad-suite/share/verilator/include/verilated.h:76:22: error: 'literals' is not a namespace-name
   76 | using namespace std::literals;  // "<std::string literal>"s; see SF.7 core guideline
      |                      ^~~~~~~~
In file included from /opt/oss-cad-suite/share/verilator/include/verilated.h:950:
/opt/oss-cad-suite/share/verilator/include/verilated_types.h: In function 'std::string VL_TO_STRING(const VlEvent&)':
/opt/oss-cad-suite/share/verilator/include/verilated_types.h:266:12: error: unable to find string literal operator 'operator""s' with 'const char [11]', 'long unsigned int' arguments
  266 |     return "triggered="s + (e.isTriggered() ? "true" : "false");
      |            ^~~~~~~~~~~~~
/opt/oss-cad-suite/share/verilator/include/verilated_types.h: In function 'std::string VL_TO_STRING(const VlEventBase&)':
/opt/oss-cad-suite/share/verilator/include/verilated_types.h:277:12: error: unable to find string literal operator 'operator""s' with 'const char [11]', 'long unsigned int' arguments
  277 |     return "triggered="s + (e.isTriggered() ? "true" : "false");
      |            ^~~~~~~~~~~~~
/opt/oss-cad-suite/share/verilator/include/verilated_types.h: In constructor 'VlClassRef<T_Class>::VlClassRef(VlClassRef<T_Class>&&)':
/opt/oss-cad-suite/share/verilator/include/verilated_types.h:1651:23: error: 'exchange' is not a member of 'std'
 1651 |         : m_objp{std::exchange(moved.m_objp, nullptr)} {}
      |                       ^~~~~~~~
/opt/oss-cad-suite/share/verilator/include/verilated_types.h:1651:23: note: 'std::exchange' is only available from C++14 onwards
/opt/oss-cad-suite/share/verilator/include/verilated_types.h: In constructor 'VlClassRef<T_Class>::VlClassRef(VlClassRef<T_OtherClass>&&)':
/opt/oss-cad-suite/share/verilator/include/verilated_types.h:1661:23: error: 'exchange' is not a member of 'std'
 1661 |         : m_objp{std::exchange(moved.m_objp, nullptr)} {}
      |                       ^~~~~~~~
/opt/oss-cad-suite/share/verilator/include/verilated_types.h:1661:23: note: 'std::exchange' is only available from C++14 onwards
/opt/oss-cad-suite/share/verilator/include/verilated_types.h: In member function 'VlClassRef<T_Class>& VlClassRef<T_Class>::operator=(VlClassRef<T_Class>&&)':
/opt/oss-cad-suite/share/verilator/include/verilated_types.h:1676:23: error: 'exchange' is not a member of 'std'
 1676 |         m_objp = std::exchange(moved.m_objp, nullptr);
      |                       ^~~~~~~~
/opt/oss-cad-suite/share/verilator/include/verilated_types.h:1676:23: note: 'std::exchange' is only available from C++14 onwards
/opt/oss-cad-suite/share/verilator/include/verilated_types.h: In member function 'VlClassRef<T_Class>& VlClassRef<T_Class>::operator=(VlClassRef<T_OtherClass>&&)':
/opt/oss-cad-suite/share/verilator/include/verilated_types.h:1691:23: error: 'exchange' is not a member of 'std'
 1691 |         m_objp = std::exchange(moved.m_objp, nullptr);
      |                       ^~~~~~~~
/opt/oss-cad-suite/share/verilator/include/verilated_types.h:1691:23: note: 'std::exchange' is only available from C++14 onwards
make[1]: *** [VsvsimTestbench.mk:65: simulation-driver.o] Error 1
make[1]: Leaving directory '/tmp/chisel3.simulator.EphemeralSimulator/357569@PeterWang-ArchLinux/workdir-default/verilated-sources'
%Error: make -C verilated-sources -f VsvsimTestbench.mk -j 1 exited with 2
%Error: Command Failed ulimit -s unlimited 2>/dev/null; exec /opt/oss-cad-suite/share/verilator/bin/verilator_bin --cc --exe --build -o ../simulation --top-module svsimTestbench --Mdir verilated-sources -CFLAGS -std=c++11\ -I/tmp/chisel3.simulator.EphemeralSimulator/357569\@PeterWang-ArchLinux/workdir-default\ -DSVSIM_ENABLE_VERILATOR_SUPPORT ../primary-sources/DecoupledGcd.sv testbench.sv ../generated-sources/c-dpi-bridge.cpp ../generated-sources/simulation-driver.cpp
make: *** [Makefile:12: simulation] Error 2
make: Leaving directory '/tmp/chisel3.simulator.EphemeralSimulator/357569@PeterWang-ArchLinux/workdir-default'
  at svsim.Workspace.compile(Workspace.scala:390)
  at chisel3.simulator.Simulator$WorkspaceCompiler.liftedTree1$1(Simulator.scala:60)
  at chisel3.simulator.Simulator$WorkspaceCompiler.process(Simulator.scala:53)
  at chisel3.simulator.SingleBackendSimulator.processBackends(Simulator.scala:139)
  at chisel3.simulator.SingleBackendSimulator.processBackends$(Simulator.scala:138)
  at chisel3.simulator.EphemeralSimulator$DefaultSimulator.processBackends(EphemeralSimulator.scala:27)
  at chisel3.simulator.Simulator._simulate(Simulator.scala:116)
  at chisel3.simulator.Simulator._simulate$(Simulator.scala:97)
  at chisel3.simulator.EphemeralSimulator$DefaultSimulator._simulate(EphemeralSimulator.scala:27)
  at chisel3.simulator.SingleBackendSimulator.simulate(Simulator.scala:146)
  ...
1 targets failed
TestProject.test.test 1 tests failed: 
  gcd.GCDSpec Gcd should calculate proper greatest common denominator

What is the use case for changing the behavior?
Circuit unit test.

[seldridge]

Fixed in #3876.