From 4f007c75835f27f94c4eec44eb894a883a066a96 Mon Sep 17 00:00:00 2001
From: cgewecke <christophergewecke@gmail.com>
Date: Thu, 8 Feb 2024 18:55:52 -0800
Subject: [PATCH] Enable coverage when `viaIR` compiler flag is true (#854)

---
 .circleci/config.yml                          | 10 ++--
 lib/api.js                                    |  3 +-
 lib/collector.js                              | 50 ++++++++++++++++--
 lib/injector.js                               | 52 ++++++++++++++++---
 lib/instrumenter.js                           |  2 +-
 package.json                                  |  5 +-
 plugins/hardhat.plugin.js                     | 11 ++--
 plugins/resources/nomiclabs.utils.js          | 21 ++++++++
 plugins/resources/plugin.utils.js             |  4 +-
 scripts/ci.sh                                 |  8 ++-
 scripts/integration.sh                        |  3 ++
 scripts/unit.sh                               |  3 ++
 scripts/zeppelin.sh                           |  1 +
 test/integration/standard.js                  | 25 +++++++++
 .../contract-subfolders/hardhat.config.js     |  8 ++-
 .../contracts/ContractA1.sol                  |  2 +-
 .../contracts/ContractB1.sol                  |  2 +-
 .../contracts/ContractC1.sol                  |  2 +-
 .../hardhat-compile-config/hardhat.config.js  | 18 +++++--
 .../hardhat-gas-reporter/hardhat.config.js    |  8 ++-
 .../projects/hardhat-mine/hardhat.config.js   |  8 ++-
 .../projects/hardhat-reset/hardhat.config.js  |  8 ++-
 .../projects/import-paths/hardhat.config.js   |  8 ++-
 .../projects/libraries/hardhat.config.js      |  8 ++-
 .../sources/projects/matrix/hardhat.config.js |  8 ++-
 .../modifiers/contracts/ModifiersA.sol        |  2 +-
 .../modifiers/contracts/ModifiersB.sol        |  2 +-
 .../modifiers/contracts/ModifiersC.sol        |  2 +-
 .../projects/modifiers/hardhat.config.js      |  8 ++-
 .../multiple-suites/hardhat.config.js         |  8 ++-
 .../projects/no-sources/hardhat.config.js     |  8 ++-
 .../projects/overrides-viaIR/.solcover.js     |  4 ++
 .../contracts/ContractOverA2.sol              | 17 ++++++
 .../contracts/ContractOverB2.sol              | 17 ++++++
 .../contracts/ContractOverC2.sol              | 17 ++++++
 .../overrides-viaIR/hardhat.config.js         | 29 +++++++++++
 .../overrides-viaIR/test/contract_over_a2.js  | 11 ++++
 .../overrides-viaIR/test/contract_over_b2.js  | 15 ++++++
 .../overrides-viaIR/test/contract_over_c2.js  | 20 +++++++
 .../projects/skipping/hardhat.config.js       |  8 ++-
 .../sources/projects/solc-8/hardhat.config.js |  8 ++-
 .../projects/task-hooks/hardhat.config.js     |  8 ++-
 .../ternary-and-logical-or/hardhat.config.js  |  8 ++-
 .../projects/test-files/hardhat.config.js     |  8 ++-
 .../projects/tests-folder/hardhat.config.js   |  8 ++-
 test/units/statements.js                      |  7 ++-
 test/util/integration.js                      |  8 ++-
 test/util/util.js                             |  6 ++-
 48 files changed, 450 insertions(+), 57 deletions(-)
 create mode 100644 test/sources/projects/overrides-viaIR/.solcover.js
 create mode 100644 test/sources/projects/overrides-viaIR/contracts/ContractOverA2.sol
 create mode 100644 test/sources/projects/overrides-viaIR/contracts/ContractOverB2.sol
 create mode 100644 test/sources/projects/overrides-viaIR/contracts/ContractOverC2.sol
 create mode 100644 test/sources/projects/overrides-viaIR/hardhat.config.js
 create mode 100644 test/sources/projects/overrides-viaIR/test/contract_over_a2.js
 create mode 100644 test/sources/projects/overrides-viaIR/test/contract_over_b2.js
 create mode 100644 test/sources/projects/overrides-viaIR/test/contract_over_c2.js

diff --git a/.circleci/config.yml b/.circleci/config.yml
index b4ced1a..fdb57df 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -12,11 +12,9 @@ step_install_nvm: &step_install_nvm
       set +e
       export NVM_DIR="/opt/circleci/.nvm"
       [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
-      nvm install v14.19.0
-      nvm alias default v14.19.0
+      nvm install v18
       echo 'export NVM_DIR="/opt/circleci/.nvm"' >> $BASH_ENV
       echo "[ -s \"$NVM_DIR/nvm.sh\" ] && . \"$NVM_DIR/nvm.sh\"" >> $BASH_ENV
-
 jobs:
   unit-test:
     docker:
@@ -32,9 +30,13 @@ jobs:
           command: |
             yarn
       - run:
-          name: Run tests
+          name: Tests ( optimizer.enabled=false )
           command: |
             npm run test:ci
+      - run:
+          name: Tests ( viaIR=true )
+          command: |
+            npm run test:ci:viaIR
       - run:
           name: Upload coverage
           command: |
diff --git a/lib/api.js b/lib/api.js
index 296fcb4..8632dcc 100644
--- a/lib/api.js
+++ b/lib/api.js
@@ -54,6 +54,7 @@ class API {
     this.istanbulFolder = config.istanbulFolder || false;
     this.istanbulReporter = config.istanbulReporter || ['html', 'lcov', 'text', 'json'];
 
+    this.viaIR = config.viaIR;
     this.solcOptimizerDetails = config.solcOptimizerDetails;
 
     this.setLoggingLevel(config.silent);
@@ -176,7 +177,7 @@ class API {
   // Hardhat
   async attachToHardhatVM(provider){
     const self = this;
-    this.collector = new DataCollector(this.instrumenter.instrumentationData);
+    this.collector = new DataCollector(this.instrumenter.instrumentationData, this.viaIR);
 
     if ('init' in provider) {
       // Newer versions of Hardhat initialize the provider lazily, so we need to
diff --git a/lib/collector.js b/lib/collector.js
index d43ee7a..062de10 100644
--- a/lib/collector.js
+++ b/lib/collector.js
@@ -3,12 +3,31 @@
  * coverage map constructed by the Instrumenter.
  */
 class DataCollector {
-  constructor(instrumentationData={}){
+  constructor(instrumentationData={}, viaIR){
     this.instrumentationData = instrumentationData;
 
     this.validOpcodes = {
       "PUSH1": true,
+      "DUP1": viaIR,
+      "DUP2": viaIR,
+      "DUP3": viaIR,
+      "DUP4": viaIR,
+      "DUP5": viaIR,
+      "DUP6": viaIR,
+      "DUP7": viaIR,
+      "DUP8": viaIR,
+      "DUP9": viaIR,
+      "DUP10": viaIR,
+      "DUP11": viaIR,
+      "DUP12": viaIR,
+      "DUP13": viaIR,
+      "DUP14": viaIR,
+      "DUP15": viaIR,
+      "DUP16": viaIR,
     }
+
+    this.lastHash = null;
+    this.viaIR = viaIR;
   }
 
   /**
@@ -46,7 +65,26 @@ class DataCollector {
     hash = this._normalizeHash(hash);
 
     if(this.instrumentationData[hash]){
-      this.instrumentationData[hash].hits++;
+      // abi.encode (used to circumvent viaIR) sometimes puts the hash on the stack twice
+      if (this.lastHash !== hash) {
+        this.lastHash = hash;
+        this.instrumentationData[hash].hits++
+      }
+      return;
+    }
+
+    // Detect and recover from viaIR mangled hashes by left-padding single `0`
+    if(this.viaIR && hash.length === 18) {
+      hash = hash.slice(2);
+      hash = '0' + hash;
+      hash = hash.slice(0,16);
+      hash = '0x' + hash;
+      if(this.instrumentationData[hash]){
+        if (this.lastHash !== hash) {
+          this.lastHash = hash;
+          this.instrumentationData[hash].hits++
+        }
+      }
     }
   }
 
@@ -56,10 +94,14 @@ class DataCollector {
    * but prevents left-padding shorter irrelevant hashes
    *
    * @param  {String} hash  data hash from evm stack.
-   * @return {String}       0x prefixed hash of length 66.
+   * @return {String}       0x prefixed hash of length 18.
    */
   _normalizeHash(hash){
-    if (hash.length < 18 && hash.length > 11){
+    // viaIR sometimes right-pads the hashes out to 32 bytes
+    // but it doesn't preserve leading zeroes when it does this
+    if (this.viaIR && hash.length >= 18) {
+      hash = hash.slice(0,18);
+    } else if (hash.length < 18 && hash.length > 11){
       hash = hash.slice(2);
       while(hash.length < 16) hash = '0' + hash;
       hash = '0x' + hash
diff --git a/lib/injector.js b/lib/injector.js
index e1bd0b0..693a28f 100644
--- a/lib/injector.js
+++ b/lib/injector.js
@@ -1,7 +1,8 @@
 const web3Utils = require("web3-utils");
 
 class Injector {
-  constructor(){
+  constructor(viaIR){
+    this.viaIR = viaIR;
     this.hashCounter = 0;
     this.modifierCounter = 0;
     this.modifiers = {};
@@ -23,7 +24,9 @@ class Injector {
       case 'modifier':
         return ` ${this._getModifierIdentifier(id)} `;
       default:
-        return `${this._getDefaultMethodIdentifier(id)}(${hash}); /* ${type} */ \n`;
+        return (this.viaIR)
+          ? `${this._getAbiEncodeStatementHash(hash)} /* ${type} */ \n`
+          : `${this._getDefaultMethodIdentifier(id)}(${hash}); /* ${type} */ \n`;
     }
   }
 
@@ -51,6 +54,16 @@ class Injector {
     return `c_mod${web3Utils.keccak256(id).slice(2,10)}`
   }
 
+  // Way to get hash on the stack with viaIR (which seems to ignore abi.encode builtin)
+  // Tested with v0.8.17, v0.8.24
+    _getAbiEncodeStatementHash(hash){
+    return `abi.encode(${hash}); `
+  }
+
+  _getAbiEncodeStatementVar(hash){
+    return `abi.encode(c__${hash}); `
+  }
+
   _getInjectionComponents(contract, injectionPoint, id, type){
     const { start, end } = this._split(contract, injectionPoint);
     const hash = this._getHash(id)
@@ -73,7 +86,10 @@ class Injector {
   _getDefaultMethodDefinition(id){
     const hash = web3Utils.keccak256(id).slice(2,10);
     const method = this._getDefaultMethodIdentifier(id);
-    return `\nfunction ${method}(bytes8 c__${hash}) internal pure {}\n`;
+
+    return (this.viaIR)
+      ? ``
+      : `\nfunction ${method}(bytes8 c__${hash}) internal pure {}\n`;
   }
 
   /**
@@ -85,7 +101,11 @@ class Injector {
   _getFileScopedHashMethodDefinition(id, contract){
     const hash = web3Utils.keccak256(id).slice(2,10);
     const method = this._getDefaultMethodIdentifier(id);
-    return `\nfunction ${method}(bytes8 c__${hash}) pure {}\n`;
+    const abi = this._getAbiEncodeStatementVar(hash);
+
+    return (this.viaIR)
+      ? `\nfunction ${method}(bytes8 c__${hash}) pure { ${abi} }\n`
+      : `\nfunction ${method}(bytes8 c__${hash}) pure {}\n`;
   }
 
   /**
@@ -97,7 +117,11 @@ class Injector {
   _getTrueMethodDefinition(id){
     const hash = web3Utils.keccak256(id).slice(2,10);
     const method = this._getTrueMethodIdentifier(id);
-    return `function ${method}(bytes8 c__${hash}) internal pure returns (bool){ return true; }\n`;
+    const abi = this._getAbiEncodeStatementVar(hash);
+
+    return (this.viaIR)
+      ? `function ${method}(bytes8 c__${hash}) internal pure returns (bool){ ${abi} return true; }\n`
+      : `function ${method}(bytes8 c__${hash}) internal pure returns (bool){ return true; }\n`;
   }
 
   /**
@@ -110,7 +134,11 @@ class Injector {
   _getFileScopeTrueMethodDefinition(id){
     const hash = web3Utils.keccak256(id).slice(2,10);
     const method = this._getTrueMethodIdentifier(id);
-    return `function ${method}(bytes8 c__${hash}) pure returns (bool){ return true; }\n`;
+    const abi = this._getAbiEncodeStatementVar(hash);
+
+    return (this.viaIR)
+      ? `function ${method}(bytes8 c__${hash}) pure returns (bool){ ${abi} return true; }\n`
+      : `function ${method}(bytes8 c__${hash}) pure returns (bool){ return true; }\n`;
   }
 
   /**
@@ -122,7 +150,11 @@ class Injector {
   _getFalseMethodDefinition(id){
     const hash = web3Utils.keccak256(id).slice(2,10);
     const method = this._getFalseMethodIdentifier(id);
-    return `function ${method}(bytes8 c__${hash}) internal pure returns (bool){ return false; }\n`;
+    const abi = this._getAbiEncodeStatementVar(hash);
+
+    return (this.viaIR)
+      ? `function ${method}(bytes8 c__${hash}) internal pure returns (bool){ ${abi} return false; }\n`
+      : `function ${method}(bytes8 c__${hash}) internal pure returns (bool){ return false; }\n`;
   }
 
   /**
@@ -135,7 +167,11 @@ class Injector {
   _getFileScopedFalseMethodDefinition(id){
     const hash = web3Utils.keccak256(id).slice(2,10);
     const method = this._getFalseMethodIdentifier(id);
-    return `function ${method}(bytes8 c__${hash}) pure returns (bool){ return false; }\n`;
+    const abi = this._getAbiEncodeStatementVar(hash);
+
+    return (this.viaIR)
+      ? `function ${method}(bytes8 c__${hash}) pure returns (bool){ ${abi} return false; }\n`
+      : `function ${method}(bytes8 c__${hash}) pure returns (bool){ return false; }\n`;
   }
 
   _getModifierDefinitions(contractId, instrumentation){
diff --git a/lib/instrumenter.js b/lib/instrumenter.js
index 68bcfe0..4ae909a 100644
--- a/lib/instrumenter.js
+++ b/lib/instrumenter.js
@@ -14,7 +14,7 @@ class Instrumenter {
 
   constructor(config={}){
     this.instrumentationData = {};
-    this.injector = new Injector();
+    this.injector = new Injector(config.viaIR);
     this.modifierWhitelist = config.modifierWhitelist || [];
     this.enabled = {
       statements: (config.measureStatementCoverage === false) ? false : true,
diff --git a/package.json b/package.json
index 299e164..e93460a 100644
--- a/package.json
+++ b/package.json
@@ -12,7 +12,10 @@
   "scripts": {
     "test:unit": "./scripts/unit.sh",
     "test:integration": "./scripts/integration.sh",
-    "test:ci": "./scripts/ci.sh"
+    "test:ci": "./scripts/ci.sh",
+    "test:uint:viaIR": "VIA_IR=true ./scripts/unit.sh",
+    "test:integration:viaIR": "VIA_IR=true ./scripts/integration.sh",
+    "test:ci:viaIR": "VIA_IR=true ./scripts/ci.sh"
   },
   "homepage": "https://github.com/sc-forks/solidity-coverage",
   "repository": {
diff --git a/plugins/hardhat.plugin.js b/plugins/hardhat.plugin.js
index e11a58a..ab8805f 100644
--- a/plugins/hardhat.plugin.js
+++ b/plugins/hardhat.plugin.js
@@ -54,11 +54,14 @@ subtask(TASK_COMPILE_SOLIDITY_GET_COMPILATION_JOB_FOR_FILE).setAction(async (_,
     }
     // Unset useLiteralContent due to solc metadata size restriction
     settings.metadata.useLiteralContent = false;
-    // Override optimizer settings for all compilers
-    settings.optimizer.enabled = false;
 
-    // This is fixes a stack too deep bug in ABIEncoderV2
-    // Experimental because not sure this works as expected across versions....
+    // Beginning with v0.8.7, we let the optimizer run if viaIR is true and
+    // instrument using `abi.encode(bytes8 covHash)`. Otherwise turn the optimizer off.
+    if (!settings.viaIR) settings.optimizer.enabled = false;
+
+    // This sometimes fixed a stack-too-deep bug in ABIEncoderV2 for coverage plugin versions up to 0.8.6
+    // Although issue should be fixed in 0.8.7, am leaving this option in because it may still be necessary
+    // to configure optimizer details in some cases.
     if (configureYulOptimizer) {
       if (optimizerDetails === undefined) {
         settings.optimizer.details = {
diff --git a/plugins/resources/nomiclabs.utils.js b/plugins/resources/nomiclabs.utils.js
index 2966d08..110199b 100644
--- a/plugins/resources/nomiclabs.utils.js
+++ b/plugins/resources/nomiclabs.utils.js
@@ -36,6 +36,10 @@ function normalizeConfig(config, args={}){
     ? sources = path.join(config.paths.sources, args.sources)
     : sources = config.paths.sources;
 
+  if (config.solidity && config.solidity.compilers.length) {
+    config.viaIR = isUsingViaIR(config.solidity);
+  }
+
   config.workingDir = config.paths.root;
   config.contractsDir = sources;
   config.testDir = config.paths.tests;
@@ -55,6 +59,23 @@ function normalizeConfig(config, args={}){
   return config;
 }
 
+function isUsingViaIR(solidity) {
+
+  for (compiler of solidity.compilers) {
+    if (compiler.settings && compiler.settings.viaIR) {
+      return true;
+    }
+  }
+  if (solidity.overrides) {
+    for (key of Object.keys(solidity.overrides)){
+      if (solidity.overrides[key].settings && solidity.overrides[key].settings.viaIR) {
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
 async function setupHardhatNetwork(env, api, ui){
   const hardhatPackage = require('hardhat/package.json');
   const { createProvider } = require("hardhat/internal/core/providers/construction");
diff --git a/plugins/resources/plugin.utils.js b/plugins/resources/plugin.utils.js
index c722a08..f2e9e89 100644
--- a/plugins/resources/plugin.utils.js
+++ b/plugins/resources/plugin.utils.js
@@ -227,7 +227,9 @@ function loadSolcoverJS(config={}){
     coverageConfig = {};
   }
 
-  // Truffle writes to coverage config
+  // viaIR is eval'd in `nomiclab.utils.normalizeConfig`
+  coverageConfig.viaIR = config.viaIR;
+
   coverageConfig.log = log;
   coverageConfig.cwd = config.workingDir;
   coverageConfig.originalContractsDir = config.contractsDir;
diff --git a/scripts/ci.sh b/scripts/ci.sh
index 84e8d30..849d047 100755
--- a/scripts/ci.sh
+++ b/scripts/ci.sh
@@ -1,6 +1,12 @@
 #!/usr/bin/env bash
 
-SILENT=true node --max-old-space-size=4096 \
+# Toggles optimizer on/off
+VIAR_IR=$VIA_IR
+
+# Minimize integration test output
+SILENT=true
+
+node --max-old-space-size=4096 \
   ./node_modules/.bin/nyc \
     --reporter=lcov \
     --exclude '**/sc_temp/**' \
diff --git a/scripts/integration.sh b/scripts/integration.sh
index c9d080a..ee2112d 100755
--- a/scripts/integration.sh
+++ b/scripts/integration.sh
@@ -1,5 +1,8 @@
 #!/usr/bin/env bash
 
+# Toggles optimizer on/off
+VIA_IR=$VIA_IR
+
 node --max-old-space-size=4096 \
   ./node_modules/.bin/nyc \
     --exclude '**/sc_temp/**' \
diff --git a/scripts/unit.sh b/scripts/unit.sh
index e727105..044a566 100755
--- a/scripts/unit.sh
+++ b/scripts/unit.sh
@@ -1,5 +1,8 @@
 #!/usr/bin/env bash
 
+# Toggles optimizer on/off
+VIAR_IR=$VIA_IR
+
 node --max-old-space-size=4096 \
   ./node_modules/.bin/nyc \
     --exclude '**/sc_temp/**' \
diff --git a/scripts/zeppelin.sh b/scripts/zeppelin.sh
index 7335361..96418b7 100755
--- a/scripts/zeppelin.sh
+++ b/scripts/zeppelin.sh
@@ -8,6 +8,7 @@ set -o errexit
 # Get rid of any caches
 sudo rm -rf node_modules
 echo "NVM CURRENT >>>>>" && nvm current
+nvm use 18
 
 # Use PR env variables (for forks) or fallback on local if PR not available
 SED_REGEX="s/git@github.com:/https:\/\/github.com\//"
diff --git a/test/integration/standard.js b/test/integration/standard.js
index fd4275f..d53ff48 100644
--- a/test/integration/standard.js
+++ b/test/integration/standard.js
@@ -348,6 +348,31 @@ describe('Hardhat Plugin: standard use cases', function() {
     verify.lineCoverage(expected);
   })
 
+  it('detects viaIR when specified in config overrides only', async function(){
+    mock.installFullProject('overrides-viaIR');
+    mock.hardhatSetupEnv(this);
+
+    await this.env.run("coverage");
+
+    const expected = [
+      {
+        file: mock.pathToContract(hardhatConfig, 'ContractOverA2.sol'),
+        pct: 33.33
+      },
+      {
+        file: mock.pathToContract(hardhatConfig, 'ContractOverB2.sol'),
+        pct: 100,
+      },
+      {
+        file: mock.pathToContract(hardhatConfig, 'ContractOverC2.sol'),
+        pct: 100,
+      },
+
+    ];
+
+    verify.lineCoverage(expected);
+  })
+
   it('locates .coverage_contracts correctly when dir is subfolder', async function(){
     mock.installFullProject('contract-subfolders');
     mock.hardhatSetupEnv(this);
diff --git a/test/sources/projects/contract-subfolders/hardhat.config.js b/test/sources/projects/contract-subfolders/hardhat.config.js
index 4e58d0c..a974066 100644
--- a/test/sources/projects/contract-subfolders/hardhat.config.js
+++ b/test/sources/projects/contract-subfolders/hardhat.config.js
@@ -8,7 +8,13 @@ module.exports={
     }
   },
   solidity: {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   paths: {
     sources: './contracts/A'
diff --git a/test/sources/projects/hardhat-compile-config/contracts/ContractA1.sol b/test/sources/projects/hardhat-compile-config/contracts/ContractA1.sol
index b6a0b09..ad19d2c 100644
--- a/test/sources/projects/hardhat-compile-config/contracts/ContractA1.sol
+++ b/test/sources/projects/hardhat-compile-config/contracts/ContractA1.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.5.5;
+pragma solidity >=0.8.0 <0.9.0;
 
 
 contract ContractA {
diff --git a/test/sources/projects/hardhat-compile-config/contracts/ContractB1.sol b/test/sources/projects/hardhat-compile-config/contracts/ContractB1.sol
index daa42f7..6d5f53d 100644
--- a/test/sources/projects/hardhat-compile-config/contracts/ContractB1.sol
+++ b/test/sources/projects/hardhat-compile-config/contracts/ContractB1.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.5.0;
+pragma solidity >=0.8.0 <0.9.0;
 
 
 contract ContractB {
diff --git a/test/sources/projects/hardhat-compile-config/contracts/ContractC1.sol b/test/sources/projects/hardhat-compile-config/contracts/ContractC1.sol
index 17ddf97..8c24195 100644
--- a/test/sources/projects/hardhat-compile-config/contracts/ContractC1.sol
+++ b/test/sources/projects/hardhat-compile-config/contracts/ContractC1.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.6.0;
+pragma solidity >=0.8.0 <0.9.0;
 
 
 contract ContractC {
diff --git a/test/sources/projects/hardhat-compile-config/hardhat.config.js b/test/sources/projects/hardhat-compile-config/hardhat.config.js
index 443e085..2eee95d 100644
--- a/test/sources/projects/hardhat-compile-config/hardhat.config.js
+++ b/test/sources/projects/hardhat-compile-config/hardhat.config.js
@@ -5,14 +5,20 @@ module.exports={
   solidity: {
     compilers: [
       {
-        version: "0.5.5"
+        version: "0.8.17",
+        settings: {
+          optimizer: {
+            enabled: true
+          },
+          viaIR: process.env.VIA_IR === "true"
+        }
       },
       {
-        version: "0.5.7"
+        version: "0.8.19"
       },
       // Make sure optimizer gets disabled
       {
-        version: "0.6.7",
+        version: "0.8.12",
         settings: {
           optimizer: {
             enabled: true,
@@ -23,11 +29,13 @@ module.exports={
     ],
     overrides: {
       "contracts/ContractA.sol": {
-        version: "0.5.5",
+        version: "0.8.24",
         settings: {
           optimizer: {
             enabled: true,
-            runs: 200
+            runs: 200,
+            viaIR: process.env.VIA_IR === "true",
+            evmVersion: 'paris'
           }
         }
       }
diff --git a/test/sources/projects/hardhat-gas-reporter/hardhat.config.js b/test/sources/projects/hardhat-gas-reporter/hardhat.config.js
index e42a38a..87417f5 100644
--- a/test/sources/projects/hardhat-gas-reporter/hardhat.config.js
+++ b/test/sources/projects/hardhat-gas-reporter/hardhat.config.js
@@ -4,7 +4,13 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports = {
   solidity: {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/sources/projects/hardhat-mine/hardhat.config.js b/test/sources/projects/hardhat-mine/hardhat.config.js
index 803b099..aac3f87 100644
--- a/test/sources/projects/hardhat-mine/hardhat.config.js
+++ b/test/sources/projects/hardhat-mine/hardhat.config.js
@@ -4,7 +4,13 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports = {
   solidity: {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/sources/projects/hardhat-reset/hardhat.config.js b/test/sources/projects/hardhat-reset/hardhat.config.js
index 7954d6c..00428ef 100644
--- a/test/sources/projects/hardhat-reset/hardhat.config.js
+++ b/test/sources/projects/hardhat-reset/hardhat.config.js
@@ -10,7 +10,13 @@ if (!process.env.ALCHEMY_TOKEN){
 
 module.exports = {
   solidity: {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   networks: {
     hardhat: {
diff --git a/test/sources/projects/import-paths/hardhat.config.js b/test/sources/projects/import-paths/hardhat.config.js
index c417cf8..cfc8f8e 100644
--- a/test/sources/projects/import-paths/hardhat.config.js
+++ b/test/sources/projects/import-paths/hardhat.config.js
@@ -3,7 +3,13 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports = {
   solidity: {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/sources/projects/libraries/hardhat.config.js b/test/sources/projects/libraries/hardhat.config.js
index c417cf8..cfc8f8e 100644
--- a/test/sources/projects/libraries/hardhat.config.js
+++ b/test/sources/projects/libraries/hardhat.config.js
@@ -3,7 +3,13 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports = {
   solidity: {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/sources/projects/matrix/hardhat.config.js b/test/sources/projects/matrix/hardhat.config.js
index 7c8bb98..983e864 100644
--- a/test/sources/projects/matrix/hardhat.config.js
+++ b/test/sources/projects/matrix/hardhat.config.js
@@ -3,7 +3,13 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports={
   solidity: {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/sources/projects/modifiers/contracts/ModifiersA.sol b/test/sources/projects/modifiers/contracts/ModifiersA.sol
index 5e00fb9..9c2497e 100644
--- a/test/sources/projects/modifiers/contracts/ModifiersA.sol
+++ b/test/sources/projects/modifiers/contracts/ModifiersA.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.6.0;
+pragma solidity >=0.8.0 <0.9.0;
 
 import "./ModifiersB.sol";
 
diff --git a/test/sources/projects/modifiers/contracts/ModifiersB.sol b/test/sources/projects/modifiers/contracts/ModifiersB.sol
index 8c60738..3d8b3d9 100644
--- a/test/sources/projects/modifiers/contracts/ModifiersB.sol
+++ b/test/sources/projects/modifiers/contracts/ModifiersB.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.6.0;
+pragma solidity >=0.8.0 <0.9.0;
 
 
 contract ModifiersB {
diff --git a/test/sources/projects/modifiers/contracts/ModifiersC.sol b/test/sources/projects/modifiers/contracts/ModifiersC.sol
index c5302b1..3d4d171 100644
--- a/test/sources/projects/modifiers/contracts/ModifiersC.sol
+++ b/test/sources/projects/modifiers/contracts/ModifiersC.sol
@@ -1,4 +1,4 @@
-pragma solidity ^0.6.0;
+pragma solidity >=0.8.0 <0.9.0;
 
 import "./ModifiersB.sol";
 
diff --git a/test/sources/projects/modifiers/hardhat.config.js b/test/sources/projects/modifiers/hardhat.config.js
index 448b09d..cfc8f8e 100644
--- a/test/sources/projects/modifiers/hardhat.config.js
+++ b/test/sources/projects/modifiers/hardhat.config.js
@@ -3,7 +3,13 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports = {
   solidity: {
-    version: "0.6.7"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/sources/projects/multiple-suites/hardhat.config.js b/test/sources/projects/multiple-suites/hardhat.config.js
index 9b8f17b..0a601f3 100644
--- a/test/sources/projects/multiple-suites/hardhat.config.js
+++ b/test/sources/projects/multiple-suites/hardhat.config.js
@@ -8,7 +8,13 @@ module.exports={
     }
   },
   solidity: {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/sources/projects/no-sources/hardhat.config.js b/test/sources/projects/no-sources/hardhat.config.js
index c417cf8..cfc8f8e 100644
--- a/test/sources/projects/no-sources/hardhat.config.js
+++ b/test/sources/projects/no-sources/hardhat.config.js
@@ -3,7 +3,13 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports = {
   solidity: {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/sources/projects/overrides-viaIR/.solcover.js b/test/sources/projects/overrides-viaIR/.solcover.js
new file mode 100644
index 0000000..71b990c
--- /dev/null
+++ b/test/sources/projects/overrides-viaIR/.solcover.js
@@ -0,0 +1,4 @@
+module.exports = {
+ "silent": false,
+ "istanbulReporter": [ "json-summary", "text"]
+}
diff --git a/test/sources/projects/overrides-viaIR/contracts/ContractOverA2.sol b/test/sources/projects/overrides-viaIR/contracts/ContractOverA2.sol
new file mode 100644
index 0000000..ad19d2c
--- /dev/null
+++ b/test/sources/projects/overrides-viaIR/contracts/ContractOverA2.sol
@@ -0,0 +1,17 @@
+pragma solidity >=0.8.0 <0.9.0;
+
+
+contract ContractA {
+  uint x;
+  constructor() public {
+  }
+
+  function sendFn() public {
+    x = 5;
+  }
+
+  function callFn() public pure returns (uint){
+    uint y = 5;
+    return y;
+  }
+}
diff --git a/test/sources/projects/overrides-viaIR/contracts/ContractOverB2.sol b/test/sources/projects/overrides-viaIR/contracts/ContractOverB2.sol
new file mode 100644
index 0000000..6d5f53d
--- /dev/null
+++ b/test/sources/projects/overrides-viaIR/contracts/ContractOverB2.sol
@@ -0,0 +1,17 @@
+pragma solidity >=0.8.0 <0.9.0;
+
+
+contract ContractB {
+  uint x;
+  constructor() public {
+  }
+
+  function sendFn() public {
+    x = 5;
+  }
+
+  function callFn() public pure returns (uint){
+    uint y = 5;
+    return y;
+  }
+}
diff --git a/test/sources/projects/overrides-viaIR/contracts/ContractOverC2.sol b/test/sources/projects/overrides-viaIR/contracts/ContractOverC2.sol
new file mode 100644
index 0000000..8c24195
--- /dev/null
+++ b/test/sources/projects/overrides-viaIR/contracts/ContractOverC2.sol
@@ -0,0 +1,17 @@
+pragma solidity >=0.8.0 <0.9.0;
+
+
+contract ContractC {
+  uint x;
+  constructor() public {
+  }
+
+  function sendFn() public {
+    x = 5;
+  }
+
+  function callFn() public pure returns (uint){
+    uint y = 5;
+    return y;
+  }
+}
diff --git a/test/sources/projects/overrides-viaIR/hardhat.config.js b/test/sources/projects/overrides-viaIR/hardhat.config.js
new file mode 100644
index 0000000..b9c83a1
--- /dev/null
+++ b/test/sources/projects/overrides-viaIR/hardhat.config.js
@@ -0,0 +1,29 @@
+require("@nomiclabs/hardhat-truffle5");
+require(__dirname + "/../plugins/nomiclabs.plugin");
+
+module.exports={
+  solidity: {
+    compilers: [
+      {
+        version: "0.8.17",
+      },
+      {
+        version: "0.8.19"
+      },
+    ],
+    overrides: {
+      "contracts/ContractA.sol": {
+        version: "0.8.24",
+        settings: {
+          optimizer: {
+            enabled: true,
+            runs: 200,
+            viaIR: process.env.VIA_IR === "true",
+            evmVersion: 'paris'
+          }
+        }
+      }
+    }
+  },
+  logger: process.env.SILENT ? { log: () => {} } : console,
+};
diff --git a/test/sources/projects/overrides-viaIR/test/contract_over_a2.js b/test/sources/projects/overrides-viaIR/test/contract_over_a2.js
new file mode 100644
index 0000000..4182d2b
--- /dev/null
+++ b/test/sources/projects/overrides-viaIR/test/contract_over_a2.js
@@ -0,0 +1,11 @@
+const ContractA = artifacts.require("ContractA");
+
+contract("contracta", function(accounts) {
+  let instance;
+
+  before(async () => instance = await ContractA.new())
+
+  it('sends', async function(){
+    await instance.sendFn();
+  });
+});
diff --git a/test/sources/projects/overrides-viaIR/test/contract_over_b2.js b/test/sources/projects/overrides-viaIR/test/contract_over_b2.js
new file mode 100644
index 0000000..42d8cb8
--- /dev/null
+++ b/test/sources/projects/overrides-viaIR/test/contract_over_b2.js
@@ -0,0 +1,15 @@
+const ContractB = artifacts.require("ContractB");
+
+contract("contractB", function(accounts) {
+  let instance;
+
+  before(async () => instance = await ContractB.new())
+
+  it('sends', async function(){
+    await instance.sendFn();
+  });
+
+  it('calls', async function(){
+    await instance.callFn();
+  })
+});
diff --git a/test/sources/projects/overrides-viaIR/test/contract_over_c2.js b/test/sources/projects/overrides-viaIR/test/contract_over_c2.js
new file mode 100644
index 0000000..9b3d950
--- /dev/null
+++ b/test/sources/projects/overrides-viaIR/test/contract_over_c2.js
@@ -0,0 +1,20 @@
+const ContractC = artifacts.require("ContractC");
+
+contract("contractc", function(accounts) {
+  let instance;
+
+  before(async () => instance = await ContractC.new())
+
+  it('sends', async function(){
+    await instance.sendFn();
+  });
+
+  it('calls', async function(){
+    await instance.callFn();
+  })
+
+  it('sends', async function(){
+    await instance.sendFn();
+  });
+
+});
diff --git a/test/sources/projects/skipping/hardhat.config.js b/test/sources/projects/skipping/hardhat.config.js
index c417cf8..cfc8f8e 100644
--- a/test/sources/projects/skipping/hardhat.config.js
+++ b/test/sources/projects/skipping/hardhat.config.js
@@ -3,7 +3,13 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports = {
   solidity: {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/sources/projects/solc-8/hardhat.config.js b/test/sources/projects/solc-8/hardhat.config.js
index 049df45..fd24249 100644
--- a/test/sources/projects/solc-8/hardhat.config.js
+++ b/test/sources/projects/solc-8/hardhat.config.js
@@ -3,7 +3,13 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports = {
   solidity: {
-    version: "0.8.21"
+    version: "0.8.21",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/sources/projects/task-hooks/hardhat.config.js b/test/sources/projects/task-hooks/hardhat.config.js
index c417cf8..cfc8f8e 100644
--- a/test/sources/projects/task-hooks/hardhat.config.js
+++ b/test/sources/projects/task-hooks/hardhat.config.js
@@ -3,7 +3,13 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports = {
   solidity: {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/sources/projects/ternary-and-logical-or/hardhat.config.js b/test/sources/projects/ternary-and-logical-or/hardhat.config.js
index c417cf8..cfc8f8e 100644
--- a/test/sources/projects/ternary-and-logical-or/hardhat.config.js
+++ b/test/sources/projects/ternary-and-logical-or/hardhat.config.js
@@ -3,7 +3,13 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports = {
   solidity: {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/sources/projects/test-files/hardhat.config.js b/test/sources/projects/test-files/hardhat.config.js
index c417cf8..5be7047 100644
--- a/test/sources/projects/test-files/hardhat.config.js
+++ b/test/sources/projects/test-files/hardhat.config.js
@@ -3,7 +3,13 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports = {
   solidity: {
-    version: "0.8.17"
+    version: "0.8.24",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/sources/projects/tests-folder/hardhat.config.js b/test/sources/projects/tests-folder/hardhat.config.js
index c417cf8..cfc8f8e 100644
--- a/test/sources/projects/tests-folder/hardhat.config.js
+++ b/test/sources/projects/tests-folder/hardhat.config.js
@@ -3,7 +3,13 @@ require(__dirname + "/../plugins/nomiclabs.plugin");
 
 module.exports = {
   solidity: {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   },
   logger: process.env.SILENT ? { log: () => {} } : console,
 };
diff --git a/test/units/statements.js b/test/units/statements.js
index ade1082..678b22d 100644
--- a/test/units/statements.js
+++ b/test/units/statements.js
@@ -51,8 +51,11 @@ describe('generic statements', () => {
     util.report(info.solcOutput.errors);
   });
 
-  // FAILING WITH 0.8.x ... unskip when viaIR work is done
-  it.skip('should instrument without triggering stack-too-deep', () => {
+  it('should instrument without triggering stack-too-deep', () => {
+    // Only compiles if compiler.settings.viaIR = true
+    // Tests run with optimizer turned on/off to validate both instrumentation techniques
+    if (!process.env.VIA_IR) return;
+
     const info = util.instrumentAndCompile('statements/stack-too-deep');
     util.report(info.solcOutput.errors);
   });
diff --git a/test/util/integration.js b/test/util/integration.js
index be672b7..027802f 100644
--- a/test/util/integration.js
+++ b/test/util/integration.js
@@ -114,7 +114,13 @@ function getDefaultHardhatConfig() {
   const config = getDefaultNomicLabsConfig()
   config.defaultNetwork = HARDHAT_NETWORK_NAME;
   config.solidity = {
-    version: "0.8.17"
+    version: "0.8.17",
+    settings: {
+      optimizer: {
+        enabled: true
+      },
+      viaIR: process.env.VIA_IR === "true"
+    }
   }
   return config;
 }
diff --git a/test/util/util.js b/test/util/util.js
index 5bb5c2d..05f44e1 100644
--- a/test/util/util.js
+++ b/test/util/util.js
@@ -61,7 +61,8 @@ function codeToCompilerInput(code) {
     sources: { 'test.sol': { content: code } },
     settings: {
       outputSelection: {'*': { '*': [ '*' ] }},
-      evmVersion: "paris"
+      evmVersion: "paris",
+      viaIR: process.env.VIA_IR === "true"
     }
   });
 }
@@ -89,7 +90,8 @@ function getDiffABIs(sourceName, testFile="test.sol", original="Old", current="N
 // ============================
 // Instrumentation Correctness
 // ============================
-function instrumentAndCompile(sourceName, api={}) {
+function instrumentAndCompile(sourceName, api={ config: {} }) {
+  api.config.viaIR = process.env.VIA_IR === "true";
   const contract = getCode(`${sourceName}.sol`)
   const instrumenter = new Instrumenter(api.config);
   const instrumented = instrumenter.instrument(contract, filePath);