move ViolationHandler to common

common/analysis/BUILD

@@ -9,6 +9,7 @@ package(
         "//verilog/CST:__subpackages__",
         "//verilog/analysis:__subpackages__",
         "//verilog/tools/kythe:__pkg__",
+        "//verilog/tools/lint:__subpackages__",
     ],
 )
 
@@ -84,6 +85,20 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "violation_handler",
+    srcs = ["violation_handler.cc"],
+    hdrs = ["violation_handler.h"],
+    deps = [
+        ":lint_rule_status",
+        "//common/strings:diff",
+        "//common/util:file_util",
+        "//common/util:user_interaction",
+        "@com_google_absl//absl/status",
+        "@com_google_absl//absl/strings",
+    ]
+)
+
 cc_test(
     name = "command_file_lexer_test",
     size = "small",

common/analysis/lint_rule_status.cc

@@ -92,19 +92,6 @@ void LintStatusFormatter::FormatLintRuleStatus(std::ostream* stream,
   }
 }
 
-struct LintViolationWithStatus {
-  const LintViolation* violation;
-  const LintRuleStatus* status;
-
-  LintViolationWithStatus(const LintViolation* v, const LintRuleStatus* s)
-      : violation(v), status(s) {}
-
-  bool operator<(const LintViolationWithStatus& r) const {
-    // compares addresses which correspond to locations within the same string
-    return violation->token.text().data() < r.violation->token.text().data();
-  }
-};
-
 void LintStatusFormatter::FormatLintRuleStatuses(
     std::ostream* stream, const std::vector<LintRuleStatus>& statuses,
     absl::string_view base, absl::string_view path,

common/analysis/lint_rule_status.h

@@ -179,6 +179,19 @@ struct LintRuleStatus {
   std::set<LintViolation> violations;
 };
 
+struct LintViolationWithStatus {
+  const LintViolation* violation;
+  const LintRuleStatus* status;
+
+  LintViolationWithStatus(const LintViolation* v, const LintRuleStatus* s)
+      : violation(v), status(s) {}
+
+  bool operator<(const LintViolationWithStatus& r) const {
+    // compares addresses which correspond to locations within the same string
+    return violation->token.text().data() < r.violation->token.text().data();
+  }
+};
+
 // LintStatusFormatter is a class for printing LintRuleStatus's and
 // LintViolations to an output stream
 // Usage:

common/analysis/violation_handler.cc

@@ -0,0 +1,248 @@
+// Copyright 2017-2021 The Verible Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "common/analysis/violation_handler.h"
+
+#include "absl/status/status.h"
+#include "common/strings/diff.h"
+#include "common/util/file_util.h"
+#include "common/util/user_interaction.h"
+
+namespace verible {
+namespace {
+
+void PrintFix(std::ostream& stream, absl::string_view text,
+              const verible::AutoFix& fix) {
+  std::string after = fix.Apply(text);
+  verible::LineDiffs diff(text, after);
+
+  verible::LineDiffsToUnifiedDiff(stream, diff, 1);
+}
+
+void PrintFixAlternatives(std::ostream& stream, absl::string_view text,
+                          const std::vector<verible::AutoFix>& fixes) {
+  const bool print_alternative_number = fixes.size() > 1;
+  for (size_t i = 0; i < fixes.size(); ++i) {
+    if (print_alternative_number) {
+      stream << verible::term::inverse(absl::StrCat(
+          "[ ", (i + 1), ". Alternative ", fixes[i].Description(), " ]\n"));
+    } else {
+      stream << verible::term::inverse(
+          absl::StrCat("[ ", fixes[i].Description(), " ]\n"));
+    }
+    PrintFix(stream, text, fixes[i]);
+  }
+}
+
+}  // namespace
+
+void ViolationPrinter::HandleViolations(
+    const std::set<LintViolationWithStatus>& violations, absl::string_view base,
+    absl::string_view path) {
+  verible::LintStatusFormatter formatter(base);
+  for (auto violation : violations) {
+    formatter.FormatViolation(stream_, *violation.violation, base, path,
+                              violation.status->url,
+                              violation.status->lint_rule_name);
+    (*stream_) << std::endl;
+  }
+}
+
+void ViolationFixer::CommitFixes(absl::string_view source_content,
+                                 absl::string_view source_path,
+                                 const verible::AutoFix& fix) const {
+  if (fix.Edits().empty()) {
+    return;
+  }
+  std::string fixed_content = fix.Apply(source_content);
+
+  if (patch_stream_) {
+    verible::LineDiffs diff(source_content, fixed_content);
+    verible::LineDiffsToUnifiedDiff(*patch_stream_, diff, 1, source_path);
+  } else {
+    const absl::Status write_status =
+        verible::file::SetContents(source_path, fixed_content);
+    if (!write_status.ok()) {
+      LOG(ERROR) << "Failed to write fixes to file '" << source_path
+                 << "': " << write_status.ToString();
+      return;
+    }
+  }
+}
+
+void ViolationFixer::HandleViolations(
+    const std::set<LintViolationWithStatus>& violations, absl::string_view base,
+    absl::string_view path) {
+  verible::AutoFix fix;
+  verible::LintStatusFormatter formatter(base);
+  for (auto violation : violations) {
+    HandleViolation(*violation.violation, base, path, violation.status->url,
+                    violation.status->lint_rule_name, formatter, &fix);
+  }
+
+  CommitFixes(base, path, fix);
+}
+
+void ViolationFixer::HandleViolation(
+    const verible::LintViolation& violation, absl::string_view base,
+    absl::string_view path, absl::string_view url, absl::string_view rule_name,
+    const verible::LintStatusFormatter& formatter, verible::AutoFix* fix) {
+  std::stringstream violation_message;
+  formatter.FormatViolation(&violation_message, violation, base, path, url,
+                            rule_name);
+  (*message_stream_) << violation_message.str() << std::endl;
+
+  if (violation.autofixes.empty()) {
+    return;
+  }
+
+  static std::string_view previous_fix_conflict =
+      "The fix conflicts with "
+      "previously applied fixes, rejecting.\n";
+
+  Answer answer;
+  for (bool first_round = true; /**/; first_round = false) {
+    if (ultimate_answer_.choice != AnswerChoice::kUnknown) {
+      answer = ultimate_answer_;
+    } else if (auto found = rule_answers_.find(rule_name);
+               found != rule_answers_.end()) {
+      answer = found->second;
+      // If the ApplyAll specifies alternative not available here, use first.
+      if (answer.alternative >= violation.autofixes.size()) {
+        answer.alternative = 0;
+      }
+    } else {
+      if (is_interactive_ && first_round) {  // Show the user what is available.
+        PrintFixAlternatives(*message_stream_, base, violation.autofixes);
+      }
+      answer = answer_chooser_(violation, rule_name);
+    }
+
+    switch (answer.choice) {
+      case AnswerChoice::kApplyAll:
+        ultimate_answer_ = {AnswerChoice::kApply};
+        [[fallthrough]];
+      case AnswerChoice::kApplyAllForRule:
+        rule_answers_[rule_name] = {AnswerChoice::kApply, answer.alternative};
+        [[fallthrough]];
+      case AnswerChoice::kApply:  // Apply fix chosen in the alternatative
+        if (answer.alternative >= violation.autofixes.size())
+          continue;  // ask again.
+        if (!fix->AddEdits(violation.autofixes[answer.alternative].Edits())) {
+          *message_stream_ << previous_fix_conflict;
+        }
+        break;
+      case AnswerChoice::kRejectAll:
+        ultimate_answer_ = {AnswerChoice::kReject};
+        [[fallthrough]];
+      case AnswerChoice::kRejectAllForRule:
+        rule_answers_[rule_name] = {AnswerChoice::kReject};
+        [[fallthrough]];
+      case AnswerChoice::kReject:
+        return;
+
+      case AnswerChoice::kPrintFix:
+        PrintFixAlternatives(*message_stream_, base, violation.autofixes);
+        continue;
+      case AnswerChoice::kPrintAppliedFixes:
+        PrintFix(*message_stream_, base, *fix);
+        continue;
+
+      default:
+        continue;
+    }
+
+    break;
+  }
+}
+
+ViolationFixer::Answer ViolationFixer::InteractiveAnswerChooser(
+    const verible::LintViolation& violation, absl::string_view rule_name) {
+  static absl::string_view fixed_help_message =
+      "n - reject fix\n"
+      "a - apply this and all remaining fixes for violations of this rule\n"
+      "d - reject this and all remaining fixes for violations of this rule\n"
+      "A - apply this and all remaining fixes\n"
+      "D - reject this and all remaining fixes\n"
+      "p - show fix\n"
+      "P - show fixes applied in this file so far\n"
+      "? - print this help and prompt again\n";
+
+  const size_t fix_count = violation.autofixes.size();
+  std::string help_message;
+  std::string alternative_list;  // Show alternatives in the short-menu.
+  if (fix_count > 1) {
+    help_message =
+        absl::StrCat("y - apply first fix\n[1-", fix_count,
+                     "] - apply given alternative\n", fixed_help_message);
+    for (size_t i = 0; i < fix_count; ++i)
+      absl::StrAppend(&alternative_list, (i + 1), ",");
+  } else {
+    help_message = absl::StrCat("y - apply fix\n", fixed_help_message);
+  }
+
+  for (;;) {
+    const char c = verible::ReadCharFromUser(
+        std::cin, std::cerr, verible::IsInteractiveTerminalSession(),
+        verible::term::bold("Autofix is available. Apply? [" +
+                            alternative_list + "y,n,a,d,A,D,p,P,?] "));
+
+    // Single character digit chooses the available alternative.
+    if (c >= '1' && c <= '9' &&
+        c < static_cast<char>('1' + violation.autofixes.size())) {
+      return {AnswerChoice::kApply, static_cast<size_t>(c - '1')};
+    }
+
+    switch (c) {
+      case 'y':
+        return {AnswerChoice::kApply, 0};
+
+        // TODO(hzeller): Should we provide a way to choose 'all for rule'
+        // including an alternative ? Maybe with a two-letter response
+        // such as 1a, 2a, 3a ? Current assumption of interaction is
+        // single character.
+      case 'a':
+        return {AnswerChoice::kApplyAllForRule};
+      case 'A':
+        return {AnswerChoice::kApplyAll};  // No alternatives
+      case 'n':
+        return {AnswerChoice::kReject};
+      case 'd':
+        return {AnswerChoice::kRejectAllForRule};
+      case 'D':
+        return {AnswerChoice::kRejectAll};
+
+      case '\0':
+        // EOF: received when too few "answers" have been piped to stdin.
+        std::cerr << "Received EOF while there are questions left. "
+                  << "Rejecting all remaining fixes." << std::endl;
+        return {AnswerChoice::kRejectAll};
+
+      case 'p':
+        return {AnswerChoice::kPrintFix};
+      case 'P':
+        return {AnswerChoice::kPrintAppliedFixes};
+
+      case '\n':
+        continue;
+
+      case '?':
+      default:
+        std::cerr << help_message << std::endl;
+        continue;
+    }
+  }
+}
+
+}  // namespace verible