string() Refactoring: creates an helper for REGEX REPLACE

1 files changed, 14 insertions, 86 deletions

diff --git a/Source/cmStringCommand.cxx b/Source/cmStringCommand.cxx
index 9631912..dabec47 100644
--- a/Source/cmStringCommand.cxx
+++ b/Source/cmStringCommand.cxx
@@ -13,6 +13,7 @@
 #include "cmCryptoHash.h"
 #include "cmGeneratorExpression.h"
 #include "cmMakefile.h"
+#include "cmStringReplaceHelper.h"
 #include "cmSystemTools.h"
 #include "cmTimestamp.h"
 #include "cmUuid.h"
@@ -344,46 +345,17 @@ bool cmStringCommand::RegexReplace(std::vector<std::string> const& args)
   std::string const& regex = args[2];
   std::string const& replace = args[3];
   std::string const& outvar = args[4];
+  cmStringReplaceHelper replaceHelper(regex, replace, this->Makefile);
 
-  // Pull apart the replace expression to find the escaped [0-9] values.
-  std::vector<RegexReplacement> replacement;
-  std::string::size_type l = 0;
-  while (l < replace.length()) {
-    std::string::size_type r = replace.find('\\', l);
-    if (r == std::string::npos) {
-      r = replace.length();
-      replacement.push_back(replace.substr(l, r - l));
-    } else {
-      if (r - l > 0) {
-        replacement.push_back(replace.substr(l, r - l));
-      }
-      if (r == (replace.length() - 1)) {
-        this->SetError("sub-command REGEX, mode REPLACE: "
-                       "replace-expression ends in a backslash.");
-        return false;
-      }
-      if ((replace[r + 1] >= '0') && (replace[r + 1] <= '9')) {
-        replacement.push_back(replace[r + 1] - '0');
-      } else if (replace[r + 1] == 'n') {
-        replacement.push_back("\n");
-      } else if (replace[r + 1] == '\\') {
-        replacement.push_back("\\");
-      } else {
-        std::string e = "sub-command REGEX, mode REPLACE: Unknown escape \"";
-        e += replace.substr(r, 2);
-        e += "\" in replace-expression.";
-        this->SetError(e);
-        return false;
-      }
-      r += 2;
-    }
-    l = r;
+  if (!replaceHelper.IsReplaceExpressionValid()) {
+    this->SetError("sub-command REGEX, mode REPLACE: " +
+                   replaceHelper.GetError() + ".");
+    return false;
   }
 
   this->Makefile->ClearMatches();
-  // Compile the regular expression.
-  cmsys::RegularExpression re;
-  if (!re.compile(regex.c_str())) {
+
+  if (!replaceHelper.IsRegularExpressionValid()) {
     std::string e =
       "sub-command REGEX, mode REPLACE failed to compile regex \"" + regex +
       "\".";
@@ -392,60 +364,16 @@ bool cmStringCommand::RegexReplace(std::vector<std::string> const& args)
   }
 
   // Concatenate all the last arguments together.
-  std::string input = cmJoin(cmMakeRange(args).advance(5), std::string());
-
-  // Scan through the input for all matches.
+  const std::string input =
+    cmJoin(cmMakeRange(args).advance(5), std::string());
   std::string output;
-  std::string::size_type base = 0;
-  while (re.find(input.c_str() + base)) {
-    this->Makefile->ClearMatches();
-    this->Makefile->StoreMatches(re);
-    std::string::size_type l2 = re.start();
-    std::string::size_type r = re.end();
-
-    // Concatenate the part of the input that was not matched.
-    output += input.substr(base, l2);
-
-    // Make sure the match had some text.
-    if (r - l2 == 0) {
-      std::string e = "sub-command REGEX, mode REPLACE regex \"" + regex +
-        "\" matched an empty string.";
-      this->SetError(e);
-      return false;
-    }
 
-    // Concatenate the replacement for the match.
-    for (RegexReplacement const& i : replacement) {
-      if (i.number < 0) {
-        // This is just a plain-text part of the replacement.
-        output += i.value;
-      } else {
-        // Replace with part of the match.
-        int n = i.number;
-        std::string::size_type start = re.start(n);
-        std::string::size_type end = re.end(n);
-        std::string::size_type len = input.length() - base;
-        if ((start != std::string::npos) && (end != std::string::npos) &&
-            (start <= len) && (end <= len)) {
-          output += input.substr(base + start, end - start);
-        } else {
-          std::string e =
-            "sub-command REGEX, mode REPLACE: replace expression \"" +
-            replace + "\" contains an out-of-range escape for regex \"" +
-            regex + "\".";
-          this->SetError(e);
-          return false;
-        }
-      }
-    }
-
-    // Move past the match.
-    base += r;
+  if (!replaceHelper.Replace(input, output)) {
+    this->SetError("sub-command REGEX, mode REPLACE: " +
+                   replaceHelper.GetError() + ".");
+    return false;
   }
 
-  // Concatenate the text after the last match.
-  output += input.substr(base, input.length() - base);
-
   // Store the output in the provided variable.
   this->Makefile->AddDefinition(outvar, output.c_str());
   return true;