Extract format_string function.

Extract format_string function and add a test.

Test: run linker-unit-tests
Change-Id: I794a29aaf62e184438ce1a9224b88aa0586c17b5

1 files changed, 24 insertions, 0 deletions

diff --git a/linker/linker_utils.cpp b/linker/linker_utils.cpp
index 6df5f6d96..5bf88e764 100644
--- a/linker/linker_utils.cpp
+++ b/linker/linker_utils.cpp
@@ -36,6 +36,30 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
+void format_string(std::string* str, const std::vector<std::pair<std::string, std::string>>& params) {
+  size_t pos = 0;
+  while (pos < str->size()) {
+    pos = str->find("$", pos);
+    if (pos == std::string::npos) break;
+    for (const auto& param : params) {
+      const std::string& token = param.first;
+      const std::string& replacement = param.second;
+      if (str->substr(pos + 1, token.size()) == token) {
+        str->replace(pos, token.size() + 1, replacement);
+        // -1 to compensate for the ++pos below.
+        pos += replacement.size() - 1;
+        break;
+      } else if (str->substr(pos + 1, token.size() + 2) == "{" + token + "}") {
+        str->replace(pos, token.size() + 3, replacement);
+        pos += replacement.size() - 1;
+        break;
+      }
+    }
+    // Skip $ in case it did not match any of the known substitutions.
+    ++pos;
+  }
+}
+
 std::string dirname(const char* path) {
   const char* last_slash = strrchr(path, '/');