cmake: Enable --warn-uninitialized inside string(CONFIGURE) and configure_file

Fixes: #18489

Source/cmCommandArgumentParserHelper.cxx

@@ -92,9 +92,11 @@ const char* cmCommandArgumentParserHelper::ExpandVariable(const char* var)
     return this->AddString(ostr.str());
   }
   const char* value = this->Makefile->GetDefinition(var);
-  if (!value && !this->RemoveEmpty) {
+  if (!value) {
     this->Makefile->MaybeWarnUninitialized(var, this->FileName);
-    return nullptr;
+    if (!this->RemoveEmpty) {
+      return nullptr;
+    }
   }
   if (this->EscapeQuotes && value) {
     return this->AddString(cmSystemTools::EscapeQuotes(value));

Source/cmMakefile.cxx

@@ -2522,9 +2522,9 @@ const std::string& cmMakefile::ExpandVariablesInString(
       // Suppress variable watches to avoid calling hooks twice. Suppress new
       // dereferences since the OLD behavior is still what is actually used.
       this->SuppressSideEffects = true;
-      newError = ExpandVariablesInStringNew(
-        newErrorstr, newResult, escapeQuotes, noEscapes, atOnly, filename,
-        line, removeEmpty, replaceAt);
+      newError = ExpandVariablesInStringNew(newErrorstr, newResult,
+                                            escapeQuotes, noEscapes, atOnly,
+                                            filename, line, replaceAt);
       this->SuppressSideEffects = false;
       CM_FALLTHROUGH;
     }
@@ -2537,9 +2537,9 @@ const std::string& cmMakefile::ExpandVariablesInString(
     case cmPolicies::REQUIRED_ALWAYS:
     // Messaging here would be *very* verbose.
     case cmPolicies::NEW:
-      mtype = ExpandVariablesInStringNew(errorstr, source, escapeQuotes,
-                                         noEscapes, atOnly, filename, line,
-                                         removeEmpty, replaceAt);
+      mtype =
+        ExpandVariablesInStringNew(errorstr, source, escapeQuotes, noEscapes,
+                                   atOnly, filename, line, replaceAt);
       break;
   }
 
@@ -2726,7 +2726,7 @@ bool cmMakefile::IsProjectFile(const char* filename) const
 cmake::MessageType cmMakefile::ExpandVariablesInStringNew(
   std::string& errorstr, std::string& source, bool escapeQuotes,
   bool noEscapes, bool atOnly, const char* filename, long line,
-  bool removeEmpty, bool replaceAt) const
+  bool replaceAt) const
 {
   // This method replaces ${VAR} and @VAR@ where VAR is looked up
   // with GetDefinition(), if not found in the map, nothing is expanded.
@@ -2783,7 +2783,7 @@ cmake::MessageType cmMakefile::ExpandVariablesInStringNew(
             } else {
               varresult = value;
             }
-          } else if (!removeEmpty && !this->SuppressSideEffects) {
+          } else if (!this->SuppressSideEffects) {
             this->MaybeWarnUninitialized(lookup, filename);
           }
           result.replace(var.loc, result.size() - var.loc, varresult);
@@ -2896,7 +2896,12 @@ cmake::MessageType cmMakefile::ExpandVariablesInStringNew(
             if (filename && variable == lineVar) {
               varresult = std::to_string(line);
             } else {
-              varresult = this->GetSafeDefinition(variable);
+              const std::string* def = this->GetDef(variable);
+              if (def) {
+                varresult = *def;
+              } else if (!this->SuppressSideEffects) {
+                this->MaybeWarnUninitialized(variable, filename);
+              }
             }
 
             if (escapeQuotes) {

Source/cmMakefile.h

@@ -990,7 +990,7 @@ private:
   cmake::MessageType ExpandVariablesInStringNew(
     std::string& errorstr, std::string& source, bool escapeQuotes,
     bool noEscapes, bool atOnly, const char* filename, long line,
-    bool removeEmpty, bool replaceAt) const;
+    bool replaceAt) const;
   /**
    * Old version of GetSourceFileWithOutput(const std::string&) kept for
    * backward-compatibility. It implements a linear search and support

Tests/RunCMake/CommandLine/RunCMakeTest.cmake

@@ -350,7 +350,7 @@ set(RunCMake_TEST_OPTIONS --trace-expand --warn-uninitialized)
 run_cmake(trace-expand-warn-uninitialized)
 unset(RunCMake_TEST_OPTIONS)
 
-set(RunCMake_TEST_OPTIONS --warn-uninitialized)
+set(RunCMake_TEST_OPTIONS -Wno-deprecated --warn-uninitialized)
 run_cmake(warn-uninitialized)
 unset(RunCMake_TEST_OPTIONS)
 

Tests/RunCMake/CommandLine/warn-uninitialized-stderr.txt

@@ -1,5 +1,53 @@
-^CMake Warning \(dev\) at warn-uninitialized.cmake:1 \(set\):
-  uninitialized variable 'WARN_FROM_NORMAL_CMAKE_FILE'
+^CMake Warning \(dev\) at warn-uninitialized.cmake:3 \(set\):
+  uninitialized variable 'OLD_WARN_FROM_NORMAL_CMAKE_FILE_INSIDE_BRACES'
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.
+
+CMake Warning \(dev\) at warn-uninitialized.cmake:4 \(set\):
+  uninitialized variable 'OLD_WARN_FROM_NORMAL_CMAKE_FILE_IN_ATS'
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.
+
+CMake Warning \(dev\) at warn-uninitialized.cmake:5 \(string\):
+  uninitialized variable 'OLD_WARN_FROM_STRING_CONFIGURE_INSIDE_BRACES'
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.
+
+CMake Warning \(dev\) at warn-uninitialized.cmake:7 \(configure_file\):
+  uninitialized variable 'OLD_WARN_FROM_CONFIGURE_FILE_INSIDE_AT'
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.
+
+CMake Warning \(dev\) at warn-uninitialized.cmake:8 \(string\):
+  uninitialized variable 'OLD_WARN_FROM_STRING_CONFIGURE_INSIDE_AT'
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.
+
+CMake Warning \(dev\) at warn-uninitialized.cmake:13 \(set\):
+  uninitialized variable 'NEW_WARN_FROM_NORMAL_CMAKE_FILE_INSIDE_BRACES'
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.
+
+CMake Warning \(dev\) at warn-uninitialized.cmake:14 \(string\):
+  uninitialized variable 'NEW_WARN_FROM_STRING_CONFIGURE_INSIDE_BRACES'
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.
+
+CMake Warning \(dev\) at warn-uninitialized.cmake:16 \(configure_file\):
+  uninitialized variable 'NEW_WARN_FROM_CONFIGURE_FILE_INSIDE_AT'
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.
+
+CMake Warning \(dev\) at warn-uninitialized.cmake:17 \(string\):
+  uninitialized variable 'NEW_WARN_FROM_STRING_CONFIGURE_INSIDE_AT'
 Call Stack \(most recent call first\):
   CMakeLists.txt:3 \(include\)
 This warning is for project developers.  Use -Wno-dev to suppress it.$

Tests/RunCMake/CommandLine/warn-uninitialized.cmake

@@ -1 +1,18 @@
-set(FOO "${WARN_FROM_NORMAL_CMAKE_FILE}")
+cmake_policy(PUSH)
+cmake_policy(SET CMP0053 OLD)
+set(FOO "${OLD_WARN_FROM_NORMAL_CMAKE_FILE_INSIDE_BRACES}")
+set(FOO "@OLD_WARN_FROM_NORMAL_CMAKE_FILE_IN_ATS@")
+string(CONFIGURE "\${OLD_WARN_FROM_STRING_CONFIGURE_INSIDE_BRACES}" OUT1)
+file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/file1.in "\@OLD_WARN_FROM_CONFIGURE_FILE_INSIDE_AT\@")
+configure_file(${CMAKE_CURRENT_BINARY_DIR}/file1.in file1.out)
+string(CONFIGURE "\@OLD_WARN_FROM_STRING_CONFIGURE_INSIDE_AT\@" OUT2)
+cmake_policy(POP)
+
+cmake_policy(PUSH)
+cmake_policy(SET CMP0053 NEW)
+set(FOO "${NEW_WARN_FROM_NORMAL_CMAKE_FILE_INSIDE_BRACES}")
+string(CONFIGURE "\${NEW_WARN_FROM_STRING_CONFIGURE_INSIDE_BRACES}" OUT3)
+file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/file2.in "\@NEW_WARN_FROM_CONFIGURE_FILE_INSIDE_AT\@")
+configure_file(${CMAKE_CURRENT_BINARY_DIR}/file2.in file2.out)
+string(CONFIGURE "@NEW_WARN_FROM_STRING_CONFIGURE_INSIDE_AT@" OUT4)
+cmake_policy(POP)