Documentation: Clarify configure_file behavior

1 files changed, 14 insertions, 6 deletions

diff --git a/Source/cmConfigureFileCommand.h b/Source/cmConfigureFileCommand.h
index a5b44d1..0393ecf 100644
--- a/Source/cmConfigureFileCommand.h
+++ b/Source/cmConfigureFileCommand.h
@@ -68,6 +68,9 @@ public:
         "If <output> names an existing directory the input file is placed "
         "in that directory with its original name.  "
         "\n"
+        "If the <input> file is modified the build system will re-run CMake "
+        "to re-configure the file and generate the build system again."
+        "\n"
         "This command replaces any variables in the input file referenced as "
         "${VAR} or @VAR@ with their values as determined by CMake.  If a "
         "variable is not defined, it will be replaced with nothing.  "
@@ -77,12 +80,17 @@ public:
         "The file will be configured with the current values of CMake "
         "variables. If @ONLY is specified, only variables "
         "of the form @VAR@ will be replaced and ${VAR} will be ignored.  "
-        "This is useful for configuring scripts that use ${VAR}. "
-        "Any occurrences of #cmakedefine VAR will be replaced with "
-        "either #define VAR or /* #undef VAR */ depending on "
-        "the setting of VAR in CMake. Any occurrences of #cmakedefine01 VAR "
-        "will be replaced with either #define VAR 1 or #define VAR 0 "
-        "depending on whether VAR evaluates to TRUE or FALSE in CMake.\n"
+        "This is useful for configuring scripts that use ${VAR}."
+        "\n"
+        "Input file lines of the form \"#cmakedefine VAR ...\" "
+        "will be replaced with either \"#define VAR ...\" or "
+        "\"/* #undef VAR */\" depending on whether VAR is set in CMake to "
+        "any value not considered a false constant by the if() command. "
+        "(Content of \"...\", if any, is processed as above.) "
+        "Input file lines of the form \"#cmakedefine01 VAR\" "
+        "will be replaced with either \"#define VAR 1\" or "
+        "\"#define VAR 0\" similarly."
+        "\n"
         "With NEWLINE_STYLE the line ending could be adjusted: \n"
         "    'UNIX' or 'LF' for \\n, 'DOS', 'WIN32' or 'CRLF' for \\r\\n.\n"
         "COPYONLY must not be used with NEWLINE_STYLE.\n";