Add shell shortcut for recompiling existing modules

This extends the shell function c/1 and c/2 so that if the argument is a
module name instead of a file name, it automatically locates the .beam file
and the corresponding source file, and then recompiles the module using the
same compiler options (plus any options passed to c/2). If compilation
fails, the old beam file is preserved. Also adds c(Mod, Opts, Filter),
where the Filter argument allows you to remove old compiler options before
the new options are added.

1 files changed, 20 insertions, 6 deletions

diff --git a/lib/stdlib/doc/src/c.xml b/lib/stdlib/doc/src/c.xml
index 55a77d1bc5..7666699183 100644
--- a/lib/stdlib/doc/src/c.xml
+++ b/lib/stdlib/doc/src/c.xml
@@ -52,13 +52,27 @@
     <func>
       <name name="c" arity="1"/>
       <name name="c" arity="2"/>
-      <fsummary>Compile and load code in a file.</fsummary>
+      <name name="c" arity="3"/>
+      <fsummary>Compile and load a file or module.</fsummary>
       <desc>
-        <p>Compiles and then purges and loads the code for a file.
-          <c><anno>Options</anno></c> defaults to <c>[]</c>. Compilation is
-          equivalent to:</p>
-        <code type="none">
-compile:file(<anno>File</anno>, <anno>Options</anno> ++ [report_errors, report_warnings])</code>
+        <p>Compiles and then purges and loads the code for a module.
+          <c><anno>Module</anno></c> can be either a module name or a source
+          file path, with or without <c>.erl</c> extension.
+          <c><anno>Options</anno></c> defaults to <c>[]</c>.</p>
+        <p>If <c><anno>Module</anno></c> is an atom and is not the path of a
+          source file, then the code path is searched to locate the object
+          file for the module and extract its original compiler options and
+          source path. If the source file is not found in the original
+          location, <seealso
+          marker="filelib#find_source/1"><c>filelib:find_source/1</c></seealso>
+          is used to search for it relative to the directory of the object
+          file.</p>
+        <p>The source file is compiled with the the original
+          options appended to the given <c><anno>Options</anno></c>, the
+          output replacing the old object file if and only if compilation
+          succeeds. A function <c><anno>Filter</anno></c> can be specified
+          for removing elements from from the original compiler options
+          before the new options are added.</p>
         <p>Notice that purging the code means that any processes
           lingering in old code for the module are killed without
           warning. For more information, see <c>code/3</c>.</p>