diff options
Diffstat (limited to 'lib/compiler/doc')
| -rw-r--r-- | lib/compiler/doc/src/compile.xml | 74 |
1 files changed, 56 insertions, 18 deletions
diff --git a/lib/compiler/doc/src/compile.xml b/lib/compiler/doc/src/compile.xml index bbd3f1043d..3a70f6277b 100644 --- a/lib/compiler/doc/src/compile.xml +++ b/lib/compiler/doc/src/compile.xml @@ -310,6 +310,23 @@ (there will not even be a warning if there is a mismatch).</p> </item> + <tag><c>{no_auto_import,[F/A, ...]}</c></tag> + <item> + <p>Makes the function <c>F/A</c> no longer beeing + auto-imported from the module <c>erlang</c>, which resolves + BIF name clashes. This option has to be used to resolve name + clashes with BIFs auto-imported before R14A, if one wants to + call the local function with the same name as an + auto-imported BIF without module prefix.</p> + <note> + <p>From R14A and forward, the compiler resolves calls + without module prefix to local or imported functions before + trying auto-imported BIFs. If the BIF is to be + called, use the <c>erlang</c> module prefix in the call, not + <c>{ no_auto_import,[F/A, ...]}</c></p> + </note> + </item> + </taglist> <p>If warnings are turned on (the <c>report_warnings</c> option @@ -338,21 +355,37 @@ <tag><c>nowarn_bif_clash</c></tag> <item> - <p>By default, there will be a compilation error if a - module contains an exported function with the same name - as an auto-imported BIF (such as <c>size/1</c>) AND - there is a call to it without a qualifying module name. - The reason is that the BIF will be called, not - the function in the same module. The recommended way to - eliminate that warning is to use a call with a module - name - either <c>erlang</c> to call the BIF or - <c>?MODULE</c> to call the function in the same module. - The warning can also be turned off using this option, - but that is not recommended.</p> - - <p><em>The use of this option is strongly discouraged, - as code that uses it will probably break in a future - major release (R14 or R15).</em></p> + <p>By default, the compiler will issue an error or warning + when replacing an auto-imported BIF. For local functions + having names clashing with an auto-imported BIF, the error + or warning is issued whenever it is called without using a + module prefix. For explicitly imported functions, the + error or warning will be issued as soon as it's imported + (regardless of calls). If the auto-imported BIF was present + before OTP R14A it will be a fatal error to override it, + otherwise only a warning will be issued.</p> + + <warning> + <p>Beginning with R14A, the compiler no longer calls the + auto-imported BIF if the name clashes with a local or + explicitly imported function and a call without explicit + module name is issued. Instead the local or imported + function is called. Use of <c>nowarn_bif_clash</c> makes a + module calling functions clashing with autoimported BIFs + compile with both the old and new compilers, but with + completely different semantics, why a warning is always + issued if any code uses this option.</p> + + <p>The use of this option has always been strongly discouraged. + From OTP R14A and forward it's also deprecated.</p> + <p>The only module who actually could have some legitimate use for + this option is the module <c>erlang</c>, which in + itself contains auto-imported functions, other modules + should never use it.</p> + <p>To resolve BIF clashes, use explicit module names or the + <c>{no_auto_import,[F/A]}</c> directive.</p> + <p><c>nowarn_bif_clash</c> <em>will</em> be removed in a future release.</p> + </warning> </item> <tag><c>{nowarn_bif_clash, FAs}</c></tag> @@ -360,9 +393,14 @@ <p>Turns off warnings as <c>nowarn_bif_clash</c> but only for the mentioned local functions. <c>FAs</c> is a tuple <c>{Name,Arity}</c> or a list of such tuples.</p> - <p><em>The use of this option is strongly discouraged, - as code that uses it will probably break in a future - major release (R14 or R15).</em></p> + <warning> + <p>The use of this option has always been strongly discouraged. + From OTP R14A and forward it's also deprecated and a warning will be issued + whenever it is used.</p> + <p>To resolve BIF clashes, use explicit module names or the + <c>{no_auto_import,[F/A]}</c> directive instead.</p> + <p><c>nowarn_bif_clash</c> <em>will</em> be removed in a future release.</p> + </warning> </item> <tag><c>warn_export_all</c></tag> |