From: Richard Purdie <richard.purdie@linuxfoundation.org>
Date: Fri, 18 Nov 2022 20:13:50 +0000 (-0700)
Subject: libcpp: Avoid remapping filenames within directives
X-Git-Tag: basepoints/gcc-14~3058
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=11543b27fe16d81ca5483ecb98ec7a5b2426e0c0;p=thirdparty%2Fgcc.git

libcpp: Avoid remapping filenames within directives

Code such as:

 #include __FILE__

can interact poorly with the *-prefix-map options when cross compiling. In
general you're after to remap filenames for use in target context but the
local paths should be used to find include files at compile time. Ingoring
filename remapping for directives allows avoiding such failures.

Fix this to improve such usage and then document this against file-prefix-map
(referenced by the other *-prefix-map options) to make the behaviour clear
and defined.

libcpp/ChangeLog:

	* macro.cc (_cpp_builtin_macro_text): Don't remap filenames within
	directives.

gcc/ChangeLog:

	* doc/invoke.texi: Document prefix-maps don't affect directives.
---

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 31d031cd25cc..0f6a1833ef1e 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -2201,7 +2201,8 @@ any references to them in the result of the compilation as if the
 files resided in directory @file{@var{new}} instead.  Specifying this
 option is equivalent to specifying all the individual
 @option{-f*-prefix-map} options.  This can be used to make reproducible
-builds that are location independent.  See also
+builds that are location independent.  Directories referenced by
+directives are not affected by these options. See also
 @option{-fmacro-prefix-map}, @option{-fdebug-prefix-map} and
 @option{-fprofile-prefix-map}.
 
diff --git a/libcpp/macro.cc b/libcpp/macro.cc
index 8ebf360c03c6..7d5a0d0fd2e7 100644
--- a/libcpp/macro.cc
+++ b/libcpp/macro.cc
@@ -563,7 +563,7 @@ _cpp_builtin_macro_text (cpp_reader *pfile, cpp_hashnode *node,
 	    if (!name)
 	      abort ();
 	  }
-	if (pfile->cb.remap_filename)
+	if (pfile->cb.remap_filename && !pfile->state.in_directive)
 	  name = pfile->cb.remap_filename (name);
 	len = strlen (name);
 	buf = _cpp_unaligned_alloc (pfile, len * 2 + 3);