From 6ac8e034f654db00a7eb680f8ee91839ed9c5b5a Mon Sep 17 00:00:00 2001
From: Serge Pavlov <sepavloff@gmail.com>
Date: Tue, 1 Nov 2016 06:53:29 +0000
Subject: Allow resolving response file names relative to including file

If a response file included by construct @file itself includes a response file
and that file is specified by relative file name, current behavior is to resolve
the name relative to the current working directory. The change adds additional
flag to ExpandResponseFiles that may be used to resolve nested response file
names relative to including file. With the new mode a set of related response
files may be kept together and reference each other with short position
independent names.

Differential Revision: https://reviews.llvm.org/D24917

llvm-svn: 285675
---
 llvm/lib/Support/CommandLine.cpp | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

(limited to 'llvm/lib/Support/CommandLine.cpp')

diff --git a/llvm/lib/Support/CommandLine.cpp b/llvm/lib/Support/CommandLine.cpp
index 07114ddcb8f..dccb5d6962f 100644
--- a/llvm/lib/Support/CommandLine.cpp
+++ b/llvm/lib/Support/CommandLine.cpp
@@ -871,10 +871,10 @@ static bool hasUTF8ByteOrderMark(ArrayRef<char> S) {
   return (S.size() >= 3 && S[0] == '\xef' && S[1] == '\xbb' && S[2] == '\xbf');
 }
 
-static bool ExpandResponseFile(const char *FName, StringSaver &Saver,
+static bool ExpandResponseFile(StringRef FName, StringSaver &Saver,
                                TokenizerCallback Tokenizer,
                                SmallVectorImpl<const char *> &NewArgv,
-                               bool MarkEOLs = false) {
+                               bool MarkEOLs, bool RelativeNames) {
   ErrorOr<std::unique_ptr<MemoryBuffer>> MemBufOrErr =
       MemoryBuffer::getFile(FName);
   if (!MemBufOrErr)
@@ -899,6 +899,25 @@ static bool ExpandResponseFile(const char *FName, StringSaver &Saver,
   // Tokenize the contents into NewArgv.
   Tokenizer(Str, Saver, NewArgv, MarkEOLs);
 
+  // If names of nested response files should be resolved relative to including
+  // file, replace the included response file names with their full paths
+  // obtained by required resolution.
+  if (RelativeNames)
+    for (unsigned I = 0; I < NewArgv.size(); ++I)
+      if (NewArgv[I]) {
+        StringRef Arg = NewArgv[I];
+        if (Arg.front() == '@') {
+          StringRef FileName = Arg.drop_front();
+          if (llvm::sys::path::is_relative(FileName)) {
+            SmallString<128> ResponseFile;
+            ResponseFile.append(1, '@');
+            llvm::sys::path::append(
+                ResponseFile, llvm::sys::path::parent_path(FName), FileName);
+            NewArgv[I] = Saver.save(ResponseFile.c_str()).data();
+          }
+        }
+      }
+
   return true;
 }
 
@@ -906,7 +925,7 @@ static bool ExpandResponseFile(const char *FName, StringSaver &Saver,
 /// StringSaver and tokenization strategy.
 bool cl::ExpandResponseFiles(StringSaver &Saver, TokenizerCallback Tokenizer,
                              SmallVectorImpl<const char *> &Argv,
-                             bool MarkEOLs) {
+                             bool MarkEOLs, bool RelativeNames) {
   unsigned RspFiles = 0;
   bool AllExpanded = true;
 
@@ -930,11 +949,9 @@ bool cl::ExpandResponseFiles(StringSaver &Saver, TokenizerCallback Tokenizer,
 
     // Replace this response file argument with the tokenization of its
     // contents.  Nested response files are expanded in subsequent iterations.
-    // FIXME: If a nested response file uses a relative path, is it relative to
-    // the cwd of the process or the response file?
     SmallVector<const char *, 0> ExpandedArgv;
     if (!ExpandResponseFile(Arg + 1, Saver, Tokenizer, ExpandedArgv,
-                            MarkEOLs)) {
+                            MarkEOLs, RelativeNames)) {
       // We couldn't read this file, so we leave it in the argument stream and
       // move on.
       AllExpanded = false;
-- 
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