Allow forwarding -fdebug-compilation-dir to cc1as

The flag -fdebug-compilation-dir is useful to make generated .o files
independent of the path of the build directory, without making the compile
command-line dependent on the path of the build directory, like
-fdebug-prefix-map requires. This change makes it so that the driver can
forward the flag to -cc1as, like it already can for -cc1. We might want to
consider making -fdebug-compilation-dir a driver flag in a follow-up.

(Since -fdebug-compilation-dir defaults to PWD, it's already possible to get
this effect by setting PWD, but explicit compiler flags are better than env
vars, because e.g. ninja tracks command lines and reruns commands that change.)

Somewhat related to PR14625.

Differential Revision: https://reviews.llvm.org/D55377

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@348515 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Driver/ToolChains/Clang.cpp b/lib/Driver/ToolChains/Clang.cpp
index 3ebf44080051de1327dbc73eb43df3fa8785427f..bd04317966f13620da84f916808c4fe2b8d8c6bc 100644 (file)
--- a/lib/Driver/ToolChains/Clang.cpp
+++ b/lib/Driver/ToolChains/Clang.cpp
@@ -2152,6 +2152,9 @@ static void CollectArgsForIntegratedAssembler(Compilation &C,
           }
           CmdArgs.push_back(Value.data());
           TakeNextArg = true;
+      } else if (Value == "-fdebug-compilation-dir") {
+        CmdArgs.push_back("-fdebug-compilation-dir");
+        TakeNextArg = true;
       } else {
         D.Diag(diag::err_drv_unsupported_option_argument)
             << A->getOption().getName() << Value;

diff --git a/test/Driver/integrated-as.s b/test/Driver/integrated-as.s
index 1dcd4f611a3a559d1ad30cd6817fc1319c745864..3ad0860b9020718645233c599e56bdb2de23c5cc 100644 (file)
--- a/test/Driver/integrated-as.s
+++ b/test/Driver/integrated-as.s
@@ -50,3 +50,9 @@
 
 // RUN: %clang -### -target x86_64--- -x assembler -c -fPIC -integrated-as %s 2>&1 | FileCheck --check-prefix=PIC %s
 // PIC: "-mrelocation-model" "pic"
+
+// RUN: %clang -### -target x86_64--- -c -integrated-as %s -Wa,-fdebug-compilation-dir,. 2>&1 | FileCheck --check-prefix=WA_DEBUGDIR %s
+// WA_DEBUGDIR: "-fdebug-compilation-dir" "."
+
+// RUN: %clang -### -target x86_64--- -c -integrated-as %s -Xassembler -fdebug-compilation-dir -Xassembler . 2>&1 | FileCheck --check-prefix=XA_DEBUGDIR %s
+// XA_DEBUGDIR: "-fdebug-compilation-dir" "."