rollup merge of #19954: michaelwoerister/rust-gdb

This pull request adds the `rust-gdb` shell script which starts GDB with Rust pretty printers enabled. The PR also makes `rustc` add a special `.debug_gdb_scripts` ELF section on Linux which tells GDB that the produced binary should use the Rust pretty printers.

Note that at the moment this script will only work and be installed on Linux. On Mac OS X there's `rust-lldb` which works much better there. On Windows I had too many problems making this stable. I'll give it another try soonish.

You can use this script just like you would use GDB from the command line. It will use the pretty printers from the Rust "installation" found first in PATH. E.g. if you have `~/rust/x86_64-linux-gnu/stage1/bin` in your path, it will use the pretty printer scripts in `~/rust/x86_64-linux-gnu/stage1/lib/rustlib/etc`.

1 files changed, 9 insertions, 3 deletions

diff --git a/src/rustllvm/RustWrapper.cpp b/src/rustllvm/RustWrapper.cpp
index 9fda05431db..bce73a27699 100644
--- a/src/rustllvm/RustWrapper.cpp
+++ b/src/rustllvm/RustWrapper.cpp
@@ -257,7 +257,7 @@ extern "C" void LLVMDIBuilderFinalize(DIBuilderRef Builder) {
     Builder->finalize();
 }
 
-extern "C" void LLVMDIBuilderCreateCompileUnit(
+extern "C" LLVMValueRef LLVMDIBuilderCreateCompileUnit(
     DIBuilderRef Builder,
     unsigned Lang,
     const char* File,
@@ -267,8 +267,14 @@ extern "C" void LLVMDIBuilderCreateCompileUnit(
     const char* Flags,
     unsigned RuntimeVer,
     const char* SplitName) {
-    Builder->createCompileUnit(Lang, File, Dir, Producer, isOptimized,
-        Flags, RuntimeVer, SplitName);
+    return wrap(Builder->createCompileUnit(Lang,
+                                           File,
+                                           Dir,
+                                           Producer,
+                                           isOptimized,
+                                           Flags,
+                                           RuntimeVer,
+                                           SplitName));
 }
 
 extern "C" LLVMValueRef LLVMDIBuilderCreateFile(