[clang] dbedcfd - [Driver] Add -dumpdir and change -gsplit-dwarf .dwo names for linking
Fangrui Song via cfe-commits
cfe-commits at lists.llvm.org
Tue May 9 14:43:50 PDT 2023
Author: Fangrui Song
Date: 2023-05-09T14:43:46-07:00
New Revision: dbedcfdc2007e235d97b38db7693bd1f5ff443d8
URL: https://github.com/llvm/llvm-project/commit/dbedcfdc2007e235d97b38db7693bd1f5ff443d8
DIFF: https://github.com/llvm/llvm-project/commit/dbedcfdc2007e235d97b38db7693bd1f5ff443d8.diff
LOG: [Driver] Add -dumpdir and change -gsplit-dwarf .dwo names for linking
When the final phase is linking, Clang currently places `.dwo` files in the
current directory (like the `-c` behavior for multiple inputs).
Strangely, -fdebug-compilation-dir=/-ffile-compilation-dir= is considered, which
is untested.
GCC has a more useful behavior that derives auxiliary filenames from the final
output (-o).
```
gcc -c -g -gsplit-dwarf d/a.c d/b.c # a.dwo b.dwo
gcc -g -gsplit-dwarf d/a.c d/b.c -o e/x # e/x-a.dwo e/x-b.dwo
gcc -g -gsplit-dwarf d/a.c d/b.c # a-a.dwo a-b.dwo
```
Port a useful subset of GCC behaviors that are easy to describe to Clang.
* Add a driver and cc1 option -dumpdir
* When the final phase is link, add a default -dumpdir if not specified by the user
* Forward -dumpdir to -cc1 command lines
* tools::SplitDebugName prefers -dumpdir when constructing the .dwo filename
GCC provides -dumpbase. If we use just one of -dumpdir and -dumpbase,
-dumpbase isn't very useful as it appends a dash.
```
gcc -g -gsplit-dwarf -dumpdir e d/a.c # ea.dwo
gcc -g -gsplit-dwarf -dumpdir e/ d/a.c # e/a.dwo
gcc -g -gsplit-dwarf -dumpbase e d/a.c # e-a.dwo
gcc -g -gsplit-dwarf -dumpbase e/ d/a.c # e/-a.dwo
```
If we specify both `-dumpdir` and `-dumpbase`, we can avoid the influence of the
source filename when there is one input file.
```
gcc -g -gsplit-dwarf -dumpdir f/ -dumpbase x d/a.c # f/x.dwo
gcc -g -gsplit-dwarf -dumpdir f/ -dumpbase x d/a.c d/b.c # f/x-a.dwo f/x-b.dwo
```
Given the above examples, I think -dumpbase is not useful.
GCC -save-temps has interesting interaction with -dumpdir as -save-temps
generated files are considered auxiliary files like .dwo files.
For Clang, with this patch, -save-temps and -dumpdir are orthogonal, which is
easier to explain.
```
gcc -g -gsplit-dwarf d/a.c -o e/x -dumpdir f/ -save-temps=obj # e/a.{i,s,o,dwo}
gcc -g -gsplit-dwarf d/a.c -o e/x -save-temps=obj -dumpdir f/ # f/a.{i,s,o,dwo}
clang -g -gsplit-dwarf d/a.c -o e/x -save-temps=obj -dumpdir f/ # e/a.{i,s,o} f/a.dwo
```
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D149193
Added:
Modified:
clang/docs/ReleaseNotes.rst
clang/include/clang/Driver/Options.td
clang/lib/Driver/Driver.cpp
clang/lib/Driver/ToolChains/Clang.cpp
clang/lib/Driver/ToolChains/CommonArgs.cpp
clang/test/Driver/hip-gsplit-dwarf-options.hip
clang/test/Driver/split-debug.c
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 4ec4e4a49de6b..c0820bd01fd5f 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -192,12 +192,20 @@ New Compiler Flags
- The flag ``-std=c++23`` has been added. This behaves the same as the existing
flag ``-std=c++2b``.
+- ``-dumpdir`` has been implemented to specify auxiliary and dump output
+ filenames for features like ``-gsplit-dwarf``.
+
Deprecated Compiler Flags
-------------------------
Modified Compiler Flags
-----------------------
+- ``clang -g -gsplit-dwarf a.c -o obj/x`` (compile and link) now generates the
+ ``.dwo`` file at ``obj/x-a.dwo``, instead of a file in the temporary
+ directory (``/tmp`` on \*NIX systems, if none of the environment variables
+ TMPDIR, TMP, and TEMP are specified).
+
Removed Compiler Flags
-------------------------
- The deprecated flag `-fmodules-ts` is removed. Please use ``-std=c++20``
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 496264b74d460..670003a3da847 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1142,6 +1142,10 @@ def module_dependency_dir : Separate<["-"], "module-dependency-dir">,
def dsym_dir : JoinedOrSeparate<["-"], "dsym-dir">,
Flags<[NoXarchOption, RenderAsInput]>,
HelpText<"Directory to output dSYM's (if any) to">, MetaVarName<"<dir>">;
+// GCC style -dumpdir. We intentionally don't implement the less useful -dumpbase{,-ext}.
+def dumpdir : Separate<["-"], "dumpdir">, Flags<[CC1Option]>,
+ MetaVarName<"<dumppfx>">,
+ HelpText<"Use <dumpfpx> as a prefix to form auxiliary and dump file names">;
def dumpmachine : Flag<["-"], "dumpmachine">;
def dumpspecs : Flag<["-"], "dumpspecs">, Flags<[Unsupported]>;
def dumpversion : Flag<["-"], "dumpversion">;
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index a2deb9b0dd9ad..879f3bf00d1cf 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -3878,6 +3878,21 @@ void Driver::handleArguments(Compilation &C, DerivedArgList &Args,
!Args.getLastArgValue(options::OPT_fuse_ld_EQ)
.equals_insensitive("lld"))
Diag(clang::diag::err_drv_lto_without_lld);
+
+ // If -dumpdir is not specified, give a default prefix derived from the link
+ // output filename. For example, `clang -g -gsplit-dwarf a.c -o x` passes
+ // `-dumpdir x-` to cc1. If -o is unspecified, use
+ // stem(getDefaultImageName()) (usually stem("a.out") = "a").
+ if (!Args.hasArg(options::OPT_dumpdir)) {
+ Arg *Arg = Args.MakeSeparateArg(
+ nullptr, getOpts().getOption(options::OPT_dumpdir),
+ Args.MakeArgString(Args.getLastArgValue(
+ options::OPT_o,
+ llvm::sys::path::stem(getDefaultImageName())) +
+ "-"));
+ Arg->claim();
+ Args.append(Arg);
+ }
}
if (FinalPhase == phases::Preprocess || Args.hasArg(options::OPT__SLASH_Y_)) {
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index c12a6ab88097b..a518cc487cfd5 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -4854,6 +4854,8 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
}
}
+ Args.AddLastArg(CmdArgs, options::OPT_dumpdir);
+
if (const Arg *A = Args.getLastArg(options::OPT_fthinlto_index_EQ)) {
if (!types::isLLVMIR(Input.getType()))
D.Diag(diag::err_drv_arg_requires_bitcode_input) << A->getAsString(Args);
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index cf21d6243b180..a6247b4cbe4ea 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1248,23 +1248,24 @@ const char *tools::SplitDebugName(const JobAction &JA, const ArgList &Args,
if (StringRef(A->getValue()) == "single")
return Args.MakeArgString(Output.getFilename());
- Arg *FinalOutput = Args.getLastArg(options::OPT_o);
- if (FinalOutput && Args.hasArg(options::OPT_c)) {
- SmallString<128> T(FinalOutput->getValue());
- llvm::sys::path::remove_filename(T);
- llvm::sys::path::append(T, llvm::sys::path::stem(FinalOutput->getValue()));
- AddPostfix(T);
- return Args.MakeArgString(T);
+ SmallString<128> T;
+ if (const Arg *A = Args.getLastArg(options::OPT_dumpdir)) {
+ T = A->getValue();
} else {
- // Use the compilation dir.
- Arg *A = Args.getLastArg(options::OPT_ffile_compilation_dir_EQ,
- options::OPT_fdebug_compilation_dir_EQ);
- SmallString<128> T(A ? A->getValue() : "");
- SmallString<128> F(llvm::sys::path::stem(Input.getBaseInput()));
- AddPostfix(F);
- T += F;
- return Args.MakeArgString(T);
+ Arg *FinalOutput = Args.getLastArg(options::OPT_o);
+ if (FinalOutput && Args.hasArg(options::OPT_c)) {
+ T = FinalOutput->getValue();
+ llvm::sys::path::remove_filename(T);
+ llvm::sys::path::append(T,
+ llvm::sys::path::stem(FinalOutput->getValue()));
+ AddPostfix(T);
+ return Args.MakeArgString(T);
+ }
}
+
+ T += llvm::sys::path::stem(Input.getBaseInput());
+ AddPostfix(T);
+ return Args.MakeArgString(T);
}
void tools::SplitDebugInfo(const ToolChain &TC, Compilation &C, const Tool &T,
diff --git a/clang/test/Driver/hip-gsplit-dwarf-options.hip b/clang/test/Driver/hip-gsplit-dwarf-options.hip
index e9f87872da869..cfd5c5020e663 100644
--- a/clang/test/Driver/hip-gsplit-dwarf-options.hip
+++ b/clang/test/Driver/hip-gsplit-dwarf-options.hip
@@ -13,13 +13,17 @@
// RUN: %clang -### --target=x86_64-unknown-linux-gnu \
// RUN: --offload-arch=gfx906:xnack+ %s -nogpulib -nogpuinc \
// RUN: --offload-arch=gfx900 \
-// RUN: -ggdb -gsplit-dwarf 2>&1 | FileCheck %s
+// RUN: -ggdb -gsplit-dwarf 2>&1 | FileCheck %s --check-prefix=LINK
// RUN: %clang -### --target=x86_64-unknown-linux-gnu \
// RUN: -fgpu-rdc --offload-arch=gfx906:xnack+ %s -nogpulib -nogpuinc \
// RUN: --offload-arch=gfx900 \
-// RUN: -ggdb -gsplit-dwarf 2>&1 | FileCheck %s
+// RUN: -ggdb -gsplit-dwarf 2>&1 | FileCheck %s --check-prefix=LINK
// CHECK-DAG: {{".*clang.*".* "-target-cpu" "gfx906".* "-split-dwarf-output" "hip-gsplit-dwarf-options_gfx906:xnack\+.dwo"}}
// CHECK-DAG: {{".*clang.*".* "-target-cpu" "gfx900".* "-split-dwarf-output" "hip-gsplit-dwarf-options_gfx900.dwo"}}
// CHECK-DAG: {{".*clang.*".* "-target-cpu" "x86-64".* "-split-dwarf-output" "hip-gsplit-dwarf-options.dwo"}}
+
+// LINK-DAG: {{".*clang.*".* "-target-cpu" "gfx906".* "-split-dwarf-output" "a-hip-gsplit-dwarf-options_gfx906:xnack\+.dwo"}}
+// LINK-DAG: {{".*clang.*".* "-target-cpu" "gfx900".* "-split-dwarf-output" "a-hip-gsplit-dwarf-options_gfx900.dwo"}}
+// LINK-DAG: {{".*clang.*".* "-target-cpu" "x86-64".* "-split-dwarf-output" "a-hip-gsplit-dwarf-options.dwo"}}
diff --git a/clang/test/Driver/split-debug.c b/clang/test/Driver/split-debug.c
index 94db20b554046..19214f997c669 100644
--- a/clang/test/Driver/split-debug.c
+++ b/clang/test/Driver/split-debug.c
@@ -9,6 +9,7 @@
// INLINE: "-fsplit-dwarf-inlining"
// NOINLINE-NOT: "-fsplit-dwarf-inlining"
+// SPLIT-NOT: "-dumpdir"
// SPLIT: "-debug-info-kind=constructor"
// SPLIT-SAME: "-ggnu-pubnames"
// SPLIT-SAME: "-split-dwarf-file" "split-debug.dwo" "-split-dwarf-output" "split-debug.dwo"
@@ -54,8 +55,29 @@
// SINGLE_WITH_FILENAME: "-split-dwarf-file" "{{.*}}foo.o"
// SINGLE_WITH_FILENAME-NOT: "-split-dwarf-output"
-/// Without -c, clang performs linking as well. The output is unchanged.
-// RUN: %clang -### -target x86_64-unknown-linux-gnu -gsplit-dwarf -g %s -o ignore.d 2>&1 | FileCheck %s --check-prefix=SPLIT
+/// If linking is the final phase, the .dwo filename is derived from -o (if specified) or "a".
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -gsplit-dwarf -g %s -o obj/out 2>&1 | FileCheck %s --check-prefix=SPLIT_LINK
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -gsplit-dwarf -g %s 2>&1 | FileCheck %s --check-prefix=SPLIT_LINK_A
+
+// SPLIT_LINK: "-dumpdir" "obj/out-"
+// SPLIT_LINK: "-debug-info-kind=constructor"
+// SPLIT_LINK-SAME: "-split-dwarf-file" "obj/out-split-debug.dwo" "-split-dwarf-output" "obj/out-split-debug.dwo"
+// SPLIT_LINK_A: "-dumpdir" "a-"
+// SPLIT_LINK_A-SAME: "-split-dwarf-file" "a-split-debug.dwo" "-split-dwarf-output" "a-split-debug.dwo"
+
+/// GCC special cases /dev/null (HOST_BIT_BUCKET) but not other special files like /dev/zero.
+/// We don't apply special rules at all.
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -gsplit-dwarf -g %s -o /dev/null 2>&1 | FileCheck %s --check-prefix=SPLIT_LINK_NULL
+
+// SPLIT_LINK_NULL: "-dumpdir" "/dev/null-"
+// SPLIT_LINK_NULL-SAME: "-split-dwarf-output" "/dev/null-split-debug.dwo"
+
+/// If -dumpdir is specified, use its value to derive the .dwo filename.
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -gsplit-dwarf -g %s -o obj/out -dumpdir pf/x -c 2>&1 | FileCheck %s --check-prefix=DUMPDIR
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -gsplit-dwarf -g %s -o obj/out -dumpdir pf/x 2>&1 | FileCheck %s --check-prefix=DUMPDIR
+
+// DUMPDIR: "-dumpdir" "pf/x"
+// DUMPDIR-SAME: "-split-dwarf-output" "pf/xsplit-debug.dwo"
/// -fsplit-dwarf-inlining
// RUN: %clang -### -c -target x86_64 -gsplit-dwarf=split -g -fsplit-dwarf-inlining %s 2>&1 | FileCheck %s --check-prefixes=INLINE,SPLIT
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