[clang] ff8c865 - [Driver] Allow -fbasic-block-sections for AArch64 ELF (#80916)

[via cfe-commits]

Author: Daniel Hoekwater
Date: 2024-02-07T15:23:32-08:00
New Revision: ff8c865838b46d0202963b816fbed50aaf96a7f4

URL: https://github.com/llvm/llvm-project/commit/ff8c865838b46d0202963b816fbed50aaf96a7f4
DIFF: https://github.com/llvm/llvm-project/commit/ff8c865838b46d0202963b816fbed50aaf96a7f4.diff

LOG: [Driver] Allow -fbasic-block-sections for AArch64 ELF  (#80916)

Basic block sections "all" doesn't work on AArch64 since branch
relaxation may create new basic blocks. However, the other basic
block section modes should work out of the box since machine function
splitting already uses the basic block sections pass.

Added: 
    

Modified: 
    clang/lib/Driver/ToolChains/Clang.cpp
    clang/test/Driver/fbasic-block-sections.c

Removed: 
    


################################################################################
diff  --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 13bf2421154372..942ebbc4106078 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -5972,6 +5972,14 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
             << A->getAsString(Args) << A->getValue();
       else
         A->render(Args, CmdArgs);
+    } else if (Triple.isAArch64() && Triple.isOSBinFormatELF()) {
+      // "all" is not supported on AArch64 since branch relaxation creates new
+      // basic blocks for some cross-section branches.
+      if (Val != "labels" && Val != "none" && !Val.starts_with("list="))
+        D.Diag(diag::err_drv_invalid_value)
+            << A->getAsString(Args) << A->getValue();
+      else
+        A->render(Args, CmdArgs);
     } else if (Triple.isNVPTX()) {
       // Do not pass the option to the GPU compilation. We still want it enabled
       // for the host-side compilation, so seeing it here is not an error.

diff  --git a/clang/test/Driver/fbasic-block-sections.c b/clang/test/Driver/fbasic-block-sections.c
index 24262209d1e4d5..e13cc81e910be3 100644
--- a/clang/test/Driver/fbasic-block-sections.c
+++ b/clang/test/Driver/fbasic-block-sections.c
@@ -2,6 +2,10 @@
 // RUN: %clang -### --target=x86_64 -fbasic-block-sections=all %s -S 2>&1 | FileCheck -check-prefix=CHECK-OPT-ALL %s
 // RUN: %clang -### --target=x86_64 -fbasic-block-sections=list=%s %s -S 2>&1 | FileCheck -check-prefix=CHECK-OPT-LIST %s
 // RUN: %clang -### --target=x86_64 -fbasic-block-sections=labels %s -S 2>&1 | FileCheck -check-prefix=CHECK-OPT-LABELS %s
+// RUN: %clang -### --target=aarch64 -fbasic-block-sections=none %s -S 2>&1 | FileCheck -check-prefix=CHECK-OPT-NONE %s
+// RUN: %clang -### --target=aarch64 -fbasic-block-sections=list=%s %s -S 2>&1 | FileCheck -check-prefix=CHECK-OPT-LIST %s
+// RUN: %clang -### --target=aarch64 -fbasic-block-sections=labels %s -S 2>&1 | FileCheck -check-prefix=CHECK-OPT-LABELS %s
+// RUN: not %clang -### --target=aarch64 -fbasic-block-sections=all %s -S 2>&1 | FileCheck -check-prefix=CHECK-INVALID-VALUE %s
 // RUN: not %clang -c --target=arm-unknown-linux -fbasic-block-sections=all %s -S 2>&1 | FileCheck -check-prefix=CHECK-TRIPLE %s
 // RUN: %clang -### --target=arm-unknown-linux -fbasic-block-sections=all -fbasic-block-sections=none %s -S 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHECK-NOOPT %s