[llvm] [Sframe] Support cfi_escape directives compatibly with gnu-gas (PR #161927)

[via llvm-commits]

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@@ -0,0 +1,37 @@
+# RUN: llvm-mc --filetype=obj --gsframe -triple x86_64 %s -o %t.o 2>&1 | FileCheck %s
+# RUN: llvm-readelf --sframe %t.o | FileCheck %s --check-prefix=NOFDES
+
+# Tests that .cfi_escape sequences that are unrepresentable in sframe warn
+# and do not produce FDEs.
+
+        .align 1024
+cfi_escape_sp:
+        .cfi_startproc
+        .long 0
+# Setting SP via other registers makes it unrepresentable in sframe
+# DW_CFA_expression,reg 0x7,length 2,DW_OP_breg6,SLEB(-8)
+# CHECK: skipping SFrame FDE; .cfi_escape DW_CFA_expression with SP reg 7
+	.cfi_escape 0x10, 0x7, 0x2, 0x76, 0x78
+        .long 0
+.cfi_endproc
+
+cfi_escape_args_sp:
+	.cfi_startproc
+	.long 0
+# DW_CFA_GNU_args_size is not OK if cfa is SP
+# CHECK: skipping SFrame FDE; .cfi_escape DW_CFA_GNU_args_size with non frame-pointer CFA
+	.cfi_escape 0x2e, 0x20
+	.cfi_endproc
+
+cfi_escape_val_offset:
+	.cfi_startproc
+	.long 0
+	.cfi_def_cfa_offset 16
+# DW_CFA_val_offset,rbp,ULEB scaled offset(16)
+# CHECK: skipping SFrame FDE;  .cfi_escape DW_CFA_val_offset with FP reg 6
+	.cfi_escape 0x14,0x6,0x2
+	.long 0
+	.cfi_endproc
+
+
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weiguozhi wrote:

Add some positive tests.

https://github.com/llvm/llvm-project/pull/161927