From: Jens Remus <jremus@linux.ibm.com>
To: binutils@sourceware.org, Indu Bhagat <indu.bhagat@oracle.com>
Cc: Jens Remus <jremus@linux.ibm.com>,
Andreas Krebbel <krebbel@linux.ibm.com>
Subject: [PATCH 8/9] gas: User readable warnings if SFrame FDE is not generated
Date: Thu, 22 Feb 2024 17:01:22 +0100 [thread overview]
Message-ID: <20240222160123.2554459-9-jremus@linux.ibm.com> (raw)
In-Reply-To: <20240222160123.2554459-1-jremus@linux.ibm.com>
The following generic warning message, which is printed whenever the
assembler skips generation of SFrame FDE, is not very helpful for the
user:
skipping SFrame FDE due to DWARF CFI op <name> (0x<hexval>)
Whenever possible print meaningful warning messages, when the assembler
skips generation of SFrame FDE:
- skipping SFrame FDE due to .cfi_def_cfa specifying CFA base register
other than SP or FP (<regno> instead of <SP-regno> or <FP-regno>)
- skipping SFrame FDE due to .cfi_def_cfa_register specifying CFA base
register other than SP or FP (<regno> instead of <SP-regno> or
<FP-regno>)
- skipping SFrame FDE due to .cfi_def_cfa_offset without CFA base
register in effect
- skipping SFrame FDE due to .cfi_def_cfa_offset while CFA base register
other than SP or FP in effect (<regno> instead of <SP-regno> or
<FP-regno>)
- skipping SFrame FDE due to .cfi_val_offset specifying {FP|RA} register
(<regno>)
- skipping SFrame FDE due to .cfi_remember_state without SFrame FRE
state
- skipping SFrame FDE due to .cfi_register specifying {SP|FP|RA}
register (<regno>)
- skipping SFrame FDE due to non-default DWARF return column (<regno>
instead of <DWARF-def-ret-col-regno>)
gas/
* gen-sframe.h (SFRAME_FRE_BASE_REG_INVAL): New macro for
invalid SFrame FRE CFA base register value of -1.
* gen-sframe.c: User readable warnings if SFrame FDE is not
generated.
Reviewed-by: Andreas Krebbel <krebbel@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
gas/gen-sframe.c | 96 ++++++++++++++-----
gas/gen-sframe.h | 2 +
gas/testsuite/gas/cfi-sframe/common-empty-1.d | 2 +-
gas/testsuite/gas/cfi-sframe/common-empty-2.d | 2 +-
gas/testsuite/gas/cfi-sframe/common-empty-3.d | 2 +-
5 files changed, 79 insertions(+), 25 deletions(-)
diff --git a/gas/gen-sframe.c b/gas/gen-sframe.c
index 28b49a2a8425..339f4412ca05 100644
--- a/gas/gen-sframe.c
+++ b/gas/gen-sframe.c
@@ -867,7 +867,7 @@ sframe_row_entry_new (void)
struct sframe_row_entry *fre = XCNEW (struct sframe_row_entry);
/* Reset cfa_base_reg to -1. A value of 0 will imply some valid register
for the supported arches. */
- fre->cfa_base_reg = -1;
+ fre->cfa_base_reg = SFRAME_FRE_BASE_REG_INVAL;
fre->merge_candidate = true;
/* Reset the mangled RA status bit to zero by default. We will initialize it in
sframe_row_entry_initialize () with the sticky bit if set. */
@@ -922,6 +922,24 @@ sframe_row_entry_initialize (struct sframe_row_entry *cur_fre,
cur_fre->mangled_ra_p = prev_fre->mangled_ra_p;
}
+/* Return SFrame register name for SP, FP, and RA, or NULL if other. */
+
+static const char *
+sframe_register_name (unsigned int reg)
+{
+ if (reg == SFRAME_CFA_SP_REG)
+ return "SP";
+ else if (reg == SFRAME_CFA_FP_REG)
+ return "FP";
+#ifdef SFRAME_FRE_RA_TRACKING
+ else if (sframe_ra_tracking_p ()
+ && (reg == SFRAME_CFA_RA_REG))
+ return "RA";
+#endif
+ else
+ return NULL;
+}
+
/* Translate DW_CFA_advance_loc into SFrame context.
Return SFRAME_XLATE_OK if success. */
@@ -990,7 +1008,12 @@ sframe_xlate_do_def_cfa (struct sframe_xlate_ctx *xlate_ctx,
SFrame stack trace info for the function. */
if (cfi_insn->u.r != SFRAME_CFA_SP_REG
&& cfi_insn->u.r != SFRAME_CFA_FP_REG)
- return SFRAME_XLATE_ERR_NOTREPRESENTED; /* Not represented. */
+ {
+ as_warn (_("skipping SFrame FDE due to .cfi_def_cfa specifying CFA base "
+ "register other than SP or FP (%u instead of %u or %u)"),
+ cfi_insn->u.r, SFRAME_CFA_SP_REG, SFRAME_CFA_FP_REG);
+ return SFRAME_XLATE_ERR_NOTREPRESENTED; /* Not represented. */
+ }
sframe_fre_set_cfa_base_reg (cur_fre, cfi_insn->u.ri.reg);
sframe_fre_set_cfa_offset (cur_fre, cfi_insn->u.ri.offset);
cur_fre->merge_candidate = false;
@@ -1015,7 +1038,12 @@ sframe_xlate_do_def_cfa_register (struct sframe_xlate_ctx *xlate_ctx,
skip creating SFrame stack trace info for the function. */
if (cfi_insn->u.r != SFRAME_CFA_SP_REG
&& cfi_insn->u.r != SFRAME_CFA_FP_REG)
- return SFRAME_XLATE_ERR_NOTREPRESENTED; /* Not represented. */
+ {
+ as_warn (_("skipping SFrame FDE due to .cfi_def_cfa_register specifying "
+ "CFA base register other than SP or FP (%u instead of %u or %u)"),
+ cfi_insn->u.r, SFRAME_CFA_SP_REG, SFRAME_CFA_FP_REG);
+ return SFRAME_XLATE_ERR_NOTREPRESENTED; /* Not represented. */
+ }
sframe_fre_set_cfa_base_reg (cur_fre, cfi_insn->u.ri.reg);
sframe_fre_set_cfa_offset (cur_fre, last_fre->cfa_offset);
cur_fre->merge_candidate = false;
@@ -1046,7 +1074,16 @@ sframe_xlate_do_def_cfa_offset (struct sframe_xlate_ctx *xlate_ctx,
cur_fre->merge_candidate = false;
}
else
- return SFRAME_XLATE_ERR_NOTREPRESENTED;
+ {
+ if (cur_fre->cfa_base_reg == SFRAME_FRE_BASE_REG_INVAL)
+ as_warn (_("skipping SFrame FDE due to .cfi_def_cfa_offset without CFA "
+ "base register in effect"));
+ else
+ as_warn (_("skipping SFrame FDE due to .cfi_def_cfa_offset while CFA "
+ "base register other than SP or FP in effect (%u instead of %u or %u)"),
+ cur_fre->cfa_base_reg, SFRAME_CFA_SP_REG, SFRAME_CFA_FP_REG);
+ return SFRAME_XLATE_ERR_NOTREPRESENTED;
+ }
return SFRAME_XLATE_OK;
}
@@ -1097,11 +1134,19 @@ sframe_xlate_do_val_offset (struct sframe_xlate_ctx *xlate_ctx ATTRIBUTE_UNUSED,
instruction can be safely skipped without sacrificing the asynchronicity of
stack trace information. */
if (cfi_insn->u.r == SFRAME_CFA_FP_REG)
- return SFRAME_XLATE_ERR_NOTREPRESENTED; /* Not represented. */
+ {
+ as_warn (_("skipping SFrame FDE due to .cfi_val_offset specifying FP register (%u)"),
+ SFRAME_CFA_FP_REG);
+ return SFRAME_XLATE_ERR_NOTREPRESENTED; /* Not represented. */
+ }
#ifdef SFRAME_FRE_RA_TRACKING
else if (sframe_ra_tracking_p ()
&& cfi_insn->u.r == SFRAME_CFA_RA_REG)
- return SFRAME_XLATE_ERR_NOTREPRESENTED; /* Not represented. */
+ {
+ as_warn (_("skipping SFrame FDE due to .cfi_val_offset specifying RA register (%u)"),
+ SFRAME_CFA_RA_REG);
+ return SFRAME_XLATE_ERR_NOTREPRESENTED; /* Not represented. */
+ }
#endif
/* Safe to skip. */
@@ -1120,7 +1165,10 @@ sframe_xlate_do_remember_state (struct sframe_xlate_ctx *xlate_ctx)
early with non-zero error code, this will cause no SFrame stack trace
info for the function involved. */
if (!last_fre)
- return SFRAME_XLATE_ERR_INVAL;
+ {
+ as_warn (_("skipping SFrame FDE due to .cfi_remember_state without SFrame FRE state"));
+ return SFRAME_XLATE_ERR_INVAL;
+ }
if (!xlate_ctx->remember_fre)
xlate_ctx->remember_fre = sframe_row_entry_new ();
@@ -1307,7 +1355,12 @@ sframe_do_cfi_insn (struct sframe_xlate_ctx *xlate_ctx,
|| cfi_insn->u.rr.reg1 == SFRAME_CFA_RA_REG
#endif
|| cfi_insn->u.rr.reg1 == SFRAME_CFA_FP_REG)
- err = SFRAME_XLATE_ERR_NOTREPRESENTED;
+ {
+ as_warn (_("skipping SFrame FDE due to .cfi_register specifying %s register (%u)"),
+ sframe_register_name (cfi_insn->u.rr.reg1),
+ cfi_insn->u.rr.reg1);
+ err = SFRAME_XLATE_ERR_NOTREPRESENTED;
+ }
break;
case DW_CFA_undefined:
case DW_CFA_same_value:
@@ -1315,21 +1368,19 @@ sframe_do_cfi_insn (struct sframe_xlate_ctx *xlate_ctx,
default:
/* Following skipped operations do, however, impact the asynchronicity:
- CFI_escape. */
- err = SFRAME_XLATE_ERR_NOTREPRESENTED;
- }
-
- /* An error here will cause no SFrame FDE later. Warn the user because this
- will affect the overall coverage and hence, asynchronicity. */
- if (err)
- {
- const char *cfi_name = sframe_get_cfi_name (op);
-
- if (!cfi_name)
- cfi_name = _("(unknown)");
- as_warn (_("skipping SFrame FDE due to DWARF CFI op %s (%#x)"),
- cfi_name, op);
+ {
+ const char *cfi_name = sframe_get_cfi_name (op);
+
+ if (!cfi_name)
+ cfi_name = _("(unknown)");
+ as_warn (_("skipping SFrame FDE due to DWARF CFI op %s (%#x)"),
+ cfi_name, op);
+ err = SFRAME_XLATE_ERR_NOTREPRESENTED;
+ }
}
+ /* Any error will cause no SFrame FDE later. The user has already been
+ warned. */
return err;
}
@@ -1346,7 +1397,8 @@ sframe_do_fde (struct sframe_xlate_ctx *xlate_ctx,
/* If the return column is not RIP, SFrame format cannot represent it. */
if (xlate_ctx->dw_fde->return_column != DWARF2_DEFAULT_RETURN_COLUMN)
{
- as_warn (_("skipping SFrame FDE due to non-default DWARF return column"));
+ as_warn (_("skipping SFrame FDE due to non-default DWARF return column (%u instead of %u)"),
+ xlate_ctx->dw_fde->return_column, DWARF2_DEFAULT_RETURN_COLUMN);
return SFRAME_XLATE_ERR_NOTREPRESENTED;
}
diff --git a/gas/gen-sframe.h b/gas/gen-sframe.h
index fbe2fd5d9368..8ed46dbb087b 100644
--- a/gas/gen-sframe.h
+++ b/gas/gen-sframe.h
@@ -24,6 +24,8 @@
#define SFRAME_FRE_ELEM_LOC_REG 0
#define SFRAME_FRE_ELEM_LOC_STACK 1
+#define SFRAME_FRE_BASE_REG_INVAL ((unsigned int)-1)
+
/* SFrame Frame Row Entry (FRE).
A frame row entry is a slice of the frame and can be valid for a set of
diff --git a/gas/testsuite/gas/cfi-sframe/common-empty-1.d b/gas/testsuite/gas/cfi-sframe/common-empty-1.d
index d7756302b559..08731b069229 100644
--- a/gas/testsuite/gas/cfi-sframe/common-empty-1.d
+++ b/gas/testsuite/gas/cfi-sframe/common-empty-1.d
@@ -1,5 +1,5 @@
#as: --gsframe
-#warning: skipping SFrame FDE due to DWARF CFI op DW_CFA_remember_state \(0xa\)
+#warning: skipping SFrame FDE due to \.cfi_remember_state without SFrame FRE state
#objdump: --sframe=.sframe
#name: Uninteresting cfi directives generate an empty SFrame section
#...
diff --git a/gas/testsuite/gas/cfi-sframe/common-empty-2.d b/gas/testsuite/gas/cfi-sframe/common-empty-2.d
index 20282c7854e8..e759cddfcc20 100644
--- a/gas/testsuite/gas/cfi-sframe/common-empty-2.d
+++ b/gas/testsuite/gas/cfi-sframe/common-empty-2.d
@@ -1,5 +1,5 @@
#as: --gsframe
-#warning: skipping SFrame FDE due to DWARF CFI op DW_CFA_def_cfa_offset \(0xe\)
+#warning: skipping SFrame FDE due to \.cfi_def_cfa_offset without CFA base register in effect
#objdump: --sframe=.sframe
#name: SFrame supports only FP/SP based CFA
#...
diff --git a/gas/testsuite/gas/cfi-sframe/common-empty-3.d b/gas/testsuite/gas/cfi-sframe/common-empty-3.d
index d17521dd88ea..9a46b016a9ba 100644
--- a/gas/testsuite/gas/cfi-sframe/common-empty-3.d
+++ b/gas/testsuite/gas/cfi-sframe/common-empty-3.d
@@ -1,5 +1,5 @@
#as: --gsframe
-#warning: skipping SFrame FDE due to non-default DWARF return column
+#warning: skipping SFrame FDE due to non-default DWARF return column \(0 instead of \d+\)
#objdump: --sframe=.sframe
#name: SFrame supports only default return column
#...
--
2.40.1
next prev parent reply other threads:[~2024-02-22 16:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-22 16:01 [RFC PATCH 0/9] s390: Initial support to generate SFrame info from CFI directives in assembler Jens Remus
2024-02-22 16:01 ` [PATCH 1/9] x86: Remove unused SFrame CFI RA register variable Jens Remus
2024-02-22 16:01 ` [PATCH 2/9] aarch64: Align SFrame terminology in comments to specs and x86 Jens Remus
2024-02-22 16:01 ` [PATCH 3/9] sframe: Enhance comments for SFRAME_CFA_*_REG macros Jens Remus
2024-02-22 16:01 ` [PATCH 4/9] readelf/objdump: Dump SFrame CFA fixed FP and RA offsets Jens Remus
2024-02-22 16:01 ` [PATCH 5/9] gas: Print DWARF call frame insn name in SFrame warning message Jens Remus
2024-02-22 16:01 ` [PATCH 6/9] gas: Skip SFrame FDE if CFI specifies non-FP/SP base register Jens Remus
2024-02-22 16:01 ` [PATCH 7/9] gas: Warn if SFrame FDE is skipped due to non-default return column Jens Remus
2024-02-22 16:01 ` Jens Remus [this message]
2024-02-22 16:01 ` [RFC PATCH 9/9] s390: Initial support to generate .sframe from CFI directives in assembler Jens Remus
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