This is the mail archive of the
gdb-patches@sourceware.org
mailing list for the GDB project.
[PATCH] target_read_memory&co: no longer return target_xfer_status
- From: Pedro Alves <palves at redhat dot com>
- To: gdb-patches at sourceware dot org
- Cc: Simon Marchi <simon dot marchi at polymtl dot ca>
- Date: Tue, 27 Oct 2015 14:44:36 +0000
- Subject: [PATCH] target_read_memory&co: no longer return target_xfer_status
- Authentication-results: sourceware.org; auth=none
Years ago, these functions used to return errno/EIO. Later, through a
series of changes that intended to remove native/remote differences,
they ended up returning a target_xfer_status in disguise.
Unlike target_xfer_partial&co, the point of target_read_memory&co is
to either fully succeed or fail. On error, they always return
TARGET_XFER_E_IO. So there's no real point in casting the return of
target_read_memory to a target_xfer_status to pass it to memory_error.
Instead, it results in clearer code to simply decouple
target_read_memory&co's return from target_xfer_status.
This fixes build errors like this in C++ mode:
../../src/gdb/corefile.c: In function âvoid read_stack(CORE_ADDR, gdb_byte*, ssize_t)â:
../../src/gdb/corefile.c:276:34: error: invalid conversion from âintâ to âtarget_xfer_statusâ [-fpermissive]
memory_error (status, memaddr);
^
../../src/gdb/corefile.c:216:1: error: initializing argument 1 of âvoid memory_error(target_xfer_status, CORE_ADDR)â [-fpermissive]
gdb/ChangeLog:
2015-10-27 Pedro Alves <palves@redhat.com>
* alpha-tdep.c (alpha_read_insn): Always pass TARGET_XFER_E_IO to
memory_error. Rename local 'status' to 'res'.
* c-lang.c (c_get_string): Always pass TARGET_XFER_E_IO to
memory_error.
* corefile.c (read_stack, read_code, write_memory): Always pass
TARGET_XFER_E_IO to memory_error.
* disasm.c (dis_asm_memory_error): Always pass TARGET_XFER_E_IO to
memory_error. Rename parameter 'status' to 'err'.
(dump_insns): Rename local 'status' to 'err'.
* mips-tdep.c (mips_fetch_instruction): Rename parameter 'statusp'
to 'errp'. Rename local 'status' to 'err'. Always pass
TARGET_XFER_E_IO to memory_error.
(mips_breakpoint_from_pc): Rename local 'status' to 'err'.
* target.c (target_read_memory, target_read_raw_memory)
(target_read_stack, target_read_code, target_write_memory)
(target_write_raw_memory): Return -1 on error instead of
TARGET_XFER_E_IO.
* valprint.c (val_print_string): Rename local 'errcode' to 'err'.
Always pass TARGET_XFER_E_IO to memory_error. Update comment.
---
gdb/alpha-tdep.c | 8 ++++----
gdb/c-lang.c | 4 ++--
gdb/corefile.c | 6 +++---
gdb/disasm.c | 12 ++++++------
gdb/mips-tdep.c | 25 +++++++++++++------------
gdb/target.c | 30 +++++++++++++++---------------
gdb/valprint.c | 14 +++++++-------
7 files changed, 50 insertions(+), 49 deletions(-)
diff --git a/gdb/alpha-tdep.c b/gdb/alpha-tdep.c
index 0696b6e..ca0e109 100644
--- a/gdb/alpha-tdep.c
+++ b/gdb/alpha-tdep.c
@@ -682,11 +682,11 @@ alpha_read_insn (struct gdbarch *gdbarch, CORE_ADDR pc)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
gdb_byte buf[ALPHA_INSN_SIZE];
- int status;
+ int res;
- status = target_read_memory (pc, buf, sizeof (buf));
- if (status)
- memory_error (status, pc);
+ res = target_read_memory (pc, buf, sizeof (buf));
+ if (res != 0)
+ memory_error (TARGET_XFER_E_IO, pc);
return extract_unsigned_integer (buf, sizeof (buf), byte_order);
}
diff --git a/gdb/c-lang.c b/gdb/c-lang.c
index 6731b43..384783c 100644
--- a/gdb/c-lang.c
+++ b/gdb/c-lang.c
@@ -327,10 +327,10 @@ c_get_string (struct value *value, gdb_byte **buffer,
err = read_string (addr, *length, width, fetchlimit,
byte_order, buffer, length);
- if (err)
+ if (err != 0)
{
xfree (*buffer);
- memory_error (err, addr);
+ memory_error (TARGET_XFER_E_IO, addr);
}
}
diff --git a/gdb/corefile.c b/gdb/corefile.c
index 31301cf..596da33 100644
--- a/gdb/corefile.c
+++ b/gdb/corefile.c
@@ -273,7 +273,7 @@ read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
status = target_read_stack (memaddr, myaddr, len);
if (status != 0)
- memory_error (status, memaddr);
+ memory_error (TARGET_XFER_E_IO, memaddr);
}
/* Same as target_read_code, but report an error if can't read. */
@@ -285,7 +285,7 @@ read_code (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
status = target_read_code (memaddr, myaddr, len);
if (status != 0)
- memory_error (status, memaddr);
+ memory_error (TARGET_XFER_E_IO, memaddr);
}
/* Read memory at MEMADDR of length LEN and put the contents in
@@ -392,7 +392,7 @@ write_memory (CORE_ADDR memaddr,
status = target_write_memory (memaddr, myaddr, len);
if (status != 0)
- memory_error (status, memaddr);
+ memory_error (TARGET_XFER_E_IO, memaddr);
}
/* Same as write_memory, but notify 'memory_changed' observers. */
diff --git a/gdb/disasm.c b/gdb/disasm.c
index 6e3d6c1..c17574e 100644
--- a/gdb/disasm.c
+++ b/gdb/disasm.c
@@ -129,10 +129,10 @@ dis_asm_read_memory (bfd_vma memaddr, gdb_byte *myaddr, unsigned int len,
/* Like memory_error with slightly different parameters. */
static void
-dis_asm_memory_error (int status, bfd_vma memaddr,
+dis_asm_memory_error (int err, bfd_vma memaddr,
struct disassemble_info *info)
{
- memory_error (status, memaddr);
+ memory_error (TARGET_XFER_E_IO, memaddr);
}
/* Like print_address with slightly different parameters. */
@@ -230,7 +230,7 @@ dump_insns (struct gdbarch *gdbarch, struct ui_out *uiout,
{
CORE_ADDR old_pc = pc;
bfd_byte data;
- int status;
+ int err;
const char *spacer = "";
/* Build the opcodes using a temporary stream so we can
@@ -242,9 +242,9 @@ dump_insns (struct gdbarch *gdbarch, struct ui_out *uiout,
pc += gdbarch_print_insn (gdbarch, pc, di);
for (;old_pc < pc; old_pc++)
{
- status = (*di->read_memory_func) (old_pc, &data, 1, di);
- if (status != 0)
- (*di->memory_error_func) (status, old_pc, di);
+ err = (*di->read_memory_func) (old_pc, &data, 1, di);
+ if (err != 0)
+ (*di->memory_error_func) (err, old_pc, di);
fprintf_filtered (opcode_stream, "%s%02x",
spacer, (unsigned) data);
spacer = " ";
diff --git a/gdb/mips-tdep.c b/gdb/mips-tdep.c
index 7cea832..6b5a1bd 100644
--- a/gdb/mips-tdep.c
+++ b/gdb/mips-tdep.c
@@ -1429,12 +1429,12 @@ mips_write_pc (struct regcache *regcache, CORE_ADDR pc)
static ULONGEST
mips_fetch_instruction (struct gdbarch *gdbarch,
- enum mips_isa isa, CORE_ADDR addr, int *statusp)
+ enum mips_isa isa, CORE_ADDR addr, int *errp)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
gdb_byte buf[MIPS_INSN32_SIZE];
int instlen;
- int status;
+ int err;
switch (isa)
{
@@ -1450,13 +1450,13 @@ mips_fetch_instruction (struct gdbarch *gdbarch,
internal_error (__FILE__, __LINE__, _("invalid ISA"));
break;
}
- status = target_read_memory (addr, buf, instlen);
- if (statusp != NULL)
- *statusp = status;
- if (status)
+ err = target_read_memory (addr, buf, instlen);
+ if (errp != NULL)
+ *errp = err;
+ if (err != 0)
{
- if (statusp == NULL)
- memory_error (status, addr);
+ if (errp == NULL)
+ memory_error (TARGET_XFER_E_IO, addr);
return 0;
}
return extract_unsigned_integer (buf, instlen, byte_order);
@@ -7118,12 +7118,13 @@ mips_breakpoint_from_pc (struct gdbarch *gdbarch,
static gdb_byte micromips16_big_breakpoint[] = { 0x46, 0x85 };
static gdb_byte micromips32_big_breakpoint[] = { 0, 0x5, 0, 0x7 };
ULONGEST insn;
- int status;
+ int err;
int size;
- insn = mips_fetch_instruction (gdbarch, ISA_MICROMIPS, pc, &status);
- size = status ? 2
- : mips_insn_size (ISA_MICROMIPS, insn) == 2 ? 2 : 4;
+ insn = mips_fetch_instruction (gdbarch, ISA_MICROMIPS, pc, &err);
+ size = (err != 0
+ ? 2 : (mips_insn_size (ISA_MICROMIPS, insn) == 2
+ ? 2 : 4));
*pcptr = unmake_compact_addr (pc);
*lenptr = size;
return (size == 2) ? micromips16_big_breakpoint
diff --git a/gdb/target.c b/gdb/target.c
index d7653c4..7ad2330 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -1380,7 +1380,7 @@ target_xfer_partial (struct target_ops *ops,
/* Read LEN bytes of target memory at address MEMADDR, placing the
results in GDB's memory at MYADDR. Returns either 0 for success or
- TARGET_XFER_E_IO if any error occurs.
+ -1 if any error occurs.
If an error occurs, no guarantee is made about the contents of the data at
MYADDR. In particular, the caller should not depend upon partial reads
@@ -1399,7 +1399,7 @@ target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
myaddr, memaddr, len) == len)
return 0;
else
- return TARGET_XFER_E_IO;
+ return -1;
}
/* See target/target.h. */
@@ -1431,7 +1431,7 @@ target_read_raw_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
myaddr, memaddr, len) == len)
return 0;
else
- return TARGET_XFER_E_IO;
+ return -1;
}
/* Like target_read_memory, but specify explicitly that this is a read from
@@ -1446,7 +1446,7 @@ target_read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
myaddr, memaddr, len) == len)
return 0;
else
- return TARGET_XFER_E_IO;
+ return -1;
}
/* Like target_read_memory, but specify explicitly that this is a read from
@@ -1461,14 +1461,14 @@ target_read_code (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
myaddr, memaddr, len) == len)
return 0;
else
- return TARGET_XFER_E_IO;
+ return -1;
}
/* Write LEN bytes from MYADDR to target memory at address MEMADDR.
- Returns either 0 for success or TARGET_XFER_E_IO if any
- error occurs. If an error occurs, no guarantee is made about how
- much data got written. Callers that can deal with partial writes
- should call target_write. */
+ Returns either 0 for success or -1 if any error occurs. If an
+ error occurs, no guarantee is made about how much data got written.
+ Callers that can deal with partial writes should call
+ target_write. */
int
target_write_memory (CORE_ADDR memaddr, const gdb_byte *myaddr, ssize_t len)
@@ -1479,14 +1479,14 @@ target_write_memory (CORE_ADDR memaddr, const gdb_byte *myaddr, ssize_t len)
myaddr, memaddr, len) == len)
return 0;
else
- return TARGET_XFER_E_IO;
+ return -1;
}
/* Write LEN bytes from MYADDR to target raw memory at address
- MEMADDR. Returns either 0 for success or TARGET_XFER_E_IO
- if any error occurs. If an error occurs, no guarantee is made
- about how much data got written. Callers that can deal with
- partial writes should call target_write. */
+ MEMADDR. Returns either 0 for success or -1 if any error occurs.
+ If an error occurs, no guarantee is made about how much data got
+ written. Callers that can deal with partial writes should call
+ target_write. */
int
target_write_raw_memory (CORE_ADDR memaddr, const gdb_byte *myaddr, ssize_t len)
@@ -1497,7 +1497,7 @@ target_write_raw_memory (CORE_ADDR memaddr, const gdb_byte *myaddr, ssize_t len)
myaddr, memaddr, len) == len)
return 0;
else
- return TARGET_XFER_E_IO;
+ return -1;
}
/* Fetch the target's memory map. */
diff --git a/gdb/valprint.c b/gdb/valprint.c
index 7e74856..7f891c9 100644
--- a/gdb/valprint.c
+++ b/gdb/valprint.c
@@ -2737,7 +2737,7 @@ val_print_string (struct type *elttype, const char *encoding,
const struct value_print_options *options)
{
int force_ellipsis = 0; /* Force ellipsis to be printed if nonzero. */
- int errcode; /* Errno returned from bad reads. */
+ int err; /* Non-zero if we got a bad read. */
int found_nul; /* Non-zero if we found the nul char. */
unsigned int fetchlimit; /* Maximum number of chars to print. */
int bytes_read;
@@ -2758,8 +2758,8 @@ val_print_string (struct type *elttype, const char *encoding,
fetchlimit = (len == -1 ? options->print_max : min (len,
options->print_max));
- errcode = read_string (addr, len, width, fetchlimit, byte_order,
- &buffer, &bytes_read);
+ err = read_string (addr, len, width, fetchlimit, byte_order,
+ &buffer, &bytes_read);
old_chain = make_cleanup (xfree, buffer);
addr += bytes_read;
@@ -2787,7 +2787,7 @@ val_print_string (struct type *elttype, const char *encoding,
&& extract_unsigned_integer (peekbuf, width, byte_order) != 0)
force_ellipsis = 1;
}
- else if ((len >= 0 && errcode != 0) || (len > bytes_read / width))
+ else if ((len >= 0 && err != 0) || (len > bytes_read / width))
{
/* Getting an error when we have a requested length, or fetching less
than the number of characters actually requested, always make us
@@ -2798,17 +2798,17 @@ val_print_string (struct type *elttype, const char *encoding,
/* If we get an error before fetching anything, don't print a string.
But if we fetch something and then get an error, print the string
and then the error message. */
- if (errcode == 0 || bytes_read > 0)
+ if (err == 0 || bytes_read > 0)
{
LA_PRINT_STRING (stream, elttype, buffer, bytes_read / width,
encoding, force_ellipsis, options);
}
- if (errcode != 0)
+ if (err != 0)
{
char *str;
- str = memory_error_message (errcode, gdbarch, addr);
+ str = memory_error_message (TARGET_XFER_E_IO, gdbarch, addr);
make_cleanup (xfree, str);
fprintf_filtered (stream, "<error: ");
--
1.9.3