From 578d3588ee67d9beb22763b0c0ac423fb25b15ec Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Wed, 9 Oct 2013 17:00:00 +0000 Subject: [PATCH] Stop using errno values around target_xfer interfaces and memory errors. target_read_memory & friends build on top of target_read (thus on top of the target_xfer machinery), but turn all errors to EIO, an errno value. I think we'd better convert all these to return a target_xfer_error too, like target_xfer_partial in a previous patch. The patch starts by doing that. (The patch does not add a enum target_xfer_error value for '0'/no error, and likewise does not change the return type of several of these functions to enum target_xfer_error, because different functions return '0' with different semantics.) I audited the tree for memory_error calls, EIO checks, places where GDB hardcodes 'errno = EIO', and also for strerror calls. What I found is that nowadays there's really no need to handle random errno values, other than the EIOs gdb itself hardcodes. No doubt errno values would appear in common code back in the day when target_xfer_memory was the main interface to access memory, but nowadays, any errno value that deprecated interface could return is just absorved by default_xfer_partial: else if (xfered == 0 && errno == 0) /* "deprecated_xfer_memory" uses 0, cross checked against ERRNO as one indication of an error. */ return 0; else return -1; There are two places in the code that check for EIO and print "out of bounds", and defer to strerror for other errors. That's c-lang.c:c_get_string, and valprint.c.:val_print_string. AFAICT, the strerror branch can never be reached nowadays, as the only error possible to get at those points is EIO, given that it's GDB itself that set that errno value (in target_read_memory, etc.). breakpoint.c:insert_bp_location always prints the error val as if an errno, returned by target_insert_breakpoint, with strerr. Now the error here is either always EIO for mem-break.c targets (again hardcoded by the target_read_memory/target_write_memory functions), so this always prints "Input/output error" or similar (depending on host), or, for remote targets (and probably others), this gem: Error accessing memory address 0x80200400: Unknown error -1. This patch makes these 3 places print the exact same error memory_error prints. This changes output, but I think this is better, for making memory error output consistent with other commands, and, it means we have a central place to tweak for memory errors. E.g., this changes: Cannot insert breakpoint 1. Error accessing memory address 0x5fc660: Input/output error. to: Cannot insert breakpoint 1. Cannot access memory at address 0x5fc660 Which I find pretty much acceptable. Surprisingly, only py-prettyprint.exp had a regression, for needing an adjustment. I also grepped the testsuite for the old errors, and found no other hits. Now that errno values aren't used anywhere in any of these memory access related routines, I made memory_error itself take a target_xfer_error instead of an errno. The new target_xfer_memory_error function added recently is no longer necessary, and is thus removed. Tested on x86_64 Fedora 17, native and gdbserver. gdb/ 2013-10-09 Pedro Alves * breakpoint.c (insert_bp_location): Use memory_error_message to build the memory error string. * c-lang.c: Include "gdbcore.h". (c_get_string): Use memory_error to throw error. (target_xfer_memory_error): Delete. (memory_error_message): New, factored out from target_xfer_memory_error. (memory_error): Change parameter type to target_xfer_error. Rewrite. (read_memory): Use memory_error instead of target_xfer_memory_error. * gdbcore.h: Include "target.h". (memory_error): Change parameter type to target_xfer_error. (memory_error_message): Declare function. * target.c (target_read_memory, target_read_stack) (target_write_memory, target_write_raw_memory): Return TARGET_XFER_E_IO on error. Adjust comments. (get_target_memory): Pass TARGET_XFER_E_IO to memory_error, instead of EIO. * target.h (target_read, target_insert_breakpoint) (target_remove_breakpoint): Adjust comments. * valprint.c (partial_memory_read): Rename parameter, and adjust comment. (val_print_string): Use memory_error_message to build the memory error string. gdb/testsuite/ 2013-10-09 Pedro Alves * gdb.python/py-prettyprint.exp (run_lang_tests): Adjust expected output. --- gdb/ChangeLog | 28 +++++++++++ gdb/breakpoint.c | 17 +++---- gdb/c-lang.c | 8 +--- gdb/corefile.c | 52 ++++++++++++--------- gdb/gdbcore.h | 9 +++- gdb/target.c | 31 ++++++------ gdb/target.h | 15 +++--- gdb/testsuite/ChangeLog | 5 ++ gdb/testsuite/gdb.python/py-prettyprint.exp | 2 +- gdb/valprint.c | 34 ++++++-------- 10 files changed, 122 insertions(+), 79 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 3dd66c8c7f..21bc3fe4ba 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,31 @@ +2013-10-09 Pedro Alves + + * breakpoint.c (insert_bp_location): Use memory_error_message to + build the memory error string. + * c-lang.c: Include "gdbcore.h". + (c_get_string): Use memory_error to throw error. + (target_xfer_memory_error): Delete. + (memory_error_message): New, factored out from + target_xfer_memory_error. + (memory_error): Change parameter type to target_xfer_error. + Rewrite. + (read_memory): Use memory_error instead of + target_xfer_memory_error. + * gdbcore.h: Include "target.h". + (memory_error): Change parameter type to target_xfer_error. + (memory_error_message): Declare function. + * target.c (target_read_memory, target_read_stack) + (target_write_memory, target_write_raw_memory): Return + TARGET_XFER_E_IO on error. Adjust comments. + (get_target_memory): Pass TARGET_XFER_E_IO to memory_error, + instead of EIO. + * target.h (target_read, target_insert_breakpoint) + (target_remove_breakpoint): Adjust comments. + * valprint.c (partial_memory_read): Rename parameter, and adjust + comment. + (val_print_string): Use memory_error_message to build the memory + error string. + 2013-10-09 Jan Kratochvil * common/filestuff.c (gdb_fopen_cloexec): Remove initialization of diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index d3e9e496f0..f0da90a5ce 100644 --- a/gdb/breakpoint.c +++ b/gdb/breakpoint.c @@ -2570,15 +2570,16 @@ insert_bp_location (struct bp_location *bl, } else { + char *message = memory_error_message (TARGET_XFER_E_IO, + bl->gdbarch, bl->address); + struct cleanup *old_chain = make_cleanup (xfree, message); + fprintf_unfiltered (tmp_error_stream, - "Cannot insert breakpoint %d.\n", - bl->owner->number); - fprintf_filtered (tmp_error_stream, - "Error accessing memory address "); - fputs_filtered (paddress (bl->gdbarch, bl->address), - tmp_error_stream); - fprintf_filtered (tmp_error_stream, ": %s.\n", - safe_strerror (val)); + "Cannot insert breakpoint %d.\n" + "%s\n", + bl->owner->number, message); + + do_cleanups (old_chain); } } diff --git a/gdb/c-lang.c b/gdb/c-lang.c index 48a1fb02be..33bb4443f0 100644 --- a/gdb/c-lang.c +++ b/gdb/c-lang.c @@ -35,6 +35,7 @@ #include "gdb_obstack.h" #include #include "exceptions.h" +#include "gdbcore.h" extern void _initialize_c_language (void); @@ -312,12 +313,7 @@ c_get_string (struct value *value, gdb_byte **buffer, if (err) { xfree (*buffer); - if (err == EIO) - throw_error (MEMORY_ERROR, "Address %s out of bounds", - paddress (get_type_arch (type), addr)); - else - error (_("Error reading string from inferior: %s"), - safe_strerror (err)); + memory_error (err, addr); } } diff --git a/gdb/corefile.c b/gdb/corefile.c index 1b733e2db0..345df90799 100644 --- a/gdb/corefile.c +++ b/gdb/corefile.c @@ -193,24 +193,20 @@ Use the \"file\" or \"exec-file\" command.")); } -/* Report a target xfer memory error by throwing a suitable - exception. */ - -static void -target_xfer_memory_error (enum target_xfer_error err, CORE_ADDR memaddr) +char * +memory_error_message (enum target_xfer_error err, + struct gdbarch *gdbarch, CORE_ADDR memaddr) { switch (err) { case TARGET_XFER_E_IO: /* Actually, address between memaddr and memaddr + len was out of bounds. */ - throw_error (MEMORY_ERROR, - _("Cannot access memory at address %s"), - paddress (target_gdbarch (), memaddr)); + return xstrprintf (_("Cannot access memory at address %s"), + paddress (gdbarch, memaddr)); case TARGET_XFER_E_UNAVAILABLE: - throw_error (NOT_AVAILABLE_ERROR, - _("Memory at address %s unavailable."), - paddress (target_gdbarch (), memaddr)); + return xstrprintf (_("Memory at address %s unavailable."), + paddress (gdbarch, memaddr)); default: internal_error (__FILE__, __LINE__, "unhandled target_xfer_error: %s (%s)", @@ -219,18 +215,30 @@ target_xfer_memory_error (enum target_xfer_error err, CORE_ADDR memaddr) } } -/* Report a memory error by throwing a MEMORY_ERROR error. */ +/* Report a memory error by throwing a suitable exception. */ void -memory_error (int status, CORE_ADDR memaddr) +memory_error (enum target_xfer_error err, CORE_ADDR memaddr) { - if (status == EIO) - target_xfer_memory_error (TARGET_XFER_E_IO, memaddr); - else - throw_error (MEMORY_ERROR, - _("Error accessing memory address %s: %s."), - paddress (target_gdbarch (), memaddr), - safe_strerror (status)); + char *str; + + /* Build error string. */ + str = memory_error_message (err, target_gdbarch (), memaddr); + make_cleanup (xfree, str); + + /* Choose the right error to throw. */ + switch (err) + { + case TARGET_XFER_E_IO: + err = MEMORY_ERROR; + break; + case TARGET_XFER_E_UNAVAILABLE: + err = NOT_AVAILABLE_ERROR; + break; + } + + /* Throw it. */ + throw_error (err, ("%s"), str); } /* Same as target_read_memory, but report an error if can't read. */ @@ -248,9 +256,9 @@ read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len) memaddr + xfered, len - xfered); if (xfer == 0) - target_xfer_memory_error (TARGET_XFER_E_IO, memaddr + xfered); + memory_error (TARGET_XFER_E_IO, memaddr + xfered); if (xfer < 0) - target_xfer_memory_error (xfer, memaddr + xfered); + memory_error (xfer, memaddr + xfered); xfered += xfer; QUIT; } diff --git a/gdb/gdbcore.h b/gdb/gdbcore.h index 01ed4df5c4..41bcf1f44e 100644 --- a/gdb/gdbcore.h +++ b/gdb/gdbcore.h @@ -27,6 +27,7 @@ struct regcache; #include "bfd.h" #include "exec.h" +#include "target.h" /* Return the name of the executable file as a string. ERR nonzero means get error if there is none specified; @@ -40,7 +41,13 @@ extern int have_core_file_p (void); /* Report a memory error with error(). */ -extern void memory_error (int status, CORE_ADDR memaddr); +extern void memory_error (enum target_xfer_error status, CORE_ADDR memaddr); + +/* The string 'memory_error' would use as exception message. Space + for the result is malloc'd, caller must free. */ + +extern char *memory_error_message (enum target_xfer_error err, + struct gdbarch *gdbarch, CORE_ADDR memaddr); /* Like target_read_memory, but report an error if can't read. */ diff --git a/gdb/target.c b/gdb/target.c index 559ae0c82b..7279359757 100644 --- a/gdb/target.c +++ b/gdb/target.c @@ -1787,9 +1787,9 @@ target_xfer_partial (struct target_ops *ops, return retval; } -/* Read LEN bytes of target memory at address MEMADDR, placing the results in - GDB's memory at MYADDR. Returns either 0 for success or an errno value - if any error occurs. +/* Read LEN bytes of target memory at address MEMADDR, placing the + results in GDB's memory at MYADDR. Returns either 0 for success or + a target_xfer_error value 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 @@ -1808,7 +1808,7 @@ target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len) myaddr, memaddr, len) == len) return 0; else - return EIO; + return TARGET_XFER_E_IO; } /* Like target_read_memory, but specify explicitly that this is a read from @@ -1825,13 +1825,14 @@ target_read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len) myaddr, memaddr, len) == len) return 0; else - return EIO; + return TARGET_XFER_E_IO; } /* Write LEN bytes from MYADDR to target memory at address MEMADDR. - Returns either 0 for success or an errno value 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 a target_xfer_error value 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) @@ -1843,14 +1844,14 @@ target_write_memory (CORE_ADDR memaddr, const gdb_byte *myaddr, ssize_t len) myaddr, memaddr, len) == len) return 0; else - return EIO; + return TARGET_XFER_E_IO; } /* Write LEN bytes from MYADDR to target raw memory at address - MEMADDR. Returns either 0 for success or an errno value 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 a target_xfer_error value + 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) @@ -1862,7 +1863,7 @@ target_write_raw_memory (CORE_ADDR memaddr, const gdb_byte *myaddr, ssize_t len) myaddr, memaddr, len) == len) return 0; else - return EIO; + return TARGET_XFER_E_IO; } /* Fetch the target's memory map. */ @@ -2440,7 +2441,7 @@ get_target_memory (struct target_ops *ops, CORE_ADDR addr, gdb_byte *buf, for this target). */ if (target_read (ops, TARGET_OBJECT_RAW_MEMORY, NULL, buf, addr, len) != len) - memory_error (EIO, addr); + memory_error (TARGET_XFER_E_IO, addr); } ULONGEST diff --git a/gdb/target.h b/gdb/target.h index 7622465554..56ca40c8b1 100644 --- a/gdb/target.h +++ b/gdb/target.h @@ -239,11 +239,12 @@ DEF_VEC_P(static_tracepoint_marker_p); starting point. The ANNEX can be used to provide additional data-specific information to the target. - Return the number of bytes actually transfered, or -1 if the - transfer is not supported or otherwise fails. Return of a positive - value less than LEN indicates that no further transfer is possible. - Unlike the raw to_xfer_partial interface, callers of these - functions do not need to retry partial transfers. */ + Return the number of bytes actually transfered, or a negative error + code (an 'enum target_xfer_error' value) if the transfer is not + supported or otherwise fails. Return of a positive value less than + LEN indicates that no further transfer is possible. Unlike the raw + to_xfer_partial interface, callers of these functions do not need + to retry partial transfers. */ extern LONGEST target_read (struct target_ops *ops, enum target_object object, @@ -1117,13 +1118,13 @@ int target_write_memory_blocks (VEC(memory_write_request_s) *requests, (*current_target.to_files_info) (¤t_target) /* Insert a breakpoint at address BP_TGT->placed_address in the target - machine. Result is 0 for success, or an errno value. */ + machine. Result is 0 for success, non-zero for error. */ extern int target_insert_breakpoint (struct gdbarch *gdbarch, struct bp_target_info *bp_tgt); /* Remove a breakpoint at address BP_TGT->placed_address in the target - machine. Result is 0 for success, or an errno value. */ + machine. Result is 0 for success, non-zero for error. */ extern int target_remove_breakpoint (struct gdbarch *gdbarch, struct bp_target_info *bp_tgt); diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 7a5f913f0d..7fc1148eee 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2013-10-09 Pedro Alves + + * gdb.python/py-prettyprint.exp (run_lang_tests): Adjust expected + output. + 2013-10-09 Pedro Alves * gdb.base/catch-syscall.exp (test_catch_syscall_without_args) diff --git a/gdb/testsuite/gdb.python/py-prettyprint.exp b/gdb/testsuite/gdb.python/py-prettyprint.exp index d124a7261e..adbe88d0b8 100644 --- a/gdb/testsuite/gdb.python/py-prettyprint.exp +++ b/gdb/testsuite/gdb.python/py-prettyprint.exp @@ -83,7 +83,7 @@ proc run_lang_tests {exefile lang} { gdb_py_test_silent_cmd "set print elements 200" "" 1 } - gdb_test "print ns2" ".error reading variable: Address 0x0 out of bounds." + gdb_test "print ns2" ".error reading variable: Cannot access memory at address 0x0." gdb_test "print x" " = \"this is x\"" gdb_test "print cstring" " = \"const string\"" diff --git a/gdb/valprint.c b/gdb/valprint.c index 61492ccba9..0ecea0c55f 100644 --- a/gdb/valprint.c +++ b/gdb/valprint.c @@ -83,7 +83,7 @@ struct cmd_list_element *showprintrawlist; /* Prototypes for local functions */ static int partial_memory_read (CORE_ADDR memaddr, gdb_byte *myaddr, - int len, int *errnoptr); + int len, int *errptr); static void show_print (char *, int); @@ -1711,15 +1711,15 @@ val_print_array_elements (struct type *type, /* Read LEN bytes of target memory at address MEMADDR, placing the results in GDB's memory at MYADDR. Returns a count of the bytes - actually read, and optionally an errno value in the location - pointed to by ERRNOPTR if ERRNOPTR is non-null. */ + actually read, and optionally a target_xfer_error value in the + location pointed to by ERRPTR if ERRPTR is non-null. */ /* FIXME: cagney/1999-10-14: Only used by val_print_string. Can this function be eliminated. */ static int partial_memory_read (CORE_ADDR memaddr, gdb_byte *myaddr, - int len, int *errnoptr) + int len, int *errptr) { int nread; /* Number of bytes actually read. */ int errcode; /* Error from last read. */ @@ -1744,9 +1744,9 @@ partial_memory_read (CORE_ADDR memaddr, gdb_byte *myaddr, nread--; } } - if (errnoptr != NULL) + if (errptr != NULL) { - *errnoptr = errcode; + *errptr = errcode; } return (nread); } @@ -1755,7 +1755,7 @@ partial_memory_read (CORE_ADDR memaddr, gdb_byte *myaddr, each. Fetch at most FETCHLIMIT characters. BUFFER will be set to a newly allocated buffer containing the string, which the caller is responsible to free, and BYTES_READ will be set to the number of bytes read. Returns 0 on - success, or errno on failure. + success, or a target_xfer_error on failure. If LEN > 0, reads exactly LEN characters (including eventual NULs in the middle or end of the string). If LEN is -1, stops at the first @@ -2524,18 +2524,14 @@ val_print_string (struct type *elttype, const char *encoding, if (errcode != 0) { - if (errcode == EIO) - { - fprintf_filtered (stream, "
"); - } - else - { - fprintf_filtered (stream, "", safe_strerror (errcode)); - } + char *str; + + str = memory_error_message (errcode, gdbarch, addr); + make_cleanup (xfree, str); + + fprintf_filtered (stream, ""); } gdb_flush (stream); -- 2.34.1