[PATCH v2 5/9] compile: Use -Wall, not -w

Jan Kratochvil
2015-04-06T17:27:07Z

Hi,

for a reason unknown to me GDB was using -w instead of -Wall for 'compile code'.
The problem is later patch for 'compile printf' really needs some warnings to
be able to catch for example missing format string parameters:
(gdb) compile printf "%d\n"
GCC does not seem to be able to cancel -w (there is nothing like -no-w).

Besides that I think even 'compile code' can benefit from -Wall.

That #ifndef hack in print_one_macro() is not nice but while GCC does not warn
for redefinitions like
#define MACRO val
#define MACRO val
together with the GCC build-in macros I haven't found any other way how to
prevent the macro-redefinition warnings (when -w is no longer in effect).

That new testsuite XFAIL is there as if one changes the struct definition to be
compliant with cv-qualifiers (to prevent the warnings):
struct struct_type {
- struct struct_type *selffield;
+ volatile struct struct_type *selffield;
only then GCC/GDB will hit the crash, described in that GDB PR 18202.

Thanks,
Jan

gdb/ChangeLog
2015-04-05 Jan Kratochvil <jan.kratochvil@redhat.com>

* compile/compile-c-support.c (print_one_macro): Use #ifndef.
(generate_register_struct): Use __gdb_uintptr for TYPE_CODE_PTR.
(c_compute_program): Call generate_register_struct after typedefs.
* compile/compile-loc2c.c (push, pushf_register_address)
(pushf_register): Cast to GCC_UINTPTR.
(do_compile_dwarf_expr_to_c): Use unused attribute. Add space after
type. Use GCC_UINTPTR instead of void *. Remove excessive cast.
(compile_dwarf_expr_to_c): Use GCC_UINTPTR instead of void *.
* compile/compile.c (_initialize_compile): Enable warnings for
COMPILE_ARGS.

gdb/testsuite/ChangeLog
2015-04-05 Jan Kratochvil <jan.kratochvil@redhat.com>

* gdb.compile/compile-ops.exp: Cast param to void.
* gdb.compile/compile.exp: Complete type for _gdb_expr.
(compile code struct_object.selffield = &struct_object): Add xfail.
---
gdb/compile/compile-c-support.c | 12 +++++++-----
gdb/compile/compile-loc2c.c | 22 +++++++++++++---------
gdb/compile/compile.c | 7 +++++--
gdb/testsuite/gdb.compile/compile-ops.exp | 2 +-
gdb/testsuite/gdb.compile/compile.exp | 15 ++++++++++-----
5 files changed, 36 insertions(+), 22 deletions(-)

diff --git a/gdb/compile/compile-c-support.c b/gdb/compile/compile-c-support.c
index 1711cda..48a17e2 100644
--- a/gdb/compile/compile-c-support.c
+++ b/gdb/compile/compile-c-support.c
@@ -131,7 +131,9 @@ print_one_macro (const char *name, const struct macro_definition *macro,
if (line == 0)
return;

- fprintf_filtered (file, "#define %s", name);
+ /* None of -Wno-builtin-macro-redefined, #undef first
+ or plain #define of the same value would avoid a warning. */
+ fprintf_filtered (file, "#ifndef %s\n# define %s", name, name);

if (macro->kind == macro_function_like)
{
@@ -147,7 +149,7 @@ print_one_macro (const char *name, const struct macro_definition *macro,
fputs_filtered (")", file);
}

- fprintf_filtered (file, " %s\n", macro->replacement);
+ fprintf_filtered (file, " %s\n#endif\n", macro->replacement);
}

/* Write macro definitions at PC to FILE. */
@@ -252,7 +254,7 @@ generate_register_struct (struct ui_file *stream, struct gdbarch *gdbarch,
switch (TYPE_CODE (regtype))
{
case TYPE_CODE_PTR:
- fprintf_filtered (stream, "void *%s", regname);
+ fprintf_filtered (stream, "__gdb_uintptr %s", regname);
break;

case TYPE_CODE_INT:
@@ -340,8 +342,6 @@ c_compute_program (struct compile_instance *inst,
expr_block, expr_pc);
make_cleanup (xfree, registers_used);

- generate_register_struct (buf, gdbarch, registers_used);
-
fputs_unfiltered ("typedef unsigned int"
" __attribute__ ((__mode__(__pointer__)))"
" __gdb_uintptr;\n",
@@ -363,6 +363,8 @@ c_compute_program (struct compile_instance *inst,
" __gdb_int_%s;\n",
mode, mode);
}
+
+ generate_register_struct (buf, gdbarch, registers_used);
}

add_code_header (inst->scope, buf);
diff --git a/gdb/compile/compile-loc2c.c b/gdb/compile/compile-loc2c.c
index 6a3615d..6f53814 100644
--- a/gdb/compile/compile-loc2c.c
+++ b/gdb/compile/compile-loc2c.c
@@ -436,7 +436,8 @@ compute_stack_depth (enum bfd_endian byte_order, unsigned int addr_size,
static void
push (int indent, struct ui_file *stream, ULONGEST l)
{
- fprintfi_filtered (indent, stream, "__gdb_stack[++__gdb_tos] = %s;\n",
+ fprintfi_filtered (indent, stream,
+ "__gdb_stack[++__gdb_tos] = (" GCC_UINTPTR ") %s;\n",
hex_string (l));
}

@@ -520,7 +521,8 @@ pushf_register_address (int indent, struct ui_file *stream,
struct cleanup *cleanups = make_cleanup (xfree, regname);

registers_used[regnum] = 1;
- pushf (indent, stream, "&" COMPILE_I_SIMPLE_REGISTER_ARG_NAME "->%s",
+ pushf (indent, stream,
+ "(" GCC_UINTPTR ") &" COMPILE_I_SIMPLE_REGISTER_ARG_NAME "->%s",
regname);

do_cleanups (cleanups);
@@ -544,7 +546,8 @@ pushf_register (int indent, struct ui_file *stream,
pushf (indent, stream, COMPILE_I_SIMPLE_REGISTER_ARG_NAME "->%s",
regname);
else
- pushf (indent, stream, COMPILE_I_SIMPLE_REGISTER_ARG_NAME "->%s + %s",
+ pushf (indent, stream,
+ COMPILE_I_SIMPLE_REGISTER_ARG_NAME "->%s + (" GCC_UINTPTR ") %s",
regname, hex_string (offset));

do_cleanups (cleanups);
@@ -605,7 +608,8 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,

++scope;

- fprintfi_filtered (indent, stream, "%s%s;\n", type_name, result_name);
+ fprintfi_filtered (indent, stream, "__attribute__ ((unused)) %s %s;\n",
+ type_name, result_name);
fprintfi_filtered (indent, stream, "{\n");
indent += 2;

@@ -899,7 +903,7 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
(long) (op_ptr - base));

do_compile_dwarf_expr_to_c (indent, stream,
- "void *", fb_name,
+ GCC_UINTPTR, fb_name,
sym, pc,
arch, registers_used, addr_size,
datastart, datastart + datalen,
@@ -1080,7 +1084,7 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
"__cfa_%ld", (long) (op_ptr - base));

do_compile_dwarf_expr_to_c (indent, stream,
- "void *", cfa_name,
+ GCC_UINTPTR, cfa_name,
sym, pc, arch, registers_used,
addr_size,
cfa_start, cfa_end,
@@ -1117,8 +1121,8 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
}
}

- fprintfi_filtered (indent, stream, "%s = (%s) __gdb_stack[__gdb_tos];\n",
- result_name, type_name);
+ fprintfi_filtered (indent, stream, "%s = __gdb_stack[__gdb_tos];\n",
+ result_name);
fprintfi_filtered (indent - 2, stream, "}\n");

do_cleanups (cleanup);
@@ -1134,7 +1138,7 @@ compile_dwarf_expr_to_c (struct ui_file *stream, const char *result_name,
const gdb_byte *op_ptr, const gdb_byte *op_end,
struct dwarf2_per_cu_data *per_cu)
{
- do_compile_dwarf_expr_to_c (2, stream, "void *", result_name, sym, pc,
+ do_compile_dwarf_expr_to_c (2, stream, GCC_UINTPTR, result_name, sym, pc,
arch, registers_used, addr_size, op_ptr, op_end,
NULL, per_cu);
}
diff --git a/gdb/compile/compile.c b/gdb/compile/compile.c
index 621de66..ab19a5d 100644
--- a/gdb/compile/compile.c
+++ b/gdb/compile/compile.c
@@ -680,8 +680,11 @@ String quoting is parsed like in shell, for example:\n\
absolute target address.
-fPIC is not used at is would require from GDB to generate .got. */
" -fPIE"
- /* We don't want warnings. */
- " -w"
+ /* We want warnings, except for some commonly happening for GDB commands. */
+ " -Wall "
+ " -Wno-implicit-function-declaration"
+ " -Wno-unused-but-set-variable"
+ " -Wno-unused-variable"
/* Override CU's possible -fstack-protector-strong. */
" -fno-stack-protector"
);
diff --git a/gdb/testsuite/gdb.compile/compile-ops.exp b/gdb/testsuite/gdb.compile/compile-ops.exp
index 26882bd..0ef3c8d 100644
--- a/gdb/testsuite/gdb.compile/compile-ops.exp
+++ b/gdb/testsuite/gdb.compile/compile-ops.exp
@@ -416,7 +416,7 @@ if {[skip_compile_feature_tests]} {
}

# If we have a bug, this will hang.
-gdb_test_no_output "compile code param"
+gdb_test_no_output "compile code (void) param"

# We can't access optimized-out variables, but their presence should
# not affect compilations that don't refer to them.
diff --git a/gdb/testsuite/gdb.compile/compile.exp b/gdb/testsuite/gdb.compile/compile.exp
index dc09770..abe5e9b 100644
--- a/gdb/testsuite/gdb.compile/compile.exp
+++ b/gdb/testsuite/gdb.compile/compile.exp
@@ -71,13 +71,13 @@ gdb_test_no_output "compile -- f = 10" \
gdb_test "compile f = 10;" ".*= 10;: No such file.*" \
"Test abbreviations and code collision"

-gdb_test_no_output "compile -r -- _gdb_expr(){int i = 5;}" \
+gdb_test_no_output "compile -r -- void _gdb_expr(){int i = 5;}" \
"Test delimiter with -r"

-gdb_test_no_output "compile -raw -- _gdb_expr(){int i = 5;}" \
+gdb_test_no_output "compile -raw -- void _gdb_expr(){int i = 5;}" \
"Test delimiter with -raw"

-gdb_test "compile -- -r _gdb_expr(){int i = 5;}" \
+gdb_test "compile -- -r void _gdb_expr(){int i = 5;}" \
".* error: 'r' undeclared \\(first use in this function\\).*" \
"Test delimiter with -r after it"

@@ -189,7 +189,12 @@ gdb_test "p localvar" " = 1"
# Test setting fields and also many different types.
#

-gdb_test_no_output "compile code struct_object.selffield = &struct_object"
+set test "compile code struct_object.selffield = &struct_object"
+gdb_test_multiple $test $test {
+ -re "gdb command line:1:25: warning: assignment discards 'volatile' qualifier from pointer target type \\\[-Wdiscarded-qualifiers\\\]\r\n$gdb_prompt $" {
+ xfail "$test (PR compile/18202)"
+ }
+}
gdb_test "print struct_object.selffield == &struct_object" " = 1"

gdb_test_no_output "compile code struct_object.charfield = 1"
@@ -261,7 +266,7 @@ gdb_test "print 'compile.c'::globalshadow" " = 77000" \

# Test GOT vs. resolving jit function pointers.

-gdb_test_no_output "compile -raw -- int func(){return 21;} _gdb_expr(){int (*funcp)()=func; if (funcp()!=21) abort();}" \
+gdb_test_no_output "compile -raw -- int func(){return 21;} void _gdb_expr(){ void abort (void); int (*funcp)()=func; if (funcp()!=21) abort(); }" \
"pointer to jit function"

#