the "compile" command

This final patch adds the new "compile" command and subcommands, and
all the machinery needed to make it work.

A shared library supplied by gcc is used for all communications with
gcc.  Types and most aspects of symbols are provided directly by gdb
to the compiler using this library.

gdb provides some information about the user's code using plain text.
Macros are emitted this way, and DWARF location expressions (and
bounds for VLA) are compiled to C code.

This hybrid approach was taken because, on the one hand, it is better
to provide global declarations and such on demand; but on the other
hand, for local variables, translating DWARF location expressions to C
was much simpler than exporting a full compiler API to gdb -- the same
result, only easier to implement, understand, and debug.

In the ordinary mode, the user's expression is wrapped in a dummy
function.  After compilation, gdb inserts the resulting object code
into the inferior, then calls this function.

Access to local variables is provided by noting which registers are
used by location expressions, and passing a structure of register
values into the function.  Writes to registers are supported by
copying out these values after the function returns.

This approach was taken so that we could eventually implement other
more interesting features based on this same infrastructure; for
example, we're planning to investigate inferior-side breakpoint
conditions.

gdb/ChangeLog
2014-12-12  Phil Muldoon  <pmuldoon@redhat.com>
	    Jan Kratochvil  <jan.kratochvil@redhat.com>
	    Tom Tromey  <tromey@redhat.com>

	* NEWS: Update.
	* symtab.h (struct symbol_computed_ops) <generate_c_location>: New
	field.
	* p-lang.c (pascal_language_defn): Update.
	* opencl-lang.c (opencl_language_defn): Update.
	* objc-lang.c (objc_language_defn): Update.
	* m2-lang.c (m2_language_defn): Update.
	* language.h (struct language_defn) <la_get_compile_instance,
	la_compute_program>: New fields.
	* language.c (unknown_language_defn, auto_language_defn)
	(local_language_defn): Update.
	* jv-lang.c (java_language_defn): Update.
	* go-lang.c (go_language_defn): Update.
	* f-lang.c (f_language_defn): Update.
	* dwarf2loc.h (dwarf2_compile_property_to_c): Declare.
	* dwarf2loc.c (dwarf2_compile_property_to_c)
	(locexpr_generate_c_location, loclist_generate_c_location): New
	functions.
	(dwarf2_locexpr_funcs, dwarf2_loclist_funcs): Update.
	* defs.h (enum compile_i_scope_types): New.
	(enum command_control_type) <compile_control>: New constant.
	(struct command_line) <control_u>: New field.
	* d-lang.c (d_language_defn): Update.
	* compile/compile.c: New file.
	* compile/compile-c-support.c: New file.
	* compile/compile-c-symbols.c: New file.
	* compile/compile-c-types.c: New file.
	* compile/compile.h: New file.
	* compile/compile-internal.h: New file.
	* compile/compile-loc2c.c: New file.
	* compile/compile-object-load.c: New file.
	* compile/compile-object-load.h: New file.
	* compile/compile-object-run.c: New file.
	* compile/compile-object-run.h: New file.
	* cli/cli-script.c (multi_line_command_p, print_command_lines)
	(execute_control_command, process_next_line)
	(recurse_read_control_structure): Handle compile_control.
	* c-lang.h (c_get_compile_context, c_compute_program): Declare.
	* c-lang.c (c_language_defn, cplus_language_defn)
	(asm_language_defn, minimal_language_defn): Update.
	* ada-lang.c (ada_language_defn): Update.
	* Makefile.in (SUBDIR_GCC_COMPILE_OBS, SUBDIR_GCC_COMPILE_SRCS):
	New variables.
	(SFILES): Add SUBDIR_GCC_COMPILE_SRCS.
	(HFILES_NO_SRCDIR): Add compile.h.
	(COMMON_OBS): Add SUBDIR_GCC_COMPILE_OBS.
	(INIT_FILES): Add SUBDIR_GCC_COMPILE_SRCS.
	(compile.o, compile-c-types.o, compile-c-symbols.o)
	(compile-object-load.o, compile-object-run.o, compile-loc2c.o)
	(compile-c-support.o): New targets.

gdb/doc/ChangeLog
2014-12-12  Phil Muldoon  <pmuldoon@redhat.com>
	    Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.texinfo (Altering): Update.
	(Compiling and Injecting Code): New node.

gdb/testsuite/ChangeLog
2014-12-12  Phil Muldoon  <pmuldoon@redhat.com>
	    Jan Kratochvil  <jan.kratochvil@redhat.com>
	    Tom Tromey  <tromey@redhat.com>

	* configure.ac: Add gdb.compile/.
	* configure: Regenerate.
	* gdb.compile/Makefile.in: New file.
	* gdb.compile/compile-ops.exp: New file.
	* gdb.compile/compile-ops.c: New file.
	* gdb.compile/compile-tls.c: New file.
	* gdb.compile/compile-tls.exp: New file.
	* gdb.compile/compile-constvar.S: New file.
	* gdb.compile/compile-constvar.c: New file.
	* gdb.compile/compile-mod.c: New file.
	* gdb.compile/compile-nodebug.c: New file.
	* gdb.compile/compile-setjmp-mod.c: New file.
	* gdb.compile/compile-setjmp.c: New file.
	* gdb.compile/compile-setjmp.exp: New file.
	* gdb.compile/compile-shlib.c: New file.
	* gdb.compile/compile.c: New file.
	* gdb.compile/compile.exp: New file.
	* lib/gdb.exp (skip_compile_feature_tests): New proc.

1 files changed, 357 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.compile/compile.exp b/gdb/testsuite/gdb.compile/compile.exp
new file mode 100644
index 0000000..d0dd791
--- /dev/null
+++ b/gdb/testsuite/gdb.compile/compile.exp
@@ -0,0 +1,357 @@
+# Copyright 2014 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+standard_testfile .c compile-shlib.c compile-constvar.S compile-nodebug.c
+
+get_compiler_info
+set options {}
+if [test_compiler_info gcc*] {
+    lappend options additional_flags=-g3
+}
+
+if { ![istarget x86_64-*-* ] || ![is_lp64_target] } {
+    verbose "Skipping x86_64 LOC_CONST test."
+    set srcfile3 ""
+}
+
+set srcfilesoptions [list ${srcfile} ${options}]
+if { $srcfile3 != "" } {
+    lappend srcfilesoptions $srcfile3 ${options}
+}
+lappend srcfilesoptions $srcfile4 "nodebug"
+if { [eval build_executable_from_specs ${testfile}.exp $testfile {$options} ${srcfilesoptions}] } {
+    return -1
+}
+
+clean_restart ${testfile}
+
+#
+# Test command without an running inferior.
+#
+gdb_test "compile code int i=2;" \
+    "The program must be running for the compile command to work.*" \
+    "Test compile code command without running inferior"
+
+gdb_test "compile int i=2;" \
+    "The program must be running for the compile command to work.*" \
+    "Test compile command without running inferior"
+
+gdb_test "compile file -r ${srcdir}/${subdir}/${testfile}-mod.c" \
+    "The program must be running for the compile command to work.*" \
+    "Test compile file command without running inferior"
+
+if ![runto_main] {
+    return -1
+}
+
+if {[skip_compile_feature_tests]} {
+    untested "could not find libcc1 shared library"
+    return -1
+}
+
+#
+# Test delimiter for code, and arguments.
+#
+
+gdb_test_no_output "compile -- f = 10" \
+    "Test abbreviations and code delimiter"
+
+gdb_test "compile f = 10;" ".*= 10;: No such file.*" \
+    "Test abbreviations and code collision"
+
+gdb_test_no_output "compile -r -- _gdb_expr(){int i = 5;}" \
+    "Test delimiter with -r"
+
+gdb_test_no_output "compile -raw -- _gdb_expr(){int i = 5;}" \
+    "Test delimiter with -raw"
+
+gdb_test "compile -- -r  _gdb_expr(){int i = 5;}" \
+    ".* error: 'r' undeclared \\(first use in this function\\).*" \
+    "Test delimiter with -r after it"
+
+gdb_test "p globalvar" " = 10" "expect 10"
+
+gdb_test_no_output "compile code globalvar = 11" \
+    "set variable without trailing semicolon"
+gdb_test "p globalvar" " = 11" "check variable without trailing semicolon"
+
+gdb_test_no_output "compile code globalvar = SOME_MACRO;" \
+    "set variable from macro"
+gdb_test "p globalvar" " = 23" "expect 23"
+
+gdb_test_no_output "compile code globalvar = ARG_MACRO(0, 0);" \
+    "set variable from function-like macro"
+gdb_test "p globalvar" " = -1" "expect -1"
+
+gdb_test_no_output "compile code globalvar = 42;" "set variable"
+gdb_test "p globalvar" " = 42" "expect 42"
+
+gdb_test_no_output "compile code globalvar *= 2;" "modify variable"
+gdb_test "p globalvar" " = 84" "expect 84"
+
+gdb_test_multiple "compile code" "compile code multiline 1" { -re "\r\n>$" {} }
+gdb_test_multiple "globalvar = 10;" "compile code multiline 2" { -re "\r\n>$" {} }
+gdb_test_multiple "globalvar *= 2;" "compile code multiline 3" { -re "\r\n>$" {} }
+gdb_test_no_output "end" "compile code multiline 4"
+gdb_test "p globalvar" " = 20" "expect 20"
+
+gdb_test_no_output "compile file -r ${srcdir}/${subdir}/${testfile}-mod.c" \
+    "use external source file"
+gdb_test "p globalvar" " = 7" "expect 7"
+
+gdb_test_no_output "compile code func_static (2);" "call static function"
+gdb_test "p globalvar" " = 9" "expect 9"
+gdb_test_no_output "compile code func_global (1);" "call global function"
+gdb_test "p globalvar" " = 8" "expect 8"
+
+gdb_test_no_output \
+    "compile code globalvar = (sizeof (ulonger) == sizeof (long))" \
+    "compute size of ulonger"
+gdb_test "p globalvar" " = 1" "check size of ulonger"
+gdb_test_no_output \
+    "compile code globalvar = (sizeof (longer) == sizeof (long))" \
+    "compute size of longer"
+gdb_test "p globalvar" " = 1" "check size of longer"
+gdb_test_no_output "compile code globalvar = MINUS_1"
+gdb_test "p globalvar" " = -1" "check MINUS_1"
+
+gdb_test_no_output "compile code globalvar = static_local"
+gdb_test "p globalvar" " = 77000" "check static_local"
+
+gdb_test_no_output "compile code static int staticvar = 5; intptr = &staticvar" \
+    "keep jit in memory"
+gdb_test "p *intptr" " = 5" "expect 5"
+
+gdb_test "compile code func_doesnotexist ();" "warning: Could not find symbol \"func_doesnotexist\" for .*"
+
+gdb_test "compile code *(volatile int *) 0 = 0;" \
+    "The program being debugged was signaled while in a function called from GDB\\.\r\nGDB remains in the frame where the signal was received\\.\r\n.*" \
+    "compile code segfault first"
+gdb_test "bt" \
+    "\r\n#0  \[^\r\n\]* in _gdb_expr \[^\r\n\]*\r\n#1  <function called from gdb>\r\n.*"
+
+set test "p/x \$pc"
+set infcall_pc 0
+gdb_test_multiple $test $test {
+    -re " = (0x\[0-9a-f\]+)\r\n$gdb_prompt $" {
+	set infcall_pc $expect_out(1,string)
+	pass $test
+    }
+}
+
+gdb_test "info sym $infcall_pc" "\r\n_gdb_expr .*" "info sym found"
+gdb_test "return" "\r\n#0  main .*" "return" \
+	 "Make _gdb_expr return now\\? \\(y or n\\) " "y"
+gdb_test "info sym $infcall_pc" "\r\nNo symbol matches .*" "info sym not found"
+
+gdb_test_no_output "set unwindonsignal on"
+gdb_test "compile code *(volatile int *) 0 = 0;" \
+    "The program being debugged was signaled while in a function called from GDB\\.\r\nGDB has restored the context to what it was before the call\\.\r\n.*" \
+    "compile code segfault second"
+
+gdb_breakpoint [gdb_get_line_number "break-here"]
+gdb_continue_to_breakpoint "break-here" ".* break-here .*"
+
+gdb_test "p localvar" " = 50" "expect localvar 50"
+
+gdb_test_no_output "compile code localvar = 12;" "set localvar"
+gdb_test "p localvar" " = 12" "expect 12"
+
+gdb_test_no_output "compile code localvar *= 2;" "modify localvar"
+gdb_test "p localvar" " = 24" "expect 24"
+
+gdb_test_no_output "compile code localvar = shadowed" \
+    "test shadowing"
+gdb_test "p localvar" " = 52" "expect 52"
+
+gdb_test_no_output "compile code localvar = externed"
+gdb_test "p localvar" " = 7" "test extern in inner scope"
+
+gdb_test_no_output "compile code vla\[2\] = 7"
+gdb_test "p vla\[2\]" " = 7"
+gdb_test_no_output \
+    "compile code localvar = (sizeof (vla) == bound * sizeof (vla\[0\]))"
+gdb_test "p localvar" " = 1"
+
+#
+# Test setting fields and also many different types.
+#
+
+gdb_test_no_output "compile code struct_object.selffield = &struct_object"
+gdb_test "print struct_object.selffield == &struct_object" " = 1"
+
+gdb_test_no_output "compile code struct_object.charfield = 1"
+gdb_test "print struct_object.charfield" " = 1 '\\\\001'"
+gdb_test_no_output "compile code struct_object.ucharfield = 1"
+gdb_test "print struct_object.ucharfield" " = 1 '\\\\001'"
+
+foreach {field value} {
+    shortfield -5
+    ushortfield 5
+    intfield -7
+    uintfield 7
+    bitfield 2
+    longfield -9
+    ulongfield 9
+    enumfield ONE
+    floatfield 1
+    doublefield 2
+} {
+    gdb_test_no_output "compile code struct_object.$field = $value"
+    gdb_test "print struct_object.$field" " = $value"
+}
+
+gdb_test_no_output "compile code struct_object.arrayfield\[2\] = 7"
+gdb_test "print struct_object.arrayfield" \
+    " = \\{0, 0, 7, 0, 0\\}"
+
+gdb_test_no_output "compile code struct_object.complexfield = 7 + 5i"
+gdb_test "print struct_object.complexfield" " = 7 \\+ 5 \\* I"
+
+gdb_test_no_output "compile code struct_object.boolfield = 1"
+gdb_test "print struct_object.boolfield" " = true"
+
+gdb_test_no_output "compile code struct_object.vectorfield\[2\] = 7"
+gdb_test "print struct_object.vectorfield" \
+    " = \\{0, 0, 7, 0\\}"
+
+gdb_test_no_output "compile code union_object.typedeffield = 7"
+gdb_test "print union_object.typedeffield" " = 7"
+gdb_test "print union_object.intfield" " = 7"
+
+
+# LOC_UNRESOLVED tests.
+
+gdb_test "print unresolved" " = 20"
+gdb_test "compile code globalvar = unresolved;"
+gdb_test "print globalvar" " = 20" "print unresolved value"
+
+# Test shadowing with global and static variables.
+
+gdb_test_no_output "compile code globalshadow += 1;"
+gdb_test "print globalshadow" " = 101"
+gdb_test_no_output "compile code extern int globalshadow; globalshadow += 5;"
+gdb_test "print 'compile.c'::globalshadow" " = 15"
+gdb_test "print globalshadow" " = 101" "print globalshadow second time"
+gdb_test_no_output "compile code staticshadow += 2;"
+gdb_test "print staticshadow" " = 202"
+# "extern int staticshadow;" cannot access static variable.
+
+# Raw code cannot refer to locals.
+# As it references global variable we need the #pragma.
+# For #pragma we need multiline input.
+gdb_test_multiple "compile code -r" "compile code -r multiline 1" { -re "\r\n>$" {} }
+gdb_test_multiple "#pragma GCC user_expression" "compile code -r multiline 2" { -re "\r\n>$" {} }
+gdb_test_multiple "void _gdb_expr(void) { globalshadow = 77000; }" "compile code -r multiline 3" { -re "\r\n>$" {} }
+gdb_test_no_output "end" "compile code -r multiline 4"
+gdb_test "print 'compile.c'::globalshadow" " = 77000" \
+    "check globalshadow with -r"
+
+#
+# Test the case where the registers structure would not normally have
+# any fields.
+#
+
+gdb_breakpoint [gdb_get_line_number "no_args_or_locals breakpoint"]
+gdb_continue_to_breakpoint "no_args_or_locals"
+
+gdb_test_no_output "compile code globalvar = 77;" "set variable to 77"
+gdb_test "p globalvar" " = 77" "expect 77"
+
+
+# Test reference to minimal_symbol, not (full) symbol.
+
+gdb_test_no_output "compile code globalvar = func_nodebug (75);" \
+    "call func_nodebug"
+gdb_test "p globalvar" " = -75" "expect -75"
+gdb_test_no_output \
+  "compile code int (*funcp) (int) = func_nodebug; globalvar = funcp (76);" \
+  "call func_nodebug indirectly"
+gdb_test "p globalvar" " = -76" "expect -76"
+
+
+# Test compiled module memory protection.
+
+gdb_test_no_output "set debug compile on"
+gdb_test "compile code static const int readonly = 1; *(int *) &readonly = 2;" \
+    "The program being debugged was signaled while in a function called from GDB\\.\r\nGDB has restored the context to what it was before the call\\.\r\n.*"
+gdb_test_no_output "set debug compile off"
+
+
+#
+# Some simple coverage tests.
+#
+
+gdb_test "show debug compile" "Compile debugging is .*"
+gdb_test "show compile-args" \
+    "Compile command command-line arguments are .*"
+gdb_test "compile code -z" "Unknown argument.*"
+
+gdb_test "set lang java" \
+    "Warning: the current language does not match this frame."
+gdb_test "compile code globalvar" "No compiler support for this language\."
+gdb_test_no_output "set lang auto"
+
+gdb_test_no_output "compile code union union_type newdecl_u"
+gdb_test_no_output "compile code struct struct_type newdecl_s"
+gdb_test_no_output "compile code inttypedef newdecl_i"
+
+gdb_test "compile file" \
+    "You must provide a filename for this command.*" \
+    "Test compile file without a filename"
+gdb_test "compile file -r" \
+    "You must provide a filename with the raw option set.*" \
+    "Test compile file and raw option without a filename"
+gdb_test "compile file -z" \
+    "Unknown argument.*" \
+    "Test compile file with unknown argument"
+
+
+# LOC_CONST tests.
+
+if { $srcfile3 != "" } {
+    gdb_test "p constvar" " = 3"
+    gdb_test "info addr constvar" {Symbol "constvar" is constant\.}
+
+    gdb_test "compile code globalvar = constvar;"
+    gdb_test "print globalvar" " = 3" "print constvar value"
+} else {
+    untested "print constvar value"
+}
+
+# Shared library tests.
+
+if {[skip_shlib_tests]} {
+    untested "skipping shlib tests"
+    return;
+}
+
+set libbin [standard_output_file ${testfile}-shlib.so]
+if { [gdb_compile_shlib ${srcdir}/${subdir}/${srcfile2} $libbin {debug}] != ""
+     || [build_executable $testfile ${testfile}-shlib $srcfile \
+	     [list debug ldflags=$libbin]] == -1 } {
+    return -1
+}
+
+clean_restart ${testfile}-shlib
+if ![runto_main] {
+    return -1
+}
+
+gdb_test_no_output "compile code shlib_func ();" "call shared library function"
+gdb_test "p globalvar" " = 1" "expect 1"
+
+gdb_test_no_output "compile code shlibvar += 5;" "modify shared library variable"
+gdb_test "p shlibvar" " = 15" "expect 15"