Fix the build system.

The improvements are:

- use most of the default "Makefile" for standard packaging;
- also use the default ".gitignore" with for the derived assets;
- don't impose so many $CFLAGS on the user.  GCC still needs to be given
  the `-ffreestanding` flag explicitly for us to get a good binary;
- stop using ad-hoc tools/* scripts, and avoid the code-generation
  anti-pattern overall on the build.  Some of the generated files were
  checked-in, and some were removed;
- remove empty files;
- use POSIX make(1) over gmake;
- add fuzz targets;
- partial "install" and "uninstall" targets;
- complete "clean" target.

The shortcomings are:
- only working on x86_64.  More platforms coming soon;
- code is still messy: way too many warnings, GNU/BSD specific
  extensions, inline assembly, and all kinds of unportable code;
- still only works with GCC and GCC-like compilers, and completly fails
  with tcc(1) and cproc(1);
- the `deps.mk` file is being maintained manually.  As I work on the
  source files I'll finish automating its generation with `mkdeps.sh`;
- still seems to be coupled with Linux;
- still is missing tests setup;
- still uses `#include <$NAME.h>` instead of the correct
  `#include "$NAME.h"` form.

The generated libgrovel.a did match the previous lib/libc.a 100%.

1 files changed, 0 insertions, 196 deletions

diff --git a/tools/add-cfi.x86_64.awk b/tools/add-cfi.x86_64.awk
deleted file mode 100644
index 7e1513d6..00000000
--- a/tools/add-cfi.x86_64.awk
+++ /dev/null
@@ -1,196 +0,0 @@
-# Insert GAS CFI directives ("control frame information") into x86-64 asm input
-
-BEGIN {
-  # don't put CFI data in the .eh_frame ELF section (which we don't keep)
-  print ".cfi_sections .debug_frame"
-
-  # only emit CFI directives inside a function
-  in_function = 0
-
-  # emit .loc directives with line numbers from original source
-  printf ".file 1 \"%s\"\n", ARGV[1]
-  line_number = 0
-
-  # used to detect "call label; label:" trick
-  called = ""
-}
-
-function get_const1() {
-  # for instructions with 2 operands, get 1st operand (assuming it is constant)
-  match($0, /-?(0x[0-9a-fA-F]+|[0-9]+),/)
-  return parse_const(substr($0, RSTART, RLENGTH-1))
-}
-
-function canonicalize_reg(register) {
-  if (match(register, /^r/))
-    return register
-  else if (match(register, /^e/))
-    return "r" substr(register, 2, length(register)-1)
-  else if (match(register, /[hl]$/)) # AH, AL, BH, BL, etc
-    return "r" substr(register, 1, 1) "x"
-  else # AX, BX, CX, etc
-    return "r" register
-}
-function get_reg() {
-  # only use if you already know there is 1 and only 1 register
-  match($0, /%[er]?([abcd][xlh]|si|di|bp|8|9|10|11|12|13|14|15)/)
-  return canonicalize_reg(substr($0, RSTART+1, RLENGTH-1))
-}
-function get_reg1() {
-  # for instructions with 2 operands, get 1st operand (assuming it is register)
-  match($0, /%[er]?([abcd][xlh]|si|di|bp|8|9|10|11|12|13|14|15),/)
-  return canonicalize_reg(substr($0, RSTART+1, RLENGTH-2))
-}
-function get_reg2() {
-  # for instructions with 2 operands, get 2nd operand (assuming it is register)
-  match($0, /,%[er]?([abcd][xlh]|si|di|bp|8|9|10|11|12|13|14|15)/)
-  return canonicalize_reg(substr($0, RSTART+2, RLENGTH-2))
-}
-
-function adjust_sp_offset(delta) {
-  if (in_function)
-    printf ".cfi_adjust_cfa_offset %d\n", delta
-}
-
-{
-  line_number = line_number + 1
-
-  # clean the input up before doing anything else
-  # delete comments
-  gsub(/(#|\/\/).*/, "")
-
-  # canonicalize whitespace
-  gsub(/[ \t]+/, " ") # mawk doesn't understand \s
-  gsub(/ *, */, ",")
-  gsub(/ *: */, ": ")
-  gsub(/ $/, "")
-  gsub(/^ /, "")
-}
-
-# check for assembler directives which we care about
-/^\.(section|data|text)/ {
-  # a .cfi_startproc/.cfi_endproc pair should be within the same section
-  # otherwise, clang will choke when generating ELF output
-  if (in_function) {
-    print ".cfi_endproc"
-    in_function = 0
-  }
-}
-/^\.type [a-zA-Z0-9_]+,@function/ {
-  functions[substr($2, 1, length($2)-10)] = 1
-}
-# not interested in assembler directives beyond this, just pass them through
-/^\./ {
-  print
-  next
-}
-
-/^[a-zA-Z0-9_]+:/ {
-  label = substr($1, 1, length($1)-1) # drop trailing :
-
-  if (called == label) {
-    # note adjustment of stack pointer from "call label; label:"
-    adjust_sp_offset(8)
-  }
-
-  if (functions[label]) {
-    if (in_function)
-      print ".cfi_endproc"
-
-    in_function = 1
-    print ".cfi_startproc"
-
-    for (register in saved)
-      delete saved[register]
-    for (register in dirty)
-      delete dirty[register]
-  }
-
-  # an instruction may follow on the same line, so continue processing
-}
-
-/^$/ { next }
-
-{
-  called = ""
-  printf ".loc 1 %d\n", line_number
-  print
-}
-
-# KEEPING UP WITH THE STACK POINTER
-# %rsp should only be adjusted by pushing/popping or adding/subtracting constants
-#
-/pushl?/ {
-  adjust_sp_offset(8)
-}
-/popl?/ {
-  adjust_sp_offset(-8)
-}
-/addl? \$-?(0x[0-9a-fA-F]+|[0-9]+),%rsp/ { adjust_sp_offset(-get_const1()) }
-/subl? \$-?(0x[0-9a-fA-F]+|[0-9]+),%rsp/ { adjust_sp_offset(get_const1()) }
-
-/call/ {
-  if (match($0, /call [0-9]+f/)) # "forward" label
-    called = substr($0, RSTART+5, RLENGTH-6)
-  else if (match($0, /call [0-9a-zA-Z_]+/))
-    called = substr($0, RSTART+5, RLENGTH-5)
-}
-
-# TRACKING REGISTER VALUES FROM THE PREVIOUS STACK FRAME
-#
-/pushl? %r(ax|bx|cx|dx|si|di|bp|8|9|10|11|12|13|14|15)/ { # don't match "push (%reg)"
-  # if a register is being pushed, and its value has not changed since the
-  #   beginning of this function, the pushed value can be used when printing
-  #   local variables at the next level up the stack
-  # emit '.cfi_rel_offset' for that
-
-  if (in_function) {
-    register = get_reg()
-    if (!saved[register] && !dirty[register]) {
-      printf ".cfi_rel_offset %s,0\n", register
-      saved[register] = 1
-    }
-  }
-}
-
-/movl? %r(ax|bx|cx|dx|si|di|bp|8|9|10|11|12|13|14|15),-?(0x[0-9a-fA-F]+|[0-9]+)?\(%rsp\)/ {
-  if (in_function) {
-    register = get_reg()
-    if (match($0, /-?(0x[0-9a-fA-F]+|[0-9]+)\(%rsp\)/)) {
-      offset = parse_const(substr($0, RSTART, RLENGTH-6))
-    } else {
-      offset = 0
-    }
-    if (!saved[register] && !dirty[register]) {
-      printf ".cfi_rel_offset %s,%d\n", register, offset
-      saved[register] = 1
-    }
-  }
-}
-
-# IF REGISTER VALUES ARE UNCEREMONIOUSLY TRASHED
-# ...then we want to know about it.
-#
-function trashed(register) {
-  if (in_function && !saved[register] && !dirty[register]) {
-    printf ".cfi_undefined %s\n", register
-  }
-  dirty[register] = 1
-}
-# this does NOT exhaustively check for all possible instructions which could
-# overwrite a register value inherited from the caller (just the common ones)
-/mov.*,%[er]?([abcd][xlh]|si|di|bp|8|9|10|11|12|13|14|15)$/ { trashed(get_reg2()) }
-/(add|addl|sub|subl|and|or|xor|lea|sal|sar|shl|shr).*,%[er]?([abcd][xlh]|si|di|bp|8|9|10|11|12|13|14|15)$/ {
-  trashed(get_reg2())
-}
-/^i?mul [^,]*$/ { trashed("rax"); trashed("rdx") }
-/^i?mul.*,%[er]?([abcd][xlh]|si|di|bp|8|9|10|11|12|13|14|15)$/ { trashed(get_reg2()) }
-/^i?div/ { trashed("rax"); trashed("rdx") }
-
-/(dec|inc|not|neg|pop) %[er]?([abcd][xlh]|si|di|bp|8|9|10|11|12|13|14|15)/  { trashed(get_reg()) }
-/cpuid/ { trashed("rax"); trashed("rbx"); trashed("rcx"); trashed("rdx") }
-
-END {
-  if (in_function)
-    print ".cfi_endproc"
-}