   ---------------------------------
   -- Summary of Debug Flag Usage --
   ---------------------------------

   --  Debug flags for compiler (GNAT1 and GNATF)

   --  da   Generate messages tracking semantic analyzer progress
   --  db
   --  dc   List names of units as they are compiled
   --  dd   Dynamic allocation of tables messages generated
   --  de   List the entity table
   --  df   Full tree/source print (includes withed units)
   --  dg   Print source from tree (generated code only)
   --  dh   Generate listing showing loading of name table hash chains
   --  di   Generate messages for visibility linking/delinking
   --  dj   Juxtapose itype declarations in listed source
   --  dk   Generate GNATBUG message on abort, even if previous errors
   --  dl   Generate unit load trace messages
   --  dm
   --  dn   Generate messages for node/list allocation
   --  do   Print source from tree (original code only)
   --  dp   Generate messages for parser scope stack push/pops
   --  dq
   --  dr   Generate parser resynchronization messages
   --  ds   Print source from tree (including original and generated stuff)
   --  dt   Print full tree
   --  du   Uncheck distribution pragmas
   --  dv   Output trace of overload resolution
   --  dw   Print trace of semantic scope stack
   --  dx   Force expansion on, even if no code being generated
   --  dy   Print tree of package Standard
   --  dz   Print source of package Standard

   --  d1   Error msgs have node numbers where possible
   --  d2   Eliminate error flags in verbose form error messages
   --  d3   Dump bad node in Comperr on an abort
   --  d4   Inhibit automatic krunch of predefined library unit files
   --  d5   Debug output for tree read/write
   --  d6   Default access unconstrained to thin pointers
   --  d7
   --  d8
   --  d9

   --  Debug flags for binder (GNATBIND)

   --  da
   --  db
   --  dc  List units as they are chosen
   --  dd
   --  de
   --  df
   --  dg
   --  dh
   --  di
   --  dj
   --  dk
   --  dl
   --  dm
   --  dn  List details of manipulation of Num_Pred values
   --  do
   --  dp
   --  dq
   --  dr
   --  ds
   --  dt
   --  du
   --  dv
   --  dw
   --  dx
   --  dy
   --  dz

   --  d1
   --  d2
   --  d3
   --  d4
   --  d5
   --  d6
   --  d7
   --  d8
   --  d9

   --  Debug flags used in package Make and its clients (e.g. GNATMAKE)

   --  da
   --  db
   --  dc
   --  dd
   --  de
   --  df
   --  dg
   --  dh
   --  di
   --  dj
   --  dk
   --  dl
   --  dm
   --  dn
   --  do
   --  dp  Prints the contents of the Q used by Make.Compile_Sources
   --  dq  Prints source files as they are enqueued and dequeued
   --  dr
   --  ds
   --  dt
   --  du
   --  dv
   --  dw  Prints the list of units withed by the unit currently explored
   --  dx
   --  dy
   --  dz

   --  d1
   --  d2
   --  d3
   --  d4
   --  d5
   --  d6
   --  d7
   --  d8
   --  d9

   --------------------------------------------
   -- Documentation for Compiler Debug Flags --
   --------------------------------------------

   --  da   Generate messages tracking semantic analyzer progress. A message
   --       is output showing each node as it gets analyzed, expanded,
   --       resolved, or evaluated. This option is useful for finding out
   --       exactly where a bomb during semantic analysis is occurring.

   --  dc   List names of units as they are compiled. One line of output will
   --       be generated at the start of compiling each unit (package or
   --       subprogram).

   --  dd   Dynamic allocation of tables messages generated. Each time a
   --       table is reallocated, a line is output indicating the expansion.

   --  de   List the entity table

   --  df   Full tree/source print (includes withed units). Normally the tree
   --       output (dt) or recreated source output (dg,do,ds) includes only
   --       the main unit. If df is set, then the output in either case
   --       includes all compiled units (see also dg,do,ds,dt). Note that to
   --       be effective, this swich must be used in combination with one or
   --       more of dt, dg, do or ds.

   --  dg   Print the source recreated from the generated tree. In the case
   --       where the tree has been rewritten this output includes only the
   --       generated code, not the original code (see also df,do,ds,dz).

   --  dh   Generates a table at the end of a compilation showing how the hash
   --       table chains built by the Namet package are loaded. This is useful
   --       in ensuring that the hashing algorithm (in Namet.Hash) is working
   --       effectively with typical sets of program identifiers.

   --  di   Generate messages for visibility linking/delinking

   --  dj   Normally the generated source listing does not include itypes,
   --       since they greatly confuse the listing. This debug switch causes
   --       the itypes to be listed right next ("juxtaposed") to the construct
   --       to which the itype is attached.

   --  dk   Immediate kill on abort. Normally on an abort (i.e. a call to
   --       Comperr.Compiler_Abort), the GNATBUG message is not given if
   --       there is a previous error. This debug switch bypasses this test
   --       and gives the message unconditionally (useful for debugging).

   --  dl   Generate unit load trace messages. A line of traceback output is
   --       generated each time a request is made to the library manager to
   --       load a new unit.

   --  dn   Generate messages for node/list allocation. Each time a node or
   --       list header is allocated, a line of output is generated. Certain
   --       other basic tree operations also cause a line of output to be
   --       generated. This option is useful in seeing where the parser is
   --       blowing up.;

   --  do   Print the source recreated from the generated tree. In the case
   --       where the tree has been rewritten, this output includes only the
   --       original code, not the generated code (see also df,dg,ds,dz).

   --  dp   Generate messages for parser scope stack push/pops. A line of
   --       output by the parser each time the parser scope stack is either
   --       pushed or popped. Useful in debugging situations where the
   --       parser scope stack ends up incorrectly synchronized

   --  dr   Generate parser resynchronization messages. Normally the parser
   --       resynchronizes quietly. With this debug option, two messages
   --       are generated, one when the parser starts a resynchronization
   --       skip, and another when it resumes parsing. Useful in debugging
   --       inadequate error recovery situations.

   --  ds   Print the source recreated from the generated tree. In the case
   --       where the tree has been rewritten this output includes both the
   --       generated code and the original code with the generated code
   --       being enlosed in curly brackets (see also df,do,ds,dz)

   --  dt   Print full tree. The generated tree is output (see also df,dy)

   --  du   Uncheck categorization pragmas. This debug switch causes the
   --       categorization pragmas (Pure, Preelaborate etc) to be ignored
   --       so that normal checks are not made (this is particularly useful
   --       for adding temporary debugging code to units that have pragmas
   --       that are inconsistent with the debugging code added.

   --  dw   Write semantic scope stack messages. Each time a scope is created
   --       or removed, a message is output (see the Sem_Ch8.New_Scope and
   --       Sem_Ch8.Pop_Scope subprograms).

   --  dx   Force expansion on, even if no code being generated. Normally the
   --       expander is inhibited if no code is generated. This switch forces
   --       expansion to proceed normally even if the backend is not being
   --       called. This is particularly useful for debugging purposes when
   --       using the front-end only version of the compiler (which normally
   --       would never do any expansion).

   --  dy   Print tree of package Standard. Normally the tree print out does
   --       not include package Standard, even if the -df switch is set. This
   --       switch forces output of the internal tree built for Standard.

   --  dz   Print source of package Standard. Normally the source print out
   --       does not include package Standard, even if the -df switch is set.
   --       This switch forces output of the source recreated from the internal
   --       tree built for Standard.

   --  d1   Error msgs have node numbers where possible. Normally error
   --       messages have only source locations. This option is useful when
   --       debugging errors caused by expanded code, where the source location
   --       does not give enough information.

   --  d2   Suppress output of the error position flags for verbose form error
   --       messages. The messages are still interspersed in the listing, but
   --       without any error flags or extra blank lines. Also causes an extra
   --       <<< to be output at the right margin. This is intended to be the
   --       easiest format for checking conformance of ACVC B tests.

   --  d3   Causes Comperr to dump the contents of the node for which an abort
   --       was detected (normally only the Node_Id of the node is output).

   --  d4   Inhibits automatic krunching of predefined library unit file names.
   --       Normally, as described in the spec of package Krunch, such files
   --       are automatically krunched to 8 characters, with special treatment
   --       of the prefixes Ada, System, and Interfaces. Setting this debug
   --       switch disables this special treatment.

   --  d6   Normally access-to-unconstrained-array types are represented
   --       using fat (double) pointers. Using this debug flag causes them
   --       to default to thin. This can be used to test the performance
   --       implications of using thin pointers, and also to test that the
   --       compiler functions correctly with this choice.

   ------------------------------------------
   -- Documentation for Binder Debug Flags --
   ------------------------------------------

   --  dc  List units as they are chosen. As units are selected for addition to
   --      the elaboration order, a line of output is generated showing which
   --      unit has been selected.

   --  dn  List details of manipulation of Num_Pred values during execution of
   --      the algorithm used to determine a correct order of elaboration. This
   --      is useful in diagnosing any problems in its behavior.

   ------------------------------------------------------------
   -- Documentation for the Debug Flags used in package Make --
   ------------------------------------------------------------

   --  Please note that such flags apply to all of Make clients,
   --  such as gnatmake.

   --  dp  Prints the Q used by routine Make.Compile_Sources every time
   --      we go around the main compile loop of Make.Compile_Sources

   --  dq  Prints source files as they are enqueued and dequeued in the Q
   --      used by routine Make.Compile_Sources. Useful to figure out the
   --      order in which sources are recompiled.

   --  dw  Prints the list of units withed by the unit currently explored
   --      during the main loop of Make.Compile_Sources.
