[multiple changes]

2004-02-09  Ed Schonberg  <schonberg@gnat.com>

	* exp_ch4.adb (Expand_N_Op_Eq): When looking for the primitive equality
	for a tagged type, verify that both formals have the same type.

	* exp_ch6.adb (Add_Call_By_Copy_Code): Initialize properly the
	temporary when the formal is an in-parameter and the actual a possibly
	unaligned slice.

	* exp_ch9.adb (Expand_Entry_Barrier): Resolve barrier expression even
	when expansion is disabled, to ensure proper name capture with
	overloaded literals.  Condition can be of any boolean type, resolve
	accordingly.

	* sem_ch8.adb (Analyze_Subprogram_Renaming): Emit warning if the
	renaming is for a formal subprogram with a default operator name, and
	there is a usable operator that is visible at the point of
	instantiation.

2004-02-09  Robert Dewar  <dewar@gnat.com>

	* ali.adb (Scan_Ali) Add Ignore_Errors argument. This is a major
	rewrite to ignore errors in ali files, intended to allow tools downward
	compatibility with new versions of ali files.

	* ali.ads: Add new parameter Ignore_Errors

	* bcheck.adb (Check_Consistent_Restrictions): Fix error of sometimes
	duplicating the error message giving the file with restrictions.

	* debug.adb: Add debug flag I for gnatbind

	* errout.adb (Set_Msg_Insertion_Node): Suppress extra quotes around
	operators for the case where the operator is a defining operator.

	* exp_ch3.adb: Minor reformatting (new function spec format).

	* exp_ch4.adb: Add comment for previous change, and make minor
	adjustment to loop to always check for improper loop termination.
	Minor reformatting throughout (new function spec format).

	* gnatbind.adb: Implement -di debug flag for gnatbind

	* gnatlink.adb: Call Scan_ALI with Ignore_Errors set to True

	* gnatls.adb: Call Scan_ALI with Ignore_Errors set to True

	* lib-load.adb: Fix bad assertion.
	Found by testing and code reading.
	Minor reformatting.

	* lib-load.ads: Minor reformatting.

	* lib-writ.adb: There is only one R line now.

	* lib-writ.ads: Add documentation on making downward compatible changes
	to ali files so old tools work with new ali files.
	There is only one R line now.
	Add documentation on format incompatibilities (with special GPS note)

	* namet.ads, namet.adb: (Is_Operator_Name): New procedure

	* par-load.adb: Minor reformatting

	* sem_ch8.adb: Fix to error message from last update
	Minor reformatting and restructuring of code from last update

	* par-prag.adb, snames.adb, snames.ads, snames.h,
	sem_prag.adb: Implement pragma Profile.

	* stylesw.adb: Implement -gnatyN switch to turn off all style check
	options.

	* usage.adb: Add line for -gnatyN switch

	* vms_data.ads: Add entry STYLE_CHECKS=NONE for -gnatyN

From-SVN: r77537

1 files changed, 70 insertions, 19 deletions

diff --git a/gcc/ada/lib-writ.ads b/gcc/ada/lib-writ.ads
index 6aa8dcf..e21112c 100644
--- a/gcc/ada/lib-writ.ads
+++ b/gcc/ada/lib-writ.ads
@@ -32,10 +32,6 @@ package Lib.Writ is
    -- Format of Library Information --
    -----------------------------------
 
-   --  Note: the contents of the ali file are summarized in the GNAT
-   --  user's guide, so if any non-trivial changes are made to this
-   --  section, they should be reflected in the user's guide.
-
    --  This section  describes the format of the library information that is
    --  associated with object files. The exact method of this association is
    --  potentially implementation dependent and is described and implemented
@@ -50,6 +46,48 @@ package Lib.Writ is
 
    --    Key_Character parameter parameter ...
 
+   --  The following sections describe the format of these lines in detail
+
+   --------------------------------------
+   -- Making Changes to the ALI Format --
+   --------------------------------------
+
+   --  A number of tools use ali.adb to parse ali files. This means
+   --  that changes to this format can cause old versions of these tools
+   --  to be incompatible with new versions of the compiler. Any changes
+   --  to ali file formats must be carefully evaluated to understand any
+   --  such possible conflicts, and in particular, it is very undesirable
+   --  to create conflicts between older versions of GPS and newer versions
+   --  of the compiler.
+
+   --  If the following guidelines are respected, downward compatibility
+   --  problems (old tools reading new ali files) should be minimized:
+
+   --    The basic key character format must be kept.
+
+   --    The V line must be the first line, this is checked by ali.adb
+   --    even in Ignore_Errors mode, and is used to verify that the file
+   --    at hand is indeed likely intended to be an ali file.
+
+   --    The P line must be present, though may be modified in contents
+   --    according to remaining guidelines. Again, ali.adb assumes the
+   --    P line is present even in Ignore_Errors mode.
+
+   --    New modifiers can generally be added (in particular adding new
+   --    two letter modifiers to the P or U lines is always safe)
+
+   --    Adding entirely new lines (with a new key letter) to the ali
+   --    file is always safe, at any point (other than before the V
+   --    line), since suchy lines will be ignored.
+
+   --  Following the guidelines in this section should ensure that this
+   --  problem is minimized and that old tools will be able to deal
+   --  successfully with new ali formats. Note that this does not apply
+   --  to the compiler itself, which always requires consistency between
+   --  the ali files and the binder. That is because one of the main
+   --  functions of the binder is to ensure consistency of the partition,
+   --  and this can be compromised if the ali files are inconsistent.
+
    ------------------
    -- Header Lines --
    ------------------
@@ -72,6 +110,10 @@ package Lib.Writ is
    --      library info described in this package, or modifications to
    --      calling sequences, or to the way that data is represented.
 
+   --    Note: the V line absolutely must be the first line, and no change
+   --    to the ALI format should change this, since even in Ignore_Errors
+   --    mode, Scan_ALI insists on finding a V line.
+
    --  ---------------------
    --  -- M  Main Program --
    --  ---------------------
@@ -201,21 +243,26 @@ package Lib.Writ is
    --      possible cases. These values are checked for consistency by the
    --      binder and then copied to the generated binder output file.
 
+   --    Note: The P line must be present. Even in Ignore_Errors mode,
+   --    Scan_ALI insists on finding a P line. So if changes are made to
+   --    the ALI format, they should not include removing the P line!
+
    --  ---------------------
    --  -- R  Restrictions --
    --  ---------------------
 
-   --  Two lines are generated to record the status of restrictions that can
-   --  be specified by pragma Restrictions. The first of these lines refers
-   --  to Restriction_Id values:
+   --  The R line records the status of restrictions generated by pragma
+   --  Restrictions encountered, as well as information on what the compiler
+   --  has been able to determine with respect to restrictions violations.
+   --  The format is:
 
-   --    R <<restriction-characters>>
+   --    R <<restriction-characters>> space <<restriction-param-id-entries>>
 
-   --      This line records information regarding restrictions that do
-   --      not take parameter values. Here "restriction-characters is a
-   --      string of characters, one for each value (in order) defined
-   --      in Restrict.All_Boolean_Restrictions. There are three possible
-   --      settings for each restriction:
+   --      The first parameter is a string of characters that records
+   --      information regarding restrictions that do not take parameter
+   --      not take parameter values. It is a string of characters, one
+   --      character for each value (in order) in All_Boolean_Restrictions.
+   --      There are three possible settings for each restriction:
 
    --        r   Restricted. Unit was compiled under control of a pragma
    --            Restrictions for the corresponding restriction. In
@@ -236,9 +283,8 @@ package Lib.Writ is
    --      has "v", which is not permitted, since these restrictions
    --      are partition-wide.
 
-   --  The second R line refers to parameter restrictions:
-
-   --    R <<restriction-parameter-id-entries>>
+   --  Following a space, the second parameter refers to restriction
+   --  identifiers for which a parameter is given.
 
    --      The parameter is a string of entries, one for each value in
    --      Restrict.All_Parameter_Restrictions. Each entry has two
@@ -284,9 +330,14 @@ package Lib.Writ is
    --         vN+ A violation was detected. The compiler cannot determine
    --             the exact count of violations, but it is at least N.
 
-   --      There are no spaces in the line, so the entry for the example
-   --      in the header of this section for Max_Tasks would appear as
-   --      the string r4v3.
+   --      There are no spaces within the parameter string, so the entry
+   --      described above in the header of this section for Max_Tasks would
+   --      appear as the string r4v3.
+
+   --      Note: The restrictions line is required to be present. Even in
+   --      Ignore_Errors mode, Scan_ALI expects to find an R line and will
+   --      signal a fatal error if it is missing. This means that future
+   --      changes to the ALI file format must retain the R line.
 
    --  ------------------------
    --  -- I Interrupt States --