FM / kernel

/usr/share/boost-build/src/kernel

Name	Size	Mode	Actions
boost-build.jam	194	0644	edit dl rm
bootstrap.jam	8374	0644	edit dl rm
class.jam	9749	0644	edit dl rm
errors.jam	7471	0644	edit dl rm
modules.jam	12071	0644	edit dl rm

Edit: /usr/share/boost-build/src/kernel/errors.jam (7471B)

# Copyright 2003 Dave Abrahams
# Copyright 2004 Vladimir Prus
# Distributed under the Boost Software License, Version 1.0.
# (See accompanying file LICENSE_1_0.txt or copy at
# http://www.boost.org/LICENSE_1_0.txt)

# Print a stack backtrace leading to this rule's caller. Each argument
# represents a line of output to be printed after the first line of the
# backtrace.
#
rule backtrace ( skip-frames prefix messages * : * )
{
    local frame-skips = 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77 81 ;
    local drop-elements = $(frame-skips[$(skip-frames)]) ;
    if ! ( $(skip-frames) in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 )
    {
        ECHO "warning: backtrace doesn't support skipping $(skip-frames) "
            "frames; using 1 instead." ;
        drop-elements = 5 ;
    }

local args = $(.args) ;
    if $(.user-modules-only)
    {
        local bt = [ nearest-user-location ] ;
        if $(bt)
        {
            ECHO $(prefix) at $(bt) ;
        }
        for local n in $(args)
        {
            if $($(n))-is-defined
            {
                ECHO $(prefix) $($(n)) ;
            }
        }
    }
    else
    {
        # Get the whole backtrace, then drop the initial quadruples
        # corresponding to the frames that must be skipped.
        local bt = [ BACKTRACE ] ;
        bt = $(bt[$(drop-elements)-]) ;

while $(bt)
        {
            local m = [ MATCH ^(.+)\\.$ : $(bt[3]) ] ;
            ECHO "$(bt[1]):$(bt[2]):" "in" $(bt[4]) "from module" $(m) ;

# The first time through, print each argument on a separate line.
            for local n in $(args)
            {
                if $($(n))-is-defined
                {
                    ECHO $(prefix) $($(n)) ;
                }
            }
            args = ;  # Kill args so that this never happens again.

# Move on to the next quadruple.
            bt = $(bt[5-]) ;
        }
    }
}

.args ?= messages 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 ;
.disabled ?= ;
.last-error-$(.args) ?= ;

# try-catch --
#
# This is not really an exception-handling mechanism, but it does allow us to
# perform some error-checking on our error-checking. Errors are suppressed after
# a try, and the first one is recorded. Use catch to check that the error
# message matched expectations.

# Begin looking for error messages.
#
rule try ( )
{
    .disabled += true ;
    .last-error-$(.args) = ;
}

# Stop looking for error messages; generate an error if an argument of messages
# is not found in the corresponding argument in the error call.
#
rule catch ( messages * : * )
{
    .disabled = $(.disabled[2-]) ;  # Pop the stack.

import sequence ;

if ! $(.last-error-$(.args))-is-defined
    {
        error-skip-frames 3 expected an error, but none occurred ;
    }
    else
    {
        for local n in $(.args)
        {
            if ! $($(n)) in $(.last-error-$(n))
            {
                local v = [ sequence.join $($(n)) : " " ] ;
                v ?= "" ;
                local joined = [ sequence.join $(.last-error-$(n)) : " " ] ;

.last-error-$(.args) = ;
                error-skip-frames 3 expected \"$(v)\" in argument $(n) of error
                    : got \"$(joined)\" instead ;
            }
        }
    }
}

rule error-skip-frames ( skip-frames messages * : * )
{
    if ! $(.disabled)
    {
        backtrace $(skip-frames) "error:" $(messages) : $(2) : $(3) : $(4) : $(5)
            : $(6) : $(7) : $(8) : $(9) : $(10) : $(11) : $(12) : $(13) : $(14)
            : $(15) : $(16) : $(17) : $(18) : $(19) ;
        EXIT ;
    }
    else if ! $(.last-error-$(.args))
    {
        for local n in $(.args)
        {
            # Add an extra empty string so that we always have something in the
            # event of an error.
            .last-error-$(n) = $($(n)) "" ;
        }
    }
}

if --no-error-backtrace in [ modules.peek : ARGV ]
{
    .no-error-backtrace = true ;
}

# Print an error message with a stack backtrace and exit.
#
rule error ( messages * : * )
{
    if $(.no-error-backtrace)
    {
        local first-printed ;
        # Print each argument on a separate line.
        for local n in $(.args)
        {
            if $($(n))-is-defined
            {
                if ! $(first-printed)
                {
                    ECHO "error:" $($(n)) ;
                    first-printed = true ;
                }
                else
                {
                    ECHO $($(n)) ;
                }
            }
        }
        EXIT ;
    }
    else
    {
        error-skip-frames 3 $(1) : $(2) : $(3) : $(4) : $(5) : $(6) : $(7) :
            $(8) : $(9) : $(10) : $(11) : $(12) : $(13) : $(14) : $(15) : $(16)
            : $(17) : $(18) : $(19) ;
    }
}

# Same as 'error', but the generated backtrace will include only user files.
#
rule user-error ( messages * : * )
{
    .user-modules-only = 1 ;
    error-skip-frames 3 $(1) : $(2) : $(3) : $(4) : $(5) : $(6) : $(7) : $(8) :
        $(9) : $(10) : $(11) : $(12) : $(13) : $(14) : $(15) : $(16) : $(17) :
        $(18) : $(19) ;
}

# Print a warning message with a stack backtrace and exit.
#
rule warning
{
    backtrace 2 "warning:" $(1) : $(2) : $(3) : $(4) : $(5) : $(6) : $(7) : $(8) :
        $(9) : $(10) : $(11) : $(12) : $(13) : $(14) : $(15) : $(16) : $(17) :
        $(18) : $(19) ;
}

# Convert an arbitrary argument list into a list with ":" separators and quoted
# elements representing the same information. This is mostly useful for
# formatting descriptions of arguments with which a rule was called when
# reporting an error.
#
rule lol->list ( * )
{
    local result ;
    local remaining = 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 ;
    while $($(remaining))
    {
        local n = $(remaining[1]) ;
        remaining = $(remaining[2-]) ;

if $(n) != 1
        {
            result += ":" ;
        }
        result += \"$($(n))\" ;
    }
    return $(result) ;
}

# Return the file:line for the nearest entry in backtrace which correspond to a
# user module.
#
rule nearest-user-location ( )
{
    local bt = [ BACKTRACE ] ;

local result ;
    while $(bt) && ! $(result)
    {
        local m = [ MATCH ^(.+)\\.$ : $(bt[3]) ] ;
        local user-modules = "([Jj]amroot(.jam|.v2|)|([Jj]amfile(.jam|.v2|)|user-config.jam|site-config.jam|project-config.jam|project-root.jam)" ;

if [ MATCH $(user-modules) : $(bt[1]:D=) ]
        {
            result = "$(bt[1]):$(bt[2])" ;
        }
        bt = $(bt[5-]) ;
    }
    return $(result) ;
}

# If optimized rule is available in Jam, use it.
if NEAREST_USER_LOCATION in [ RULENAMES ]
{
    rule nearest-user-location ( )
    {
        local r = [ NEAREST_USER_LOCATION ] ;
        return "$(r[1]):$(r[2])" ;
    }
}

rule __test__ ( )
{
    # Show that we can correctly catch an expected error.
    try ;
    {
        error an error occurred : somewhere ;
    }
    catch an error occurred : somewhere ;

# Show that unexpected errors generate real errors.
    try ;
    {
        try ;
        {
            error an error occurred : somewhere ;
        }
        catch an error occurred : nowhere ;
    }
    catch expected \"nowhere\" in argument 2 ;

# Show that not catching an error where one was expected is an error.
    try ;
    {
        try ;
        {
        }
        catch ;
    }
    catch expected an error, but none occurred ;
}

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