make: sync VarEvalMode constant names with their debug log names

make: clean up comments

No binary change, except for line numbers in assertions.

tests/make: replace 'variable expression' with 'expression'

Each expression is based on a variable, there's no need for the
verbosity. The wording in make's diagnostics will be changed in a
follow-up commit.

tests/make: fix grammar in a test comment

tests/make: extend test for the 'empty' function in conditions

tests/make: force line-based diagnostics to be listed in the tests

This way, contradictions between the intended output and the actual
output are closer together and have a better chance of being spotted.

tests/make: clean up comments, extend a few tests

tests/make: improve explanations in test for 'empty' function

tests/make: test function names without following '('

make: inline ParseEmptyArg into CondParser_FuncCallEmpty

No functional change.

tests/make: proofread and clean up comments for function 'empty'

This prepares a refactoring for handling the function 'empty' in
conditionals like '.if'.

The function 'empty' is fundamentally different from all other functions
since it is parsed differently and passes its result on different path
than the other functions. Splitting up these code paths will untangle
the control flow of parsing a condition like 'empty(VARNAME)'. It will
also remove several ARGSUSED and MAKE_ATTR_UNUSED that make the current
code smell.

make: clean up remaining references to VarEvalFlags

VarEvalFlags has been replaced with VarEvalMode. There were some
comments and tests that still referred to the old names.

No functional change.

make: replace enum bit-field with struct bit-field for VarEvalFlags

This makes the code easier to read, especially in var.c. It also makes
debugging sessions easier since some debuggers don't show enum
bit-fields symbolically as soon as more than one bit is set.

The code outside var.c is basically unchanged, except that instead of
passing the individual flags, there are 4 predefined evaluation modes.
These suffice for all practical use cases. Only in the implementation
deep inside var.c, the value of the flags keepDollar and keepUndef
differs.

There is no way of passing the struct to EnumFlags_ToString, which means
the ToString function has to be spelled out explicitly. This allows for
fine-tuning the representation in the debug log, to reduce the amount of
uppercae letters.

No functional change.

make: update constant names in comments

No functional change.

make(1): move test for recursive variable to cond-func-empty

Previously, the documentation of that test was much too short to explain
all the effects that happened in the bug situation from 2020-06-28 until
2020-07-02.

make(1): clean up some tests

Fix some mistakes in comments.

Improve some comments to be easier understandable.

Inline variables that are irrelevant for the test at hand (RUN,
MAKE_CMD).

Remove references to functions and constants that have since been removed
or renamed.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

make: clean up comments

No binary change, except for line numbers in assertions.

tests/make: replace 'variable expression' with 'expression'

Each expression is based on a variable, there's no need for the
verbosity. The wording in make's diagnostics will be changed in a
follow-up commit.

tests/make: fix grammar in a test comment

tests/make: extend test for the 'empty' function in conditions

tests/make: force line-based diagnostics to be listed in the tests

This way, contradictions between the intended output and the actual
output are closer together and have a better chance of being spotted.

tests/make: clean up comments, extend a few tests

tests/make: improve explanations in test for 'empty' function

tests/make: test function names without following '('

make: inline ParseEmptyArg into CondParser_FuncCallEmpty

No functional change.

tests/make: proofread and clean up comments for function 'empty'

This prepares a refactoring for handling the function 'empty' in
conditionals like '.if'.

The function 'empty' is fundamentally different from all other functions
since it is parsed differently and passes its result on different path
than the other functions. Splitting up these code paths will untangle
the control flow of parsing a condition like 'empty(VARNAME)'. It will
also remove several ARGSUSED and MAKE_ATTR_UNUSED that make the current
code smell.

make: clean up remaining references to VarEvalFlags

VarEvalFlags has been replaced with VarEvalMode. There were some
comments and tests that still referred to the old names.

No functional change.

make: replace enum bit-field with struct bit-field for VarEvalFlags

This makes the code easier to read, especially in var.c. It also makes
debugging sessions easier since some debuggers don't show enum
bit-fields symbolically as soon as more than one bit is set.

The code outside var.c is basically unchanged, except that instead of
passing the individual flags, there are 4 predefined evaluation modes.
These suffice for all practical use cases. Only in the implementation
deep inside var.c, the value of the flags keepDollar and keepUndef
differs.

There is no way of passing the struct to EnumFlags_ToString, which means
the ToString function has to be spelled out explicitly. This allows for
fine-tuning the representation in the debug log, to reduce the amount of
uppercae letters.

No functional change.

make: update constant names in comments

No functional change.

make(1): move test for recursive variable to cond-func-empty

Previously, the documentation of that test was much too short to explain
all the effects that happened in the bug situation from 2020-06-28 until
2020-07-02.

make(1): clean up some tests

Fix some mistakes in comments.

Improve some comments to be easier understandable.

Inline variables that are irrelevant for the test at hand (RUN,
MAKE_CMD).

Remove references to functions and constants that have since been removed
or renamed.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

tests/make: replace 'variable expression' with 'expression'

Each expression is based on a variable, there's no need for the
verbosity. The wording in make's diagnostics will be changed in a
follow-up commit.

tests/make: fix grammar in a test comment

tests/make: extend test for the 'empty' function in conditions

tests/make: force line-based diagnostics to be listed in the tests

This way, contradictions between the intended output and the actual
output are closer together and have a better chance of being spotted.

tests/make: clean up comments, extend a few tests

tests/make: improve explanations in test for 'empty' function

tests/make: test function names without following '('

make: inline ParseEmptyArg into CondParser_FuncCallEmpty

No functional change.

tests/make: proofread and clean up comments for function 'empty'

This prepares a refactoring for handling the function 'empty' in
conditionals like '.if'.

The function 'empty' is fundamentally different from all other functions
since it is parsed differently and passes its result on different path
than the other functions. Splitting up these code paths will untangle
the control flow of parsing a condition like 'empty(VARNAME)'. It will
also remove several ARGSUSED and MAKE_ATTR_UNUSED that make the current
code smell.

make: clean up remaining references to VarEvalFlags

VarEvalFlags has been replaced with VarEvalMode. There were some
comments and tests that still referred to the old names.

No functional change.

make: replace enum bit-field with struct bit-field for VarEvalFlags

This makes the code easier to read, especially in var.c. It also makes
debugging sessions easier since some debuggers don't show enum
bit-fields symbolically as soon as more than one bit is set.

The code outside var.c is basically unchanged, except that instead of
passing the individual flags, there are 4 predefined evaluation modes.
These suffice for all practical use cases. Only in the implementation
deep inside var.c, the value of the flags keepDollar and keepUndef
differs.

There is no way of passing the struct to EnumFlags_ToString, which means
the ToString function has to be spelled out explicitly. This allows for
fine-tuning the representation in the debug log, to reduce the amount of
uppercae letters.

No functional change.

make: update constant names in comments

No functional change.

make(1): move test for recursive variable to cond-func-empty

Previously, the documentation of that test was much too short to explain
all the effects that happened in the bug situation from 2020-06-28 until
2020-07-02.

make(1): clean up some tests

Fix some mistakes in comments.

Improve some comments to be easier understandable.

Inline variables that are irrelevant for the test at hand (RUN,
MAKE_CMD).

Remove references to functions and constants that have since been removed
or renamed.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

tests/make: fix grammar in a test comment

tests/make: extend test for the 'empty' function in conditions

tests/make: force line-based diagnostics to be listed in the tests

This way, contradictions between the intended output and the actual
output are closer together and have a better chance of being spotted.

tests/make: clean up comments, extend a few tests

tests/make: improve explanations in test for 'empty' function

tests/make: test function names without following '('

make: inline ParseEmptyArg into CondParser_FuncCallEmpty

No functional change.

tests/make: proofread and clean up comments for function 'empty'

This prepares a refactoring for handling the function 'empty' in
conditionals like '.if'.

The function 'empty' is fundamentally different from all other functions
since it is parsed differently and passes its result on different path
than the other functions. Splitting up these code paths will untangle
the control flow of parsing a condition like 'empty(VARNAME)'. It will
also remove several ARGSUSED and MAKE_ATTR_UNUSED that make the current
code smell.

make: clean up remaining references to VarEvalFlags

VarEvalFlags has been replaced with VarEvalMode. There were some
comments and tests that still referred to the old names.

No functional change.

make: replace enum bit-field with struct bit-field for VarEvalFlags

This makes the code easier to read, especially in var.c. It also makes
debugging sessions easier since some debuggers don't show enum
bit-fields symbolically as soon as more than one bit is set.

The code outside var.c is basically unchanged, except that instead of
passing the individual flags, there are 4 predefined evaluation modes.
These suffice for all practical use cases. Only in the implementation
deep inside var.c, the value of the flags keepDollar and keepUndef
differs.

There is no way of passing the struct to EnumFlags_ToString, which means
the ToString function has to be spelled out explicitly. This allows for
fine-tuning the representation in the debug log, to reduce the amount of
uppercae letters.

No functional change.

make: update constant names in comments

No functional change.

make(1): move test for recursive variable to cond-func-empty

Previously, the documentation of that test was much too short to explain
all the effects that happened in the bug situation from 2020-06-28 until
2020-07-02.

make(1): clean up some tests

Fix some mistakes in comments.

Improve some comments to be easier understandable.

Inline variables that are irrelevant for the test at hand (RUN,
MAKE_CMD).

Remove references to functions and constants that have since been removed
or renamed.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

tests/make: extend test for the 'empty' function in conditions

tests/make: force line-based diagnostics to be listed in the tests

This way, contradictions between the intended output and the actual
output are closer together and have a better chance of being spotted.

tests/make: clean up comments, extend a few tests

tests/make: improve explanations in test for 'empty' function

tests/make: test function names without following '('

make: inline ParseEmptyArg into CondParser_FuncCallEmpty

No functional change.

tests/make: proofread and clean up comments for function 'empty'

This prepares a refactoring for handling the function 'empty' in
conditionals like '.if'.

The function 'empty' is fundamentally different from all other functions
since it is parsed differently and passes its result on different path
than the other functions. Splitting up these code paths will untangle
the control flow of parsing a condition like 'empty(VARNAME)'. It will
also remove several ARGSUSED and MAKE_ATTR_UNUSED that make the current
code smell.

make: clean up remaining references to VarEvalFlags

VarEvalFlags has been replaced with VarEvalMode. There were some
comments and tests that still referred to the old names.

No functional change.

make: replace enum bit-field with struct bit-field for VarEvalFlags

This makes the code easier to read, especially in var.c. It also makes
debugging sessions easier since some debuggers don't show enum
bit-fields symbolically as soon as more than one bit is set.

The code outside var.c is basically unchanged, except that instead of
passing the individual flags, there are 4 predefined evaluation modes.
These suffice for all practical use cases. Only in the implementation
deep inside var.c, the value of the flags keepDollar and keepUndef
differs.

There is no way of passing the struct to EnumFlags_ToString, which means
the ToString function has to be spelled out explicitly. This allows for
fine-tuning the representation in the debug log, to reduce the amount of
uppercae letters.

No functional change.

make: update constant names in comments

No functional change.

make(1): move test for recursive variable to cond-func-empty

Previously, the documentation of that test was much too short to explain
all the effects that happened in the bug situation from 2020-06-28 until
2020-07-02.

make(1): clean up some tests

Fix some mistakes in comments.

Improve some comments to be easier understandable.

Inline variables that are irrelevant for the test at hand (RUN,
MAKE_CMD).

Remove references to functions and constants that have since been removed
or renamed.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

tests/make: improve explanations in test for 'empty' function

tests/make: test function names without following '('

make: inline ParseEmptyArg into CondParser_FuncCallEmpty

No functional change.

tests/make: proofread and clean up comments for function 'empty'

This prepares a refactoring for handling the function 'empty' in
conditionals like '.if'.

The function 'empty' is fundamentally different from all other functions
since it is parsed differently and passes its result on different path
than the other functions. Splitting up these code paths will untangle
the control flow of parsing a condition like 'empty(VARNAME)'. It will
also remove several ARGSUSED and MAKE_ATTR_UNUSED that make the current
code smell.

make: clean up remaining references to VarEvalFlags

VarEvalFlags has been replaced with VarEvalMode. There were some
comments and tests that still referred to the old names.

No functional change.

make: replace enum bit-field with struct bit-field for VarEvalFlags

This makes the code easier to read, especially in var.c. It also makes
debugging sessions easier since some debuggers don't show enum
bit-fields symbolically as soon as more than one bit is set.

The code outside var.c is basically unchanged, except that instead of
passing the individual flags, there are 4 predefined evaluation modes.
These suffice for all practical use cases. Only in the implementation
deep inside var.c, the value of the flags keepDollar and keepUndef
differs.

There is no way of passing the struct to EnumFlags_ToString, which means
the ToString function has to be spelled out explicitly. This allows for
fine-tuning the representation in the debug log, to reduce the amount of
uppercae letters.

No functional change.

make: update constant names in comments

No functional change.

make(1): move test for recursive variable to cond-func-empty

Previously, the documentation of that test was much too short to explain
all the effects that happened in the bug situation from 2020-06-28 until
2020-07-02.

make(1): clean up some tests

Fix some mistakes in comments.

Improve some comments to be easier understandable.

Inline variables that are irrelevant for the test at hand (RUN,
MAKE_CMD).

Remove references to functions and constants that have since been removed
or renamed.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

tests/make: test function names without following '('

make: inline ParseEmptyArg into CondParser_FuncCallEmpty

No functional change.

tests/make: proofread and clean up comments for function 'empty'

This prepares a refactoring for handling the function 'empty' in
conditionals like '.if'.

The function 'empty' is fundamentally different from all other functions
since it is parsed differently and passes its result on different path
than the other functions. Splitting up these code paths will untangle
the control flow of parsing a condition like 'empty(VARNAME)'. It will
also remove several ARGSUSED and MAKE_ATTR_UNUSED that make the current
code smell.

make: clean up remaining references to VarEvalFlags

VarEvalFlags has been replaced with VarEvalMode. There were some
comments and tests that still referred to the old names.

No functional change.

make: replace enum bit-field with struct bit-field for VarEvalFlags

This makes the code easier to read, especially in var.c. It also makes
debugging sessions easier since some debuggers don't show enum
bit-fields symbolically as soon as more than one bit is set.

The code outside var.c is basically unchanged, except that instead of
passing the individual flags, there are 4 predefined evaluation modes.
These suffice for all practical use cases. Only in the implementation
deep inside var.c, the value of the flags keepDollar and keepUndef
differs.

There is no way of passing the struct to EnumFlags_ToString, which means
the ToString function has to be spelled out explicitly. This allows for
fine-tuning the representation in the debug log, to reduce the amount of
uppercae letters.

No functional change.

make: update constant names in comments

No functional change.

make(1): move test for recursive variable to cond-func-empty

Previously, the documentation of that test was much too short to explain
all the effects that happened in the bug situation from 2020-06-28 until
2020-07-02.

make(1): clean up some tests

Fix some mistakes in comments.

Improve some comments to be easier understandable.

Inline variables that are irrelevant for the test at hand (RUN,
MAKE_CMD).

Remove references to functions and constants that have since been removed
or renamed.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

make: inline ParseEmptyArg into CondParser_FuncCallEmpty

No functional change.

tests/make: proofread and clean up comments for function 'empty'

This prepares a refactoring for handling the function 'empty' in
conditionals like '.if'.

The function 'empty' is fundamentally different from all other functions
since it is parsed differently and passes its result on different path
than the other functions. Splitting up these code paths will untangle
the control flow of parsing a condition like 'empty(VARNAME)'. It will
also remove several ARGSUSED and MAKE_ATTR_UNUSED that make the current
code smell.

make: clean up remaining references to VarEvalFlags

VarEvalFlags has been replaced with VarEvalMode. There were some
comments and tests that still referred to the old names.

No functional change.

make: replace enum bit-field with struct bit-field for VarEvalFlags

This makes the code easier to read, especially in var.c. It also makes
debugging sessions easier since some debuggers don't show enum
bit-fields symbolically as soon as more than one bit is set.

The code outside var.c is basically unchanged, except that instead of
passing the individual flags, there are 4 predefined evaluation modes.
These suffice for all practical use cases. Only in the implementation
deep inside var.c, the value of the flags keepDollar and keepUndef
differs.

There is no way of passing the struct to EnumFlags_ToString, which means
the ToString function has to be spelled out explicitly. This allows for
fine-tuning the representation in the debug log, to reduce the amount of
uppercae letters.

No functional change.

make: update constant names in comments

No functional change.

make(1): move test for recursive variable to cond-func-empty

Previously, the documentation of that test was much too short to explain
all the effects that happened in the bug situation from 2020-06-28 until
2020-07-02.

make(1): clean up some tests

Fix some mistakes in comments.

Improve some comments to be easier understandable.

Inline variables that are irrelevant for the test at hand (RUN,
MAKE_CMD).

Remove references to functions and constants that have since been removed
or renamed.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

make: clean up remaining references to VarEvalFlags

VarEvalFlags has been replaced with VarEvalMode. There were some
comments and tests that still referred to the old names.

No functional change.

make: replace enum bit-field with struct bit-field for VarEvalFlags

This makes the code easier to read, especially in var.c. It also makes
debugging sessions easier since some debuggers don't show enum
bit-fields symbolically as soon as more than one bit is set.

The code outside var.c is basically unchanged, except that instead of
passing the individual flags, there are 4 predefined evaluation modes.
These suffice for all practical use cases. Only in the implementation
deep inside var.c, the value of the flags keepDollar and keepUndef
differs.

There is no way of passing the struct to EnumFlags_ToString, which means
the ToString function has to be spelled out explicitly. This allows for
fine-tuning the representation in the debug log, to reduce the amount of
uppercae letters.

No functional change.

make: update constant names in comments

No functional change.

make(1): move test for recursive variable to cond-func-empty

Previously, the documentation of that test was much too short to explain
all the effects that happened in the bug situation from 2020-06-28 until
2020-07-02.

make(1): clean up some tests

Fix some mistakes in comments.

Improve some comments to be easier understandable.

Inline variables that are irrelevant for the test at hand (RUN,
MAKE_CMD).

Remove references to functions and constants that have since been removed
or renamed.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

make: replace enum bit-field with struct bit-field for VarEvalFlags

This makes the code easier to read, especially in var.c. It also makes
debugging sessions easier since some debuggers don't show enum
bit-fields symbolically as soon as more than one bit is set.

The code outside var.c is basically unchanged, except that instead of
passing the individual flags, there are 4 predefined evaluation modes.
These suffice for all practical use cases. Only in the implementation
deep inside var.c, the value of the flags keepDollar and keepUndef
differs.

There is no way of passing the struct to EnumFlags_ToString, which means
the ToString function has to be spelled out explicitly. This allows for
fine-tuning the representation in the debug log, to reduce the amount of
uppercae letters.

No functional change.

make: update constant names in comments

No functional change.

make(1): move test for recursive variable to cond-func-empty

Previously, the documentation of that test was much too short to explain
all the effects that happened in the bug situation from 2020-06-28 until
2020-07-02.

make(1): clean up some tests

Fix some mistakes in comments.

Improve some comments to be easier understandable.

Inline variables that are irrelevant for the test at hand (RUN,
MAKE_CMD).

Remove references to functions and constants that have since been removed
or renamed.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

make: update constant names in comments

No functional change.

make(1): move test for recursive variable to cond-func-empty

Previously, the documentation of that test was much too short to explain
all the effects that happened in the bug situation from 2020-06-28 until
2020-07-02.

make(1): clean up some tests

Fix some mistakes in comments.

Improve some comments to be easier understandable.

Inline variables that are irrelevant for the test at hand (RUN,
MAKE_CMD).

Remove references to functions and constants that have since been removed
or renamed.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

make(1): move test for recursive variable to cond-func-empty

Previously, the documentation of that test was much too short to explain
all the effects that happened in the bug situation from 2020-06-28 until
2020-07-02.

make(1): clean up some tests

Fix some mistakes in comments.

Improve some comments to be easier understandable.

Inline variables that are irrelevant for the test at hand (RUN,
MAKE_CMD).

Remove references to functions and constants that have since been removed
or renamed.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

make(1): clean up some tests

Fix some mistakes in comments.

Improve some comments to be easier understandable.

Inline variables that are irrelevant for the test at hand (RUN,
MAKE_CMD).

Remove references to functions and constants that have since been removed
or renamed.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

make(1): add test for parse error in condition using empty()

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

make(1): add tests for spaces in condition functions

make(1): fix unexpected behavior in ::= variable modifier

Previously, the ::= modifier had returned an error value, which caused
the variable expression to be preserved. This behavior was not useful
in this case; it had only been intended to be used for undefined
variables.

To fix it, distinguish between parse errors, undefined variables and
regular empty strings.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.

make(1): rename local functions for parsing conditions

The word "get" implies a cheap operation without side effects. Parsing
instead has lots of side effects, even if it's only that the parsing
position is updated.

make(1): migrate get_mpt_arg to Var_ParsePP

This part is covered well by the unit tests. When I forgot to decrement
the linePtr, several of them failed reliably.

make(1): add more explanation for undefined variable expressions

make(1): add test for the empty function in conditionals

make(1): describe the purpose of each newly added unit test dummy

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.