diff options
| -rw-r--r-- | AUTHORS | 1 | ||||
| -rw-r--r-- | ChangeLog | 17 | ||||
| -rw-r--r-- | NEWS | 9 | ||||
| -rw-r--r-- | doc/make.texi | 50 | ||||
| -rw-r--r-- | function.c | 36 | ||||
| -rw-r--r-- | read.c | 5 | ||||
| -rw-r--r-- | tests/ChangeLog | 4 | ||||
| -rw-r--r-- | tests/scripts/features/shell_assignment | 65 | ||||
| -rw-r--r-- | variable.c | 38 | ||||
| -rw-r--r-- | variable.h | 5 |
10 files changed, 213 insertions, 17 deletions
@@ -61,6 +61,7 @@ Other contributors: Carl Staelin (Princeton University) Ian Stewartson (Data Logic Limited) Ramon Garcia Fernandez <ramon.garcia.f@gmail.com> + David A. Wheeler <dwheeler@dwheeler.com> With suggestions/comments/bug reports from a cast of ... well ... hundreds, anyway :) @@ -1,3 +1,20 @@ +2011-04-17 David A. Wheeler <dwheeler@dwheeler.com> + + * doc/make.texi (Reading Makefiles): Document "!=". + (Setting): Ditto. + (Features): Ditto. + * variable.h (enum variable_flavor): New type "f_shell". + * variable.c (shell_result): Send a string to the shell and store + the output. + (do_variable_definition): Handle f_shell variables: expand the + value, then send it to the shell and store the result. + (parse_variable_definition): Parse "!=" shell assignments. + * read.c (get_next_mword): Treat "!=" as a varassign word. + * function.c (fold_newlines): If trim_newlines is set remove all + trailing newlines; otherwise remove only the last newline. + (func_shell_base): Move the guts of the shell function here. + (func_shell): Call func_shell_base(). + 2011-02-21 Paul Smith <psmith@gnu.org> * strcache.c (various): Increase performance based on comments @@ -1,6 +1,6 @@ GNU make NEWS -*-indented-text-*- History of user-visible changes. - 29 August 2010 + 17 April 2011 See the end of this file for copyrights and conditions. @@ -22,6 +22,13 @@ http://sv.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=101&set multiple consecutive backslash/newlines do not condense into one space. * In recipes, a recipe prefix following a backslash-newlines is removed. +* New feature: "!=" shell assignment operator as an alternative to the + $(shell ...) function. Implemented for portability of BSD makefiles. + WARNING: Backward-incompatibility! + Variables ending in "!" previously defined as "variable!= value" will now be + interpreted as shell assignment. Change your assignment to add whitespace + between the "!" and "=": "variable! = value" + * New command line option: --trace enables tracing of targets. When enabled the recipe to be invoked is printed even if it would otherwise be suppressed by .SILENT or a "@" prefix character. Also before each recipe is run the diff --git a/doc/make.texi b/doc/make.texi index 2965540..b62fee0 100644 --- a/doc/make.texi +++ b/doc/make.texi @@ -1305,7 +1305,7 @@ specified by the existing contents of @file{mfile}. Sometimes it is useful to have a makefile that is mostly just like another makefile. You can often use the @samp{include} directive to include one in the other, and add more targets or variable definitions. -However, it is illegal for two makefiles to give different recipes for +However, it is invalid for two makefiles to give different recipes for the same target. But there is another way. @cindex match-anything rule, used to override @@ -1379,6 +1379,7 @@ chapters. @cindex =, expansion @cindex ?=, expansion @cindex +=, expansion +@cindex !=, expansion @cindex define, expansion Variable definitions are parsed as follows: @@ -1388,6 +1389,7 @@ Variable definitions are parsed as follows: @var{immediate} ?= @var{deferred} @var{immediate} := @var{immediate} @var{immediate} += @var{deferred} or @var{immediate} +@var{immediate} != @var{immediate} define @var{immediate} @var{deferred} @@ -1408,12 +1410,21 @@ endef define @var{immediate} += @var{deferred} or @var{immediate} endef + +define @var{immediate} != + @var{immediate} +endef @end example For the append operator, @samp{+=}, the right-hand side is considered immediate if the variable was previously set as a simple variable (@samp{:=}), and deferred otherwise. +For the shell assignment operator, @samp{!=}, the right-hand side is +evaluated immediately and handed to the shell. The result is stored in the +variable named on the left, and that variable becomes a simple variable +(and will thus be re-evaluated on each reference). + @subheading Conditional Directives @cindex ifdef, expansion @cindex ifeq, expansion @@ -5402,6 +5413,7 @@ Several variables have constant initial values. @cindex = @cindex := @cindex ?= +@cindex != To set a variable from the makefile, write a line starting with the variable name followed by @samp{=} or @samp{:=}. Whatever follows the @@ -5457,6 +5469,33 @@ FOO = bar endif @end example +The shell assignment operator @samp{!=} can be used to execute a +program and set a variable to its output. This operator first +evaluates the right-hand side, then passes that result to the shell +for execution. If the result of the execution ends in a newline, that +one newline is removed; all other newlines are replaced by spaces. +The resulting string is then placed into the named +recursively-expanded variable. For example: + +@example +hash != printf '\043' +file_list != find . -name '*.c' +@end example + +If the result of the execution could produce a @code{$}, and you don't +intend what follows that to be interpreted as a make variable or +function reference, then you must replace every @code{$} with +@code{$$} as part of the execution. Alternatively, you can set a +simply expanded variable to the result of running a program using the +@code{shell} function call. @xref{Shell Function, , The @code{shell} +Function}. For example: + +@example +hash := $(shell printf '\043') +var := $(shell find . -name "*.c") +@end example + + @node Appending, Override Directive, Setting, Using Variables @section Appending More Text to Variables @cindex += @@ -5977,7 +6016,7 @@ prog: a.o b.o Due to the @code{private} modifier, @code{a.o} and @code{b.o} will not inherit the @code{EXTRA_CFLAGS} variable assignment from the -@code{progs} target. +@code{prog} target. @node Special Variables, , Suppressing Inheritance, Using Variables @comment node-name, next, previous, up @@ -6073,7 +6112,7 @@ foo @end example Note that assigning more than one target name to @code{.DEFAULT_GOAL} is -illegal and will result in an error. +invalid and will result in an error. @vindex MAKE_RESTARTS @r{(number of times @code{make} has restarted)} @item MAKE_RESTARTS @@ -10444,6 +10483,11 @@ nonexistent file comes from SunOS 4 @code{make}. (But note that SunOS 4 @code{make} does not allow multiple makefiles to be specified in one @code{-include} directive.) The same feature appears with the name @code{sinclude} in SGI @code{make} and perhaps others. + +@item +The @code{!=} shell assignment operator exists in many BSD of +@code{make} and is purposefully implemented here to behave identically +to those implementations. @end itemize The remaining features are inventions new in GNU @code{make}: @@ -1393,14 +1393,14 @@ func_value (char *o, char **argv, const char *funcname UNUSED) } /* - \r is replaced on UNIX as well. Is this desirable? + \r is replaced on UNIX as well. Is this desirable? */ static void -fold_newlines (char *buffer, unsigned int *length) +fold_newlines (char *buffer, unsigned int *length, int trim_newlines) { char *dst = buffer; char *src = buffer; - char *last_nonnl = buffer -1; + char *last_nonnl = buffer - 1; src[*length] = 0; for (; *src != '\0'; ++src) { @@ -1416,6 +1416,10 @@ fold_newlines (char *buffer, unsigned int *length) *dst++ = *src; } } + + if (!trim_newlines && (last_nonnl < (dst - 2))) + last_nonnl = dst - 2; + *(++last_nonnl) = '\0'; *length = last_nonnl - buffer; } @@ -1578,12 +1582,20 @@ msdos_openpipe (int* pipedes, int *pidp, char *text) #ifdef VMS /* VMS can't do $(shell ...) */ + +char * +func_shell_base (char *o, char **argv, int trim_newlines) +{ + fprintf (stderr, "This platform does not support shell\n"); + die (EXIT_FAILURE); +} + #define func_shell 0 #else #ifndef _AMIGA -static char * -func_shell (char *o, char **argv, const char *funcname UNUSED) +char * +func_shell_base (char *o, char **argv, int trim_newlines) { char *batch_filename = NULL; @@ -1762,7 +1774,7 @@ func_shell (char *o, char **argv, const char *funcname UNUSED) { /* The child finished normally. Replace all newlines in its output with spaces, and put that in the variable output buffer. */ - fold_newlines (buffer, &i); + fold_newlines (buffer, &i, trim_newlines); o = variable_buffer_output (o, buffer, i); } @@ -1776,8 +1788,8 @@ func_shell (char *o, char **argv, const char *funcname UNUSED) /* Do the Amiga version of func_shell. */ -static char * -func_shell (char *o, char **argv, const char *funcname) +char * +func_shell_base (char *o, char **argv, int trim_newlines) { /* Amiga can't fork nor spawn, but I can start a program with redirection of my choice. However, this means that we @@ -1854,12 +1866,18 @@ func_shell (char *o, char **argv, const char *funcname) Close (child_stdout); - fold_newlines (buffer, &i); + fold_newlines (buffer, &i, trim_newlines); o = variable_buffer_output (o, buffer, i); free (buffer); return o; } #endif /* _AMIGA */ + +char * +func_shell (char *o, char **argv, const char *funcname UNUSED) +{ + return func_shell_base (o, argv, 1); +} #endif /* !VMS */ #ifdef EXPERIMENTAL @@ -2463,7 +2463,7 @@ readline (struct ebuffer *ebuf) w_colon A colon w_dcolon A double-colon w_semicolon A semicolon - w_varassign A variable assignment operator (=, :=, +=, or ?=) + w_varassign A variable assignment operator (=, :=, +=, ?=, or !=) Note that this function is only used when reading certain parts of the makefile. Don't use it where special rules hold sway (RHS of a variable, @@ -2514,6 +2514,7 @@ get_next_mword (char *buffer, char *delim, char **startp, unsigned int *length) case '+': case '?': + case '!': if (*p == '=') { ++p; @@ -2533,7 +2534,7 @@ get_next_mword (char *buffer, char *delim, char **startp, unsigned int *length) /* This is some non-operator word. A word consists of the longest string of characters that doesn't contain whitespace, one of [:=#], - or [?+]=, or one of the chars in the DELIM string. */ + or [?+!]=, or one of the chars in the DELIM string. */ /* We start out assuming a static word; if we see a variable we'll adjust our assumptions then. */ diff --git a/tests/ChangeLog b/tests/ChangeLog index b13e2ae..3fdf5ca 100644 --- a/tests/ChangeLog +++ b/tests/ChangeLog @@ -1,3 +1,7 @@ +2011-04-17 David A. Wheeler <dwheeler@dwheeler.com> + + * scripts/features/shell_assignment: Regression for "!=" feature + 2010-11-06 Paul Smith <psmith@gnu.org> * scripts/features/targetvars: Fix known-good output for BS/NL changes. diff --git a/tests/scripts/features/shell_assignment b/tests/scripts/features/shell_assignment new file mode 100644 index 0000000..686e4bd --- /dev/null +++ b/tests/scripts/features/shell_assignment @@ -0,0 +1,65 @@ +# -*-perl-*- + +$description = "Test BSD-style shell assignments (VAR != VAL) for variables."; + +$details = ""; + +# TEST 0: Basic shell assignment (!=). + +run_make_test(' +.POSIX: + +demo1!=printf \' 1 2 3\n4\n\n5 \n \n 6\n\n\n\n\' +demo2 != printf \'7 8\n \' +demo3 != printf \'$$(demo2)\' +demo4 != printf \' 2 3 \n\' +demo5 != printf \' 2 3 \n\n\' +all: ; @echo "<$(demo1)> <$(demo2)> <$(demo3)> <$(demo4)> <${demo5}>" +', + '', "< 1 2 3 4 5 6 > <7 8 > <7 8 > < 2 3 > < 2 3 >\n"); + +# TEST 1: Handle '#' the same way as BSD make + +run_make_test(' +foo1!=echo bar#baz +hash != printf \'\043\' +foo2!= echo "bar$(hash)baz" + +all: ; @echo "<$(foo1)> <$(hash)> <$(foo2)>" +', + '', "<bar> <#> <bar#baz>\n"); + +# TEST 2: shell assignment variables (from !=) should be recursive. +# Note that variables are re-evaluated later, so the shell can output +# a value like $(XYZZY) as part of !=. The $(XYZZY) will be EVALUATED +# when the value containing it is evaluated. On the negative side, this +# means if you don't want this, you need to escape dollar signs as $$. +# On the positive side, it means that shell programs can output macros +# that are then evaluated as they are traditionally evaluated.. and that +# you can use traditional macro evaluation semantics to implement !=. + +run_make_test(' +XYZZY = fiddle-dee-dee +dollar = $$ +VAR3 != printf \'%s\' \'$(dollar)(XYZZY)\' + +all: ; @echo "<$(VAR3)>" +', + '', "<fiddle-dee-dee>\n"); + + +# TEST 3: Overrides invoke shell anyway; they just don't store the result +# in a way that is visible. + +run_make_test(' + +override != echo abc > ,abc ; cat ,abc + +all: ; @echo "<$(override)>" ; cat ,abc +', + 'override=xyz', "<xyz>\nabc\n"); + +unlink(',abc'); + + +1; @@ -1111,6 +1111,29 @@ set_special_var (struct variable *var) return var; } +/* Given a string, shell-execute it and return a malloc'ed string of the + * result. This removes only ONE newline (if any) at the end, for maximum + * compatibility with the *BSD makes. If it fails, returns NULL. */ + +char * +shell_result (const char *p) +{ + char *buf; + unsigned int len; + char *args[2]; + char *result; + + install_variable_buffer (&buf, &len); + + args[0] = (char *) p; + args[1] = NULL; + variable_buffer_output (func_shell_base (variable_buffer, args, 0), "\0", 1); + result = strdup (variable_buffer); + + restore_variable_buffer (buf, len); + return result; +} + /* Given a variable, a value, and a flavor, define the variable. See the try_variable_definition() function for details on the parameters. */ @@ -1140,6 +1163,16 @@ do_variable_definition (const struct floc *flocp, const char *varname, target-specific variable. */ p = alloc_value = allocated_variable_expand (value); break; + case f_shell: + { + /* A shell definition "var != value". Expand value, pass it to + the shell, and store the result in recursively-expanded var. */ + char *q = allocated_variable_expand (value); + p = alloc_value = shell_result (q); + free (q); + flavor = f_recursive; + break; + } case f_conditional: /* A conditional variable definition "var ?= value". The value is set IFF the variable is not defined yet. */ @@ -1432,7 +1465,7 @@ parse_variable_definition (const char *p, enum variable_flavor *flavor) return (char *)p; } - /* Match assignment variants (:=, +=, ?=) */ + /* Match assignment variants (:=, +=, ?=, !=) */ if (*p == '=') { switch (c) @@ -1446,6 +1479,9 @@ parse_variable_definition (const char *p, enum variable_flavor *flavor) case '?': *flavor = f_conditional; break; + case '!': + *flavor = f_shell; + break; default: /* If we skipped whitespace, non-assignments means no var. */ if (wspace) @@ -38,7 +38,8 @@ enum variable_flavor f_simple, /* Simple definition (:=) */ f_recursive, /* Recursive definition (=) */ f_append, /* Appending definition (+=) */ - f_conditional /* Conditional definition (?=) */ + f_conditional, /* Conditional definition (?=) */ + f_shell /* Shell assignment (!=) */ }; /* Structure that represents one variable definition. @@ -134,6 +135,8 @@ char *patsubst_expand_pat (char *o, const char *text, const char *pattern, const char *replace, const char *pattern_percent, const char *replace_percent); char *patsubst_expand (char *o, const char *text, char *pattern, char *replace); +char *func_shell_base (char *o, char **argv, int trim_newlines); + /* expand.c */ char *recursively_expand_for_file (struct variable *v, struct file *file); |