Add shorthand macros for some conventient Lua string operations

Despite all the Lua magic we already do, it's annoyingly often the case
that shelling out is easier (or at least shorter) than doing the same in
Lua (substrings, length etc)

Add shorthand macros %gsub, %len, %lower, %rep, %reverse, %sub and
%upper which simply wrap the corresponding Lua string.* functions for
convenience.

docs/manual/macros.md

@@ -84,6 +84,15 @@ to perform useful operations. The current list is
 
 	%{macrobody:...}	literal body of a macro
 
+	%{gsub:...}	replace occurences of pattern in a string
+                        (see Lua `string.gsub()`)
+	%{len:...}	string length
+	%{lower:...}	lowercase a string
+	%{rep:...}	repeat a string (see Lua `string.rep()`)
+	%{reverse:...}	reverse a string
+	%{sub:...}	expand to substring (see Lua `string.sub()`)
+	%{upper:...}	uppercase a string
+
 	%{basename:...}	basename(1) macro analogue
 	%{dirname:...}	dirname(1) macro analogue
 	%{exists:...}	test file existence, expands to 1/0

rpmio/macro.c

@@ -1096,6 +1096,30 @@ static void doLua(MacroBuf mb,  rpmMacroEntry me, ARGV_t argv, size_t *parsed)
     }
 }
 
+/*
+ * Wrap a call to Lua string functions.
+ * Note extra parentheses to force only one result returned, multi-value
+ * returns such as from string.gsub() make no sense in this context.
+ */
+static void doString(MacroBuf mb, rpmMacroEntry me, ARGV_t argv, size_t *parsed)
+{
+    rpmlua lua = NULL; /* Global state. */
+    char *printbuf = NULL;
+    char *s = rstrscat(NULL,
+		"return (string.", argv[0], "(table.unpack(arg)))", NULL);
+
+    rpmluaPushPrintBuffer(lua);
+    if (rpmluaRunScript(lua, s, argv[0], NULL, argv+1) == -1)
+	mb->error = 1;
+    printbuf = rpmluaPopPrintBuffer(lua);
+
+    if (printbuf) {
+	mbAppendStr(mb, printbuf);
+	free(printbuf);
+    }
+    free(s);
+}
+
 static void doSP(MacroBuf mb, rpmMacroEntry me, ARGV_t argv, size_t *parsed)
 {
     char *s = NULL;
@@ -1245,17 +1269,24 @@ static struct builtins_s {
     { "getenv",		doFoo,		1,	0 },
     { "getncpus",	doFoo,		0,	0 },
     { "global",		doGlobal,	1,	ME_PARSE },
+    { "gsub",		doString,	1,	0 },
+    { "len",		doString,	1,	0 },
     { "load",		doLoad,		1,	0 },
+    { "lower",		doString,	1,	0 },
     { "lua",		doLua,		1,	ME_PARSE },
     { "macrobody",	doBody,		1,	0 },
     { "quote",		doFoo,		1,	0 },
+    { "rep",		doString,	1,	0 },
+    { "reverse",	doString,	1,	0 },
     { "shrink",		doFoo,		1,	0 },
+    { "sub",		doString,	1,	0 },
     { "suffix",		doFoo,		1,	0 },
     { "trace",		doTrace,	0,	0 },
     { "u2p",		doFoo,		1,	0 },
     { "shescape",	doShescape,	1,	0 },
     { "uncompress",	doUncompress,	1,	0 },
     { "undefine",	doUndefine,	1,	0 },
+    { "upper",		doString,	1,	0 },
     { "url2path",	doFoo,		1,	0 },
     { "verbose",	doVerbose,	-1,	ME_PARSE },
     { "warn",		doOutput,	1,	0 },

tests/data/SPECS/configtest.spec

@@ -3,7 +3,7 @@
 
 %{!?filetype: %global filetype file}
 
-Name:		configtest%{?sub:-%{sub}}
+Name:		configtest%{?subpkg:-%{subpkg}}
 Version:	%{ver}
 Release:	1
 Summary:	Testing config file behavior

tests/data/SPECS/replacetest.spec

@@ -3,7 +3,7 @@
 %{!?user: %global user root}
 %{!?grp: %global grp root}
 
-Name:		replacetest%{?sub:-%{sub}}
+Name:		replacetest%{?subpkg:-%{subpkg}}
 Version:	%{ver}
 Release:	1
 Summary:	Testing file replacement behavior

tests/rpmconfig.at

@@ -402,7 +402,7 @@ RPMDB_INIT
 for s in "A" "B"; do
     for v in "1.0" "2.0"; do
         runroot rpmbuild --quiet -bb \
-            --define "sub $s" \
+            --define "subpkg $s" \
             --define "ver $v" \
 	    --define "filedata foo" \
               /data/SPECS/configtest.spec
@@ -462,7 +462,7 @@ RPMDB_INIT
 for s in "A" "B"; do
     for v in "1.0" "2.0"; do
         runroot rpmbuild --quiet -bb \
-            --define "sub $s" \
+            --define "subpkg $s" \
             --define "ver $v" \
 	    --define "filedata foo-$v" \
               /data/SPECS/configtest.spec
@@ -552,7 +552,7 @@ RPMDB_INIT
 for s in "A" "B"; do
     for v in "1.0" "2.0"; do
         runroot rpmbuild --quiet -bb \
-            --define "sub $s" \
+            --define "subpkg $s" \
             --define "ver $v" \
 	    --define "filedata foo-$v" \
 	    --define "noreplace 1" \

tests/rpmconfig2.at

@@ -352,7 +352,7 @@ RPMDB_INIT
 for s in "A" "B"; do
     for v in "1.0" "2.0"; do
         runroot rpmbuild --quiet -bb \
-            --define "sub $s" \
+            --define "subpkg $s" \
             --define "ver $v" \
 	    --define "filedata foo" \
 	    --define "filetype link" \
@@ -414,7 +414,7 @@ RPMDB_INIT
 for s in "A" "B"; do
     for v in "1.0" "2.0"; do
         runroot rpmbuild --quiet -bb \
-            --define "sub $s" \
+            --define "subpkg $s" \
             --define "ver $v" \
 	    --define "filedata foo-$v" \
 	    --define "filetype link" \
@@ -504,7 +504,7 @@ RPMDB_INIT
 for s in "A" "B"; do
     for v in "1.0" "2.0"; do
         runroot rpmbuild --quiet -bb \
-            --define "sub $s" \
+            --define "subpkg $s" \
             --define "ver $v" \
 	    --define "filedata foo-$v" \
 	    --define "filetype link" \

tests/rpmmacro.at

@@ -387,6 +387,39 @@ runroot rpm \
 ])
 AT_CLEANUP
 
+AT_SETUP([string functions])
+AT_KEYWORDS([macros])
+AT_CHECK([
+runroot rpm \
+    --eval "%sub cd6317ba61e6c27b92d6bbdf2702094ff3c0c732 1 7" \
+    --eval "%sub cd6317ba61e6c27b92d6bbdf2702094ff3c0c732 7 -7" \
+    --eval "%sub cd6317ba61e6c27b92d6bbdf2702094ff3c0c732 -7" \
+    --eval "%len cd6317ba61e6c27b92d6bbdf2702094ff3c0c732" \
+    --eval "%upper abba" \
+    --eval "%lower Beatles" \
+    --eval "%rep ai 2" \
+    --eval "%reverse live" \
+    --eval "%reverse a'b" \
+    --eval "%reverse a\"b" \
+    --eval "%gsub aaa a b 2"
+],
+[0],
+[cd6317b
+ba61e6c27b92d6bbdf2702094ff3
+3c0c732
+40
+ABBA
+beatles
+aiai
+evil
+b'a
+b"a
+bba
+],
+[])
+AT_CLEANUP
+
+
 AT_SETUP([expr macro 1])
 AT_KEYWORDS([macros])
 AT_CHECK([