Teach build to build only the toys/*.c selected in .config, and teach

CFG_TOYSH_DEBUG to shut up the spurious "gcc can't tell that this is never
actually used uninitialized because gcc is stupid" warnings.

4 files changed, 25 insertions, 8 deletions

diff --git a/Makefile b/Makefile
index 011a5624..97482ae1 100644
--- a/Makefile
+++ b/Makefile
@@ -37,13 +37,16 @@ baseline: toybox_unstripped
 bloatcheck: toybox_old toybox_unstripped
 	@scripts/bloat-o-meter toybox_old toybox_unstripped
 
-# Actual build
+# Get list of toys/*.c files from .config
 
-toyfiles = main.c toys/*.c lib/*.c
-toybox_unstripped: gen_config.h $(toyfiles) toys/toylist.h lib/lib.h toys.h
+toysfiles = $(shell sed -nre 's/^CONFIG_(.*)=y/\1/;t skip;b;:skip;s/_.*//;p' .config | sort -u | tr A-Z a-z | grep -v '^toybox$$' | sed -r 's@(.*)@toys/\1.c@')
+
+# Compile toybox from source
+
+toyfiles = main.c lib/*.c $(toysfiles)
+toybox_unstripped: gen_config.h $(toyfiles) toys/toylist.h lib/*.h toys.h
 	$(CC) $(CFLAGS) -I . $(toyfiles) -o toybox_unstripped \
-		-ffunction-sections -fdata-sections -Wl,--gc-sections #\
-		#2>&1 | sed -n -e '/may be used uninitialized/{s/.*/\n/;h;b};1{x;b};: print;=;p;x;/\n/b thing;p;: thing;${x;p}' >&2
+		-ffunction-sections -fdata-sections -Wl,--gc-sections
 
 toybox: toybox_unstripped
 	$(STRIP) toybox_unstripped -o toybox
diff --git a/lib/bunzip.c b/lib/bunzip.c
index 049dc02e..b7996983 100644
--- a/lib/bunzip.c
+++ b/lib/bunzip.c
@@ -111,9 +111,9 @@ static unsigned int get_bits(bunzip_data *bd, char bits_wanted)
 // Decompress a block of text to intermediate buffer
 int read_bunzip_data(bunzip_data *bd)
 {
-	struct group_data *hufGroup;
+	struct group_data *hufGroup GCC_BUG;
 	unsigned origPtr;
-	int dbufCount, nextSym, dbufSize, groupCount, *base, *limit,
+	int dbufCount, nextSym, dbufSize, groupCount, *base GCC_BUG, *limit GCC_BUG,
 		selector, i, j, k, t, runPos, symCount, symTotal, nSelectors,
 		byteCount[256];
 	char uc, mtfSymbol[256], symToByte[256], *selectors;
diff --git a/lib/portability.h b/lib/portability.h
index 5aa4a0bf..9f3f1b78 100644
--- a/lib/portability.h
+++ b/lib/portability.h
@@ -25,3 +25,15 @@
 #define SWAP_LE32(x) (x)
 #define SWAP_LE64(x) (x)
 #endif
+
+// Some versions of gcc produce spurious "may be uninitialized" warnings in
+// cases where it provably can't happen.  Unfortunately, although this warning
+// is calculated and produced separately from the "is definitely used
+// uninitialized" warnings, there's no way to turn off the broken spurious "may
+// be" warnings without also turning off the non-broken "is" warnings.
+
+#if CFG_TOYBOX_DEBUG
+#define GCC_BUG =0
+#else
+#define GCC_BUG
+#endif
diff --git a/toys.h b/toys.h
index e1e25210..3c6cec92 100644
--- a/toys.h
+++ b/toys.h
@@ -6,9 +6,12 @@
  * Licensed under GPL version 2, see file LICENSE in this tarball for details.
  */
 
+#include "gen_config.h"
+
 #include "lib/portability.h"
 
 #include <ctype.h>
+#include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
@@ -30,7 +33,6 @@
 #include <unistd.h>
 
 #include "lib/lib.h"
-#include "gen_config.h"
 #include "toys/e2fs.h"
 #include "toys/toylist.h"