Fix handling of SOURCE_DATE_EPOCH

If no SOURCE_DATE_EPOCH is specified via configure, then it can't be set as an environment variable in doc/Makefile.am build rules. Change the build rules to check if SOURCE_DATE_EPOCH is non-empty and use it if so, otherwise leave it out of the commands. Also fix verbosity for make in doc/Makefile.am. If V=1 is passed on the make command line, echo the build commands, otherwise echo abbreviated commands. Special handling is needed because of the "if" commands in the build rules have echo unconditionally disabled via @.
erlyaws · Jan 31, 2022 · 9ddb504 · 9ddb504
1 parent ada124f
commit 9ddb504
Show file tree

Hide file tree

Showing 2 changed files with 84 additions and 14 deletions.
diff --git a/README.md b/README.md
@@ -140,7 +140,10 @@ The above configurations for enabling deterministic builds add the erlc flag
 `yaws_generated.beam`, and set e.g. creation date in `yaws.ps` and `yaws.pdf`
 from the value of `SOURCE_DATE_EPOCH`, which is expected to be an integer
 reflecting a number of seconds since the Unix epoch. (One way to get an epoch
-integer value is via the command `date '+%s'` on Linux or macOS, for example.)
+integer value is via the command `date '+%s'` on Linux or macOS, for example.
+If you're using the bash shell version 4.2 or newer, `printf '%(%s)T\n' -1`
+gives an epoch integer value, and starting at version 5, the bash shell
+provides the `$EPOCHSECONDS` variable.)
 
 Note that various paths in configuration files, templates, examples etc. are
 generated from the configured installation prefix config files; thus they

diff --git a/doc/Makefile.am b/doc/Makefile.am
@@ -47,10 +47,26 @@ endif
 
 # For reproducible builds, SOURCE_DATE_EPOCH replaces DVIPSSource date if set
 yaws.ps: yaws.dvi
-	$(AM_V_GEN)TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+	@if [ x"$(SOURCE_DATE_EPOCH)" == x ]; then \
+	  if [ x'$(AM_V_GEN)' != x ]; then \
+	    echo '  $(DVIPS)     $<' ; \
+	  else \
+	    echo TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+		$(DVIPS) -q -o $@ $< ; \
+	  fi; \
+	  TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+		$(DVIPS) -q -o $@ $< ; \
+	else \
+	  if [ x'$(AM_V_GEN)' != x ]; then \
+	    echo '  $(DVIPS)     $<' ; \
+	  else \
+	    echo TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
 		SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH) \
-		$(DVIPS) -q -o $@ $<
-	$(AM_V_at)if [ x"$(SOURCE_DATE_EPOCH)" != "x" ]; then \
+		$(DVIPS) -q -o $@ $< ; \
+	  fi; \
+	  TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+		SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH) \
+		$(DVIPS) -q -o $@ $< ; \
 	  code='{{Y,Mo,D},{H,Mi,S}} = calendar:system_time_to_local_time('$(SOURCE_DATE_EPOCH)', 1),' ; \
 	  code="$$code "'io:format("~4.4w~2.2.0w~2.2.0w:~2.2.0w~2.2.0w~2.2.0w\n", [Y,Mo,D,H,Mi,S]).' ; \
 	  newdate=`$(ERL) -noshell -noinput -eval "$$code" -s init stop` || exit 1; \
@@ -62,24 +78,75 @@ yaws.ps: yaws.dvi
 	fi
 
 yaws.pdf: yaws.tex $(IMG_PDF)
-	$(AM_V_GEN)TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+	@if [ x"$(SOURCE_DATE_EPOCH)" != x ]; then \
+	  if [ x'$(AM_V_GEN)' != x ]; then \
+	    echo '  $(PDFLATEX)  $<' ; \
+	  else \
+	    echo TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+		SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH) \
+		$(PDFLATEX) $< ; \
+	  fi ; \
+	  TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
 		SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH) \
-		$(PDFLATEX) yaws.tex > /dev/null
-	$(AM_V_at)TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+		$(PDFLATEX) $< > /dev/null; \
+	  if [ x'$(AM_V_at)' = x ]; then \
+	    echo TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+		SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH)  \
+		$(PDFLATEX) $< ; \
+	  fi ; \
+	  TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
 		SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH)  \
-		$(PDFLATEX) yaws.tex > /dev/null
+		$(PDFLATEX) $< > /dev/null; \
+	else \
+	  if [ x'$(AM_V_GEN)' != x ]; then \
+	    echo '  $(PDFLATEX)  $<' ; \
+	  else \
+	    echo TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+		$(PDFLATEX) $< ; \
+	  fi ; \
+	  TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+		$(PDFLATEX) $< > /dev/null; \
+	  if [ x'$(AM_V_at)' = x ]; then \
+	    echo TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+		$(PDFLATEX) $< ; \
+	  fi ; \
+	  TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+		$(PDFLATEX) $< > /dev/null; \
+	fi
 
 yaws.dvi: yaws.tex $(IMG_EPS)
-	$(AM_V_GEN)TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+	@if [ x"$(SOURCE_DATE_EPOCH)" != x ]; then \
+	  if [ x'$(AM_V_at)' = x ]; then \
+	    echo TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
 		SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH) \
-		$(DVILATEX) yaws.tex > /dev/null
-	$(AM_V_at)TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+		$(DVILATEX) $< ; \
+	  fi ; \
+	  TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
 		SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH) \
-		$(DVILATEX) yaws.tex > /dev/null
+		$(DVILATEX) $< > /dev/null; \
+	else \
+	  if [ x'$(AM_V_at)' = x ]; then \
+	    echo TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+		$(DVILATEX) $< ; \
+	  fi ; \
+	  TEXINPUTS="$${TEXTINPUTS}:@srcdir@" \
+		$(DVILATEX) $< > /dev/null; \
+	fi
 
 .eps.pdf:
-	$(AM_V_GEN)SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH) \
-		$(EPSTOPDF) --outfile=$@ $< > /dev/null
+	@if [ x"$(SOURCE_DATE_EPOCH)" != x ]; then \
+	  if [ x'$(AM_V_at)' = x ]; then \
+	    echo SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH) \
+		$(EPSTOPDF) --outfile=$@ $< ; \
+	  fi ; \
+	  SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH) \
+		$(EPSTOPDF) --outfile=$@ $< > /dev/null; \
+	else \
+	  if [ x'$(AM_V_at)' = x ]; then \
+	    echo $(EPSTOPDF) --outfile=$@ $< ; \
+	  fi ; \
+	  $(EPSTOPDF) --outfile=$@ $< > /dev/null; \
+	fi
 
 .NOTPARALLEL:
 # Local Variables: