depend mode: Support multiple versions of dependencies (#363)

Depend mode fix for a case with unchaged common hash (unchanged source file and
other parameters that affect the hash), but with changes in the header file[s]
the source file depends on. This allows for multiple versions of the object
file and dependency file to exist for one common hash. Added unit tests in
test/suites/depend_different_headers.bash to test this behavior.

diff --git a/src/ccache.c b/src/ccache.c
index 0bd683fb337e5b9244ae59516aa61f3afc14c560..43512d782afbcb61a64542fbb40c987efc2088df 100644 (file)
--- a/src/ccache.c
+++ b/src/ccache.c
@@ -1479,10 +1479,6 @@ to_cache(struct args *args, struct hash *depend_mode_hash)
                        failed();
                }
                update_cached_result_globals(object_hash);
-
-               // It does not make sense to update an existing manifest file in the depend
-               // mode.
-               x_unlink(manifest_path);
        }
 
        if (stat(output_obj, &st) != 0) {

diff --git a/test/run b/test/run
index fa607336243ce7e7489fe73801bf6e33ca444298..2729801e73086d2c8bfe5d926f883a133821feb0 100755 (executable)
--- a/test/run
+++ b/test/run
@@ -385,6 +385,7 @@ hardlink
 direct
 direct_gcc
 depend
+depend_different_headers
 basedir
 compression
 readonly

diff --git a/test/suites/depend_different_headers.bash b/test/suites/depend_different_headers.bash
new file mode 100755 (executable)
index 0000000..b10f600
--- /dev/null
+++ b/test/suites/depend_different_headers.bash
@@ -0,0 +1,181 @@
+SUITE_depend_different_headers_SETUP() {
+    unset CCACHE_NODIRECT
+
+    BASEDIR=`pwd`
+    BASEDIR1="${BASEDIR}/test/dir1/"
+    BASEDIR2="${BASEDIR}/test/dir2/"
+    BASEDIR3="${BASEDIR}/test/dir3/"
+    BASEDIR4="${BASEDIR}/test/dir4/"
+
+    mkdir -p ${BASEDIR1} ${BASEDIR2} ${BASEDIR3} ${BASEDIR4}
+
+    cat <<EOF >${BASEDIR1}/test.c
+#include "header.h"
+#include <stdio.h>
+
+void test(){
+#ifdef CHANGE_THAT_AFFECTS_OBJECT_FILE
+printf("with change");
+#else
+printf("no change");
+#endif
+}
+EOF
+    cp -f "${BASEDIR1}/test.c" ${BASEDIR2}
+    cp -f "${BASEDIR1}/test.c" ${BASEDIR3}
+    cp -f "${BASEDIR1}/test.c" ${BASEDIR4}
+
+    cat <<EOF >"${BASEDIR1}/header.h"
+void test();
+EOF
+
+    cat <<EOF >"${BASEDIR2}/header.h"
+#define CHANGE_THAT_AFFECTS_OBJECT_FILE
+void test();
+EOF
+
+    cat <<EOF >"${BASEDIR3}/header.h"
+#define CHANGE_THAT_DOES_NOT_AFFECT_OBJECT_FILE
+void test();
+EOF
+
+    cat <<EOF >"${BASEDIR4}/header.h"
+#include "header2.h"
+void test();
+EOF
+    cat <<EOF >"${BASEDIR4}/header2.h"
+static void some_function(){};
+EOF
+
+    backdate "${BASEDIR1}/header.h" "${BASEDIR1}/test.c"
+    backdate "${BASEDIR2}/header.h" "${BASEDIR2}/test.c"
+    backdate "${BASEDIR3}/header.h" "${BASEDIR3}/test.c"
+    backdate "${BASEDIR4}/header.h" "${BASEDIR4}/test.c" "${BASEDIR4}/header2.h"
+
+    DEPFLAGS="-MD -MF test.d"
+}
+
+generate_reference_compiler_output() {
+    rm -f *.o *.d
+    ${REAL_COMPILER} ${DEPFLAGS} -c -o test.o test.c
+    mv test.o reference_test.o
+    mv test.d reference_test.d
+}
+
+SUITE_depend_different_headers() {
+    # This test case covers a case in depend mode with unchanged source file between compilations,
+    # but with changed headers. Header contents do not affect the common hash (by which .manifest
+    # is stored in cache), only the object's hash.
+    #
+    # dir1 is baseline
+    # dir2 has a change in header which affects object file
+    # dir3 has a change in header which does not affect object file
+    # dir4 has an additional include header which should change the dependency file
+    # -------------------------------------------------------------------------
+    TEST "Depend mode - test unique sets of headers for the same source code"
+
+    # Compile dir1
+    cd ${BASEDIR1}
+
+    generate_reference_compiler_output
+    CCACHE_DEPEND=1 CCACHE_BASEDIR=${BASEDIR1} $CCACHE_COMPILE $DEPFLAGS -c test.c
+    expect_equal_object_files reference_test.o test.o
+    expect_equal_files reference_test.d test.d
+    expect_stat 'cache hit (direct)' 0
+    expect_stat 'cache hit (preprocessed)' 0
+    expect_stat 'cache miss' 1
+    expect_stat 'files in cache' 3      # .o + .manifest + .d
+
+    # Recompile dir1 - 1st time
+    generate_reference_compiler_output
+    CCACHE_DEPEND=1 CCACHE_BASEDIR=${BASEDIR1} $CCACHE_COMPILE $DEPFLAGS -c test.c
+    expect_equal_object_files reference_test.o test.o
+    expect_equal_files reference_test.d test.d
+    expect_stat 'cache hit (direct)' 1
+    expect_stat 'cache hit (preprocessed)' 0
+    expect_stat 'cache miss' 1
+    expect_stat 'files in cache' 3
+
+    # Compile dir2
+    # dir2 header changes the object file compared to dir1
+    cd ${BASEDIR2}
+    generate_reference_compiler_output
+    CCACHE_DEPEND=1 CCACHE_BASEDIR=${BASEDIR2} $CCACHE_COMPILE $DEPFLAGS -c test.c
+    expect_equal_object_files reference_test.o test.o
+    expect_equal_files reference_test.d test.d
+    expect_stat 'cache hit (direct)' 1
+    expect_stat 'cache hit (preprocessed)' 0
+    expect_stat 'cache miss' 2
+    expect_stat 'files in cache' 5      # 2x .o, 2x .d, 1x manifest
+
+    # Compile dir3
+    # dir3 header change does not change object file compared to dir1, but ccache still adds
+    # additional .o/.d file in the cache due to different contents of the header file
+    cd ${BASEDIR3}
+    generate_reference_compiler_output
+    CCACHE_DEPEND=1 CCACHE_BASEDIR=${BASEDIR3} $CCACHE_COMPILE $DEPFLAGS -c test.c
+    expect_equal_object_files reference_test.o test.o
+    expect_equal_files reference_test.d test.d
+    expect_stat 'cache hit (direct)' 1
+    expect_stat 'cache hit (preprocessed)' 0
+    expect_stat 'cache miss' 3
+    expect_stat 'files in cache' 7      # 3x .o, 3x .d, 1x manifest
+
+    # Compile dir4
+    # dir4 header adds a new dependency
+    cd ${BASEDIR4}
+    generate_reference_compiler_output
+    CCACHE_DEPEND=1 CCACHE_BASEDIR=${BASEDIR4} $CCACHE_COMPILE $DEPFLAGS -c test.c
+    expect_equal_object_files reference_test.o test.o
+    expect_equal_files reference_test.d test.d
+    expect_different_files reference_test.d ${BASEDIR1}/test.d
+    expect_stat 'cache hit (direct)' 1
+    expect_stat 'cache hit (preprocessed)' 0
+    expect_stat 'cache miss' 4
+    expect_stat 'files in cache' 9      # 4x .o, 4x .d, 1x manifest
+
+    # Recompile dir1 - 2nd time
+    cd ${BASEDIR1}
+    generate_reference_compiler_output
+    CCACHE_DEPEND=1 CCACHE_BASEDIR=${BASEDIR1} $CCACHE_COMPILE $DEPFLAGS -c test.c
+    expect_equal_object_files reference_test.o test.o
+    expect_equal_files reference_test.d test.d
+    expect_stat 'cache hit (direct)' 2
+    expect_stat 'cache hit (preprocessed)' 0
+    expect_stat 'cache miss' 4
+    expect_stat 'files in cache' 9
+
+    # Recompile dir2
+    cd ${BASEDIR2}
+    generate_reference_compiler_output
+    CCACHE_DEPEND=1 CCACHE_BASEDIR=${BASEDIR2} $CCACHE_COMPILE $DEPFLAGS -c test.c
+    expect_equal_object_files test.o test.o
+    expect_equal_files reference_test.d test.d
+    expect_stat 'cache hit (direct)' 3
+    expect_stat 'cache hit (preprocessed)' 0
+    expect_stat 'cache miss' 4
+    expect_stat 'files in cache' 9
+
+    # Recompile dir3
+    cd ${BASEDIR3}
+    generate_reference_compiler_output
+    CCACHE_DEPEND=1 CCACHE_BASEDIR=${BASEDIR3} $CCACHE_COMPILE $DEPFLAGS -c test.c
+    expect_equal_object_files reference_test.o test.o
+    expect_equal_files reference_test.d test.d
+    expect_stat 'cache hit (direct)' 4
+    expect_stat 'cache hit (preprocessed)' 0
+    expect_stat 'cache miss' 4
+    expect_stat 'files in cache' 9
+
+    # Recompile dir4
+    cd ${BASEDIR4}
+    generate_reference_compiler_output
+    CCACHE_DEPEND=1 CCACHE_BASEDIR=${BASEDIR4} $CCACHE_COMPILE $DEPFLAGS -c test.c
+    expect_equal_object_files reference_test.o test.o
+    expect_equal_files reference_test.d test.d
+    expect_different_files reference_test.d ${BASEDIR1}/test.d
+    expect_stat 'cache hit (direct)' 5
+    expect_stat 'cache hit (preprocessed)' 0
+    expect_stat 'cache miss' 4
+    expect_stat 'files in cache' 9
+}